Changes between Initial Version and Version 1 of Ticket #18428


Ignore:
Timestamp:
Aug 13, 2025, 9:30:14 AM (2 months ago)
Author:
Eric Pettersen
Comment:

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  • Ticket #18428

    • Property Component Unassigned → Graphics
    • Property Owner set to Tom Goddard
    • Property Platform → all
    • Property Project → ChimeraX
    • Property Status new → assigned
    • Property Summary ChimeraX bug report submission → Picking: Singular matrix

  • Ticket #18428 – Description

    initial v1  
    23512351> hide sel cartoons
    23522352
    2353 Traceback (most recent call last): 
    2354 File
    2355 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2356 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    2357 self.session.ui.mouse_modes.mouse_pause_tracking() 
    2358 File
    2359 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2360 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    2361 mouse_pause_tracking 
    2362 self._mouse_pause() 
    2363 File
    2364 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2365 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    2366 m.pause(self._mouse_pause_position) 
    2367 File
    2368 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2369 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    2370 p = self.view.picked_object(x, y) 
    2371 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2372 File
    2373 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2374 packages/chimerax/graphics/view.py", line 838, in picked_object 
    2375 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    2376 beyond, 
    2377 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2378 File
    2379 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2380 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    2381 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    2382 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2383 File
    2384 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2385 packages/chimerax/core/models.py", line 143, in first_intercept 
    2386 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    2387 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2388 File
    2389 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2390 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    2391 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    2392 exclude=exclude) 
    2393 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2394 File
    2395 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2396 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    2397 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    2398 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2399 File
    2400 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2401 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    2402 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    2403 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2404 File
    2405 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2406 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    2407 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    2408 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2409 File
    2410 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2411 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    2412 p = super().first_intercept(mxyz1, mxyz2) 
    2413 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2414 File
    2415 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2416 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    2417 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    2418 exclude=exclude) 
    2419 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2420 File
    2421 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2422 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    2423 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    2424 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2425 File
    2426 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2427 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    2428 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    2429 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2430 File
    2431 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2432 packages/chimerax/graphics/drawing.py", line 1108, in
    2433 _first_intercept_excluding_children 
    2434 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    2435 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2436 File
    2437 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2438 packages/chimerax/geometry/place.py", line 201, in inverse 
    2439 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    2440 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2441 File
    2442 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2443 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    2444 rinv[:, :] = matrix_inverse(r) 
    2445 ^^^^^^^^^^^^^^^^^ 
    2446 File
    2447 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2448 packages/numpy/linalg/linalg.py", line 561, in inv 
    2449 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    2450 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2451 File
    2452 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2453 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    2454 raise LinAlgError("Singular matrix") 
    2455 numpy.linalg.LinAlgError: Singular matrix 
    2456  
    2457 numpy.linalg.LinAlgError: Singular matrix 
    2458  
    2459 File
    2460 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2461 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    2462 raise LinAlgError("Singular matrix") 
    2463  
    2464 See log for complete Python traceback. 
    2465  
    2466 
    2467 > select add #5/B:475
    2468 
    2469 21 atoms, 15 bonds, 6 residues, 1 model selected 
    2470 Drag select of 11 atoms, 8 residues, 4 bonds, 6 shapes 
    2471 Drag select of 2 residues, 2 pseudobonds 
    2472 
    2473 > select clear
    2474 
    2475 > select add #5/B:1001@MG
    2476 
    2477 1 atom, 1 residue, 1 model selected 
    2478 Drag select of 37 atoms, 158 residues, 6 pseudobonds, 25 bonds, 14 shapes 
    2479 
    2480 > select clear
    2481 
    2482 Traceback (most recent call last): 
    2483 File
    2484 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2485 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    2486 self.session.ui.mouse_modes.mouse_pause_tracking() 
    2487 File
    2488 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2489 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    2490 mouse_pause_tracking 
    2491 self._mouse_pause() 
    2492 File
    2493 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2494 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    2495 m.pause(self._mouse_pause_position) 
    2496 File
    2497 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2498 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    2499 p = self.view.picked_object(x, y) 
    2500 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2501 File
    2502 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2503 packages/chimerax/graphics/view.py", line 838, in picked_object 
    2504 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    2505 beyond, 
    2506 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2507 File
    2508 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2509 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    2510 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    2511 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2512 File
    2513 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2514 packages/chimerax/core/models.py", line 143, in first_intercept 
    2515 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    2516 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2517 File
    2518 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2519 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    2520 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    2521 exclude=exclude) 
    2522 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2523 File
    2524 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2525 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    2526 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    2527 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2528 File
    2529 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2530 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    2531 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    2532 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2533 File
    2534 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2535 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    2536 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    2537 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2538 File
    2539 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2540 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    2541 p = super().first_intercept(mxyz1, mxyz2) 
    2542 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2543 File
    2544 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2545 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    2546 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    2547 exclude=exclude) 
    2548 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2549 File
    2550 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2551 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    2552 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    2553 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2554 File
    2555 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2556 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    2557 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    2558 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2559 File
    2560 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2561 packages/chimerax/graphics/drawing.py", line 1108, in
    2562 _first_intercept_excluding_children 
    2563 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    2564 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2565 File
    2566 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2567 packages/chimerax/geometry/place.py", line 201, in inverse 
    2568 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    2569 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2570 File
    2571 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2572 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    2573 rinv[:, :] = matrix_inverse(r) 
    2574 ^^^^^^^^^^^^^^^^^ 
    2575 File
    2576 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2577 packages/numpy/linalg/linalg.py", line 561, in inv 
    2578 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    2579 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2580 File
    2581 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2582 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    2583 raise LinAlgError("Singular matrix") 
    2584 numpy.linalg.LinAlgError: Singular matrix 
    2585  
    2586 numpy.linalg.LinAlgError: Singular matrix 
    2587  
    2588 File
    2589 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2590 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    2591 raise LinAlgError("Singular matrix") 
    2592  
    2593 See log for complete Python traceback. 
    2594  
    2595 
    2596 > select add #1/D:462
    2597 
    2598 9 atoms, 8 bonds, 1 residue, 1 model selected 
    2599 
    2600 > select add #1/D:461
    2601 
    2602 13 atoms, 11 bonds, 2 residues, 1 model selected 
    2603 Traceback (most recent call last): 
    2604 File
    2605 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2606 packages/chimerax/mouse_modes/mousemodes.py", line 656, in <lambda> 
    2607 gw.mouseReleaseEvent = lambda e, s=self: s._dispatch_mouse_event(e,
    2608 "mouse_up") 
    2609 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2610 File
    2611 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2612 packages/chimerax/mouse_modes/mousemodes.py", line 556, in
    2613 _dispatch_mouse_event 
    2614 f(MouseEvent(event, modifiers=modifiers)) 
    2615 File
    2616 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2617 packages/chimerax/mouse_modes/std_modes.py", line 70, in mouse_up 
    2618 mouse_select(event, mode, self.session, self.view) 
    2619 File
    2620 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2621 packages/chimerax/mouse_modes/std_modes.py", line 209, in mouse_select 
    2622 pick = view.picked_object(x, y) 
    2623 ^^^^^^^^^^^^^^^^^^^^^^^^ 
    2624 File
    2625 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2626 packages/chimerax/graphics/view.py", line 838, in picked_object 
    2627 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    2628 beyond, 
    2629 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2630 File
    2631 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2632 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    2633 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    2634 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2635 File
    2636 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2637 packages/chimerax/core/models.py", line 143, in first_intercept 
    2638 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    2639 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2640 File
    2641 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2642 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    2643 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    2644 exclude=exclude) 
    2645 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2646 File
    2647 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2648 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    2649 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    2650 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2651 File
    2652 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2653 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    2654 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    2655 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2656 File
    2657 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2658 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    2659 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    2660 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2661 File
    2662 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2663 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    2664 p = super().first_intercept(mxyz1, mxyz2) 
    2665 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2666 File
    2667 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2668 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    2669 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    2670 exclude=exclude) 
    2671 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2672 File
    2673 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2674 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    2675 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    2676 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2677 File
    2678 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2679 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    2680 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    2681 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2682 File
    2683 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2684 packages/chimerax/graphics/drawing.py", line 1108, in
    2685 _first_intercept_excluding_children 
    2686 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    2687 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2688 File
    2689 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2690 packages/chimerax/geometry/place.py", line 201, in inverse 
    2691 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    2692 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2693 File
    2694 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2695 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    2696 rinv[:, :] = matrix_inverse(r) 
    2697 ^^^^^^^^^^^^^^^^^ 
    2698 File
    2699 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2700 packages/numpy/linalg/linalg.py", line 561, in inv 
    2701 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    2702 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2703 File
    2704 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2705 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    2706 raise LinAlgError("Singular matrix") 
    2707 numpy.linalg.LinAlgError: Singular matrix 
    2708  
    2709 numpy.linalg.LinAlgError: Singular matrix 
    2710  
    2711 File
    2712 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2713 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    2714 raise LinAlgError("Singular matrix") 
    2715  
    2716 See log for complete Python traceback. 
    2717  
    2718 
    2719 > select add #1/D:460
    2720 
    2721 22 atoms, 19 bonds, 3 residues, 1 model selected 
    2722 
    2723 > hide sel cartoons
    2724 
    2725 > select add #1/D:479
    2726 
    2727 31 atoms, 27 bonds, 4 residues, 1 model selected 
    2728 
    2729 > select add #1/D:480
    2730 
    2731 38 atoms, 33 bonds, 5 residues, 1 model selected 
    2732 
    2733 > select add #1/D:482
    2734 
    2735 45 atoms, 39 bonds, 6 residues, 1 model selected 
    2736 
    2737 > hide sel cartoons
    2738 
    2739 > select add #1/D:478
    2740 
    2741 54 atoms, 47 bonds, 7 residues, 1 model selected 
    2742 
    2743 > select add #1/D:481
    2744 
    2745 58 atoms, 50 bonds, 8 residues, 1 model selected 
    2746 
    2747 > hide sel cartoons
    2748 
    2749 Traceback (most recent call last): 
    2750 File
    2751 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2752 packages/chimerax/mouse_modes/mousemodes.py", line 656, in <lambda> 
    2753 gw.mouseReleaseEvent = lambda e, s=self: s._dispatch_mouse_event(e,
    2754 "mouse_up") 
    2755 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2756 File
    2757 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2758 packages/chimerax/mouse_modes/mousemodes.py", line 556, in
    2759 _dispatch_mouse_event 
    2760 f(MouseEvent(event, modifiers=modifiers)) 
    2761 File
    2762 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2763 packages/chimerax/mouse_modes/std_modes.py", line 70, in mouse_up 
    2764 mouse_select(event, mode, self.session, self.view) 
    2765 File
    2766 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2767 packages/chimerax/mouse_modes/std_modes.py", line 209, in mouse_select 
    2768 pick = view.picked_object(x, y) 
    2769 ^^^^^^^^^^^^^^^^^^^^^^^^ 
    2770 File
    2771 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2772 packages/chimerax/graphics/view.py", line 838, in picked_object 
    2773 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    2774 beyond, 
    2775 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2776 File
    2777 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2778 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    2779 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    2780 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2781 File
    2782 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2783 packages/chimerax/core/models.py", line 143, in first_intercept 
    2784 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    2785 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2786 File
    2787 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2788 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    2789 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    2790 exclude=exclude) 
    2791 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2792 File
    2793 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2794 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    2795 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    2796 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2797 File
    2798 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2799 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    2800 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    2801 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2802 File
    2803 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2804 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    2805 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    2806 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2807 File
    2808 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2809 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    2810 p = super().first_intercept(mxyz1, mxyz2) 
    2811 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2812 File
    2813 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2814 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    2815 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    2816 exclude=exclude) 
    2817 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2818 File
    2819 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2820 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    2821 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    2822 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2823 File
    2824 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2825 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    2826 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    2827 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2828 File
    2829 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2830 packages/chimerax/graphics/drawing.py", line 1108, in
    2831 _first_intercept_excluding_children 
    2832 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    2833 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2834 File
    2835 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2836 packages/chimerax/geometry/place.py", line 201, in inverse 
    2837 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    2838 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2839 File
    2840 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2841 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    2842 rinv[:, :] = matrix_inverse(r) 
    2843 ^^^^^^^^^^^^^^^^^ 
    2844 File
    2845 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2846 packages/numpy/linalg/linalg.py", line 561, in inv 
    2847 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    2848 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2849 File
    2850 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2851 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    2852 raise LinAlgError("Singular matrix") 
    2853 numpy.linalg.LinAlgError: Singular matrix 
    2854  
    2855 numpy.linalg.LinAlgError: Singular matrix 
    2856  
    2857 File
    2858 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2859 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    2860 raise LinAlgError("Singular matrix") 
    2861  
    2862 See log for complete Python traceback. 
    2863  
    2864 Traceback (most recent call last): 
    2865 File
    2866 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2867 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    2868 self.session.ui.mouse_modes.mouse_pause_tracking() 
    2869 File
    2870 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2871 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    2872 mouse_pause_tracking 
    2873 self._mouse_pause() 
    2874 File
    2875 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2876 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    2877 m.pause(self._mouse_pause_position) 
    2878 File
    2879 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2880 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    2881 p = self.view.picked_object(x, y) 
    2882 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2883 File
    2884 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2885 packages/chimerax/graphics/view.py", line 838, in picked_object 
    2886 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    2887 beyond, 
    2888 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2889 File
    2890 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2891 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    2892 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    2893 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2894 File
    2895 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2896 packages/chimerax/core/models.py", line 143, in first_intercept 
    2897 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    2898 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2899 File
    2900 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2901 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    2902 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    2903 exclude=exclude) 
    2904 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2905 File
    2906 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2907 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    2908 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    2909 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2910 File
    2911 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2912 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    2913 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    2914 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2915 File
    2916 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2917 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    2918 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    2919 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2920 File
    2921 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2922 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    2923 p = super().first_intercept(mxyz1, mxyz2) 
    2924 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2925 File
    2926 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2927 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    2928 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    2929 exclude=exclude) 
    2930 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2931 File
    2932 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2933 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    2934 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    2935 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2936 File
    2937 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2938 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    2939 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    2940 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2941 File
    2942 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2943 packages/chimerax/graphics/drawing.py", line 1108, in
    2944 _first_intercept_excluding_children 
    2945 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    2946 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2947 File
    2948 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2949 packages/chimerax/geometry/place.py", line 201, in inverse 
    2950 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    2951 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2952 File
    2953 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2954 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    2955 rinv[:, :] = matrix_inverse(r) 
    2956 ^^^^^^^^^^^^^^^^^ 
    2957 File
    2958 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2959 packages/numpy/linalg/linalg.py", line 561, in inv 
    2960 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    2961 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2962 File
    2963 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2964 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    2965 raise LinAlgError("Singular matrix") 
    2966 numpy.linalg.LinAlgError: Singular matrix 
    2967  
    2968 numpy.linalg.LinAlgError: Singular matrix 
    2969  
    2970 File
    2971 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2972 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    2973 raise LinAlgError("Singular matrix") 
    2974  
    2975 See log for complete Python traceback. 
    2976  
    2977 Traceback (most recent call last): 
    2978 File
    2979 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2980 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    2981 self.session.ui.mouse_modes.mouse_pause_tracking() 
    2982 File
    2983 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2984 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    2985 mouse_pause_tracking 
    2986 self._mouse_pause() 
    2987 File
    2988 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2989 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    2990 m.pause(self._mouse_pause_position) 
    2991 File
    2992 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2993 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    2994 p = self.view.picked_object(x, y) 
    2995 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    2996 File
    2997 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    2998 packages/chimerax/graphics/view.py", line 838, in picked_object 
    2999 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    3000 beyond, 
    3001 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3002 File
    3003 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3004 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    3005 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    3006 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3007 File
    3008 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3009 packages/chimerax/core/models.py", line 143, in first_intercept 
    3010 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    3011 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3012 File
    3013 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3014 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    3015 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    3016 exclude=exclude) 
    3017 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3018 File
    3019 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3020 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    3021 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    3022 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3023 File
    3024 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3025 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    3026 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    3027 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3028 File
    3029 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3030 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    3031 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    3032 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3033 File
    3034 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3035 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    3036 p = super().first_intercept(mxyz1, mxyz2) 
    3037 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3038 File
    3039 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3040 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    3041 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    3042 exclude=exclude) 
    3043 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3044 File
    3045 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3046 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    3047 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    3048 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3049 File
    3050 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3051 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    3052 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    3053 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3054 File
    3055 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3056 packages/chimerax/graphics/drawing.py", line 1108, in
    3057 _first_intercept_excluding_children 
    3058 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    3059 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3060 File
    3061 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3062 packages/chimerax/geometry/place.py", line 201, in inverse 
    3063 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    3064 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3065 File
    3066 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3067 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    3068 rinv[:, :] = matrix_inverse(r) 
    3069 ^^^^^^^^^^^^^^^^^ 
    3070 File
    3071 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3072 packages/numpy/linalg/linalg.py", line 561, in inv 
    3073 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    3074 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3075 File
    3076 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3077 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    3078 raise LinAlgError("Singular matrix") 
    3079 numpy.linalg.LinAlgError: Singular matrix 
    3080  
    3081 numpy.linalg.LinAlgError: Singular matrix 
    3082  
    3083 File
    3084 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3085 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    3086 raise LinAlgError("Singular matrix") 
    3087  
    3088 See log for complete Python traceback. 
    3089  
    3090 Traceback (most recent call last): 
    3091 File
    3092 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3093 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    3094 self.session.ui.mouse_modes.mouse_pause_tracking() 
    3095 File
    3096 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3097 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    3098 mouse_pause_tracking 
    3099 self._mouse_pause() 
    3100 File
    3101 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3102 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    3103 m.pause(self._mouse_pause_position) 
    3104 File
    3105 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3106 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    3107 p = self.view.picked_object(x, y) 
    3108 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3109 File
    3110 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3111 packages/chimerax/graphics/view.py", line 838, in picked_object 
    3112 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    3113 beyond, 
    3114 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3115 File
    3116 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3117 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    3118 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    3119 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3120 File
    3121 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3122 packages/chimerax/core/models.py", line 143, in first_intercept 
    3123 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    3124 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3125 File
    3126 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3127 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    3128 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    3129 exclude=exclude) 
    3130 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3131 File
    3132 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3133 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    3134 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    3135 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3136 File
    3137 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3138 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    3139 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    3140 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3141 File
    3142 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3143 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    3144 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    3145 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3146 File
    3147 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3148 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    3149 p = super().first_intercept(mxyz1, mxyz2) 
    3150 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3151 File
    3152 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3153 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    3154 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    3155 exclude=exclude) 
    3156 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3157 File
    3158 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3159 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    3160 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    3161 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3162 File
    3163 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3164 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    3165 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    3166 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3167 File
    3168 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3169 packages/chimerax/graphics/drawing.py", line 1108, in
    3170 _first_intercept_excluding_children 
    3171 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    3172 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3173 File
    3174 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3175 packages/chimerax/geometry/place.py", line 201, in inverse 
    3176 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    3177 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3178 File
    3179 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3180 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    3181 rinv[:, :] = matrix_inverse(r) 
    3182 ^^^^^^^^^^^^^^^^^ 
    3183 File
    3184 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3185 packages/numpy/linalg/linalg.py", line 561, in inv 
    3186 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    3187 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3188 File
    3189 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3190 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    3191 raise LinAlgError("Singular matrix") 
    3192 numpy.linalg.LinAlgError: Singular matrix 
    3193  
    3194 numpy.linalg.LinAlgError: Singular matrix 
    3195  
    3196 File
    3197 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3198 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    3199 raise LinAlgError("Singular matrix") 
    3200  
    3201 See log for complete Python traceback. 
    3202  
    3203 Traceback (most recent call last): 
    3204 File
    3205 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3206 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    3207 self.session.ui.mouse_modes.mouse_pause_tracking() 
    3208 File
    3209 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3210 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    3211 mouse_pause_tracking 
    3212 self._mouse_pause() 
    3213 File
    3214 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3215 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    3216 m.pause(self._mouse_pause_position) 
    3217 File
    3218 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3219 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    3220 p = self.view.picked_object(x, y) 
    3221 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3222 File
    3223 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3224 packages/chimerax/graphics/view.py", line 838, in picked_object 
    3225 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    3226 beyond, 
    3227 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3228 File
    3229 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3230 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    3231 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    3232 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3233 File
    3234 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3235 packages/chimerax/core/models.py", line 143, in first_intercept 
    3236 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    3237 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3238 File
    3239 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3240 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    3241 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    3242 exclude=exclude) 
    3243 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3244 File
    3245 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3246 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    3247 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    3248 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3249 File
    3250 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3251 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    3252 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    3253 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3254 File
    3255 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3256 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    3257 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    3258 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3259 File
    3260 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3261 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    3262 p = super().first_intercept(mxyz1, mxyz2) 
    3263 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3264 File
    3265 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3266 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    3267 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    3268 exclude=exclude) 
    3269 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3270 File
    3271 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3272 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    3273 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    3274 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3275 File
    3276 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3277 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    3278 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    3279 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3280 File
    3281 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3282 packages/chimerax/graphics/drawing.py", line 1108, in
    3283 _first_intercept_excluding_children 
    3284 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    3285 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3286 File
    3287 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3288 packages/chimerax/geometry/place.py", line 201, in inverse 
    3289 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    3290 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3291 File
    3292 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3293 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    3294 rinv[:, :] = matrix_inverse(r) 
    3295 ^^^^^^^^^^^^^^^^^ 
    3296 File
    3297 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3298 packages/numpy/linalg/linalg.py", line 561, in inv 
    3299 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    3300 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3301 File
    3302 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3303 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    3304 raise LinAlgError("Singular matrix") 
    3305 numpy.linalg.LinAlgError: Singular matrix 
    3306  
    3307 numpy.linalg.LinAlgError: Singular matrix 
    3308  
    3309 File
    3310 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3311 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    3312 raise LinAlgError("Singular matrix") 
    3313  
    3314 See log for complete Python traceback. 
    3315  
    3316 Traceback (most recent call last): 
    3317 File
    3318 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3319 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    3320 self.session.ui.mouse_modes.mouse_pause_tracking() 
    3321 File
    3322 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3323 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    3324 mouse_pause_tracking 
    3325 self._mouse_pause() 
    3326 File
    3327 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3328 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    3329 m.pause(self._mouse_pause_position) 
    3330 File
    3331 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3332 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    3333 p = self.view.picked_object(x, y) 
    3334 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3335 File
    3336 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3337 packages/chimerax/graphics/view.py", line 838, in picked_object 
    3338 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    3339 beyond, 
    3340 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3341 File
    3342 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3343 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    3344 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    3345 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3346 File
    3347 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3348 packages/chimerax/core/models.py", line 143, in first_intercept 
    3349 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    3350 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3351 File
    3352 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3353 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    3354 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    3355 exclude=exclude) 
    3356 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3357 File
    3358 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3359 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    3360 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    3361 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3362 File
    3363 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3364 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    3365 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    3366 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3367 File
    3368 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3369 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    3370 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    3371 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3372 File
    3373 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3374 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    3375 p = super().first_intercept(mxyz1, mxyz2) 
    3376 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3377 File
    3378 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3379 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    3380 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    3381 exclude=exclude) 
    3382 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3383 File
    3384 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3385 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    3386 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    3387 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3388 File
    3389 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3390 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    3391 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    3392 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3393 File
    3394 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3395 packages/chimerax/graphics/drawing.py", line 1108, in
    3396 _first_intercept_excluding_children 
    3397 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    3398 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3399 File
    3400 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3401 packages/chimerax/geometry/place.py", line 201, in inverse 
    3402 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    3403 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3404 File
    3405 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3406 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    3407 rinv[:, :] = matrix_inverse(r) 
    3408 ^^^^^^^^^^^^^^^^^ 
    3409 File
    3410 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3411 packages/numpy/linalg/linalg.py", line 561, in inv 
    3412 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    3413 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3414 File
    3415 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3416 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    3417 raise LinAlgError("Singular matrix") 
    3418 numpy.linalg.LinAlgError: Singular matrix 
    3419  
    3420 numpy.linalg.LinAlgError: Singular matrix 
    3421  
    3422 File
    3423 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3424 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    3425 raise LinAlgError("Singular matrix") 
    3426  
    3427 See log for complete Python traceback. 
    3428  
    3429 Traceback (most recent call last): 
    3430 File
    3431 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3432 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    3433 self.session.ui.mouse_modes.mouse_pause_tracking() 
    3434 File
    3435 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3436 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    3437 mouse_pause_tracking 
    3438 self._mouse_pause() 
    3439 File
    3440 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3441 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    3442 m.pause(self._mouse_pause_position) 
    3443 File
    3444 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3445 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    3446 p = self.view.picked_object(x, y) 
    3447 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3448 File
    3449 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3450 packages/chimerax/graphics/view.py", line 838, in picked_object 
    3451 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    3452 beyond, 
    3453 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3454 File
    3455 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3456 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    3457 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    3458 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3459 File
    3460 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3461 packages/chimerax/core/models.py", line 143, in first_intercept 
    3462 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    3463 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3464 File
    3465 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3466 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    3467 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    3468 exclude=exclude) 
    3469 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3470 File
    3471 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3472 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    3473 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    3474 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3475 File
    3476 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3477 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    3478 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    3479 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3480 File
    3481 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3482 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    3483 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    3484 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3485 File
    3486 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3487 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    3488 p = super().first_intercept(mxyz1, mxyz2) 
    3489 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3490 File
    3491 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3492 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    3493 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    3494 exclude=exclude) 
    3495 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3496 File
    3497 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3498 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    3499 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    3500 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3501 File
    3502 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3503 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    3504 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    3505 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3506 File
    3507 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3508 packages/chimerax/graphics/drawing.py", line 1108, in
    3509 _first_intercept_excluding_children 
    3510 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    3511 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3512 File
    3513 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3514 packages/chimerax/geometry/place.py", line 201, in inverse 
    3515 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    3516 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3517 File
    3518 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3519 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    3520 rinv[:, :] = matrix_inverse(r) 
    3521 ^^^^^^^^^^^^^^^^^ 
    3522 File
    3523 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3524 packages/numpy/linalg/linalg.py", line 561, in inv 
    3525 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    3526 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3527 File
    3528 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3529 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    3530 raise LinAlgError("Singular matrix") 
    3531 numpy.linalg.LinAlgError: Singular matrix 
    3532  
    3533 numpy.linalg.LinAlgError: Singular matrix 
    3534  
    3535 File
    3536 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3537 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    3538 raise LinAlgError("Singular matrix") 
    3539  
    3540 See log for complete Python traceback. 
    3541  
    3542 Traceback (most recent call last): 
    3543 File
    3544 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3545 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    3546 self.session.ui.mouse_modes.mouse_pause_tracking() 
    3547 File
    3548 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3549 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    3550 mouse_pause_tracking 
    3551 self._mouse_pause() 
    3552 File
    3553 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3554 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    3555 m.pause(self._mouse_pause_position) 
    3556 File
    3557 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3558 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    3559 p = self.view.picked_object(x, y) 
    3560 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3561 File
    3562 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3563 packages/chimerax/graphics/view.py", line 838, in picked_object 
    3564 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    3565 beyond, 
    3566 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3567 File
    3568 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3569 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    3570 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    3571 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3572 File
    3573 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3574 packages/chimerax/core/models.py", line 143, in first_intercept 
    3575 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    3576 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3577 File
    3578 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3579 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    3580 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    3581 exclude=exclude) 
    3582 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3583 File
    3584 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3585 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    3586 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    3587 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3588 File
    3589 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3590 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    3591 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    3592 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3593 File
    3594 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3595 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    3596 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    3597 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3598 File
    3599 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3600 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    3601 p = super().first_intercept(mxyz1, mxyz2) 
    3602 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3603 File
    3604 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3605 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    3606 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    3607 exclude=exclude) 
    3608 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3609 File
    3610 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3611 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    3612 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    3613 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3614 File
    3615 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3616 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    3617 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    3618 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3619 File
    3620 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3621 packages/chimerax/graphics/drawing.py", line 1108, in
    3622 _first_intercept_excluding_children 
    3623 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    3624 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3625 File
    3626 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3627 packages/chimerax/geometry/place.py", line 201, in inverse 
    3628 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    3629 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3630 File
    3631 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3632 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    3633 rinv[:, :] = matrix_inverse(r) 
    3634 ^^^^^^^^^^^^^^^^^ 
    3635 File
    3636 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3637 packages/numpy/linalg/linalg.py", line 561, in inv 
    3638 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    3639 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3640 File
    3641 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3642 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    3643 raise LinAlgError("Singular matrix") 
    3644 numpy.linalg.LinAlgError: Singular matrix 
    3645  
    3646 numpy.linalg.LinAlgError: Singular matrix 
    3647  
    3648 File
    3649 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3650 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    3651 raise LinAlgError("Singular matrix") 
    3652  
    3653 See log for complete Python traceback. 
    3654  
    3655 Traceback (most recent call last): 
    3656 File
    3657 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3658 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    3659 self.session.ui.mouse_modes.mouse_pause_tracking() 
    3660 File
    3661 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3662 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    3663 mouse_pause_tracking 
    3664 self._mouse_pause() 
    3665 File
    3666 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3667 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    3668 m.pause(self._mouse_pause_position) 
    3669 File
    3670 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3671 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    3672 p = self.view.picked_object(x, y) 
    3673 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3674 File
    3675 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3676 packages/chimerax/graphics/view.py", line 838, in picked_object 
    3677 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    3678 beyond, 
    3679 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3680 File
    3681 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3682 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    3683 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    3684 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3685 File
    3686 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3687 packages/chimerax/core/models.py", line 143, in first_intercept 
    3688 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    3689 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3690 File
    3691 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3692 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    3693 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    3694 exclude=exclude) 
    3695 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3696 File
    3697 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3698 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    3699 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    3700 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3701 File
    3702 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3703 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    3704 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    3705 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3706 File
    3707 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3708 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    3709 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    3710 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3711 File
    3712 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3713 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    3714 p = super().first_intercept(mxyz1, mxyz2) 
    3715 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3716 File
    3717 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3718 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    3719 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    3720 exclude=exclude) 
    3721 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3722 File
    3723 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3724 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    3725 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    3726 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3727 File
    3728 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3729 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    3730 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    3731 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3732 File
    3733 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3734 packages/chimerax/graphics/drawing.py", line 1108, in
    3735 _first_intercept_excluding_children 
    3736 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    3737 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3738 File
    3739 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3740 packages/chimerax/geometry/place.py", line 201, in inverse 
    3741 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    3742 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3743 File
    3744 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3745 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    3746 rinv[:, :] = matrix_inverse(r) 
    3747 ^^^^^^^^^^^^^^^^^ 
    3748 File
    3749 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3750 packages/numpy/linalg/linalg.py", line 561, in inv 
    3751 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    3752 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3753 File
    3754 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3755 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    3756 raise LinAlgError("Singular matrix") 
    3757 numpy.linalg.LinAlgError: Singular matrix 
    3758  
    3759 numpy.linalg.LinAlgError: Singular matrix 
    3760  
    3761 File
    3762 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3763 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    3764 raise LinAlgError("Singular matrix") 
    3765  
    3766 See log for complete Python traceback. 
    3767  
    3768 Traceback (most recent call last): 
    3769 File
    3770 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3771 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    3772 self.session.ui.mouse_modes.mouse_pause_tracking() 
    3773 File
    3774 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3775 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    3776 mouse_pause_tracking 
    3777 self._mouse_pause() 
    3778 File
    3779 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3780 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    3781 m.pause(self._mouse_pause_position) 
    3782 File
    3783 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3784 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    3785 p = self.view.picked_object(x, y) 
    3786 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3787 File
    3788 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3789 packages/chimerax/graphics/view.py", line 838, in picked_object 
    3790 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    3791 beyond, 
    3792 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3793 File
    3794 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3795 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    3796 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    3797 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3798 File
    3799 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3800 packages/chimerax/core/models.py", line 143, in first_intercept 
    3801 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    3802 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3803 File
    3804 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3805 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    3806 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    3807 exclude=exclude) 
    3808 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3809 File
    3810 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3811 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    3812 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    3813 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3814 File
    3815 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3816 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    3817 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    3818 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3819 File
    3820 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3821 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    3822 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    3823 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3824 File
    3825 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3826 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    3827 p = super().first_intercept(mxyz1, mxyz2) 
    3828 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3829 File
    3830 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3831 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    3832 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    3833 exclude=exclude) 
    3834 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3835 File
    3836 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3837 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    3838 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    3839 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3840 File
    3841 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3842 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    3843 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    3844 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3845 File
    3846 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3847 packages/chimerax/graphics/drawing.py", line 1108, in
    3848 _first_intercept_excluding_children 
    3849 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    3850 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3851 File
    3852 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3853 packages/chimerax/geometry/place.py", line 201, in inverse 
    3854 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    3855 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3856 File
    3857 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3858 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    3859 rinv[:, :] = matrix_inverse(r) 
    3860 ^^^^^^^^^^^^^^^^^ 
    3861 File
    3862 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3863 packages/numpy/linalg/linalg.py", line 561, in inv 
    3864 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    3865 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3866 File
    3867 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3868 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    3869 raise LinAlgError("Singular matrix") 
    3870 numpy.linalg.LinAlgError: Singular matrix 
    3871  
    3872 numpy.linalg.LinAlgError: Singular matrix 
    3873  
    3874 File
    3875 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3876 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    3877 raise LinAlgError("Singular matrix") 
    3878  
    3879 See log for complete Python traceback. 
    3880  
    3881 Traceback (most recent call last): 
    3882 File
    3883 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3884 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    3885 self.session.ui.mouse_modes.mouse_pause_tracking() 
    3886 File
    3887 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3888 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    3889 mouse_pause_tracking 
    3890 self._mouse_pause() 
    3891 File
    3892 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3893 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    3894 m.pause(self._mouse_pause_position) 
    3895 File
    3896 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3897 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    3898 p = self.view.picked_object(x, y) 
    3899 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3900 File
    3901 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3902 packages/chimerax/graphics/view.py", line 838, in picked_object 
    3903 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    3904 beyond, 
    3905 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3906 File
    3907 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3908 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    3909 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    3910 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3911 File
    3912 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3913 packages/chimerax/core/models.py", line 143, in first_intercept 
    3914 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    3915 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3916 File
    3917 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3918 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    3919 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    3920 exclude=exclude) 
    3921 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3922 File
    3923 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3924 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    3925 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    3926 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3927 File
    3928 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3929 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    3930 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    3931 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3932 File
    3933 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3934 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    3935 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    3936 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3937 File
    3938 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3939 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    3940 p = super().first_intercept(mxyz1, mxyz2) 
    3941 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3942 File
    3943 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3944 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    3945 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    3946 exclude=exclude) 
    3947 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3948 File
    3949 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3950 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    3951 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    3952 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3953 File
    3954 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3955 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    3956 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    3957 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3958 File
    3959 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3960 packages/chimerax/graphics/drawing.py", line 1108, in
    3961 _first_intercept_excluding_children 
    3962 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    3963 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3964 File
    3965 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3966 packages/chimerax/geometry/place.py", line 201, in inverse 
    3967 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    3968 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3969 File
    3970 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3971 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    3972 rinv[:, :] = matrix_inverse(r) 
    3973 ^^^^^^^^^^^^^^^^^ 
    3974 File
    3975 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3976 packages/numpy/linalg/linalg.py", line 561, in inv 
    3977 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    3978 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    3979 File
    3980 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3981 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    3982 raise LinAlgError("Singular matrix") 
    3983 numpy.linalg.LinAlgError: Singular matrix 
    3984  
    3985 numpy.linalg.LinAlgError: Singular matrix 
    3986  
    3987 File
    3988 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3989 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    3990 raise LinAlgError("Singular matrix") 
    3991  
    3992 See log for complete Python traceback. 
    3993  
    3994 Traceback (most recent call last): 
    3995 File
    3996 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    3997 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    3998 self.session.ui.mouse_modes.mouse_pause_tracking() 
    3999 File
    4000 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4001 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    4002 mouse_pause_tracking 
    4003 self._mouse_pause() 
    4004 File
    4005 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4006 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    4007 m.pause(self._mouse_pause_position) 
    4008 File
    4009 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4010 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    4011 p = self.view.picked_object(x, y) 
    4012 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4013 File
    4014 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4015 packages/chimerax/graphics/view.py", line 838, in picked_object 
    4016 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    4017 beyond, 
    4018 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4019 File
    4020 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4021 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    4022 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    4023 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4024 File
    4025 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4026 packages/chimerax/core/models.py", line 143, in first_intercept 
    4027 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    4028 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4029 File
    4030 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4031 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    4032 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    4033 exclude=exclude) 
    4034 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4035 File
    4036 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4037 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    4038 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    4039 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4040 File
    4041 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4042 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    4043 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    4044 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4045 File
    4046 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4047 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    4048 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    4049 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4050 File
    4051 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4052 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    4053 p = super().first_intercept(mxyz1, mxyz2) 
    4054 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4055 File
    4056 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4057 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    4058 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    4059 exclude=exclude) 
    4060 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4061 File
    4062 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4063 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    4064 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    4065 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4066 File
    4067 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4068 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    4069 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    4070 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4071 File
    4072 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4073 packages/chimerax/graphics/drawing.py", line 1108, in
    4074 _first_intercept_excluding_children 
    4075 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    4076 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4077 File
    4078 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4079 packages/chimerax/geometry/place.py", line 201, in inverse 
    4080 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    4081 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4082 File
    4083 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4084 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    4085 rinv[:, :] = matrix_inverse(r) 
    4086 ^^^^^^^^^^^^^^^^^ 
    4087 File
    4088 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4089 packages/numpy/linalg/linalg.py", line 561, in inv 
    4090 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    4091 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4092 File
    4093 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4094 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    4095 raise LinAlgError("Singular matrix") 
    4096 numpy.linalg.LinAlgError: Singular matrix 
    4097  
    4098 numpy.linalg.LinAlgError: Singular matrix 
    4099  
    4100 File
    4101 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4102 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    4103 raise LinAlgError("Singular matrix") 
    4104  
    4105 See log for complete Python traceback. 
    4106  
    4107 Traceback (most recent call last): 
    4108 File
    4109 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4110 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    4111 self.session.ui.mouse_modes.mouse_pause_tracking() 
    4112 File
    4113 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4114 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    4115 mouse_pause_tracking 
    4116 self._mouse_pause() 
    4117 File
    4118 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4119 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    4120 m.pause(self._mouse_pause_position) 
    4121 File
    4122 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4123 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    4124 p = self.view.picked_object(x, y) 
    4125 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4126 File
    4127 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4128 packages/chimerax/graphics/view.py", line 838, in picked_object 
    4129 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    4130 beyond, 
    4131 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4132 File
    4133 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4134 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    4135 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    4136 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4137 File
    4138 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4139 packages/chimerax/core/models.py", line 143, in first_intercept 
    4140 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    4141 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4142 File
    4143 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4144 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    4145 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    4146 exclude=exclude) 
    4147 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4148 File
    4149 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4150 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    4151 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    4152 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4153 File
    4154 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4155 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    4156 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    4157 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4158 File
    4159 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4160 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    4161 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    4162 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4163 File
    4164 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4165 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    4166 p = super().first_intercept(mxyz1, mxyz2) 
    4167 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4168 File
    4169 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4170 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    4171 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    4172 exclude=exclude) 
    4173 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4174 File
    4175 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4176 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    4177 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    4178 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4179 File
    4180 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4181 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    4182 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    4183 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4184 File
    4185 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4186 packages/chimerax/graphics/drawing.py", line 1108, in
    4187 _first_intercept_excluding_children 
    4188 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    4189 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4190 File
    4191 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4192 packages/chimerax/geometry/place.py", line 201, in inverse 
    4193 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    4194 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4195 File
    4196 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4197 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    4198 rinv[:, :] = matrix_inverse(r) 
    4199 ^^^^^^^^^^^^^^^^^ 
    4200 File
    4201 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4202 packages/numpy/linalg/linalg.py", line 561, in inv 
    4203 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    4204 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4205 File
    4206 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4207 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    4208 raise LinAlgError("Singular matrix") 
    4209 numpy.linalg.LinAlgError: Singular matrix 
    4210  
    4211 numpy.linalg.LinAlgError: Singular matrix 
    4212  
    4213 File
    4214 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4215 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    4216 raise LinAlgError("Singular matrix") 
    4217  
    4218 See log for complete Python traceback. 
    4219  
    4220 Traceback (most recent call last): 
    4221 File
    4222 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4223 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    4224 self.session.ui.mouse_modes.mouse_pause_tracking() 
    4225 File
    4226 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4227 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    4228 mouse_pause_tracking 
    4229 self._mouse_pause() 
    4230 File
    4231 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4232 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    4233 m.pause(self._mouse_pause_position) 
    4234 File
    4235 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4236 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    4237 p = self.view.picked_object(x, y) 
    4238 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4239 File
    4240 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4241 packages/chimerax/graphics/view.py", line 838, in picked_object 
    4242 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    4243 beyond, 
    4244 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4245 File
    4246 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4247 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    4248 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    4249 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4250 File
    4251 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4252 packages/chimerax/core/models.py", line 143, in first_intercept 
    4253 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    4254 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4255 File
    4256 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4257 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    4258 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    4259 exclude=exclude) 
    4260 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4261 File
    4262 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4263 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    4264 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    4265 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4266 File
    4267 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4268 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    4269 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    4270 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4271 File
    4272 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4273 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    4274 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    4275 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4276 File
    4277 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4278 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    4279 p = super().first_intercept(mxyz1, mxyz2) 
    4280 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4281 File
    4282 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4283 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    4284 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    4285 exclude=exclude) 
    4286 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4287 File
    4288 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4289 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    4290 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    4291 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4292 File
    4293 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4294 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    4295 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    4296 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4297 File
    4298 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4299 packages/chimerax/graphics/drawing.py", line 1108, in
    4300 _first_intercept_excluding_children 
    4301 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    4302 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4303 File
    4304 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4305 packages/chimerax/geometry/place.py", line 201, in inverse 
    4306 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    4307 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4308 File
    4309 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4310 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    4311 rinv[:, :] = matrix_inverse(r) 
    4312 ^^^^^^^^^^^^^^^^^ 
    4313 File
    4314 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4315 packages/numpy/linalg/linalg.py", line 561, in inv 
    4316 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    4317 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4318 File
    4319 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4320 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    4321 raise LinAlgError("Singular matrix") 
    4322 numpy.linalg.LinAlgError: Singular matrix 
    4323  
    4324 numpy.linalg.LinAlgError: Singular matrix 
    4325  
    4326 File
    4327 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4328 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    4329 raise LinAlgError("Singular matrix") 
    4330  
    4331 See log for complete Python traceback. 
    4332  
    4333 Traceback (most recent call last): 
    4334 File
    4335 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4336 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    4337 self.session.ui.mouse_modes.mouse_pause_tracking() 
    4338 File
    4339 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4340 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    4341 mouse_pause_tracking 
    4342 self._mouse_pause() 
    4343 File
    4344 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4345 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    4346 m.pause(self._mouse_pause_position) 
    4347 File
    4348 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4349 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    4350 p = self.view.picked_object(x, y) 
    4351 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4352 File
    4353 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4354 packages/chimerax/graphics/view.py", line 838, in picked_object 
    4355 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    4356 beyond, 
    4357 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4358 File
    4359 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4360 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    4361 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    4362 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4363 File
    4364 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4365 packages/chimerax/core/models.py", line 143, in first_intercept 
    4366 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    4367 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4368 File
    4369 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4370 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    4371 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    4372 exclude=exclude) 
    4373 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4374 File
    4375 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4376 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    4377 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    4378 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4379 File
    4380 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4381 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    4382 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    4383 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4384 File
    4385 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4386 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    4387 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    4388 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4389 File
    4390 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4391 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    4392 p = super().first_intercept(mxyz1, mxyz2) 
    4393 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4394 File
    4395 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4396 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    4397 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    4398 exclude=exclude) 
    4399 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4400 File
    4401 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4402 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    4403 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    4404 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4405 File
    4406 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4407 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    4408 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    4409 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4410 File
    4411 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4412 packages/chimerax/graphics/drawing.py", line 1108, in
    4413 _first_intercept_excluding_children 
    4414 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    4415 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4416 File
    4417 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4418 packages/chimerax/geometry/place.py", line 201, in inverse 
    4419 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    4420 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4421 File
    4422 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4423 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    4424 rinv[:, :] = matrix_inverse(r) 
    4425 ^^^^^^^^^^^^^^^^^ 
    4426 File
    4427 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4428 packages/numpy/linalg/linalg.py", line 561, in inv 
    4429 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    4430 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4431 File
    4432 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4433 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    4434 raise LinAlgError("Singular matrix") 
    4435 numpy.linalg.LinAlgError: Singular matrix 
    4436  
    4437 numpy.linalg.LinAlgError: Singular matrix 
    4438  
    4439 File
    4440 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4441 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    4442 raise LinAlgError("Singular matrix") 
    4443  
    4444 See log for complete Python traceback. 
    4445  
    4446 Traceback (most recent call last): 
    4447 File
    4448 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4449 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    4450 self.session.ui.mouse_modes.mouse_pause_tracking() 
    4451 File
    4452 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4453 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    4454 mouse_pause_tracking 
    4455 self._mouse_pause() 
    4456 File
    4457 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4458 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    4459 m.pause(self._mouse_pause_position) 
    4460 File
    4461 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4462 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    4463 p = self.view.picked_object(x, y) 
    4464 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4465 File
    4466 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4467 packages/chimerax/graphics/view.py", line 838, in picked_object 
    4468 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    4469 beyond, 
    4470 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4471 File
    4472 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4473 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    4474 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    4475 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4476 File
    4477 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4478 packages/chimerax/core/models.py", line 143, in first_intercept 
    4479 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    4480 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4481 File
    4482 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4483 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    4484 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    4485 exclude=exclude) 
    4486 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4487 File
    4488 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4489 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    4490 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    4491 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4492 File
    4493 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4494 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    4495 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    4496 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4497 File
    4498 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4499 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    4500 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    4501 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4502 File
    4503 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4504 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    4505 p = super().first_intercept(mxyz1, mxyz2) 
    4506 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4507 File
    4508 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4509 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    4510 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    4511 exclude=exclude) 
    4512 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4513 File
    4514 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4515 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    4516 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    4517 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4518 File
    4519 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4520 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    4521 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    4522 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4523 File
    4524 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4525 packages/chimerax/graphics/drawing.py", line 1108, in
    4526 _first_intercept_excluding_children 
    4527 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    4528 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4529 File
    4530 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4531 packages/chimerax/geometry/place.py", line 201, in inverse 
    4532 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    4533 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4534 File
    4535 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4536 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    4537 rinv[:, :] = matrix_inverse(r) 
    4538 ^^^^^^^^^^^^^^^^^ 
    4539 File
    4540 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4541 packages/numpy/linalg/linalg.py", line 561, in inv 
    4542 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    4543 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4544 File
    4545 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4546 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    4547 raise LinAlgError("Singular matrix") 
    4548 numpy.linalg.LinAlgError: Singular matrix 
    4549  
    4550 numpy.linalg.LinAlgError: Singular matrix 
    4551  
    4552 File
    4553 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4554 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    4555 raise LinAlgError("Singular matrix") 
    4556  
    4557 See log for complete Python traceback. 
    4558  
    4559 Traceback (most recent call last): 
    4560 File
    4561 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4562 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    4563 self.session.ui.mouse_modes.mouse_pause_tracking() 
    4564 File
    4565 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4566 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    4567 mouse_pause_tracking 
    4568 self._mouse_pause() 
    4569 File
    4570 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4571 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    4572 m.pause(self._mouse_pause_position) 
    4573 File
    4574 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4575 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    4576 p = self.view.picked_object(x, y) 
    4577 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4578 File
    4579 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4580 packages/chimerax/graphics/view.py", line 838, in picked_object 
    4581 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    4582 beyond, 
    4583 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4584 File
    4585 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4586 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    4587 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    4588 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4589 File
    4590 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4591 packages/chimerax/core/models.py", line 143, in first_intercept 
    4592 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    4593 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4594 File
    4595 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4596 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    4597 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    4598 exclude=exclude) 
    4599 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4600 File
    4601 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4602 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    4603 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    4604 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4605 File
    4606 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4607 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    4608 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    4609 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4610 File
    4611 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4612 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    4613 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    4614 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4615 File
    4616 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4617 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    4618 p = super().first_intercept(mxyz1, mxyz2) 
    4619 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4620 File
    4621 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4622 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    4623 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    4624 exclude=exclude) 
    4625 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4626 File
    4627 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4628 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    4629 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    4630 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4631 File
    4632 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4633 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    4634 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    4635 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4636 File
    4637 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4638 packages/chimerax/graphics/drawing.py", line 1108, in
    4639 _first_intercept_excluding_children 
    4640 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    4641 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4642 File
    4643 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4644 packages/chimerax/geometry/place.py", line 201, in inverse 
    4645 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    4646 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4647 File
    4648 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4649 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    4650 rinv[:, :] = matrix_inverse(r) 
    4651 ^^^^^^^^^^^^^^^^^ 
    4652 File
    4653 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4654 packages/numpy/linalg/linalg.py", line 561, in inv 
    4655 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    4656 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4657 File
    4658 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4659 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    4660 raise LinAlgError("Singular matrix") 
    4661 numpy.linalg.LinAlgError: Singular matrix 
    4662  
    4663 numpy.linalg.LinAlgError: Singular matrix 
    4664  
    4665 File
    4666 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4667 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    4668 raise LinAlgError("Singular matrix") 
    4669  
    4670 See log for complete Python traceback. 
    4671  
    4672 Traceback (most recent call last): 
    4673 File
    4674 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4675 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    4676 self.session.ui.mouse_modes.mouse_pause_tracking() 
    4677 File
    4678 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4679 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    4680 mouse_pause_tracking 
    4681 self._mouse_pause() 
    4682 File
    4683 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4684 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    4685 m.pause(self._mouse_pause_position) 
    4686 File
    4687 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4688 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    4689 p = self.view.picked_object(x, y) 
    4690 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4691 File
    4692 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4693 packages/chimerax/graphics/view.py", line 838, in picked_object 
    4694 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    4695 beyond, 
    4696 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4697 File
    4698 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4699 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    4700 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    4701 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4702 File
    4703 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4704 packages/chimerax/core/models.py", line 143, in first_intercept 
    4705 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    4706 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4707 File
    4708 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4709 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    4710 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    4711 exclude=exclude) 
    4712 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4713 File
    4714 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4715 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    4716 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    4717 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4718 File
    4719 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4720 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    4721 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    4722 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4723 File
    4724 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4725 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    4726 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    4727 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4728 File
    4729 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4730 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    4731 p = super().first_intercept(mxyz1, mxyz2) 
    4732 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4733 File
    4734 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4735 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    4736 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    4737 exclude=exclude) 
    4738 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4739 File
    4740 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4741 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    4742 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    4743 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4744 File
    4745 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4746 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    4747 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    4748 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4749 File
    4750 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4751 packages/chimerax/graphics/drawing.py", line 1108, in
    4752 _first_intercept_excluding_children 
    4753 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    4754 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4755 File
    4756 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4757 packages/chimerax/geometry/place.py", line 201, in inverse 
    4758 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    4759 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4760 File
    4761 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4762 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    4763 rinv[:, :] = matrix_inverse(r) 
    4764 ^^^^^^^^^^^^^^^^^ 
    4765 File
    4766 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4767 packages/numpy/linalg/linalg.py", line 561, in inv 
    4768 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    4769 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4770 File
    4771 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4772 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    4773 raise LinAlgError("Singular matrix") 
    4774 numpy.linalg.LinAlgError: Singular matrix 
    4775  
    4776 numpy.linalg.LinAlgError: Singular matrix 
    4777  
    4778 File
    4779 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4780 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    4781 raise LinAlgError("Singular matrix") 
    4782  
    4783 See log for complete Python traceback. 
    4784  
    4785 Traceback (most recent call last): 
    4786 File
    4787 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4788 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    4789 self.session.ui.mouse_modes.mouse_pause_tracking() 
    4790 File
    4791 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4792 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    4793 mouse_pause_tracking 
    4794 self._mouse_pause() 
    4795 File
    4796 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4797 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    4798 m.pause(self._mouse_pause_position) 
    4799 File
    4800 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4801 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    4802 p = self.view.picked_object(x, y) 
    4803 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4804 File
    4805 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4806 packages/chimerax/graphics/view.py", line 838, in picked_object 
    4807 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    4808 beyond, 
    4809 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4810 File
    4811 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4812 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    4813 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    4814 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4815 File
    4816 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4817 packages/chimerax/core/models.py", line 143, in first_intercept 
    4818 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    4819 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4820 File
    4821 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4822 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    4823 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    4824 exclude=exclude) 
    4825 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4826 File
    4827 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4828 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    4829 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    4830 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4831 File
    4832 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4833 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    4834 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    4835 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4836 File
    4837 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4838 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    4839 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    4840 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4841 File
    4842 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4843 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    4844 p = super().first_intercept(mxyz1, mxyz2) 
    4845 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4846 File
    4847 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4848 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    4849 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    4850 exclude=exclude) 
    4851 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4852 File
    4853 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4854 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    4855 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    4856 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4857 File
    4858 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4859 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    4860 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    4861 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4862 File
    4863 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4864 packages/chimerax/graphics/drawing.py", line 1108, in
    4865 _first_intercept_excluding_children 
    4866 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    4867 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4868 File
    4869 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4870 packages/chimerax/geometry/place.py", line 201, in inverse 
    4871 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    4872 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4873 File
    4874 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4875 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    4876 rinv[:, :] = matrix_inverse(r) 
    4877 ^^^^^^^^^^^^^^^^^ 
    4878 File
    4879 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4880 packages/numpy/linalg/linalg.py", line 561, in inv 
    4881 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    4882 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4883 File
    4884 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4885 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    4886 raise LinAlgError("Singular matrix") 
    4887 numpy.linalg.LinAlgError: Singular matrix 
    4888  
    4889 numpy.linalg.LinAlgError: Singular matrix 
    4890  
    4891 File
    4892 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4893 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    4894 raise LinAlgError("Singular matrix") 
    4895  
    4896 See log for complete Python traceback. 
    4897  
    4898 Traceback (most recent call last): 
    4899 File
    4900 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4901 packages/chimerax/mouse_modes/mousemodes.py", line 656, in <lambda> 
    4902 gw.mouseReleaseEvent = lambda e, s=self: s._dispatch_mouse_event(e,
    4903 "mouse_up") 
    4904 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4905 File
    4906 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4907 packages/chimerax/mouse_modes/mousemodes.py", line 556, in
    4908 _dispatch_mouse_event 
    4909 f(MouseEvent(event, modifiers=modifiers)) 
    4910 File
    4911 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4912 packages/chimerax/mouse_modes/std_modes.py", line 70, in mouse_up 
    4913 mouse_select(event, mode, self.session, self.view) 
    4914 File
    4915 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4916 packages/chimerax/mouse_modes/std_modes.py", line 209, in mouse_select 
    4917 pick = view.picked_object(x, y) 
    4918 ^^^^^^^^^^^^^^^^^^^^^^^^ 
    4919 File
    4920 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4921 packages/chimerax/graphics/view.py", line 838, in picked_object 
    4922 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    4923 beyond, 
    4924 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4925 File
    4926 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4927 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    4928 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    4929 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4930 File
    4931 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4932 packages/chimerax/core/models.py", line 143, in first_intercept 
    4933 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    4934 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4935 File
    4936 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4937 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    4938 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    4939 exclude=exclude) 
    4940 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4941 File
    4942 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4943 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    4944 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    4945 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4946 File
    4947 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4948 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    4949 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    4950 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4951 File
    4952 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4953 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    4954 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    4955 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4956 File
    4957 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4958 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    4959 p = super().first_intercept(mxyz1, mxyz2) 
    4960 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4961 File
    4962 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4963 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    4964 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    4965 exclude=exclude) 
    4966 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4967 File
    4968 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4969 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    4970 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    4971 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4972 File
    4973 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4974 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    4975 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    4976 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4977 File
    4978 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4979 packages/chimerax/graphics/drawing.py", line 1108, in
    4980 _first_intercept_excluding_children 
    4981 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    4982 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4983 File
    4984 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4985 packages/chimerax/geometry/place.py", line 201, in inverse 
    4986 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    4987 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4988 File
    4989 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4990 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    4991 rinv[:, :] = matrix_inverse(r) 
    4992 ^^^^^^^^^^^^^^^^^ 
    4993 File
    4994 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    4995 packages/numpy/linalg/linalg.py", line 561, in inv 
    4996 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    4997 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    4998 File
    4999 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5000 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    5001 raise LinAlgError("Singular matrix") 
    5002 numpy.linalg.LinAlgError: Singular matrix 
    5003  
    5004 numpy.linalg.LinAlgError: Singular matrix 
    5005  
    5006 File
    5007 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5008 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    5009 raise LinAlgError("Singular matrix") 
    5010  
    5011 See log for complete Python traceback. 
    5012  
    5013 Traceback (most recent call last): 
    5014 File
    5015 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5016 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    5017 self.session.ui.mouse_modes.mouse_pause_tracking() 
    5018 File
    5019 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5020 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    5021 mouse_pause_tracking 
    5022 self._mouse_pause() 
    5023 File
    5024 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5025 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    5026 m.pause(self._mouse_pause_position) 
    5027 File
    5028 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5029 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    5030 p = self.view.picked_object(x, y) 
    5031 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5032 File
    5033 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5034 packages/chimerax/graphics/view.py", line 838, in picked_object 
    5035 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    5036 beyond, 
    5037 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5038 File
    5039 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5040 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    5041 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    5042 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5043 File
    5044 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5045 packages/chimerax/core/models.py", line 143, in first_intercept 
    5046 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    5047 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5048 File
    5049 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5050 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    5051 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    5052 exclude=exclude) 
    5053 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5054 File
    5055 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5056 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    5057 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    5058 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5059 File
    5060 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5061 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    5062 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    5063 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5064 File
    5065 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5066 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    5067 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    5068 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5069 File
    5070 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5071 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    5072 p = super().first_intercept(mxyz1, mxyz2) 
    5073 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5074 File
    5075 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5076 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    5077 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    5078 exclude=exclude) 
    5079 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5080 File
    5081 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5082 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    5083 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    5084 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5085 File
    5086 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5087 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    5088 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    5089 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5090 File
    5091 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5092 packages/chimerax/graphics/drawing.py", line 1108, in
    5093 _first_intercept_excluding_children 
    5094 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    5095 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5096 File
    5097 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5098 packages/chimerax/geometry/place.py", line 201, in inverse 
    5099 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    5100 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5101 File
    5102 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5103 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    5104 rinv[:, :] = matrix_inverse(r) 
    5105 ^^^^^^^^^^^^^^^^^ 
    5106 File
    5107 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5108 packages/numpy/linalg/linalg.py", line 561, in inv 
    5109 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    5110 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5111 File
    5112 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5113 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    5114 raise LinAlgError("Singular matrix") 
    5115 numpy.linalg.LinAlgError: Singular matrix 
    5116  
    5117 numpy.linalg.LinAlgError: Singular matrix 
    5118  
    5119 File
    5120 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5121 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    5122 raise LinAlgError("Singular matrix") 
    5123  
    5124 See log for complete Python traceback. 
    5125  
    5126 Traceback (most recent call last): 
    5127 File
    5128 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5129 packages/chimerax/mouse_modes/mousemodes.py", line 656, in <lambda> 
    5130 gw.mouseReleaseEvent = lambda e, s=self: s._dispatch_mouse_event(e,
    5131 "mouse_up") 
    5132 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5133 File
    5134 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5135 packages/chimerax/mouse_modes/mousemodes.py", line 556, in
    5136 _dispatch_mouse_event 
    5137 f(MouseEvent(event, modifiers=modifiers)) 
    5138 File
    5139 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5140 packages/chimerax/mouse_modes/std_modes.py", line 70, in mouse_up 
    5141 mouse_select(event, mode, self.session, self.view) 
    5142 File
    5143 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5144 packages/chimerax/mouse_modes/std_modes.py", line 209, in mouse_select 
    5145 pick = view.picked_object(x, y) 
    5146 ^^^^^^^^^^^^^^^^^^^^^^^^ 
    5147 File
    5148 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5149 packages/chimerax/graphics/view.py", line 838, in picked_object 
    5150 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    5151 beyond, 
    5152 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5153 File
    5154 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5155 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    5156 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    5157 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5158 File
    5159 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5160 packages/chimerax/core/models.py", line 143, in first_intercept 
    5161 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    5162 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5163 File
    5164 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5165 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    5166 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    5167 exclude=exclude) 
    5168 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5169 File
    5170 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5171 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    5172 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    5173 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5174 File
    5175 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5176 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    5177 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    5178 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5179 File
    5180 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5181 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    5182 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    5183 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5184 File
    5185 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5186 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    5187 p = super().first_intercept(mxyz1, mxyz2) 
    5188 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5189 File
    5190 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5191 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    5192 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    5193 exclude=exclude) 
    5194 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5195 File
    5196 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5197 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    5198 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    5199 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5200 File
    5201 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5202 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    5203 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    5204 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5205 File
    5206 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5207 packages/chimerax/graphics/drawing.py", line 1108, in
    5208 _first_intercept_excluding_children 
    5209 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    5210 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5211 File
    5212 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5213 packages/chimerax/geometry/place.py", line 201, in inverse 
    5214 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    5215 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5216 File
    5217 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5218 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    5219 rinv[:, :] = matrix_inverse(r) 
    5220 ^^^^^^^^^^^^^^^^^ 
    5221 File
    5222 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5223 packages/numpy/linalg/linalg.py", line 561, in inv 
    5224 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    5225 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5226 File
    5227 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5228 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    5229 raise LinAlgError("Singular matrix") 
    5230 numpy.linalg.LinAlgError: Singular matrix 
    5231  
    5232 numpy.linalg.LinAlgError: Singular matrix 
    5233  
    5234 File
    5235 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5236 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    5237 raise LinAlgError("Singular matrix") 
    5238  
    5239 See log for complete Python traceback. 
    5240  
    5241 Traceback (most recent call last): 
    5242 File
    5243 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5244 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    5245 self.session.ui.mouse_modes.mouse_pause_tracking() 
    5246 File
    5247 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5248 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    5249 mouse_pause_tracking 
    5250 self._mouse_pause() 
    5251 File
    5252 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5253 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    5254 m.pause(self._mouse_pause_position) 
    5255 File
    5256 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5257 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    5258 p = self.view.picked_object(x, y) 
    5259 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5260 File
    5261 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5262 packages/chimerax/graphics/view.py", line 838, in picked_object 
    5263 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    5264 beyond, 
    5265 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5266 File
    5267 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5268 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    5269 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    5270 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5271 File
    5272 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5273 packages/chimerax/core/models.py", line 143, in first_intercept 
    5274 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    5275 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5276 File
    5277 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5278 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    5279 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    5280 exclude=exclude) 
    5281 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5282 File
    5283 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5284 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    5285 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    5286 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5287 File
    5288 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5289 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    5290 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    5291 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5292 File
    5293 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5294 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    5295 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    5296 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5297 File
    5298 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5299 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    5300 p = super().first_intercept(mxyz1, mxyz2) 
    5301 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5302 File
    5303 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5304 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    5305 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    5306 exclude=exclude) 
    5307 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5308 File
    5309 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5310 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    5311 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    5312 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5313 File
    5314 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5315 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    5316 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    5317 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5318 File
    5319 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5320 packages/chimerax/graphics/drawing.py", line 1108, in
    5321 _first_intercept_excluding_children 
    5322 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    5323 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5324 File
    5325 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5326 packages/chimerax/geometry/place.py", line 201, in inverse 
    5327 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    5328 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5329 File
    5330 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5331 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    5332 rinv[:, :] = matrix_inverse(r) 
    5333 ^^^^^^^^^^^^^^^^^ 
    5334 File
    5335 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5336 packages/numpy/linalg/linalg.py", line 561, in inv 
    5337 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    5338 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5339 File
    5340 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5341 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    5342 raise LinAlgError("Singular matrix") 
    5343 numpy.linalg.LinAlgError: Singular matrix 
    5344  
    5345 numpy.linalg.LinAlgError: Singular matrix 
    5346  
    5347 File
    5348 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5349 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    5350 raise LinAlgError("Singular matrix") 
    5351  
    5352 See log for complete Python traceback. 
    5353  
    5354 Traceback (most recent call last): 
    5355 File
    5356 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5357 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    5358 self.session.ui.mouse_modes.mouse_pause_tracking() 
    5359 File
    5360 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5361 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    5362 mouse_pause_tracking 
    5363 self._mouse_pause() 
    5364 File
    5365 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5366 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    5367 m.pause(self._mouse_pause_position) 
    5368 File
    5369 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5370 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    5371 p = self.view.picked_object(x, y) 
    5372 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5373 File
    5374 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5375 packages/chimerax/graphics/view.py", line 838, in picked_object 
    5376 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    5377 beyond, 
    5378 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5379 File
    5380 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5381 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    5382 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    5383 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5384 File
    5385 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5386 packages/chimerax/core/models.py", line 143, in first_intercept 
    5387 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    5388 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5389 File
    5390 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5391 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    5392 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    5393 exclude=exclude) 
    5394 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5395 File
    5396 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5397 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    5398 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    5399 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5400 File
    5401 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5402 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    5403 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    5404 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5405 File
    5406 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5407 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    5408 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    5409 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5410 File
    5411 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5412 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    5413 p = super().first_intercept(mxyz1, mxyz2) 
    5414 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5415 File
    5416 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5417 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    5418 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    5419 exclude=exclude) 
    5420 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5421 File
    5422 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5423 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    5424 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    5425 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5426 File
    5427 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5428 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    5429 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    5430 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5431 File
    5432 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5433 packages/chimerax/graphics/drawing.py", line 1108, in
    5434 _first_intercept_excluding_children 
    5435 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    5436 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5437 File
    5438 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5439 packages/chimerax/geometry/place.py", line 201, in inverse 
    5440 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    5441 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5442 File
    5443 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5444 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    5445 rinv[:, :] = matrix_inverse(r) 
    5446 ^^^^^^^^^^^^^^^^^ 
    5447 File
    5448 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5449 packages/numpy/linalg/linalg.py", line 561, in inv 
    5450 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    5451 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5452 File
    5453 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5454 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    5455 raise LinAlgError("Singular matrix") 
    5456 numpy.linalg.LinAlgError: Singular matrix 
    5457  
    5458 numpy.linalg.LinAlgError: Singular matrix 
    5459  
    5460 File
    5461 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5462 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    5463 raise LinAlgError("Singular matrix") 
    5464  
    5465 See log for complete Python traceback. 
    5466  
    5467 Traceback (most recent call last): 
    5468 File
    5469 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5470 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    5471 self.session.ui.mouse_modes.mouse_pause_tracking() 
    5472 File
    5473 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5474 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    5475 mouse_pause_tracking 
    5476 self._mouse_pause() 
    5477 File
    5478 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5479 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    5480 m.pause(self._mouse_pause_position) 
    5481 File
    5482 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5483 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    5484 p = self.view.picked_object(x, y) 
    5485 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5486 File
    5487 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5488 packages/chimerax/graphics/view.py", line 838, in picked_object 
    5489 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    5490 beyond, 
    5491 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5492 File
    5493 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5494 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    5495 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    5496 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5497 File
    5498 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5499 packages/chimerax/core/models.py", line 143, in first_intercept 
    5500 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    5501 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5502 File
    5503 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5504 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    5505 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    5506 exclude=exclude) 
    5507 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5508 File
    5509 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5510 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    5511 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    5512 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5513 File
    5514 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5515 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    5516 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    5517 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5518 File
    5519 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5520 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    5521 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    5522 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5523 File
    5524 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5525 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    5526 p = super().first_intercept(mxyz1, mxyz2) 
    5527 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5528 File
    5529 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5530 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    5531 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    5532 exclude=exclude) 
    5533 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5534 File
    5535 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5536 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    5537 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    5538 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5539 File
    5540 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5541 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    5542 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    5543 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5544 File
    5545 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5546 packages/chimerax/graphics/drawing.py", line 1108, in
    5547 _first_intercept_excluding_children 
    5548 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    5549 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5550 File
    5551 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5552 packages/chimerax/geometry/place.py", line 201, in inverse 
    5553 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    5554 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5555 File
    5556 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5557 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    5558 rinv[:, :] = matrix_inverse(r) 
    5559 ^^^^^^^^^^^^^^^^^ 
    5560 File
    5561 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5562 packages/numpy/linalg/linalg.py", line 561, in inv 
    5563 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    5564 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5565 File
    5566 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5567 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    5568 raise LinAlgError("Singular matrix") 
    5569 numpy.linalg.LinAlgError: Singular matrix 
    5570  
    5571 numpy.linalg.LinAlgError: Singular matrix 
    5572  
    5573 File
    5574 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5575 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    5576 raise LinAlgError("Singular matrix") 
    5577  
    5578 See log for complete Python traceback. 
    5579  
    5580 Traceback (most recent call last): 
    5581 File
    5582 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5583 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    5584 self.session.ui.mouse_modes.mouse_pause_tracking() 
    5585 File
    5586 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5587 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    5588 mouse_pause_tracking 
    5589 self._mouse_pause() 
    5590 File
    5591 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5592 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    5593 m.pause(self._mouse_pause_position) 
    5594 File
    5595 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5596 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    5597 p = self.view.picked_object(x, y) 
    5598 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5599 File
    5600 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5601 packages/chimerax/graphics/view.py", line 838, in picked_object 
    5602 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    5603 beyond, 
    5604 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5605 File
    5606 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5607 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    5608 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    5609 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5610 File
    5611 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5612 packages/chimerax/core/models.py", line 143, in first_intercept 
    5613 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    5614 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5615 File
    5616 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5617 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    5618 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    5619 exclude=exclude) 
    5620 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5621 File
    5622 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5623 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    5624 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    5625 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5626 File
    5627 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5628 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    5629 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    5630 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5631 File
    5632 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5633 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    5634 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    5635 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5636 File
    5637 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5638 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    5639 p = super().first_intercept(mxyz1, mxyz2) 
    5640 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5641 File
    5642 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5643 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    5644 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    5645 exclude=exclude) 
    5646 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5647 File
    5648 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5649 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    5650 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    5651 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5652 File
    5653 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5654 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    5655 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    5656 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5657 File
    5658 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5659 packages/chimerax/graphics/drawing.py", line 1108, in
    5660 _first_intercept_excluding_children 
    5661 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    5662 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5663 File
    5664 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5665 packages/chimerax/geometry/place.py", line 201, in inverse 
    5666 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    5667 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5668 File
    5669 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5670 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    5671 rinv[:, :] = matrix_inverse(r) 
    5672 ^^^^^^^^^^^^^^^^^ 
    5673 File
    5674 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5675 packages/numpy/linalg/linalg.py", line 561, in inv 
    5676 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    5677 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5678 File
    5679 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5680 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    5681 raise LinAlgError("Singular matrix") 
    5682 numpy.linalg.LinAlgError: Singular matrix 
    5683  
    5684 numpy.linalg.LinAlgError: Singular matrix 
    5685  
    5686 File
    5687 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5688 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    5689 raise LinAlgError("Singular matrix") 
    5690  
    5691 See log for complete Python traceback. 
    5692  
    5693 Traceback (most recent call last): 
    5694 File
    5695 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5696 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    5697 self.session.ui.mouse_modes.mouse_pause_tracking() 
    5698 File
    5699 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5700 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    5701 mouse_pause_tracking 
    5702 self._mouse_pause() 
    5703 File
    5704 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5705 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    5706 m.pause(self._mouse_pause_position) 
    5707 File
    5708 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5709 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    5710 p = self.view.picked_object(x, y) 
    5711 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5712 File
    5713 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5714 packages/chimerax/graphics/view.py", line 838, in picked_object 
    5715 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    5716 beyond, 
    5717 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5718 File
    5719 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5720 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    5721 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    5722 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5723 File
    5724 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5725 packages/chimerax/core/models.py", line 143, in first_intercept 
    5726 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    5727 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5728 File
    5729 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5730 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    5731 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    5732 exclude=exclude) 
    5733 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5734 File
    5735 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5736 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    5737 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    5738 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5739 File
    5740 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5741 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    5742 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    5743 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5744 File
    5745 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5746 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    5747 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    5748 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5749 File
    5750 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5751 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    5752 p = super().first_intercept(mxyz1, mxyz2) 
    5753 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5754 File
    5755 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5756 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    5757 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    5758 exclude=exclude) 
    5759 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5760 File
    5761 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5762 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    5763 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    5764 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5765 File
    5766 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5767 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    5768 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    5769 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5770 File
    5771 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5772 packages/chimerax/graphics/drawing.py", line 1108, in
    5773 _first_intercept_excluding_children 
    5774 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    5775 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5776 File
    5777 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5778 packages/chimerax/geometry/place.py", line 201, in inverse 
    5779 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    5780 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5781 File
    5782 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5783 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    5784 rinv[:, :] = matrix_inverse(r) 
    5785 ^^^^^^^^^^^^^^^^^ 
    5786 File
    5787 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5788 packages/numpy/linalg/linalg.py", line 561, in inv 
    5789 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    5790 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5791 File
    5792 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5793 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    5794 raise LinAlgError("Singular matrix") 
    5795 numpy.linalg.LinAlgError: Singular matrix 
    5796  
    5797 numpy.linalg.LinAlgError: Singular matrix 
    5798  
    5799 File
    5800 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5801 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    5802 raise LinAlgError("Singular matrix") 
    5803  
    5804 See log for complete Python traceback. 
    5805  
    5806 Traceback (most recent call last): 
    5807 File
    5808 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5809 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    5810 self.session.ui.mouse_modes.mouse_pause_tracking() 
    5811 File
    5812 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5813 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    5814 mouse_pause_tracking 
    5815 self._mouse_pause() 
    5816 File
    5817 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5818 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    5819 m.pause(self._mouse_pause_position) 
    5820 File
    5821 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5822 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    5823 p = self.view.picked_object(x, y) 
    5824 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5825 File
    5826 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5827 packages/chimerax/graphics/view.py", line 838, in picked_object 
    5828 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    5829 beyond, 
    5830 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5831 File
    5832 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5833 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    5834 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    5835 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5836 File
    5837 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5838 packages/chimerax/core/models.py", line 143, in first_intercept 
    5839 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    5840 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5841 File
    5842 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5843 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    5844 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    5845 exclude=exclude) 
    5846 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5847 File
    5848 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5849 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    5850 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    5851 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5852 File
    5853 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5854 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    5855 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    5856 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5857 File
    5858 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5859 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    5860 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    5861 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5862 File
    5863 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5864 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    5865 p = super().first_intercept(mxyz1, mxyz2) 
    5866 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5867 File
    5868 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5869 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    5870 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    5871 exclude=exclude) 
    5872 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5873 File
    5874 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5875 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    5876 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    5877 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5878 File
    5879 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5880 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    5881 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    5882 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5883 File
    5884 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5885 packages/chimerax/graphics/drawing.py", line 1108, in
    5886 _first_intercept_excluding_children 
    5887 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    5888 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5889 File
    5890 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5891 packages/chimerax/geometry/place.py", line 201, in inverse 
    5892 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    5893 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5894 File
    5895 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5896 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    5897 rinv[:, :] = matrix_inverse(r) 
    5898 ^^^^^^^^^^^^^^^^^ 
    5899 File
    5900 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5901 packages/numpy/linalg/linalg.py", line 561, in inv 
    5902 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    5903 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5904 File
    5905 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5906 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    5907 raise LinAlgError("Singular matrix") 
    5908 numpy.linalg.LinAlgError: Singular matrix 
    5909  
    5910 numpy.linalg.LinAlgError: Singular matrix 
    5911  
    5912 File
    5913 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5914 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    5915 raise LinAlgError("Singular matrix") 
    5916  
    5917 See log for complete Python traceback. 
    5918  
    5919 Traceback (most recent call last): 
    5920 File
    5921 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5922 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    5923 self.session.ui.mouse_modes.mouse_pause_tracking() 
    5924 File
    5925 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5926 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    5927 mouse_pause_tracking 
    5928 self._mouse_pause() 
    5929 File
    5930 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5931 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    5932 m.pause(self._mouse_pause_position) 
    5933 File
    5934 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5935 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    5936 p = self.view.picked_object(x, y) 
    5937 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5938 File
    5939 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5940 packages/chimerax/graphics/view.py", line 838, in picked_object 
    5941 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    5942 beyond, 
    5943 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5944 File
    5945 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5946 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    5947 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    5948 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5949 File
    5950 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5951 packages/chimerax/core/models.py", line 143, in first_intercept 
    5952 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    5953 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5954 File
    5955 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5956 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    5957 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    5958 exclude=exclude) 
    5959 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5960 File
    5961 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5962 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    5963 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    5964 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5965 File
    5966 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5967 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    5968 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    5969 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5970 File
    5971 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5972 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    5973 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    5974 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5975 File
    5976 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5977 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    5978 p = super().first_intercept(mxyz1, mxyz2) 
    5979 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5980 File
    5981 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5982 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    5983 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    5984 exclude=exclude) 
    5985 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5986 File
    5987 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5988 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    5989 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    5990 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5991 File
    5992 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5993 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    5994 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    5995 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    5996 File
    5997 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    5998 packages/chimerax/graphics/drawing.py", line 1108, in
    5999 _first_intercept_excluding_children 
    6000 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    6001 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6002 File
    6003 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6004 packages/chimerax/geometry/place.py", line 201, in inverse 
    6005 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    6006 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6007 File
    6008 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6009 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    6010 rinv[:, :] = matrix_inverse(r) 
    6011 ^^^^^^^^^^^^^^^^^ 
    6012 File
    6013 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6014 packages/numpy/linalg/linalg.py", line 561, in inv 
    6015 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    6016 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6017 File
    6018 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6019 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    6020 raise LinAlgError("Singular matrix") 
    6021 numpy.linalg.LinAlgError: Singular matrix 
    6022  
    6023 numpy.linalg.LinAlgError: Singular matrix 
    6024  
    6025 File
    6026 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6027 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    6028 raise LinAlgError("Singular matrix") 
    6029  
    6030 See log for complete Python traceback. 
    6031  
    6032 Traceback (most recent call last): 
    6033 File
    6034 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6035 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    6036 self.session.ui.mouse_modes.mouse_pause_tracking() 
    6037 File
    6038 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6039 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    6040 mouse_pause_tracking 
    6041 self._mouse_pause() 
    6042 File
    6043 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6044 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    6045 m.pause(self._mouse_pause_position) 
    6046 File
    6047 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6048 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    6049 p = self.view.picked_object(x, y) 
    6050 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6051 File
    6052 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6053 packages/chimerax/graphics/view.py", line 838, in picked_object 
    6054 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    6055 beyond, 
    6056 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6057 File
    6058 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6059 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    6060 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    6061 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6062 File
    6063 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6064 packages/chimerax/core/models.py", line 143, in first_intercept 
    6065 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    6066 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6067 File
    6068 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6069 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    6070 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    6071 exclude=exclude) 
    6072 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6073 File
    6074 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6075 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    6076 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    6077 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6078 File
    6079 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6080 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    6081 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    6082 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6083 File
    6084 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6085 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    6086 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    6087 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6088 File
    6089 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6090 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    6091 p = super().first_intercept(mxyz1, mxyz2) 
    6092 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6093 File
    6094 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6095 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    6096 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    6097 exclude=exclude) 
    6098 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6099 File
    6100 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6101 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    6102 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    6103 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6104 File
    6105 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6106 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    6107 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    6108 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6109 File
    6110 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6111 packages/chimerax/graphics/drawing.py", line 1108, in
    6112 _first_intercept_excluding_children 
    6113 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    6114 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6115 File
    6116 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6117 packages/chimerax/geometry/place.py", line 201, in inverse 
    6118 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    6119 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6120 File
    6121 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6122 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    6123 rinv[:, :] = matrix_inverse(r) 
    6124 ^^^^^^^^^^^^^^^^^ 
    6125 File
    6126 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6127 packages/numpy/linalg/linalg.py", line 561, in inv 
    6128 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    6129 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6130 File
    6131 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6132 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    6133 raise LinAlgError("Singular matrix") 
    6134 numpy.linalg.LinAlgError: Singular matrix 
    6135  
    6136 numpy.linalg.LinAlgError: Singular matrix 
    6137  
    6138 File
    6139 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6140 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    6141 raise LinAlgError("Singular matrix") 
    6142  
    6143 See log for complete Python traceback. 
    6144  
    6145 Traceback (most recent call last): 
    6146 File
    6147 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6148 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    6149 self.session.ui.mouse_modes.mouse_pause_tracking() 
    6150 File
    6151 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6152 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    6153 mouse_pause_tracking 
    6154 self._mouse_pause() 
    6155 File
    6156 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6157 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    6158 m.pause(self._mouse_pause_position) 
    6159 File
    6160 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6161 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    6162 p = self.view.picked_object(x, y) 
    6163 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6164 File
    6165 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6166 packages/chimerax/graphics/view.py", line 838, in picked_object 
    6167 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    6168 beyond, 
    6169 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6170 File
    6171 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6172 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    6173 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    6174 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6175 File
    6176 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6177 packages/chimerax/core/models.py", line 143, in first_intercept 
    6178 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    6179 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6180 File
    6181 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6182 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    6183 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    6184 exclude=exclude) 
    6185 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6186 File
    6187 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6188 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    6189 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    6190 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6191 File
    6192 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6193 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    6194 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    6195 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6196 File
    6197 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6198 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    6199 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    6200 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6201 File
    6202 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6203 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    6204 p = super().first_intercept(mxyz1, mxyz2) 
    6205 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6206 File
    6207 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6208 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    6209 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    6210 exclude=exclude) 
    6211 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6212 File
    6213 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6214 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    6215 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    6216 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6217 File
    6218 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6219 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    6220 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    6221 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6222 File
    6223 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6224 packages/chimerax/graphics/drawing.py", line 1108, in
    6225 _first_intercept_excluding_children 
    6226 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    6227 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6228 File
    6229 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6230 packages/chimerax/geometry/place.py", line 201, in inverse 
    6231 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    6232 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6233 File
    6234 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6235 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    6236 rinv[:, :] = matrix_inverse(r) 
    6237 ^^^^^^^^^^^^^^^^^ 
    6238 File
    6239 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6240 packages/numpy/linalg/linalg.py", line 561, in inv 
    6241 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    6242 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6243 File
    6244 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6245 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    6246 raise LinAlgError("Singular matrix") 
    6247 numpy.linalg.LinAlgError: Singular matrix 
    6248  
    6249 numpy.linalg.LinAlgError: Singular matrix 
    6250  
    6251 File
    6252 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6253 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    6254 raise LinAlgError("Singular matrix") 
    6255  
    6256 See log for complete Python traceback. 
    6257  
    6258 Traceback (most recent call last): 
    6259 File
    6260 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6261 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    6262 self.session.ui.mouse_modes.mouse_pause_tracking() 
    6263 File
    6264 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6265 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    6266 mouse_pause_tracking 
    6267 self._mouse_pause() 
    6268 File
    6269 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6270 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    6271 m.pause(self._mouse_pause_position) 
    6272 File
    6273 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6274 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    6275 p = self.view.picked_object(x, y) 
    6276 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6277 File
    6278 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6279 packages/chimerax/graphics/view.py", line 838, in picked_object 
    6280 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    6281 beyond, 
    6282 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6283 File
    6284 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6285 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    6286 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    6287 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6288 File
    6289 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6290 packages/chimerax/core/models.py", line 143, in first_intercept 
    6291 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    6292 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6293 File
    6294 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6295 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    6296 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    6297 exclude=exclude) 
    6298 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6299 File
    6300 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6301 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    6302 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    6303 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6304 File
    6305 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6306 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    6307 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    6308 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6309 File
    6310 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6311 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    6312 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    6313 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6314 File
    6315 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6316 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    6317 p = super().first_intercept(mxyz1, mxyz2) 
    6318 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6319 File
    6320 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6321 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    6322 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    6323 exclude=exclude) 
    6324 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6325 File
    6326 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6327 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    6328 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    6329 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6330 File
    6331 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6332 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    6333 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    6334 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6335 File
    6336 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6337 packages/chimerax/graphics/drawing.py", line 1108, in
    6338 _first_intercept_excluding_children 
    6339 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    6340 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6341 File
    6342 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6343 packages/chimerax/geometry/place.py", line 201, in inverse 
    6344 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    6345 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6346 File
    6347 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6348 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    6349 rinv[:, :] = matrix_inverse(r) 
    6350 ^^^^^^^^^^^^^^^^^ 
    6351 File
    6352 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6353 packages/numpy/linalg/linalg.py", line 561, in inv 
    6354 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    6355 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6356 File
    6357 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6358 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    6359 raise LinAlgError("Singular matrix") 
    6360 numpy.linalg.LinAlgError: Singular matrix 
    6361  
    6362 numpy.linalg.LinAlgError: Singular matrix 
    6363  
    6364 File
    6365 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6366 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    6367 raise LinAlgError("Singular matrix") 
    6368  
    6369 See log for complete Python traceback. 
    6370  
    6371 Traceback (most recent call last): 
    6372 File
    6373 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6374 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    6375 self.session.ui.mouse_modes.mouse_pause_tracking() 
    6376 File
    6377 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6378 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    6379 mouse_pause_tracking 
    6380 self._mouse_pause() 
    6381 File
    6382 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6383 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    6384 m.pause(self._mouse_pause_position) 
    6385 File
    6386 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6387 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    6388 p = self.view.picked_object(x, y) 
    6389 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6390 File
    6391 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6392 packages/chimerax/graphics/view.py", line 838, in picked_object 
    6393 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    6394 beyond, 
    6395 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6396 File
    6397 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6398 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    6399 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    6400 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6401 File
    6402 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6403 packages/chimerax/core/models.py", line 143, in first_intercept 
    6404 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    6405 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6406 File
    6407 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6408 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    6409 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    6410 exclude=exclude) 
    6411 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6412 File
    6413 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6414 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    6415 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    6416 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6417 File
    6418 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6419 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    6420 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    6421 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6422 File
    6423 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6424 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    6425 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    6426 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6427 File
    6428 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6429 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    6430 p = super().first_intercept(mxyz1, mxyz2) 
    6431 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6432 File
    6433 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6434 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    6435 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    6436 exclude=exclude) 
    6437 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6438 File
    6439 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6440 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    6441 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    6442 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6443 File
    6444 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6445 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    6446 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    6447 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6448 File
    6449 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6450 packages/chimerax/graphics/drawing.py", line 1108, in
    6451 _first_intercept_excluding_children 
    6452 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    6453 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6454 File
    6455 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6456 packages/chimerax/geometry/place.py", line 201, in inverse 
    6457 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    6458 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6459 File
    6460 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6461 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    6462 rinv[:, :] = matrix_inverse(r) 
    6463 ^^^^^^^^^^^^^^^^^ 
    6464 File
    6465 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6466 packages/numpy/linalg/linalg.py", line 561, in inv 
    6467 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    6468 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6469 File
    6470 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6471 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    6472 raise LinAlgError("Singular matrix") 
    6473 numpy.linalg.LinAlgError: Singular matrix 
    6474  
    6475 numpy.linalg.LinAlgError: Singular matrix 
    6476  
    6477 File
    6478 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6479 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    6480 raise LinAlgError("Singular matrix") 
    6481  
    6482 See log for complete Python traceback. 
    6483  
    6484 Traceback (most recent call last): 
    6485 File
    6486 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6487 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    6488 self.session.ui.mouse_modes.mouse_pause_tracking() 
    6489 File
    6490 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6491 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    6492 mouse_pause_tracking 
    6493 self._mouse_pause() 
    6494 File
    6495 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6496 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    6497 m.pause(self._mouse_pause_position) 
    6498 File
    6499 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6500 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    6501 p = self.view.picked_object(x, y) 
    6502 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6503 File
    6504 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6505 packages/chimerax/graphics/view.py", line 838, in picked_object 
    6506 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    6507 beyond, 
    6508 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6509 File
    6510 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6511 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    6512 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    6513 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6514 File
    6515 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6516 packages/chimerax/core/models.py", line 143, in first_intercept 
    6517 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    6518 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6519 File
    6520 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6521 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    6522 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    6523 exclude=exclude) 
    6524 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6525 File
    6526 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6527 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    6528 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    6529 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6530 File
    6531 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6532 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    6533 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    6534 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6535 File
    6536 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6537 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    6538 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    6539 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6540 File
    6541 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6542 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    6543 p = super().first_intercept(mxyz1, mxyz2) 
    6544 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6545 File
    6546 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6547 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    6548 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    6549 exclude=exclude) 
    6550 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6551 File
    6552 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6553 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    6554 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    6555 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6556 File
    6557 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6558 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    6559 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    6560 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6561 File
    6562 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6563 packages/chimerax/graphics/drawing.py", line 1108, in
    6564 _first_intercept_excluding_children 
    6565 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    6566 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6567 File
    6568 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6569 packages/chimerax/geometry/place.py", line 201, in inverse 
    6570 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    6571 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6572 File
    6573 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6574 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    6575 rinv[:, :] = matrix_inverse(r) 
    6576 ^^^^^^^^^^^^^^^^^ 
    6577 File
    6578 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6579 packages/numpy/linalg/linalg.py", line 561, in inv 
    6580 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    6581 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6582 File
    6583 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6584 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    6585 raise LinAlgError("Singular matrix") 
    6586 numpy.linalg.LinAlgError: Singular matrix 
    6587  
    6588 numpy.linalg.LinAlgError: Singular matrix 
    6589  
    6590 File
    6591 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6592 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    6593 raise LinAlgError("Singular matrix") 
    6594  
    6595 See log for complete Python traceback. 
    6596  
    6597 Traceback (most recent call last): 
    6598 File
    6599 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6600 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    6601 self.session.ui.mouse_modes.mouse_pause_tracking() 
    6602 File
    6603 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6604 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    6605 mouse_pause_tracking 
    6606 self._mouse_pause() 
    6607 File
    6608 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6609 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    6610 m.pause(self._mouse_pause_position) 
    6611 File
    6612 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6613 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    6614 p = self.view.picked_object(x, y) 
    6615 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6616 File
    6617 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6618 packages/chimerax/graphics/view.py", line 838, in picked_object 
    6619 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    6620 beyond, 
    6621 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6622 File
    6623 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6624 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    6625 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    6626 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6627 File
    6628 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6629 packages/chimerax/core/models.py", line 143, in first_intercept 
    6630 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    6631 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6632 File
    6633 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6634 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    6635 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    6636 exclude=exclude) 
    6637 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6638 File
    6639 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6640 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    6641 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    6642 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6643 File
    6644 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6645 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    6646 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    6647 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6648 File
    6649 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6650 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    6651 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    6652 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6653 File
    6654 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6655 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    6656 p = super().first_intercept(mxyz1, mxyz2) 
    6657 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6658 File
    6659 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6660 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    6661 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    6662 exclude=exclude) 
    6663 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6664 File
    6665 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6666 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    6667 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    6668 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6669 File
    6670 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6671 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    6672 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    6673 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6674 File
    6675 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6676 packages/chimerax/graphics/drawing.py", line 1108, in
    6677 _first_intercept_excluding_children 
    6678 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    6679 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6680 File
    6681 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6682 packages/chimerax/geometry/place.py", line 201, in inverse 
    6683 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    6684 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6685 File
    6686 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6687 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    6688 rinv[:, :] = matrix_inverse(r) 
    6689 ^^^^^^^^^^^^^^^^^ 
    6690 File
    6691 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6692 packages/numpy/linalg/linalg.py", line 561, in inv 
    6693 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    6694 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6695 File
    6696 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6697 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    6698 raise LinAlgError("Singular matrix") 
    6699 numpy.linalg.LinAlgError: Singular matrix 
    6700  
    6701 numpy.linalg.LinAlgError: Singular matrix 
    6702  
    6703 File
    6704 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6705 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    6706 raise LinAlgError("Singular matrix") 
    6707  
    6708 See log for complete Python traceback. 
    6709  
    6710 Traceback (most recent call last): 
    6711 File
    6712 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6713 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    6714 self.session.ui.mouse_modes.mouse_pause_tracking() 
    6715 File
    6716 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6717 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    6718 mouse_pause_tracking 
    6719 self._mouse_pause() 
    6720 File
    6721 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6722 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    6723 m.pause(self._mouse_pause_position) 
    6724 File
    6725 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6726 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    6727 p = self.view.picked_object(x, y) 
    6728 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6729 File
    6730 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6731 packages/chimerax/graphics/view.py", line 838, in picked_object 
    6732 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    6733 beyond, 
    6734 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6735 File
    6736 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6737 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    6738 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    6739 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6740 File
    6741 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6742 packages/chimerax/core/models.py", line 143, in first_intercept 
    6743 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    6744 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6745 File
    6746 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6747 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    6748 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    6749 exclude=exclude) 
    6750 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6751 File
    6752 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6753 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    6754 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    6755 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6756 File
    6757 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6758 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    6759 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    6760 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6761 File
    6762 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6763 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    6764 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    6765 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6766 File
    6767 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6768 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    6769 p = super().first_intercept(mxyz1, mxyz2) 
    6770 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6771 File
    6772 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6773 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    6774 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    6775 exclude=exclude) 
    6776 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6777 File
    6778 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6779 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    6780 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    6781 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6782 File
    6783 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6784 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    6785 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    6786 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6787 File
    6788 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6789 packages/chimerax/graphics/drawing.py", line 1108, in
    6790 _first_intercept_excluding_children 
    6791 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    6792 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6793 File
    6794 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6795 packages/chimerax/geometry/place.py", line 201, in inverse 
    6796 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    6797 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6798 File
    6799 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6800 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    6801 rinv[:, :] = matrix_inverse(r) 
    6802 ^^^^^^^^^^^^^^^^^ 
    6803 File
    6804 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6805 packages/numpy/linalg/linalg.py", line 561, in inv 
    6806 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    6807 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6808 File
    6809 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6810 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    6811 raise LinAlgError("Singular matrix") 
    6812 numpy.linalg.LinAlgError: Singular matrix 
    6813  
    6814 numpy.linalg.LinAlgError: Singular matrix 
    6815  
    6816 File
    6817 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6818 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    6819 raise LinAlgError("Singular matrix") 
    6820  
    6821 See log for complete Python traceback. 
    6822  
    6823 Traceback (most recent call last): 
    6824 File
    6825 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6826 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    6827 self.session.ui.mouse_modes.mouse_pause_tracking() 
    6828 File
    6829 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6830 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    6831 mouse_pause_tracking 
    6832 self._mouse_pause() 
    6833 File
    6834 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6835 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    6836 m.pause(self._mouse_pause_position) 
    6837 File
    6838 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6839 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    6840 p = self.view.picked_object(x, y) 
    6841 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6842 File
    6843 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6844 packages/chimerax/graphics/view.py", line 838, in picked_object 
    6845 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    6846 beyond, 
    6847 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6848 File
    6849 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6850 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    6851 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    6852 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6853 File
    6854 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6855 packages/chimerax/core/models.py", line 143, in first_intercept 
    6856 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    6857 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6858 File
    6859 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6860 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    6861 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    6862 exclude=exclude) 
    6863 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6864 File
    6865 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6866 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    6867 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    6868 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6869 File
    6870 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6871 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    6872 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    6873 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6874 File
    6875 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6876 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    6877 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    6878 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6879 File
    6880 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6881 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    6882 p = super().first_intercept(mxyz1, mxyz2) 
    6883 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6884 File
    6885 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6886 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    6887 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    6888 exclude=exclude) 
    6889 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6890 File
    6891 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6892 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    6893 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    6894 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6895 File
    6896 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6897 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    6898 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    6899 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6900 File
    6901 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6902 packages/chimerax/graphics/drawing.py", line 1108, in
    6903 _first_intercept_excluding_children 
    6904 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    6905 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6906 File
    6907 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6908 packages/chimerax/geometry/place.py", line 201, in inverse 
    6909 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    6910 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6911 File
    6912 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6913 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    6914 rinv[:, :] = matrix_inverse(r) 
    6915 ^^^^^^^^^^^^^^^^^ 
    6916 File
    6917 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6918 packages/numpy/linalg/linalg.py", line 561, in inv 
    6919 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    6920 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6921 File
    6922 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6923 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    6924 raise LinAlgError("Singular matrix") 
    6925 numpy.linalg.LinAlgError: Singular matrix 
    6926  
    6927 numpy.linalg.LinAlgError: Singular matrix 
    6928  
    6929 File
    6930 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6931 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    6932 raise LinAlgError("Singular matrix") 
    6933  
    6934 See log for complete Python traceback. 
    6935  
    6936 Traceback (most recent call last): 
    6937 File
    6938 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6939 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    6940 self.session.ui.mouse_modes.mouse_pause_tracking() 
    6941 File
    6942 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6943 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    6944 mouse_pause_tracking 
    6945 self._mouse_pause() 
    6946 File
    6947 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6948 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    6949 m.pause(self._mouse_pause_position) 
    6950 File
    6951 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6952 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    6953 p = self.view.picked_object(x, y) 
    6954 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6955 File
    6956 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6957 packages/chimerax/graphics/view.py", line 838, in picked_object 
    6958 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    6959 beyond, 
    6960 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6961 File
    6962 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6963 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    6964 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    6965 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6966 File
    6967 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6968 packages/chimerax/core/models.py", line 143, in first_intercept 
    6969 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    6970 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6971 File
    6972 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6973 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    6974 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    6975 exclude=exclude) 
    6976 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6977 File
    6978 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6979 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    6980 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    6981 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6982 File
    6983 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6984 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    6985 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    6986 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6987 File
    6988 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6989 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    6990 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    6991 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6992 File
    6993 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6994 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    6995 p = super().first_intercept(mxyz1, mxyz2) 
    6996 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    6997 File
    6998 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    6999 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    7000 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    7001 exclude=exclude) 
    7002 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7003 File
    7004 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7005 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    7006 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    7007 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7008 File
    7009 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7010 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    7011 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    7012 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7013 File
    7014 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7015 packages/chimerax/graphics/drawing.py", line 1108, in
    7016 _first_intercept_excluding_children 
    7017 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    7018 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7019 File
    7020 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7021 packages/chimerax/geometry/place.py", line 201, in inverse 
    7022 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    7023 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7024 File
    7025 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7026 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    7027 rinv[:, :] = matrix_inverse(r) 
    7028 ^^^^^^^^^^^^^^^^^ 
    7029 File
    7030 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7031 packages/numpy/linalg/linalg.py", line 561, in inv 
    7032 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    7033 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7034 File
    7035 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7036 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    7037 raise LinAlgError("Singular matrix") 
    7038 numpy.linalg.LinAlgError: Singular matrix 
    7039  
    7040 numpy.linalg.LinAlgError: Singular matrix 
    7041  
    7042 File
    7043 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7044 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    7045 raise LinAlgError("Singular matrix") 
    7046  
    7047 See log for complete Python traceback. 
    7048  
    7049 Traceback (most recent call last): 
    7050 File
    7051 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7052 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    7053 self.session.ui.mouse_modes.mouse_pause_tracking() 
    7054 File
    7055 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7056 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    7057 mouse_pause_tracking 
    7058 self._mouse_pause() 
    7059 File
    7060 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7061 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    7062 m.pause(self._mouse_pause_position) 
    7063 File
    7064 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7065 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    7066 p = self.view.picked_object(x, y) 
    7067 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7068 File
    7069 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7070 packages/chimerax/graphics/view.py", line 838, in picked_object 
    7071 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    7072 beyond, 
    7073 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7074 File
    7075 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7076 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    7077 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    7078 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7079 File
    7080 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7081 packages/chimerax/core/models.py", line 143, in first_intercept 
    7082 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    7083 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7084 File
    7085 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7086 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    7087 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    7088 exclude=exclude) 
    7089 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7090 File
    7091 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7092 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    7093 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    7094 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7095 File
    7096 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7097 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    7098 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    7099 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7100 File
    7101 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7102 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    7103 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    7104 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7105 File
    7106 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7107 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    7108 p = super().first_intercept(mxyz1, mxyz2) 
    7109 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7110 File
    7111 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7112 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    7113 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    7114 exclude=exclude) 
    7115 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7116 File
    7117 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7118 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    7119 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    7120 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7121 File
    7122 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7123 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    7124 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    7125 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7126 File
    7127 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7128 packages/chimerax/graphics/drawing.py", line 1108, in
    7129 _first_intercept_excluding_children 
    7130 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    7131 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7132 File
    7133 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7134 packages/chimerax/geometry/place.py", line 201, in inverse 
    7135 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    7136 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7137 File
    7138 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7139 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    7140 rinv[:, :] = matrix_inverse(r) 
    7141 ^^^^^^^^^^^^^^^^^ 
    7142 File
    7143 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7144 packages/numpy/linalg/linalg.py", line 561, in inv 
    7145 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    7146 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7147 File
    7148 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7149 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    7150 raise LinAlgError("Singular matrix") 
    7151 numpy.linalg.LinAlgError: Singular matrix 
    7152  
    7153 numpy.linalg.LinAlgError: Singular matrix 
    7154  
    7155 File
    7156 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7157 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    7158 raise LinAlgError("Singular matrix") 
    7159  
    7160 See log for complete Python traceback. 
    7161  
    7162 Traceback (most recent call last): 
    7163 File
    7164 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7165 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    7166 self.session.ui.mouse_modes.mouse_pause_tracking() 
    7167 File
    7168 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7169 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    7170 mouse_pause_tracking 
    7171 self._mouse_pause() 
    7172 File
    7173 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7174 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    7175 m.pause(self._mouse_pause_position) 
    7176 File
    7177 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7178 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    7179 p = self.view.picked_object(x, y) 
    7180 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7181 File
    7182 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7183 packages/chimerax/graphics/view.py", line 838, in picked_object 
    7184 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    7185 beyond, 
    7186 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7187 File
    7188 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7189 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    7190 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    7191 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7192 File
    7193 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7194 packages/chimerax/core/models.py", line 143, in first_intercept 
    7195 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    7196 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7197 File
    7198 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7199 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    7200 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    7201 exclude=exclude) 
    7202 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7203 File
    7204 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7205 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    7206 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    7207 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7208 File
    7209 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7210 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    7211 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    7212 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7213 File
    7214 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7215 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    7216 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    7217 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7218 File
    7219 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7220 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    7221 p = super().first_intercept(mxyz1, mxyz2) 
    7222 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7223 File
    7224 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7225 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    7226 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    7227 exclude=exclude) 
    7228 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7229 File
    7230 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7231 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    7232 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    7233 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7234 File
    7235 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7236 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    7237 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    7238 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7239 File
    7240 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7241 packages/chimerax/graphics/drawing.py", line 1108, in
    7242 _first_intercept_excluding_children 
    7243 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    7244 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7245 File
    7246 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7247 packages/chimerax/geometry/place.py", line 201, in inverse 
    7248 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    7249 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7250 File
    7251 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7252 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    7253 rinv[:, :] = matrix_inverse(r) 
    7254 ^^^^^^^^^^^^^^^^^ 
    7255 File
    7256 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7257 packages/numpy/linalg/linalg.py", line 561, in inv 
    7258 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    7259 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7260 File
    7261 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7262 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    7263 raise LinAlgError("Singular matrix") 
    7264 numpy.linalg.LinAlgError: Singular matrix 
    7265  
    7266 numpy.linalg.LinAlgError: Singular matrix 
    7267  
    7268 File
    7269 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7270 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    7271 raise LinAlgError("Singular matrix") 
    7272  
    7273 See log for complete Python traceback. 
    7274  
    7275 Traceback (most recent call last): 
    7276 File
    7277 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7278 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    7279 self.session.ui.mouse_modes.mouse_pause_tracking() 
    7280 File
    7281 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7282 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    7283 mouse_pause_tracking 
    7284 self._mouse_pause() 
    7285 File
    7286 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7287 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    7288 m.pause(self._mouse_pause_position) 
    7289 File
    7290 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7291 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    7292 p = self.view.picked_object(x, y) 
    7293 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7294 File
    7295 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7296 packages/chimerax/graphics/view.py", line 838, in picked_object 
    7297 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    7298 beyond, 
    7299 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7300 File
    7301 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7302 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    7303 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    7304 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7305 File
    7306 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7307 packages/chimerax/core/models.py", line 143, in first_intercept 
    7308 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    7309 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7310 File
    7311 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7312 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    7313 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    7314 exclude=exclude) 
    7315 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7316 File
    7317 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7318 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    7319 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    7320 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7321 File
    7322 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7323 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    7324 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    7325 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7326 File
    7327 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7328 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    7329 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    7330 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7331 File
    7332 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7333 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    7334 p = super().first_intercept(mxyz1, mxyz2) 
    7335 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7336 File
    7337 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7338 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    7339 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    7340 exclude=exclude) 
    7341 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7342 File
    7343 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7344 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    7345 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    7346 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7347 File
    7348 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7349 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    7350 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    7351 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7352 File
    7353 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7354 packages/chimerax/graphics/drawing.py", line 1108, in
    7355 _first_intercept_excluding_children 
    7356 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    7357 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7358 File
    7359 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7360 packages/chimerax/geometry/place.py", line 201, in inverse 
    7361 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    7362 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7363 File
    7364 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7365 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    7366 rinv[:, :] = matrix_inverse(r) 
    7367 ^^^^^^^^^^^^^^^^^ 
    7368 File
    7369 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7370 packages/numpy/linalg/linalg.py", line 561, in inv 
    7371 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    7372 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7373 File
    7374 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7375 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    7376 raise LinAlgError("Singular matrix") 
    7377 numpy.linalg.LinAlgError: Singular matrix 
    7378  
    7379 numpy.linalg.LinAlgError: Singular matrix 
    7380  
    7381 File
    7382 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7383 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    7384 raise LinAlgError("Singular matrix") 
    7385  
    7386 See log for complete Python traceback. 
    7387  
    7388 Traceback (most recent call last): 
    7389 File
    7390 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7391 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    7392 self.session.ui.mouse_modes.mouse_pause_tracking() 
    7393 File
    7394 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7395 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    7396 mouse_pause_tracking 
    7397 self._mouse_pause() 
    7398 File
    7399 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7400 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    7401 m.pause(self._mouse_pause_position) 
    7402 File
    7403 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7404 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    7405 p = self.view.picked_object(x, y) 
    7406 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7407 File
    7408 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7409 packages/chimerax/graphics/view.py", line 838, in picked_object 
    7410 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    7411 beyond, 
    7412 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7413 File
    7414 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7415 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    7416 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    7417 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7418 File
    7419 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7420 packages/chimerax/core/models.py", line 143, in first_intercept 
    7421 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    7422 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7423 File
    7424 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7425 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    7426 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    7427 exclude=exclude) 
    7428 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7429 File
    7430 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7431 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    7432 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    7433 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7434 File
    7435 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7436 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    7437 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    7438 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7439 File
    7440 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7441 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    7442 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    7443 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7444 File
    7445 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7446 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    7447 p = super().first_intercept(mxyz1, mxyz2) 
    7448 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7449 File
    7450 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7451 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    7452 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    7453 exclude=exclude) 
    7454 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7455 File
    7456 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7457 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    7458 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    7459 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7460 File
    7461 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7462 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    7463 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    7464 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7465 File
    7466 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7467 packages/chimerax/graphics/drawing.py", line 1108, in
    7468 _first_intercept_excluding_children 
    7469 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    7470 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7471 File
    7472 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7473 packages/chimerax/geometry/place.py", line 201, in inverse 
    7474 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    7475 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7476 File
    7477 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7478 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    7479 rinv[:, :] = matrix_inverse(r) 
    7480 ^^^^^^^^^^^^^^^^^ 
    7481 File
    7482 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7483 packages/numpy/linalg/linalg.py", line 561, in inv 
    7484 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    7485 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7486 File
    7487 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7488 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    7489 raise LinAlgError("Singular matrix") 
    7490 numpy.linalg.LinAlgError: Singular matrix 
    7491  
    7492 numpy.linalg.LinAlgError: Singular matrix 
    7493  
    7494 File
    7495 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7496 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    7497 raise LinAlgError("Singular matrix") 
    7498  
    7499 See log for complete Python traceback. 
    7500  
    7501 Traceback (most recent call last): 
    7502 File
    7503 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7504 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    7505 self.session.ui.mouse_modes.mouse_pause_tracking() 
    7506 File
    7507 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7508 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    7509 mouse_pause_tracking 
    7510 self._mouse_pause() 
    7511 File
    7512 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7513 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    7514 m.pause(self._mouse_pause_position) 
    7515 File
    7516 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7517 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    7518 p = self.view.picked_object(x, y) 
    7519 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7520 File
    7521 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7522 packages/chimerax/graphics/view.py", line 838, in picked_object 
    7523 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    7524 beyond, 
    7525 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7526 File
    7527 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7528 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    7529 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    7530 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7531 File
    7532 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7533 packages/chimerax/core/models.py", line 143, in first_intercept 
    7534 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    7535 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7536 File
    7537 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7538 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    7539 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    7540 exclude=exclude) 
    7541 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7542 File
    7543 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7544 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    7545 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    7546 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7547 File
    7548 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7549 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    7550 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    7551 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7552 File
    7553 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7554 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    7555 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    7556 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7557 File
    7558 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7559 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    7560 p = super().first_intercept(mxyz1, mxyz2) 
    7561 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7562 File
    7563 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7564 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    7565 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    7566 exclude=exclude) 
    7567 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7568 File
    7569 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7570 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    7571 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    7572 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7573 File
    7574 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7575 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    7576 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    7577 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7578 File
    7579 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7580 packages/chimerax/graphics/drawing.py", line 1108, in
    7581 _first_intercept_excluding_children 
    7582 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    7583 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7584 File
    7585 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7586 packages/chimerax/geometry/place.py", line 201, in inverse 
    7587 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    7588 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7589 File
    7590 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7591 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    7592 rinv[:, :] = matrix_inverse(r) 
    7593 ^^^^^^^^^^^^^^^^^ 
    7594 File
    7595 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7596 packages/numpy/linalg/linalg.py", line 561, in inv 
    7597 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    7598 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7599 File
    7600 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7601 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    7602 raise LinAlgError("Singular matrix") 
    7603 numpy.linalg.LinAlgError: Singular matrix 
    7604  
    7605 numpy.linalg.LinAlgError: Singular matrix 
    7606  
    7607 File
    7608 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7609 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    7610 raise LinAlgError("Singular matrix") 
    7611  
    7612 See log for complete Python traceback. 
    7613  
    7614 Traceback (most recent call last): 
    7615 File
    7616 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7617 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    7618 self.session.ui.mouse_modes.mouse_pause_tracking() 
    7619 File
    7620 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7621 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    7622 mouse_pause_tracking 
    7623 self._mouse_pause() 
    7624 File
    7625 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7626 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    7627 m.pause(self._mouse_pause_position) 
    7628 File
    7629 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7630 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    7631 p = self.view.picked_object(x, y) 
    7632 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7633 File
    7634 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7635 packages/chimerax/graphics/view.py", line 838, in picked_object 
    7636 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    7637 beyond, 
    7638 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7639 File
    7640 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7641 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    7642 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    7643 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7644 File
    7645 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7646 packages/chimerax/core/models.py", line 143, in first_intercept 
    7647 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    7648 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7649 File
    7650 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7651 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    7652 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    7653 exclude=exclude) 
    7654 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7655 File
    7656 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7657 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    7658 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    7659 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7660 File
    7661 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7662 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    7663 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    7664 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7665 File
    7666 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7667 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    7668 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    7669 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7670 File
    7671 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7672 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    7673 p = super().first_intercept(mxyz1, mxyz2) 
    7674 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7675 File
    7676 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7677 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    7678 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    7679 exclude=exclude) 
    7680 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7681 File
    7682 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7683 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    7684 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    7685 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7686 File
    7687 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7688 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    7689 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    7690 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7691 File
    7692 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7693 packages/chimerax/graphics/drawing.py", line 1108, in
    7694 _first_intercept_excluding_children 
    7695 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    7696 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7697 File
    7698 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7699 packages/chimerax/geometry/place.py", line 201, in inverse 
    7700 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    7701 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7702 File
    7703 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7704 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    7705 rinv[:, :] = matrix_inverse(r) 
    7706 ^^^^^^^^^^^^^^^^^ 
    7707 File
    7708 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7709 packages/numpy/linalg/linalg.py", line 561, in inv 
    7710 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    7711 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7712 File
    7713 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7714 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    7715 raise LinAlgError("Singular matrix") 
    7716 numpy.linalg.LinAlgError: Singular matrix 
    7717  
    7718 numpy.linalg.LinAlgError: Singular matrix 
    7719  
    7720 File
    7721 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7722 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    7723 raise LinAlgError("Singular matrix") 
    7724  
    7725 See log for complete Python traceback. 
    7726  
    7727 Traceback (most recent call last): 
    7728 File
    7729 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7730 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    7731 self.session.ui.mouse_modes.mouse_pause_tracking() 
    7732 File
    7733 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7734 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    7735 mouse_pause_tracking 
    7736 self._mouse_pause() 
    7737 File
    7738 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7739 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    7740 m.pause(self._mouse_pause_position) 
    7741 File
    7742 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7743 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    7744 p = self.view.picked_object(x, y) 
    7745 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7746 File
    7747 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7748 packages/chimerax/graphics/view.py", line 838, in picked_object 
    7749 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    7750 beyond, 
    7751 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7752 File
    7753 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7754 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    7755 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    7756 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7757 File
    7758 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7759 packages/chimerax/core/models.py", line 143, in first_intercept 
    7760 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    7761 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7762 File
    7763 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7764 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    7765 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    7766 exclude=exclude) 
    7767 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7768 File
    7769 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7770 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    7771 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    7772 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7773 File
    7774 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7775 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    7776 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    7777 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7778 File
    7779 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7780 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    7781 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    7782 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7783 File
    7784 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7785 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    7786 p = super().first_intercept(mxyz1, mxyz2) 
    7787 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7788 File
    7789 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7790 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    7791 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    7792 exclude=exclude) 
    7793 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7794 File
    7795 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7796 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    7797 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    7798 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7799 File
    7800 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7801 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    7802 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    7803 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7804 File
    7805 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7806 packages/chimerax/graphics/drawing.py", line 1108, in
    7807 _first_intercept_excluding_children 
    7808 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    7809 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7810 File
    7811 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7812 packages/chimerax/geometry/place.py", line 201, in inverse 
    7813 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    7814 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7815 File
    7816 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7817 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    7818 rinv[:, :] = matrix_inverse(r) 
    7819 ^^^^^^^^^^^^^^^^^ 
    7820 File
    7821 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7822 packages/numpy/linalg/linalg.py", line 561, in inv 
    7823 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    7824 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7825 File
    7826 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7827 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    7828 raise LinAlgError("Singular matrix") 
    7829 numpy.linalg.LinAlgError: Singular matrix 
    7830  
    7831 numpy.linalg.LinAlgError: Singular matrix 
    7832  
    7833 File
    7834 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7835 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    7836 raise LinAlgError("Singular matrix") 
    7837  
    7838 See log for complete Python traceback. 
    7839  
    7840 Traceback (most recent call last): 
    7841 File
    7842 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7843 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    7844 self.session.ui.mouse_modes.mouse_pause_tracking() 
    7845 File
    7846 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7847 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    7848 mouse_pause_tracking 
    7849 self._mouse_pause() 
    7850 File
    7851 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7852 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    7853 m.pause(self._mouse_pause_position) 
    7854 File
    7855 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7856 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    7857 p = self.view.picked_object(x, y) 
    7858 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7859 File
    7860 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7861 packages/chimerax/graphics/view.py", line 838, in picked_object 
    7862 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    7863 beyond, 
    7864 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7865 File
    7866 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7867 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    7868 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    7869 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7870 File
    7871 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7872 packages/chimerax/core/models.py", line 143, in first_intercept 
    7873 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    7874 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7875 File
    7876 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7877 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    7878 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    7879 exclude=exclude) 
    7880 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7881 File
    7882 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7883 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    7884 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    7885 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7886 File
    7887 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7888 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    7889 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    7890 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7891 File
    7892 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7893 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    7894 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    7895 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7896 File
    7897 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7898 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    7899 p = super().first_intercept(mxyz1, mxyz2) 
    7900 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7901 File
    7902 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7903 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    7904 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    7905 exclude=exclude) 
    7906 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7907 File
    7908 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7909 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    7910 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    7911 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7912 File
    7913 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7914 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    7915 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    7916 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7917 File
    7918 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7919 packages/chimerax/graphics/drawing.py", line 1108, in
    7920 _first_intercept_excluding_children 
    7921 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    7922 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7923 File
    7924 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7925 packages/chimerax/geometry/place.py", line 201, in inverse 
    7926 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    7927 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7928 File
    7929 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7930 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    7931 rinv[:, :] = matrix_inverse(r) 
    7932 ^^^^^^^^^^^^^^^^^ 
    7933 File
    7934 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7935 packages/numpy/linalg/linalg.py", line 561, in inv 
    7936 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    7937 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7938 File
    7939 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7940 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    7941 raise LinAlgError("Singular matrix") 
    7942 numpy.linalg.LinAlgError: Singular matrix 
    7943  
    7944 numpy.linalg.LinAlgError: Singular matrix 
    7945  
    7946 File
    7947 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7948 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    7949 raise LinAlgError("Singular matrix") 
    7950  
    7951 See log for complete Python traceback. 
    7952  
    7953 Traceback (most recent call last): 
    7954 File
    7955 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7956 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    7957 self.session.ui.mouse_modes.mouse_pause_tracking() 
    7958 File
    7959 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7960 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    7961 mouse_pause_tracking 
    7962 self._mouse_pause() 
    7963 File
    7964 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7965 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    7966 m.pause(self._mouse_pause_position) 
    7967 File
    7968 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7969 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    7970 p = self.view.picked_object(x, y) 
    7971 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7972 File
    7973 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7974 packages/chimerax/graphics/view.py", line 838, in picked_object 
    7975 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    7976 beyond, 
    7977 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7978 File
    7979 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7980 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    7981 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    7982 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7983 File
    7984 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7985 packages/chimerax/core/models.py", line 143, in first_intercept 
    7986 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    7987 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7988 File
    7989 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7990 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    7991 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    7992 exclude=exclude) 
    7993 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7994 File
    7995 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    7996 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    7997 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    7998 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    7999 File
    8000 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8001 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    8002 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    8003 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8004 File
    8005 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8006 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    8007 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    8008 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8009 File
    8010 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8011 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    8012 p = super().first_intercept(mxyz1, mxyz2) 
    8013 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8014 File
    8015 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8016 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    8017 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    8018 exclude=exclude) 
    8019 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8020 File
    8021 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8022 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    8023 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    8024 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8025 File
    8026 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8027 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    8028 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    8029 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8030 File
    8031 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8032 packages/chimerax/graphics/drawing.py", line 1108, in
    8033 _first_intercept_excluding_children 
    8034 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    8035 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8036 File
    8037 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8038 packages/chimerax/geometry/place.py", line 201, in inverse 
    8039 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    8040 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8041 File
    8042 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8043 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    8044 rinv[:, :] = matrix_inverse(r) 
    8045 ^^^^^^^^^^^^^^^^^ 
    8046 File
    8047 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8048 packages/numpy/linalg/linalg.py", line 561, in inv 
    8049 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    8050 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8051 File
    8052 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8053 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    8054 raise LinAlgError("Singular matrix") 
    8055 numpy.linalg.LinAlgError: Singular matrix 
    8056  
    8057 numpy.linalg.LinAlgError: Singular matrix 
    8058  
    8059 File
    8060 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8061 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    8062 raise LinAlgError("Singular matrix") 
    8063  
    8064 See log for complete Python traceback. 
    8065  
    8066 Traceback (most recent call last): 
    8067 File
    8068 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8069 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    8070 self.session.ui.mouse_modes.mouse_pause_tracking() 
    8071 File
    8072 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8073 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    8074 mouse_pause_tracking 
    8075 self._mouse_pause() 
    8076 File
    8077 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8078 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    8079 m.pause(self._mouse_pause_position) 
    8080 File
    8081 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8082 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    8083 p = self.view.picked_object(x, y) 
    8084 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8085 File
    8086 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8087 packages/chimerax/graphics/view.py", line 838, in picked_object 
    8088 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    8089 beyond, 
    8090 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8091 File
    8092 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8093 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    8094 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    8095 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8096 File
    8097 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8098 packages/chimerax/core/models.py", line 143, in first_intercept 
    8099 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    8100 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8101 File
    8102 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8103 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    8104 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    8105 exclude=exclude) 
    8106 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8107 File
    8108 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8109 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    8110 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    8111 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8112 File
    8113 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8114 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    8115 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    8116 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8117 File
    8118 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8119 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    8120 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    8121 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8122 File
    8123 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8124 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    8125 p = super().first_intercept(mxyz1, mxyz2) 
    8126 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8127 File
    8128 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8129 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    8130 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    8131 exclude=exclude) 
    8132 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8133 File
    8134 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8135 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    8136 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    8137 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8138 File
    8139 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8140 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    8141 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    8142 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8143 File
    8144 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8145 packages/chimerax/graphics/drawing.py", line 1108, in
    8146 _first_intercept_excluding_children 
    8147 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    8148 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8149 File
    8150 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8151 packages/chimerax/geometry/place.py", line 201, in inverse 
    8152 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    8153 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8154 File
    8155 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8156 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    8157 rinv[:, :] = matrix_inverse(r) 
    8158 ^^^^^^^^^^^^^^^^^ 
    8159 File
    8160 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8161 packages/numpy/linalg/linalg.py", line 561, in inv 
    8162 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    8163 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8164 File
    8165 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8166 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    8167 raise LinAlgError("Singular matrix") 
    8168 numpy.linalg.LinAlgError: Singular matrix 
    8169  
    8170 numpy.linalg.LinAlgError: Singular matrix 
    8171  
    8172 File
    8173 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8174 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    8175 raise LinAlgError("Singular matrix") 
    8176  
    8177 See log for complete Python traceback. 
    8178  
    8179 Traceback (most recent call last): 
    8180 File
    8181 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8182 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    8183 self.session.ui.mouse_modes.mouse_pause_tracking() 
    8184 File
    8185 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8186 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    8187 mouse_pause_tracking 
    8188 self._mouse_pause() 
    8189 File
    8190 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8191 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    8192 m.pause(self._mouse_pause_position) 
    8193 File
    8194 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8195 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    8196 p = self.view.picked_object(x, y) 
    8197 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8198 File
    8199 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8200 packages/chimerax/graphics/view.py", line 838, in picked_object 
    8201 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    8202 beyond, 
    8203 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8204 File
    8205 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8206 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    8207 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    8208 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8209 File
    8210 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8211 packages/chimerax/core/models.py", line 143, in first_intercept 
    8212 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    8213 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8214 File
    8215 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8216 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    8217 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    8218 exclude=exclude) 
    8219 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8220 File
    8221 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8222 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    8223 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    8224 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8225 File
    8226 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8227 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    8228 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    8229 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8230 File
    8231 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8232 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    8233 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    8234 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8235 File
    8236 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8237 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    8238 p = super().first_intercept(mxyz1, mxyz2) 
    8239 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8240 File
    8241 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8242 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    8243 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    8244 exclude=exclude) 
    8245 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8246 File
    8247 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8248 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    8249 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    8250 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8251 File
    8252 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8253 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    8254 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    8255 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8256 File
    8257 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8258 packages/chimerax/graphics/drawing.py", line 1108, in
    8259 _first_intercept_excluding_children 
    8260 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    8261 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8262 File
    8263 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8264 packages/chimerax/geometry/place.py", line 201, in inverse 
    8265 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    8266 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8267 File
    8268 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8269 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    8270 rinv[:, :] = matrix_inverse(r) 
    8271 ^^^^^^^^^^^^^^^^^ 
    8272 File
    8273 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8274 packages/numpy/linalg/linalg.py", line 561, in inv 
    8275 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    8276 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8277 File
    8278 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8279 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    8280 raise LinAlgError("Singular matrix") 
    8281 numpy.linalg.LinAlgError: Singular matrix 
    8282  
    8283 numpy.linalg.LinAlgError: Singular matrix 
    8284  
    8285 File
    8286 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8287 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    8288 raise LinAlgError("Singular matrix") 
    8289  
    8290 See log for complete Python traceback. 
    8291  
    8292 Traceback (most recent call last): 
    8293 File
    8294 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8295 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    8296 self.session.ui.mouse_modes.mouse_pause_tracking() 
    8297 File
    8298 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8299 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    8300 mouse_pause_tracking 
    8301 self._mouse_pause() 
    8302 File
    8303 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8304 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    8305 m.pause(self._mouse_pause_position) 
    8306 File
    8307 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8308 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    8309 p = self.view.picked_object(x, y) 
    8310 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8311 File
    8312 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8313 packages/chimerax/graphics/view.py", line 838, in picked_object 
    8314 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    8315 beyond, 
    8316 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8317 File
    8318 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8319 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    8320 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    8321 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8322 File
    8323 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8324 packages/chimerax/core/models.py", line 143, in first_intercept 
    8325 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    8326 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8327 File
    8328 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8329 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    8330 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    8331 exclude=exclude) 
    8332 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8333 File
    8334 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8335 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    8336 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    8337 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8338 File
    8339 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8340 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    8341 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    8342 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8343 File
    8344 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8345 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    8346 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    8347 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8348 File
    8349 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8350 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    8351 p = super().first_intercept(mxyz1, mxyz2) 
    8352 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8353 File
    8354 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8355 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    8356 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    8357 exclude=exclude) 
    8358 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8359 File
    8360 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8361 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    8362 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    8363 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8364 File
    8365 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8366 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    8367 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    8368 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8369 File
    8370 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8371 packages/chimerax/graphics/drawing.py", line 1108, in
    8372 _first_intercept_excluding_children 
    8373 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    8374 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8375 File
    8376 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8377 packages/chimerax/geometry/place.py", line 201, in inverse 
    8378 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    8379 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8380 File
    8381 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8382 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    8383 rinv[:, :] = matrix_inverse(r) 
    8384 ^^^^^^^^^^^^^^^^^ 
    8385 File
    8386 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8387 packages/numpy/linalg/linalg.py", line 561, in inv 
    8388 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    8389 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8390 File
    8391 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8392 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    8393 raise LinAlgError("Singular matrix") 
    8394 numpy.linalg.LinAlgError: Singular matrix 
    8395  
    8396 numpy.linalg.LinAlgError: Singular matrix 
    8397  
    8398 File
    8399 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8400 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    8401 raise LinAlgError("Singular matrix") 
    8402  
    8403 See log for complete Python traceback. 
    8404  
    8405 Traceback (most recent call last): 
    8406 File
    8407 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8408 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    8409 self.session.ui.mouse_modes.mouse_pause_tracking() 
    8410 File
    8411 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8412 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    8413 mouse_pause_tracking 
    8414 self._mouse_pause() 
    8415 File
    8416 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8417 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    8418 m.pause(self._mouse_pause_position) 
    8419 File
    8420 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8421 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    8422 p = self.view.picked_object(x, y) 
    8423 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8424 File
    8425 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8426 packages/chimerax/graphics/view.py", line 838, in picked_object 
    8427 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    8428 beyond, 
    8429 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8430 File
    8431 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8432 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    8433 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    8434 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8435 File
    8436 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8437 packages/chimerax/core/models.py", line 143, in first_intercept 
    8438 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    8439 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8440 File
    8441 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8442 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    8443 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    8444 exclude=exclude) 
    8445 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8446 File
    8447 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8448 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    8449 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    8450 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8451 File
    8452 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8453 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    8454 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    8455 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8456 File
    8457 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8458 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    8459 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    8460 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8461 File
    8462 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8463 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    8464 p = super().first_intercept(mxyz1, mxyz2) 
    8465 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8466 File
    8467 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8468 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    8469 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    8470 exclude=exclude) 
    8471 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8472 File
    8473 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8474 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    8475 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    8476 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8477 File
    8478 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8479 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    8480 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    8481 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8482 File
    8483 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8484 packages/chimerax/graphics/drawing.py", line 1108, in
    8485 _first_intercept_excluding_children 
    8486 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    8487 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8488 File
    8489 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8490 packages/chimerax/geometry/place.py", line 201, in inverse 
    8491 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    8492 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8493 File
    8494 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8495 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    8496 rinv[:, :] = matrix_inverse(r) 
    8497 ^^^^^^^^^^^^^^^^^ 
    8498 File
    8499 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8500 packages/numpy/linalg/linalg.py", line 561, in inv 
    8501 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    8502 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8503 File
    8504 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8505 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    8506 raise LinAlgError("Singular matrix") 
    8507 numpy.linalg.LinAlgError: Singular matrix 
    8508  
    8509 numpy.linalg.LinAlgError: Singular matrix 
    8510  
    8511 File
    8512 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8513 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    8514 raise LinAlgError("Singular matrix") 
    8515  
    8516 See log for complete Python traceback. 
    8517  
    8518 Traceback (most recent call last): 
    8519 File
    8520 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8521 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    8522 self.session.ui.mouse_modes.mouse_pause_tracking() 
    8523 File
    8524 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8525 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    8526 mouse_pause_tracking 
    8527 self._mouse_pause() 
    8528 File
    8529 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8530 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    8531 m.pause(self._mouse_pause_position) 
    8532 File
    8533 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8534 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    8535 p = self.view.picked_object(x, y) 
    8536 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8537 File
    8538 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8539 packages/chimerax/graphics/view.py", line 838, in picked_object 
    8540 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    8541 beyond, 
    8542 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8543 File
    8544 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8545 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    8546 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    8547 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8548 File
    8549 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8550 packages/chimerax/core/models.py", line 143, in first_intercept 
    8551 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    8552 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8553 File
    8554 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8555 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    8556 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    8557 exclude=exclude) 
    8558 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8559 File
    8560 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8561 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    8562 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    8563 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8564 File
    8565 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8566 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    8567 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    8568 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8569 File
    8570 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8571 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    8572 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    8573 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8574 File
    8575 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8576 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    8577 p = super().first_intercept(mxyz1, mxyz2) 
    8578 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8579 File
    8580 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8581 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    8582 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    8583 exclude=exclude) 
    8584 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8585 File
    8586 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8587 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    8588 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    8589 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8590 File
    8591 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8592 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    8593 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    8594 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8595 File
    8596 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8597 packages/chimerax/graphics/drawing.py", line 1108, in
    8598 _first_intercept_excluding_children 
    8599 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    8600 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8601 File
    8602 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8603 packages/chimerax/geometry/place.py", line 201, in inverse 
    8604 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    8605 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8606 File
    8607 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8608 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    8609 rinv[:, :] = matrix_inverse(r) 
    8610 ^^^^^^^^^^^^^^^^^ 
    8611 File
    8612 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8613 packages/numpy/linalg/linalg.py", line 561, in inv 
    8614 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    8615 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8616 File
    8617 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8618 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    8619 raise LinAlgError("Singular matrix") 
    8620 numpy.linalg.LinAlgError: Singular matrix 
    8621  
    8622 numpy.linalg.LinAlgError: Singular matrix 
    8623  
    8624 File
    8625 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8626 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    8627 raise LinAlgError("Singular matrix") 
    8628  
    8629 See log for complete Python traceback. 
    8630  
    8631 Traceback (most recent call last): 
    8632 File
    8633 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8634 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    8635 self.session.ui.mouse_modes.mouse_pause_tracking() 
    8636 File
    8637 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8638 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    8639 mouse_pause_tracking 
    8640 self._mouse_pause() 
    8641 File
    8642 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8643 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    8644 m.pause(self._mouse_pause_position) 
    8645 File
    8646 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8647 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    8648 p = self.view.picked_object(x, y) 
    8649 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8650 File
    8651 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8652 packages/chimerax/graphics/view.py", line 838, in picked_object 
    8653 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    8654 beyond, 
    8655 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8656 File
    8657 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8658 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    8659 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    8660 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8661 File
    8662 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8663 packages/chimerax/core/models.py", line 143, in first_intercept 
    8664 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    8665 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8666 File
    8667 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8668 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    8669 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    8670 exclude=exclude) 
    8671 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8672 File
    8673 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8674 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    8675 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    8676 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8677 File
    8678 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8679 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    8680 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    8681 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8682 File
    8683 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8684 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    8685 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    8686 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8687 File
    8688 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8689 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    8690 p = super().first_intercept(mxyz1, mxyz2) 
    8691 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8692 File
    8693 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8694 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    8695 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    8696 exclude=exclude) 
    8697 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8698 File
    8699 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8700 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    8701 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    8702 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8703 File
    8704 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8705 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    8706 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    8707 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8708 File
    8709 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8710 packages/chimerax/graphics/drawing.py", line 1108, in
    8711 _first_intercept_excluding_children 
    8712 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    8713 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8714 File
    8715 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8716 packages/chimerax/geometry/place.py", line 201, in inverse 
    8717 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    8718 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8719 File
    8720 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8721 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    8722 rinv[:, :] = matrix_inverse(r) 
    8723 ^^^^^^^^^^^^^^^^^ 
    8724 File
    8725 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8726 packages/numpy/linalg/linalg.py", line 561, in inv 
    8727 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    8728 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8729 File
    8730 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8731 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    8732 raise LinAlgError("Singular matrix") 
    8733 numpy.linalg.LinAlgError: Singular matrix 
    8734  
    8735 numpy.linalg.LinAlgError: Singular matrix 
    8736  
    8737 File
    8738 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8739 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    8740 raise LinAlgError("Singular matrix") 
    8741  
    8742 See log for complete Python traceback. 
    8743  
    8744 Traceback (most recent call last): 
    8745 File
    8746 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8747 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    8748 self.session.ui.mouse_modes.mouse_pause_tracking() 
    8749 File
    8750 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8751 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    8752 mouse_pause_tracking 
    8753 self._mouse_pause() 
    8754 File
    8755 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8756 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    8757 m.pause(self._mouse_pause_position) 
    8758 File
    8759 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8760 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    8761 p = self.view.picked_object(x, y) 
    8762 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8763 File
    8764 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8765 packages/chimerax/graphics/view.py", line 838, in picked_object 
    8766 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    8767 beyond, 
    8768 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8769 File
    8770 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8771 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    8772 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    8773 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8774 File
    8775 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8776 packages/chimerax/core/models.py", line 143, in first_intercept 
    8777 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    8778 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8779 File
    8780 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8781 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    8782 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    8783 exclude=exclude) 
    8784 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8785 File
    8786 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8787 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    8788 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    8789 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8790 File
    8791 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8792 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    8793 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    8794 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8795 File
    8796 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8797 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    8798 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    8799 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8800 File
    8801 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8802 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    8803 p = super().first_intercept(mxyz1, mxyz2) 
    8804 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8805 File
    8806 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8807 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    8808 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    8809 exclude=exclude) 
    8810 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8811 File
    8812 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8813 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    8814 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    8815 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8816 File
    8817 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8818 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    8819 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    8820 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8821 File
    8822 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8823 packages/chimerax/graphics/drawing.py", line 1108, in
    8824 _first_intercept_excluding_children 
    8825 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    8826 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8827 File
    8828 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8829 packages/chimerax/geometry/place.py", line 201, in inverse 
    8830 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    8831 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8832 File
    8833 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8834 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    8835 rinv[:, :] = matrix_inverse(r) 
    8836 ^^^^^^^^^^^^^^^^^ 
    8837 File
    8838 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8839 packages/numpy/linalg/linalg.py", line 561, in inv 
    8840 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    8841 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8842 File
    8843 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8844 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    8845 raise LinAlgError("Singular matrix") 
    8846 numpy.linalg.LinAlgError: Singular matrix 
    8847  
    8848 numpy.linalg.LinAlgError: Singular matrix 
    8849  
    8850 File
    8851 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8852 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    8853 raise LinAlgError("Singular matrix") 
    8854  
    8855 See log for complete Python traceback. 
    8856  
    8857 Traceback (most recent call last): 
    8858 File
    8859 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8860 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    8861 self.session.ui.mouse_modes.mouse_pause_tracking() 
    8862 File
    8863 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8864 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    8865 mouse_pause_tracking 
    8866 self._mouse_pause() 
    8867 File
    8868 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8869 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    8870 m.pause(self._mouse_pause_position) 
    8871 File
    8872 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8873 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    8874 p = self.view.picked_object(x, y) 
    8875 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8876 File
    8877 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8878 packages/chimerax/graphics/view.py", line 838, in picked_object 
    8879 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    8880 beyond, 
    8881 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8882 File
    8883 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8884 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    8885 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    8886 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8887 File
    8888 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8889 packages/chimerax/core/models.py", line 143, in first_intercept 
    8890 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    8891 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8892 File
    8893 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8894 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    8895 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    8896 exclude=exclude) 
    8897 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8898 File
    8899 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8900 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    8901 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    8902 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8903 File
    8904 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8905 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    8906 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    8907 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8908 File
    8909 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8910 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    8911 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    8912 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8913 File
    8914 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8915 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    8916 p = super().first_intercept(mxyz1, mxyz2) 
    8917 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8918 File
    8919 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8920 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    8921 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    8922 exclude=exclude) 
    8923 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8924 File
    8925 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8926 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    8927 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    8928 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8929 File
    8930 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8931 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    8932 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    8933 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8934 File
    8935 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8936 packages/chimerax/graphics/drawing.py", line 1108, in
    8937 _first_intercept_excluding_children 
    8938 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    8939 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8940 File
    8941 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8942 packages/chimerax/geometry/place.py", line 201, in inverse 
    8943 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    8944 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8945 File
    8946 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8947 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    8948 rinv[:, :] = matrix_inverse(r) 
    8949 ^^^^^^^^^^^^^^^^^ 
    8950 File
    8951 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8952 packages/numpy/linalg/linalg.py", line 561, in inv 
    8953 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    8954 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8955 File
    8956 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8957 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    8958 raise LinAlgError("Singular matrix") 
    8959 numpy.linalg.LinAlgError: Singular matrix 
    8960  
    8961 numpy.linalg.LinAlgError: Singular matrix 
    8962  
    8963 File
    8964 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8965 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    8966 raise LinAlgError("Singular matrix") 
    8967  
    8968 See log for complete Python traceback. 
    8969  
    8970 Traceback (most recent call last): 
    8971 File
    8972 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8973 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    8974 self.session.ui.mouse_modes.mouse_pause_tracking() 
    8975 File
    8976 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8977 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    8978 mouse_pause_tracking 
    8979 self._mouse_pause() 
    8980 File
    8981 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8982 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    8983 m.pause(self._mouse_pause_position) 
    8984 File
    8985 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8986 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    8987 p = self.view.picked_object(x, y) 
    8988 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8989 File
    8990 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8991 packages/chimerax/graphics/view.py", line 838, in picked_object 
    8992 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    8993 beyond, 
    8994 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    8995 File
    8996 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    8997 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    8998 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    8999 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9000 File
    9001 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9002 packages/chimerax/core/models.py", line 143, in first_intercept 
    9003 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    9004 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9005 File
    9006 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9007 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    9008 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    9009 exclude=exclude) 
    9010 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9011 File
    9012 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9013 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    9014 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    9015 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9016 File
    9017 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9018 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    9019 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    9020 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9021 File
    9022 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9023 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    9024 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    9025 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9026 File
    9027 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9028 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    9029 p = super().first_intercept(mxyz1, mxyz2) 
    9030 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9031 File
    9032 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9033 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    9034 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    9035 exclude=exclude) 
    9036 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9037 File
    9038 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9039 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    9040 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    9041 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9042 File
    9043 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9044 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    9045 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    9046 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9047 File
    9048 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9049 packages/chimerax/graphics/drawing.py", line 1108, in
    9050 _first_intercept_excluding_children 
    9051 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    9052 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9053 File
    9054 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9055 packages/chimerax/geometry/place.py", line 201, in inverse 
    9056 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    9057 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9058 File
    9059 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9060 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    9061 rinv[:, :] = matrix_inverse(r) 
    9062 ^^^^^^^^^^^^^^^^^ 
    9063 File
    9064 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9065 packages/numpy/linalg/linalg.py", line 561, in inv 
    9066 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    9067 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9068 File
    9069 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9070 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    9071 raise LinAlgError("Singular matrix") 
    9072 numpy.linalg.LinAlgError: Singular matrix 
    9073  
    9074 numpy.linalg.LinAlgError: Singular matrix 
    9075  
    9076 File
    9077 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9078 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    9079 raise LinAlgError("Singular matrix") 
    9080  
    9081 See log for complete Python traceback. 
    9082  
    9083 Traceback (most recent call last): 
    9084 File
    9085 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9086 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    9087 self.session.ui.mouse_modes.mouse_pause_tracking() 
    9088 File
    9089 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9090 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    9091 mouse_pause_tracking 
    9092 self._mouse_pause() 
    9093 File
    9094 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9095 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    9096 m.pause(self._mouse_pause_position) 
    9097 File
    9098 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9099 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    9100 p = self.view.picked_object(x, y) 
    9101 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9102 File
    9103 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9104 packages/chimerax/graphics/view.py", line 838, in picked_object 
    9105 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    9106 beyond, 
    9107 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9108 File
    9109 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9110 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    9111 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    9112 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9113 File
    9114 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9115 packages/chimerax/core/models.py", line 143, in first_intercept 
    9116 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    9117 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9118 File
    9119 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9120 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    9121 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    9122 exclude=exclude) 
    9123 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9124 File
    9125 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9126 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    9127 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    9128 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9129 File
    9130 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9131 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    9132 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    9133 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9134 File
    9135 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9136 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    9137 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    9138 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9139 File
    9140 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9141 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    9142 p = super().first_intercept(mxyz1, mxyz2) 
    9143 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9144 File
    9145 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9146 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    9147 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    9148 exclude=exclude) 
    9149 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9150 File
    9151 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9152 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    9153 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    9154 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9155 File
    9156 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9157 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    9158 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    9159 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9160 File
    9161 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9162 packages/chimerax/graphics/drawing.py", line 1108, in
    9163 _first_intercept_excluding_children 
    9164 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    9165 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9166 File
    9167 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9168 packages/chimerax/geometry/place.py", line 201, in inverse 
    9169 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    9170 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9171 File
    9172 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9173 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    9174 rinv[:, :] = matrix_inverse(r) 
    9175 ^^^^^^^^^^^^^^^^^ 
    9176 File
    9177 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9178 packages/numpy/linalg/linalg.py", line 561, in inv 
    9179 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    9180 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9181 File
    9182 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9183 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    9184 raise LinAlgError("Singular matrix") 
    9185 numpy.linalg.LinAlgError: Singular matrix 
    9186  
    9187 numpy.linalg.LinAlgError: Singular matrix 
    9188  
    9189 File
    9190 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9191 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    9192 raise LinAlgError("Singular matrix") 
    9193  
    9194 See log for complete Python traceback. 
    9195  
    9196 Traceback (most recent call last): 
    9197 File
    9198 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9199 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    9200 self.session.ui.mouse_modes.mouse_pause_tracking() 
    9201 File
    9202 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9203 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    9204 mouse_pause_tracking 
    9205 self._mouse_pause() 
    9206 File
    9207 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9208 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    9209 m.pause(self._mouse_pause_position) 
    9210 File
    9211 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9212 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    9213 p = self.view.picked_object(x, y) 
    9214 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9215 File
    9216 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9217 packages/chimerax/graphics/view.py", line 838, in picked_object 
    9218 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    9219 beyond, 
    9220 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9221 File
    9222 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9223 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    9224 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    9225 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9226 File
    9227 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9228 packages/chimerax/core/models.py", line 143, in first_intercept 
    9229 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    9230 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9231 File
    9232 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9233 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    9234 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    9235 exclude=exclude) 
    9236 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9237 File
    9238 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9239 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    9240 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    9241 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9242 File
    9243 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9244 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    9245 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    9246 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9247 File
    9248 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9249 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    9250 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    9251 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9252 File
    9253 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9254 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    9255 p = super().first_intercept(mxyz1, mxyz2) 
    9256 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9257 File
    9258 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9259 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    9260 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    9261 exclude=exclude) 
    9262 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9263 File
    9264 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9265 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    9266 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    9267 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9268 File
    9269 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9270 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    9271 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    9272 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9273 File
    9274 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9275 packages/chimerax/graphics/drawing.py", line 1108, in
    9276 _first_intercept_excluding_children 
    9277 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    9278 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9279 File
    9280 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9281 packages/chimerax/geometry/place.py", line 201, in inverse 
    9282 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    9283 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9284 File
    9285 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9286 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    9287 rinv[:, :] = matrix_inverse(r) 
    9288 ^^^^^^^^^^^^^^^^^ 
    9289 File
    9290 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9291 packages/numpy/linalg/linalg.py", line 561, in inv 
    9292 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    9293 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9294 File
    9295 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9296 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    9297 raise LinAlgError("Singular matrix") 
    9298 numpy.linalg.LinAlgError: Singular matrix 
    9299  
    9300 numpy.linalg.LinAlgError: Singular matrix 
    9301  
    9302 File
    9303 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9304 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    9305 raise LinAlgError("Singular matrix") 
    9306  
    9307 See log for complete Python traceback. 
    9308  
    9309 Traceback (most recent call last): 
    9310 File
    9311 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9312 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    9313 self.session.ui.mouse_modes.mouse_pause_tracking() 
    9314 File
    9315 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9316 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    9317 mouse_pause_tracking 
    9318 self._mouse_pause() 
    9319 File
    9320 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9321 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    9322 m.pause(self._mouse_pause_position) 
    9323 File
    9324 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9325 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    9326 p = self.view.picked_object(x, y) 
    9327 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9328 File
    9329 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9330 packages/chimerax/graphics/view.py", line 838, in picked_object 
    9331 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    9332 beyond, 
    9333 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9334 File
    9335 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9336 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    9337 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    9338 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9339 File
    9340 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9341 packages/chimerax/core/models.py", line 143, in first_intercept 
    9342 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    9343 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9344 File
    9345 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9346 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    9347 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    9348 exclude=exclude) 
    9349 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9350 File
    9351 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9352 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    9353 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    9354 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9355 File
    9356 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9357 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    9358 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    9359 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9360 File
    9361 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9362 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    9363 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    9364 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9365 File
    9366 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9367 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    9368 p = super().first_intercept(mxyz1, mxyz2) 
    9369 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9370 File
    9371 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9372 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    9373 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    9374 exclude=exclude) 
    9375 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9376 File
    9377 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9378 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    9379 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    9380 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9381 File
    9382 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9383 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    9384 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    9385 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9386 File
    9387 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9388 packages/chimerax/graphics/drawing.py", line 1108, in
    9389 _first_intercept_excluding_children 
    9390 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    9391 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9392 File
    9393 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9394 packages/chimerax/geometry/place.py", line 201, in inverse 
    9395 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    9396 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9397 File
    9398 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9399 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    9400 rinv[:, :] = matrix_inverse(r) 
    9401 ^^^^^^^^^^^^^^^^^ 
    9402 File
    9403 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9404 packages/numpy/linalg/linalg.py", line 561, in inv 
    9405 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    9406 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9407 File
    9408 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9409 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    9410 raise LinAlgError("Singular matrix") 
    9411 numpy.linalg.LinAlgError: Singular matrix 
    9412  
    9413 numpy.linalg.LinAlgError: Singular matrix 
    9414  
    9415 File
    9416 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9417 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    9418 raise LinAlgError("Singular matrix") 
    9419  
    9420 See log for complete Python traceback. 
    9421  
    9422 Traceback (most recent call last): 
    9423 File
    9424 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9425 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    9426 self.session.ui.mouse_modes.mouse_pause_tracking() 
    9427 File
    9428 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9429 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    9430 mouse_pause_tracking 
    9431 self._mouse_pause() 
    9432 File
    9433 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9434 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    9435 m.pause(self._mouse_pause_position) 
    9436 File
    9437 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9438 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    9439 p = self.view.picked_object(x, y) 
    9440 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9441 File
    9442 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9443 packages/chimerax/graphics/view.py", line 838, in picked_object 
    9444 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    9445 beyond, 
    9446 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9447 File
    9448 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9449 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    9450 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    9451 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9452 File
    9453 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9454 packages/chimerax/core/models.py", line 143, in first_intercept 
    9455 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    9456 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9457 File
    9458 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9459 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    9460 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    9461 exclude=exclude) 
    9462 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9463 File
    9464 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9465 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    9466 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    9467 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9468 File
    9469 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9470 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    9471 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    9472 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9473 File
    9474 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9475 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    9476 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    9477 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9478 File
    9479 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9480 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    9481 p = super().first_intercept(mxyz1, mxyz2) 
    9482 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9483 File
    9484 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9485 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    9486 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    9487 exclude=exclude) 
    9488 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9489 File
    9490 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9491 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    9492 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    9493 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9494 File
    9495 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9496 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    9497 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    9498 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9499 File
    9500 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9501 packages/chimerax/graphics/drawing.py", line 1108, in
    9502 _first_intercept_excluding_children 
    9503 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    9504 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9505 File
    9506 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9507 packages/chimerax/geometry/place.py", line 201, in inverse 
    9508 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    9509 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9510 File
    9511 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9512 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    9513 rinv[:, :] = matrix_inverse(r) 
    9514 ^^^^^^^^^^^^^^^^^ 
    9515 File
    9516 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9517 packages/numpy/linalg/linalg.py", line 561, in inv 
    9518 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    9519 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9520 File
    9521 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9522 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    9523 raise LinAlgError("Singular matrix") 
    9524 numpy.linalg.LinAlgError: Singular matrix 
    9525  
    9526 numpy.linalg.LinAlgError: Singular matrix 
    9527  
    9528 File
    9529 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9530 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    9531 raise LinAlgError("Singular matrix") 
    9532  
    9533 See log for complete Python traceback. 
    9534  
    9535 Traceback (most recent call last): 
    9536 File
    9537 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9538 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    9539 self.session.ui.mouse_modes.mouse_pause_tracking() 
    9540 File
    9541 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9542 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    9543 mouse_pause_tracking 
    9544 self._mouse_pause() 
    9545 File
    9546 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9547 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    9548 m.pause(self._mouse_pause_position) 
    9549 File
    9550 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9551 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    9552 p = self.view.picked_object(x, y) 
    9553 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9554 File
    9555 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9556 packages/chimerax/graphics/view.py", line 838, in picked_object 
    9557 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    9558 beyond, 
    9559 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9560 File
    9561 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9562 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    9563 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    9564 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9565 File
    9566 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9567 packages/chimerax/core/models.py", line 143, in first_intercept 
    9568 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    9569 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9570 File
    9571 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9572 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    9573 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    9574 exclude=exclude) 
    9575 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9576 File
    9577 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9578 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    9579 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    9580 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9581 File
    9582 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9583 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    9584 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    9585 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9586 File
    9587 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9588 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    9589 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    9590 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9591 File
    9592 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9593 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    9594 p = super().first_intercept(mxyz1, mxyz2) 
    9595 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9596 File
    9597 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9598 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    9599 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    9600 exclude=exclude) 
    9601 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9602 File
    9603 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9604 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    9605 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    9606 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9607 File
    9608 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9609 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    9610 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    9611 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9612 File
    9613 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9614 packages/chimerax/graphics/drawing.py", line 1108, in
    9615 _first_intercept_excluding_children 
    9616 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    9617 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9618 File
    9619 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9620 packages/chimerax/geometry/place.py", line 201, in inverse 
    9621 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    9622 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9623 File
    9624 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9625 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    9626 rinv[:, :] = matrix_inverse(r) 
    9627 ^^^^^^^^^^^^^^^^^ 
    9628 File
    9629 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9630 packages/numpy/linalg/linalg.py", line 561, in inv 
    9631 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    9632 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9633 File
    9634 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9635 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    9636 raise LinAlgError("Singular matrix") 
    9637 numpy.linalg.LinAlgError: Singular matrix 
    9638  
    9639 numpy.linalg.LinAlgError: Singular matrix 
    9640  
    9641 File
    9642 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9643 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    9644 raise LinAlgError("Singular matrix") 
    9645  
    9646 See log for complete Python traceback. 
    9647  
    9648 Traceback (most recent call last): 
    9649 File
    9650 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9651 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    9652 self.session.ui.mouse_modes.mouse_pause_tracking() 
    9653 File
    9654 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9655 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    9656 mouse_pause_tracking 
    9657 self._mouse_pause() 
    9658 File
    9659 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9660 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    9661 m.pause(self._mouse_pause_position) 
    9662 File
    9663 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9664 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    9665 p = self.view.picked_object(x, y) 
    9666 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9667 File
    9668 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9669 packages/chimerax/graphics/view.py", line 838, in picked_object 
    9670 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    9671 beyond, 
    9672 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9673 File
    9674 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9675 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    9676 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    9677 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9678 File
    9679 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9680 packages/chimerax/core/models.py", line 143, in first_intercept 
    9681 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    9682 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9683 File
    9684 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9685 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    9686 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    9687 exclude=exclude) 
    9688 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9689 File
    9690 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9691 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    9692 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    9693 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9694 File
    9695 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9696 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    9697 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    9698 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9699 File
    9700 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9701 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    9702 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    9703 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9704 File
    9705 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9706 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    9707 p = super().first_intercept(mxyz1, mxyz2) 
    9708 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9709 File
    9710 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9711 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    9712 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    9713 exclude=exclude) 
    9714 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9715 File
    9716 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9717 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    9718 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    9719 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9720 File
    9721 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9722 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    9723 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    9724 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9725 File
    9726 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9727 packages/chimerax/graphics/drawing.py", line 1108, in
    9728 _first_intercept_excluding_children 
    9729 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    9730 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9731 File
    9732 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9733 packages/chimerax/geometry/place.py", line 201, in inverse 
    9734 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    9735 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9736 File
    9737 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9738 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    9739 rinv[:, :] = matrix_inverse(r) 
    9740 ^^^^^^^^^^^^^^^^^ 
    9741 File
    9742 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9743 packages/numpy/linalg/linalg.py", line 561, in inv 
    9744 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    9745 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9746 File
    9747 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9748 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    9749 raise LinAlgError("Singular matrix") 
    9750 numpy.linalg.LinAlgError: Singular matrix 
    9751  
    9752 numpy.linalg.LinAlgError: Singular matrix 
    9753  
    9754 File
    9755 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9756 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    9757 raise LinAlgError("Singular matrix") 
    9758  
    9759 See log for complete Python traceback. 
    9760  
    9761 Traceback (most recent call last): 
    9762 File
    9763 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9764 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    9765 self.session.ui.mouse_modes.mouse_pause_tracking() 
    9766 File
    9767 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9768 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    9769 mouse_pause_tracking 
    9770 self._mouse_pause() 
    9771 File
    9772 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9773 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    9774 m.pause(self._mouse_pause_position) 
    9775 File
    9776 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9777 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    9778 p = self.view.picked_object(x, y) 
    9779 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9780 File
    9781 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9782 packages/chimerax/graphics/view.py", line 838, in picked_object 
    9783 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    9784 beyond, 
    9785 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9786 File
    9787 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9788 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    9789 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    9790 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9791 File
    9792 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9793 packages/chimerax/core/models.py", line 143, in first_intercept 
    9794 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    9795 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9796 File
    9797 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9798 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    9799 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    9800 exclude=exclude) 
    9801 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9802 File
    9803 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9804 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    9805 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    9806 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9807 File
    9808 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9809 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    9810 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    9811 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9812 File
    9813 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9814 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    9815 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    9816 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9817 File
    9818 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9819 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    9820 p = super().first_intercept(mxyz1, mxyz2) 
    9821 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9822 File
    9823 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9824 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    9825 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    9826 exclude=exclude) 
    9827 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9828 File
    9829 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9830 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    9831 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    9832 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9833 File
    9834 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9835 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    9836 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    9837 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9838 File
    9839 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9840 packages/chimerax/graphics/drawing.py", line 1108, in
    9841 _first_intercept_excluding_children 
    9842 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    9843 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9844 File
    9845 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9846 packages/chimerax/geometry/place.py", line 201, in inverse 
    9847 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    9848 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9849 File
    9850 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9851 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    9852 rinv[:, :] = matrix_inverse(r) 
    9853 ^^^^^^^^^^^^^^^^^ 
    9854 File
    9855 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9856 packages/numpy/linalg/linalg.py", line 561, in inv 
    9857 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    9858 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9859 File
    9860 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9861 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    9862 raise LinAlgError("Singular matrix") 
    9863 numpy.linalg.LinAlgError: Singular matrix 
    9864  
    9865 numpy.linalg.LinAlgError: Singular matrix 
    9866  
    9867 File
    9868 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9869 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    9870 raise LinAlgError("Singular matrix") 
    9871  
    9872 See log for complete Python traceback. 
    9873  
    9874 Traceback (most recent call last): 
    9875 File
    9876 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9877 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    9878 self.session.ui.mouse_modes.mouse_pause_tracking() 
    9879 File
    9880 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9881 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    9882 mouse_pause_tracking 
    9883 self._mouse_pause() 
    9884 File
    9885 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9886 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    9887 m.pause(self._mouse_pause_position) 
    9888 File
    9889 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9890 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    9891 p = self.view.picked_object(x, y) 
    9892 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9893 File
    9894 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9895 packages/chimerax/graphics/view.py", line 838, in picked_object 
    9896 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    9897 beyond, 
    9898 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9899 File
    9900 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9901 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    9902 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    9903 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9904 File
    9905 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9906 packages/chimerax/core/models.py", line 143, in first_intercept 
    9907 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    9908 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9909 File
    9910 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9911 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    9912 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    9913 exclude=exclude) 
    9914 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9915 File
    9916 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9917 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    9918 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    9919 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9920 File
    9921 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9922 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    9923 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    9924 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9925 File
    9926 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9927 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    9928 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    9929 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9930 File
    9931 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9932 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    9933 p = super().first_intercept(mxyz1, mxyz2) 
    9934 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9935 File
    9936 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9937 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    9938 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    9939 exclude=exclude) 
    9940 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9941 File
    9942 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9943 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    9944 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    9945 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9946 File
    9947 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9948 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    9949 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    9950 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9951 File
    9952 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9953 packages/chimerax/graphics/drawing.py", line 1108, in
    9954 _first_intercept_excluding_children 
    9955 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    9956 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9957 File
    9958 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9959 packages/chimerax/geometry/place.py", line 201, in inverse 
    9960 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    9961 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9962 File
    9963 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9964 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    9965 rinv[:, :] = matrix_inverse(r) 
    9966 ^^^^^^^^^^^^^^^^^ 
    9967 File
    9968 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9969 packages/numpy/linalg/linalg.py", line 561, in inv 
    9970 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    9971 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    9972 File
    9973 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9974 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    9975 raise LinAlgError("Singular matrix") 
    9976 numpy.linalg.LinAlgError: Singular matrix 
    9977  
    9978 numpy.linalg.LinAlgError: Singular matrix 
    9979  
    9980 File
    9981 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9982 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    9983 raise LinAlgError("Singular matrix") 
    9984  
    9985 See log for complete Python traceback. 
    9986  
    9987 Traceback (most recent call last): 
    9988 File
    9989 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9990 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    9991 self.session.ui.mouse_modes.mouse_pause_tracking() 
    9992 File
    9993 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9994 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    9995 mouse_pause_tracking 
    9996 self._mouse_pause() 
    9997 File
    9998 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    9999 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    10000 m.pause(self._mouse_pause_position) 
    10001 File
    10002 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10003 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    10004 p = self.view.picked_object(x, y) 
    10005 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10006 File
    10007 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10008 packages/chimerax/graphics/view.py", line 838, in picked_object 
    10009 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    10010 beyond, 
    10011 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10012 File
    10013 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10014 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    10015 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    10016 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10017 File
    10018 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10019 packages/chimerax/core/models.py", line 143, in first_intercept 
    10020 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    10021 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10022 File
    10023 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10024 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    10025 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    10026 exclude=exclude) 
    10027 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10028 File
    10029 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10030 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    10031 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    10032 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10033 File
    10034 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10035 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    10036 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    10037 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10038 File
    10039 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10040 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    10041 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    10042 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10043 File
    10044 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10045 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    10046 p = super().first_intercept(mxyz1, mxyz2) 
    10047 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10048 File
    10049 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10050 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    10051 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    10052 exclude=exclude) 
    10053 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10054 File
    10055 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10056 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    10057 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    10058 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10059 File
    10060 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10061 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    10062 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    10063 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10064 File
    10065 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10066 packages/chimerax/graphics/drawing.py", line 1108, in
    10067 _first_intercept_excluding_children 
    10068 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    10069 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10070 File
    10071 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10072 packages/chimerax/geometry/place.py", line 201, in inverse 
    10073 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    10074 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10075 File
    10076 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10077 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    10078 rinv[:, :] = matrix_inverse(r) 
    10079 ^^^^^^^^^^^^^^^^^ 
    10080 File
    10081 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10082 packages/numpy/linalg/linalg.py", line 561, in inv 
    10083 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    10084 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10085 File
    10086 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10087 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    10088 raise LinAlgError("Singular matrix") 
    10089 numpy.linalg.LinAlgError: Singular matrix 
    10090  
    10091 numpy.linalg.LinAlgError: Singular matrix 
    10092  
    10093 File
    10094 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10095 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    10096 raise LinAlgError("Singular matrix") 
    10097  
    10098 See log for complete Python traceback. 
    10099  
    10100 Traceback (most recent call last): 
    10101 File
    10102 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10103 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    10104 self.session.ui.mouse_modes.mouse_pause_tracking() 
    10105 File
    10106 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10107 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    10108 mouse_pause_tracking 
    10109 self._mouse_pause() 
    10110 File
    10111 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10112 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    10113 m.pause(self._mouse_pause_position) 
    10114 File
    10115 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10116 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    10117 p = self.view.picked_object(x, y) 
    10118 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10119 File
    10120 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10121 packages/chimerax/graphics/view.py", line 838, in picked_object 
    10122 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    10123 beyond, 
    10124 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10125 File
    10126 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10127 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    10128 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    10129 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10130 File
    10131 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10132 packages/chimerax/core/models.py", line 143, in first_intercept 
    10133 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    10134 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10135 File
    10136 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10137 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    10138 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    10139 exclude=exclude) 
    10140 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10141 File
    10142 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10143 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    10144 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    10145 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10146 File
    10147 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10148 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    10149 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    10150 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10151 File
    10152 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10153 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    10154 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    10155 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10156 File
    10157 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10158 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    10159 p = super().first_intercept(mxyz1, mxyz2) 
    10160 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10161 File
    10162 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10163 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    10164 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    10165 exclude=exclude) 
    10166 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10167 File
    10168 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10169 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    10170 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    10171 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10172 File
    10173 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10174 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    10175 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    10176 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10177 File
    10178 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10179 packages/chimerax/graphics/drawing.py", line 1108, in
    10180 _first_intercept_excluding_children 
    10181 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    10182 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10183 File
    10184 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10185 packages/chimerax/geometry/place.py", line 201, in inverse 
    10186 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    10187 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10188 File
    10189 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10190 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    10191 rinv[:, :] = matrix_inverse(r) 
    10192 ^^^^^^^^^^^^^^^^^ 
    10193 File
    10194 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10195 packages/numpy/linalg/linalg.py", line 561, in inv 
    10196 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    10197 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10198 File
    10199 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10200 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    10201 raise LinAlgError("Singular matrix") 
    10202 numpy.linalg.LinAlgError: Singular matrix 
    10203  
    10204 numpy.linalg.LinAlgError: Singular matrix 
    10205  
    10206 File
    10207 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10208 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    10209 raise LinAlgError("Singular matrix") 
    10210  
    10211 See log for complete Python traceback. 
    10212  
    10213 Traceback (most recent call last): 
    10214 File
    10215 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10216 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    10217 self.session.ui.mouse_modes.mouse_pause_tracking() 
    10218 File
    10219 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10220 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    10221 mouse_pause_tracking 
    10222 self._mouse_pause() 
    10223 File
    10224 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10225 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    10226 m.pause(self._mouse_pause_position) 
    10227 File
    10228 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10229 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    10230 p = self.view.picked_object(x, y) 
    10231 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10232 File
    10233 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10234 packages/chimerax/graphics/view.py", line 838, in picked_object 
    10235 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    10236 beyond, 
    10237 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10238 File
    10239 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10240 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    10241 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    10242 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10243 File
    10244 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10245 packages/chimerax/core/models.py", line 143, in first_intercept 
    10246 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    10247 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10248 File
    10249 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10250 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    10251 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    10252 exclude=exclude) 
    10253 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10254 File
    10255 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10256 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    10257 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    10258 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10259 File
    10260 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10261 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    10262 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    10263 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10264 File
    10265 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10266 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    10267 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    10268 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10269 File
    10270 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10271 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    10272 p = super().first_intercept(mxyz1, mxyz2) 
    10273 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10274 File
    10275 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10276 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    10277 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    10278 exclude=exclude) 
    10279 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10280 File
    10281 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10282 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    10283 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    10284 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10285 File
    10286 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10287 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    10288 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    10289 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10290 File
    10291 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10292 packages/chimerax/graphics/drawing.py", line 1108, in
    10293 _first_intercept_excluding_children 
    10294 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    10295 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10296 File
    10297 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10298 packages/chimerax/geometry/place.py", line 201, in inverse 
    10299 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    10300 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10301 File
    10302 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10303 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    10304 rinv[:, :] = matrix_inverse(r) 
    10305 ^^^^^^^^^^^^^^^^^ 
    10306 File
    10307 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10308 packages/numpy/linalg/linalg.py", line 561, in inv 
    10309 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    10310 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10311 File
    10312 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10313 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    10314 raise LinAlgError("Singular matrix") 
    10315 numpy.linalg.LinAlgError: Singular matrix 
    10316  
    10317 numpy.linalg.LinAlgError: Singular matrix 
    10318  
    10319 File
    10320 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10321 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    10322 raise LinAlgError("Singular matrix") 
    10323  
    10324 See log for complete Python traceback. 
    10325  
    10326 Traceback (most recent call last): 
    10327 File
    10328 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10329 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    10330 self.session.ui.mouse_modes.mouse_pause_tracking() 
    10331 File
    10332 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10333 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    10334 mouse_pause_tracking 
    10335 self._mouse_pause() 
    10336 File
    10337 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10338 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    10339 m.pause(self._mouse_pause_position) 
    10340 File
    10341 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10342 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    10343 p = self.view.picked_object(x, y) 
    10344 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10345 File
    10346 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10347 packages/chimerax/graphics/view.py", line 838, in picked_object 
    10348 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    10349 beyond, 
    10350 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10351 File
    10352 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10353 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    10354 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    10355 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10356 File
    10357 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10358 packages/chimerax/core/models.py", line 143, in first_intercept 
    10359 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    10360 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10361 File
    10362 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10363 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    10364 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    10365 exclude=exclude) 
    10366 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10367 File
    10368 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10369 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    10370 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    10371 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10372 File
    10373 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10374 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    10375 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    10376 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10377 File
    10378 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10379 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    10380 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    10381 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10382 File
    10383 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10384 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    10385 p = super().first_intercept(mxyz1, mxyz2) 
    10386 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10387 File
    10388 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10389 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    10390 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    10391 exclude=exclude) 
    10392 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10393 File
    10394 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10395 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    10396 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    10397 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10398 File
    10399 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10400 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    10401 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    10402 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10403 File
    10404 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10405 packages/chimerax/graphics/drawing.py", line 1108, in
    10406 _first_intercept_excluding_children 
    10407 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    10408 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10409 File
    10410 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10411 packages/chimerax/geometry/place.py", line 201, in inverse 
    10412 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    10413 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10414 File
    10415 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10416 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    10417 rinv[:, :] = matrix_inverse(r) 
    10418 ^^^^^^^^^^^^^^^^^ 
    10419 File
    10420 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10421 packages/numpy/linalg/linalg.py", line 561, in inv 
    10422 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    10423 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10424 File
    10425 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10426 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    10427 raise LinAlgError("Singular matrix") 
    10428 numpy.linalg.LinAlgError: Singular matrix 
    10429  
    10430 numpy.linalg.LinAlgError: Singular matrix 
    10431  
    10432 File
    10433 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10434 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    10435 raise LinAlgError("Singular matrix") 
    10436  
    10437 See log for complete Python traceback. 
    10438  
    10439 Traceback (most recent call last): 
    10440 File
    10441 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10442 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    10443 self.session.ui.mouse_modes.mouse_pause_tracking() 
    10444 File
    10445 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10446 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    10447 mouse_pause_tracking 
    10448 self._mouse_pause() 
    10449 File
    10450 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10451 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    10452 m.pause(self._mouse_pause_position) 
    10453 File
    10454 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10455 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    10456 p = self.view.picked_object(x, y) 
    10457 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10458 File
    10459 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10460 packages/chimerax/graphics/view.py", line 838, in picked_object 
    10461 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    10462 beyond, 
    10463 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10464 File
    10465 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10466 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    10467 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    10468 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10469 File
    10470 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10471 packages/chimerax/core/models.py", line 143, in first_intercept 
    10472 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    10473 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10474 File
    10475 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10476 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    10477 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    10478 exclude=exclude) 
    10479 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10480 File
    10481 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10482 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    10483 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    10484 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10485 File
    10486 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10487 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    10488 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    10489 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10490 File
    10491 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10492 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    10493 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    10494 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10495 File
    10496 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10497 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    10498 p = super().first_intercept(mxyz1, mxyz2) 
    10499 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10500 File
    10501 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10502 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    10503 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    10504 exclude=exclude) 
    10505 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10506 File
    10507 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10508 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    10509 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    10510 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10511 File
    10512 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10513 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    10514 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    10515 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10516 File
    10517 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10518 packages/chimerax/graphics/drawing.py", line 1108, in
    10519 _first_intercept_excluding_children 
    10520 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    10521 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10522 File
    10523 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10524 packages/chimerax/geometry/place.py", line 201, in inverse 
    10525 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    10526 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10527 File
    10528 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10529 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    10530 rinv[:, :] = matrix_inverse(r) 
    10531 ^^^^^^^^^^^^^^^^^ 
    10532 File
    10533 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10534 packages/numpy/linalg/linalg.py", line 561, in inv 
    10535 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    10536 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10537 File
    10538 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10539 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    10540 raise LinAlgError("Singular matrix") 
    10541 numpy.linalg.LinAlgError: Singular matrix 
    10542  
    10543 numpy.linalg.LinAlgError: Singular matrix 
    10544  
    10545 File
    10546 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10547 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    10548 raise LinAlgError("Singular matrix") 
    10549  
    10550 See log for complete Python traceback. 
    10551  
    10552 Traceback (most recent call last): 
    10553 File
    10554 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10555 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    10556 self.session.ui.mouse_modes.mouse_pause_tracking() 
    10557 File
    10558 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10559 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    10560 mouse_pause_tracking 
    10561 self._mouse_pause() 
    10562 File
    10563 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10564 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    10565 m.pause(self._mouse_pause_position) 
    10566 File
    10567 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10568 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    10569 p = self.view.picked_object(x, y) 
    10570 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10571 File
    10572 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10573 packages/chimerax/graphics/view.py", line 838, in picked_object 
    10574 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    10575 beyond, 
    10576 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10577 File
    10578 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10579 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    10580 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    10581 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10582 File
    10583 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10584 packages/chimerax/core/models.py", line 143, in first_intercept 
    10585 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    10586 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10587 File
    10588 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10589 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    10590 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    10591 exclude=exclude) 
    10592 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10593 File
    10594 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10595 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    10596 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    10597 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10598 File
    10599 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10600 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    10601 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    10602 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10603 File
    10604 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10605 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    10606 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    10607 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10608 File
    10609 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10610 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    10611 p = super().first_intercept(mxyz1, mxyz2) 
    10612 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10613 File
    10614 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10615 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    10616 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    10617 exclude=exclude) 
    10618 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10619 File
    10620 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10621 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    10622 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    10623 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10624 File
    10625 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10626 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    10627 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    10628 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10629 File
    10630 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10631 packages/chimerax/graphics/drawing.py", line 1108, in
    10632 _first_intercept_excluding_children 
    10633 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    10634 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10635 File
    10636 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10637 packages/chimerax/geometry/place.py", line 201, in inverse 
    10638 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    10639 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10640 File
    10641 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10642 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    10643 rinv[:, :] = matrix_inverse(r) 
    10644 ^^^^^^^^^^^^^^^^^ 
    10645 File
    10646 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10647 packages/numpy/linalg/linalg.py", line 561, in inv 
    10648 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    10649 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10650 File
    10651 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10652 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    10653 raise LinAlgError("Singular matrix") 
    10654 numpy.linalg.LinAlgError: Singular matrix 
    10655  
    10656 numpy.linalg.LinAlgError: Singular matrix 
    10657  
    10658 File
    10659 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10660 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    10661 raise LinAlgError("Singular matrix") 
    10662  
    10663 See log for complete Python traceback. 
    10664  
    10665 Traceback (most recent call last): 
    10666 File
    10667 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10668 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    10669 self.session.ui.mouse_modes.mouse_pause_tracking() 
    10670 File
    10671 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10672 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    10673 mouse_pause_tracking 
    10674 self._mouse_pause() 
    10675 File
    10676 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10677 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    10678 m.pause(self._mouse_pause_position) 
    10679 File
    10680 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10681 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    10682 p = self.view.picked_object(x, y) 
    10683 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10684 File
    10685 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10686 packages/chimerax/graphics/view.py", line 838, in picked_object 
    10687 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    10688 beyond, 
    10689 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10690 File
    10691 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10692 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    10693 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    10694 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10695 File
    10696 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10697 packages/chimerax/core/models.py", line 143, in first_intercept 
    10698 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    10699 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10700 File
    10701 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10702 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    10703 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    10704 exclude=exclude) 
    10705 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10706 File
    10707 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10708 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    10709 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    10710 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10711 File
    10712 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10713 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    10714 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    10715 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10716 File
    10717 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10718 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    10719 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    10720 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10721 File
    10722 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10723 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    10724 p = super().first_intercept(mxyz1, mxyz2) 
    10725 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10726 File
    10727 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10728 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    10729 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    10730 exclude=exclude) 
    10731 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10732 File
    10733 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10734 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    10735 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    10736 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10737 File
    10738 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10739 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    10740 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    10741 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10742 File
    10743 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10744 packages/chimerax/graphics/drawing.py", line 1108, in
    10745 _first_intercept_excluding_children 
    10746 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    10747 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10748 File
    10749 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10750 packages/chimerax/geometry/place.py", line 201, in inverse 
    10751 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    10752 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10753 File
    10754 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10755 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    10756 rinv[:, :] = matrix_inverse(r) 
    10757 ^^^^^^^^^^^^^^^^^ 
    10758 File
    10759 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10760 packages/numpy/linalg/linalg.py", line 561, in inv 
    10761 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    10762 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10763 File
    10764 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10765 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    10766 raise LinAlgError("Singular matrix") 
    10767 numpy.linalg.LinAlgError: Singular matrix 
    10768  
    10769 numpy.linalg.LinAlgError: Singular matrix 
    10770  
    10771 File
    10772 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10773 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    10774 raise LinAlgError("Singular matrix") 
    10775  
    10776 See log for complete Python traceback. 
    10777  
    10778 Traceback (most recent call last): 
    10779 File
    10780 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10781 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    10782 self.session.ui.mouse_modes.mouse_pause_tracking() 
    10783 File
    10784 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10785 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    10786 mouse_pause_tracking 
    10787 self._mouse_pause() 
    10788 File
    10789 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10790 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    10791 m.pause(self._mouse_pause_position) 
    10792 File
    10793 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10794 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    10795 p = self.view.picked_object(x, y) 
    10796 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10797 File
    10798 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10799 packages/chimerax/graphics/view.py", line 838, in picked_object 
    10800 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    10801 beyond, 
    10802 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10803 File
    10804 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10805 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    10806 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    10807 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10808 File
    10809 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10810 packages/chimerax/core/models.py", line 143, in first_intercept 
    10811 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    10812 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10813 File
    10814 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10815 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    10816 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    10817 exclude=exclude) 
    10818 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10819 File
    10820 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10821 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    10822 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    10823 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10824 File
    10825 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10826 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    10827 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    10828 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10829 File
    10830 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10831 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    10832 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    10833 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10834 File
    10835 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10836 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    10837 p = super().first_intercept(mxyz1, mxyz2) 
    10838 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10839 File
    10840 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10841 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    10842 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    10843 exclude=exclude) 
    10844 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10845 File
    10846 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10847 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    10848 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    10849 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10850 File
    10851 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10852 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    10853 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    10854 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10855 File
    10856 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10857 packages/chimerax/graphics/drawing.py", line 1108, in
    10858 _first_intercept_excluding_children 
    10859 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    10860 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10861 File
    10862 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10863 packages/chimerax/geometry/place.py", line 201, in inverse 
    10864 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    10865 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10866 File
    10867 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10868 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    10869 rinv[:, :] = matrix_inverse(r) 
    10870 ^^^^^^^^^^^^^^^^^ 
    10871 File
    10872 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10873 packages/numpy/linalg/linalg.py", line 561, in inv 
    10874 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    10875 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10876 File
    10877 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10878 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    10879 raise LinAlgError("Singular matrix") 
    10880 numpy.linalg.LinAlgError: Singular matrix 
    10881  
    10882 numpy.linalg.LinAlgError: Singular matrix 
    10883  
    10884 File
    10885 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10886 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    10887 raise LinAlgError("Singular matrix") 
    10888  
    10889 See log for complete Python traceback. 
    10890  
    10891 Traceback (most recent call last): 
    10892 File
    10893 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10894 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    10895 self.session.ui.mouse_modes.mouse_pause_tracking() 
    10896 File
    10897 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10898 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    10899 mouse_pause_tracking 
    10900 self._mouse_pause() 
    10901 File
    10902 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10903 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    10904 m.pause(self._mouse_pause_position) 
    10905 File
    10906 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10907 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    10908 p = self.view.picked_object(x, y) 
    10909 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10910 File
    10911 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10912 packages/chimerax/graphics/view.py", line 838, in picked_object 
    10913 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    10914 beyond, 
    10915 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10916 File
    10917 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10918 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    10919 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    10920 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10921 File
    10922 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10923 packages/chimerax/core/models.py", line 143, in first_intercept 
    10924 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    10925 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10926 File
    10927 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10928 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    10929 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    10930 exclude=exclude) 
    10931 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10932 File
    10933 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10934 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    10935 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    10936 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10937 File
    10938 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10939 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    10940 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    10941 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10942 File
    10943 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10944 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    10945 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    10946 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10947 File
    10948 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10949 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    10950 p = super().first_intercept(mxyz1, mxyz2) 
    10951 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10952 File
    10953 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10954 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    10955 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    10956 exclude=exclude) 
    10957 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10958 File
    10959 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10960 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    10961 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    10962 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10963 File
    10964 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10965 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    10966 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    10967 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10968 File
    10969 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10970 packages/chimerax/graphics/drawing.py", line 1108, in
    10971 _first_intercept_excluding_children 
    10972 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    10973 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10974 File
    10975 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10976 packages/chimerax/geometry/place.py", line 201, in inverse 
    10977 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    10978 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10979 File
    10980 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10981 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    10982 rinv[:, :] = matrix_inverse(r) 
    10983 ^^^^^^^^^^^^^^^^^ 
    10984 File
    10985 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10986 packages/numpy/linalg/linalg.py", line 561, in inv 
    10987 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    10988 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    10989 File
    10990 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10991 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    10992 raise LinAlgError("Singular matrix") 
    10993 numpy.linalg.LinAlgError: Singular matrix 
    10994  
    10995 numpy.linalg.LinAlgError: Singular matrix 
    10996  
    10997 File
    10998 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    10999 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    11000 raise LinAlgError("Singular matrix") 
    11001  
    11002 See log for complete Python traceback. 
    11003  
    11004 Traceback (most recent call last): 
    11005 File
    11006 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11007 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    11008 self.session.ui.mouse_modes.mouse_pause_tracking() 
    11009 File
    11010 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11011 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    11012 mouse_pause_tracking 
    11013 self._mouse_pause() 
    11014 File
    11015 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11016 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    11017 m.pause(self._mouse_pause_position) 
    11018 File
    11019 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11020 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    11021 p = self.view.picked_object(x, y) 
    11022 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11023 File
    11024 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11025 packages/chimerax/graphics/view.py", line 838, in picked_object 
    11026 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    11027 beyond, 
    11028 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11029 File
    11030 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11031 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    11032 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    11033 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11034 File
    11035 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11036 packages/chimerax/core/models.py", line 143, in first_intercept 
    11037 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    11038 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11039 File
    11040 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11041 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    11042 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    11043 exclude=exclude) 
    11044 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11045 File
    11046 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11047 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    11048 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    11049 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11050 File
    11051 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11052 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    11053 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    11054 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11055 File
    11056 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11057 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    11058 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    11059 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11060 File
    11061 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11062 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    11063 p = super().first_intercept(mxyz1, mxyz2) 
    11064 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11065 File
    11066 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11067 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    11068 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    11069 exclude=exclude) 
    11070 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11071 File
    11072 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11073 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    11074 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    11075 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11076 File
    11077 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11078 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    11079 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    11080 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11081 File
    11082 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11083 packages/chimerax/graphics/drawing.py", line 1108, in
    11084 _first_intercept_excluding_children 
    11085 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    11086 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11087 File
    11088 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11089 packages/chimerax/geometry/place.py", line 201, in inverse 
    11090 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    11091 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11092 File
    11093 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11094 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    11095 rinv[:, :] = matrix_inverse(r) 
    11096 ^^^^^^^^^^^^^^^^^ 
    11097 File
    11098 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11099 packages/numpy/linalg/linalg.py", line 561, in inv 
    11100 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    11101 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11102 File
    11103 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11104 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    11105 raise LinAlgError("Singular matrix") 
    11106 numpy.linalg.LinAlgError: Singular matrix 
    11107  
    11108 numpy.linalg.LinAlgError: Singular matrix 
    11109  
    11110 File
    11111 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11112 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    11113 raise LinAlgError("Singular matrix") 
    11114  
    11115 See log for complete Python traceback. 
    11116  
    11117 Traceback (most recent call last): 
    11118 File
    11119 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11120 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    11121 self.session.ui.mouse_modes.mouse_pause_tracking() 
    11122 File
    11123 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11124 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    11125 mouse_pause_tracking 
    11126 self._mouse_pause() 
    11127 File
    11128 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11129 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    11130 m.pause(self._mouse_pause_position) 
    11131 File
    11132 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11133 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    11134 p = self.view.picked_object(x, y) 
    11135 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11136 File
    11137 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11138 packages/chimerax/graphics/view.py", line 838, in picked_object 
    11139 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    11140 beyond, 
    11141 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11142 File
    11143 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11144 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    11145 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    11146 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11147 File
    11148 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11149 packages/chimerax/core/models.py", line 143, in first_intercept 
    11150 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    11151 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11152 File
    11153 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11154 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    11155 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    11156 exclude=exclude) 
    11157 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11158 File
    11159 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11160 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    11161 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    11162 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11163 File
    11164 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11165 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    11166 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    11167 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11168 File
    11169 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11170 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    11171 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    11172 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11173 File
    11174 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11175 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    11176 p = super().first_intercept(mxyz1, mxyz2) 
    11177 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11178 File
    11179 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11180 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    11181 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    11182 exclude=exclude) 
    11183 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11184 File
    11185 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11186 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    11187 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    11188 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11189 File
    11190 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11191 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    11192 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    11193 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11194 File
    11195 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11196 packages/chimerax/graphics/drawing.py", line 1108, in
    11197 _first_intercept_excluding_children 
    11198 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    11199 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11200 File
    11201 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11202 packages/chimerax/geometry/place.py", line 201, in inverse 
    11203 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    11204 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11205 File
    11206 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11207 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    11208 rinv[:, :] = matrix_inverse(r) 
    11209 ^^^^^^^^^^^^^^^^^ 
    11210 File
    11211 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11212 packages/numpy/linalg/linalg.py", line 561, in inv 
    11213 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    11214 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11215 File
    11216 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11217 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    11218 raise LinAlgError("Singular matrix") 
    11219 numpy.linalg.LinAlgError: Singular matrix 
    11220  
    11221 numpy.linalg.LinAlgError: Singular matrix 
    11222  
    11223 File
    11224 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11225 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    11226 raise LinAlgError("Singular matrix") 
    11227  
    11228 See log for complete Python traceback. 
    11229  
    11230 Traceback (most recent call last): 
    11231 File
    11232 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11233 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    11234 self.session.ui.mouse_modes.mouse_pause_tracking() 
    11235 File
    11236 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11237 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    11238 mouse_pause_tracking 
    11239 self._mouse_pause() 
    11240 File
    11241 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11242 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    11243 m.pause(self._mouse_pause_position) 
    11244 File
    11245 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11246 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    11247 p = self.view.picked_object(x, y) 
    11248 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11249 File
    11250 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11251 packages/chimerax/graphics/view.py", line 838, in picked_object 
    11252 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    11253 beyond, 
    11254 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11255 File
    11256 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11257 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    11258 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    11259 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11260 File
    11261 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11262 packages/chimerax/core/models.py", line 143, in first_intercept 
    11263 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    11264 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11265 File
    11266 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11267 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    11268 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    11269 exclude=exclude) 
    11270 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11271 File
    11272 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11273 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    11274 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    11275 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11276 File
    11277 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11278 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    11279 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    11280 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11281 File
    11282 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11283 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    11284 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    11285 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11286 File
    11287 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11288 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    11289 p = super().first_intercept(mxyz1, mxyz2) 
    11290 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11291 File
    11292 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11293 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    11294 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    11295 exclude=exclude) 
    11296 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11297 File
    11298 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11299 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    11300 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    11301 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11302 File
    11303 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11304 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    11305 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    11306 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11307 File
    11308 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11309 packages/chimerax/graphics/drawing.py", line 1108, in
    11310 _first_intercept_excluding_children 
    11311 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    11312 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11313 File
    11314 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11315 packages/chimerax/geometry/place.py", line 201, in inverse 
    11316 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    11317 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11318 File
    11319 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11320 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    11321 rinv[:, :] = matrix_inverse(r) 
    11322 ^^^^^^^^^^^^^^^^^ 
    11323 File
    11324 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11325 packages/numpy/linalg/linalg.py", line 561, in inv 
    11326 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    11327 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11328 File
    11329 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11330 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    11331 raise LinAlgError("Singular matrix") 
    11332 numpy.linalg.LinAlgError: Singular matrix 
    11333  
    11334 numpy.linalg.LinAlgError: Singular matrix 
    11335  
    11336 File
    11337 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11338 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    11339 raise LinAlgError("Singular matrix") 
    11340  
    11341 See log for complete Python traceback. 
    11342  
    11343 Traceback (most recent call last): 
    11344 File
    11345 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11346 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    11347 self.session.ui.mouse_modes.mouse_pause_tracking() 
    11348 File
    11349 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11350 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    11351 mouse_pause_tracking 
    11352 self._mouse_pause() 
    11353 File
    11354 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11355 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    11356 m.pause(self._mouse_pause_position) 
    11357 File
    11358 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11359 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    11360 p = self.view.picked_object(x, y) 
    11361 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11362 File
    11363 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11364 packages/chimerax/graphics/view.py", line 838, in picked_object 
    11365 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    11366 beyond, 
    11367 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11368 File
    11369 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11370 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    11371 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    11372 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11373 File
    11374 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11375 packages/chimerax/core/models.py", line 143, in first_intercept 
    11376 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    11377 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11378 File
    11379 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11380 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    11381 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    11382 exclude=exclude) 
    11383 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11384 File
    11385 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11386 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    11387 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    11388 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11389 File
    11390 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11391 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    11392 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    11393 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11394 File
    11395 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11396 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    11397 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    11398 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11399 File
    11400 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11401 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    11402 p = super().first_intercept(mxyz1, mxyz2) 
    11403 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11404 File
    11405 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11406 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    11407 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    11408 exclude=exclude) 
    11409 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11410 File
    11411 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11412 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    11413 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    11414 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11415 File
    11416 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11417 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    11418 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    11419 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11420 File
    11421 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11422 packages/chimerax/graphics/drawing.py", line 1108, in
    11423 _first_intercept_excluding_children 
    11424 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    11425 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11426 File
    11427 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11428 packages/chimerax/geometry/place.py", line 201, in inverse 
    11429 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    11430 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11431 File
    11432 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11433 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    11434 rinv[:, :] = matrix_inverse(r) 
    11435 ^^^^^^^^^^^^^^^^^ 
    11436 File
    11437 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11438 packages/numpy/linalg/linalg.py", line 561, in inv 
    11439 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    11440 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11441 File
    11442 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11443 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    11444 raise LinAlgError("Singular matrix") 
    11445 numpy.linalg.LinAlgError: Singular matrix 
    11446  
    11447 numpy.linalg.LinAlgError: Singular matrix 
    11448  
    11449 File
    11450 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11451 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    11452 raise LinAlgError("Singular matrix") 
    11453  
    11454 See log for complete Python traceback. 
    11455  
    11456 Traceback (most recent call last): 
    11457 File
    11458 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11459 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    11460 self.session.ui.mouse_modes.mouse_pause_tracking() 
    11461 File
    11462 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11463 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    11464 mouse_pause_tracking 
    11465 self._mouse_pause() 
    11466 File
    11467 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11468 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    11469 m.pause(self._mouse_pause_position) 
    11470 File
    11471 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11472 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    11473 p = self.view.picked_object(x, y) 
    11474 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11475 File
    11476 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11477 packages/chimerax/graphics/view.py", line 838, in picked_object 
    11478 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    11479 beyond, 
    11480 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11481 File
    11482 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11483 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    11484 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    11485 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11486 File
    11487 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11488 packages/chimerax/core/models.py", line 143, in first_intercept 
    11489 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    11490 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11491 File
    11492 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11493 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    11494 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    11495 exclude=exclude) 
    11496 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11497 File
    11498 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11499 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    11500 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    11501 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11502 File
    11503 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11504 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    11505 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    11506 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11507 File
    11508 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11509 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    11510 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    11511 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11512 File
    11513 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11514 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    11515 p = super().first_intercept(mxyz1, mxyz2) 
    11516 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11517 File
    11518 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11519 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    11520 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    11521 exclude=exclude) 
    11522 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11523 File
    11524 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11525 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    11526 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    11527 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11528 File
    11529 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11530 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    11531 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    11532 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11533 File
    11534 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11535 packages/chimerax/graphics/drawing.py", line 1108, in
    11536 _first_intercept_excluding_children 
    11537 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    11538 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11539 File
    11540 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11541 packages/chimerax/geometry/place.py", line 201, in inverse 
    11542 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    11543 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11544 File
    11545 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11546 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    11547 rinv[:, :] = matrix_inverse(r) 
    11548 ^^^^^^^^^^^^^^^^^ 
    11549 File
    11550 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11551 packages/numpy/linalg/linalg.py", line 561, in inv 
    11552 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    11553 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11554 File
    11555 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11556 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    11557 raise LinAlgError("Singular matrix") 
    11558 numpy.linalg.LinAlgError: Singular matrix 
    11559  
    11560 numpy.linalg.LinAlgError: Singular matrix 
    11561  
    11562 File
    11563 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11564 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    11565 raise LinAlgError("Singular matrix") 
    11566  
    11567 See log for complete Python traceback. 
    11568  
    11569 Traceback (most recent call last): 
    11570 File
    11571 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11572 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    11573 self.session.ui.mouse_modes.mouse_pause_tracking() 
    11574 File
    11575 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11576 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    11577 mouse_pause_tracking 
    11578 self._mouse_pause() 
    11579 File
    11580 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11581 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    11582 m.pause(self._mouse_pause_position) 
    11583 File
    11584 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11585 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    11586 p = self.view.picked_object(x, y) 
    11587 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11588 File
    11589 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11590 packages/chimerax/graphics/view.py", line 838, in picked_object 
    11591 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    11592 beyond, 
    11593 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11594 File
    11595 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11596 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    11597 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    11598 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11599 File
    11600 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11601 packages/chimerax/core/models.py", line 143, in first_intercept 
    11602 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    11603 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11604 File
    11605 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11606 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    11607 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    11608 exclude=exclude) 
    11609 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11610 File
    11611 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11612 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    11613 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    11614 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11615 File
    11616 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11617 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    11618 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    11619 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11620 File
    11621 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11622 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    11623 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    11624 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11625 File
    11626 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11627 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    11628 p = super().first_intercept(mxyz1, mxyz2) 
    11629 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11630 File
    11631 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11632 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    11633 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    11634 exclude=exclude) 
    11635 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11636 File
    11637 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11638 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    11639 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    11640 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11641 File
    11642 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11643 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    11644 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    11645 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11646 File
    11647 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11648 packages/chimerax/graphics/drawing.py", line 1108, in
    11649 _first_intercept_excluding_children 
    11650 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    11651 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11652 File
    11653 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11654 packages/chimerax/geometry/place.py", line 201, in inverse 
    11655 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    11656 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11657 File
    11658 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11659 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    11660 rinv[:, :] = matrix_inverse(r) 
    11661 ^^^^^^^^^^^^^^^^^ 
    11662 File
    11663 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11664 packages/numpy/linalg/linalg.py", line 561, in inv 
    11665 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    11666 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11667 File
    11668 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11669 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    11670 raise LinAlgError("Singular matrix") 
    11671 numpy.linalg.LinAlgError: Singular matrix 
    11672  
    11673 numpy.linalg.LinAlgError: Singular matrix 
    11674  
    11675 File
    11676 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11677 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    11678 raise LinAlgError("Singular matrix") 
    11679  
    11680 See log for complete Python traceback. 
    11681  
    11682 Traceback (most recent call last): 
    11683 File
    11684 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11685 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    11686 self.session.ui.mouse_modes.mouse_pause_tracking() 
    11687 File
    11688 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11689 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    11690 mouse_pause_tracking 
    11691 self._mouse_pause() 
    11692 File
    11693 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11694 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    11695 m.pause(self._mouse_pause_position) 
    11696 File
    11697 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11698 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    11699 p = self.view.picked_object(x, y) 
    11700 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11701 File
    11702 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11703 packages/chimerax/graphics/view.py", line 838, in picked_object 
    11704 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    11705 beyond, 
    11706 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11707 File
    11708 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11709 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    11710 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    11711 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11712 File
    11713 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11714 packages/chimerax/core/models.py", line 143, in first_intercept 
    11715 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    11716 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11717 File
    11718 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11719 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    11720 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    11721 exclude=exclude) 
    11722 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11723 File
    11724 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11725 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    11726 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    11727 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11728 File
    11729 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11730 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    11731 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    11732 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11733 File
    11734 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11735 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    11736 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    11737 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11738 File
    11739 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11740 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    11741 p = super().first_intercept(mxyz1, mxyz2) 
    11742 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11743 File
    11744 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11745 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    11746 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    11747 exclude=exclude) 
    11748 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11749 File
    11750 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11751 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    11752 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    11753 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11754 File
    11755 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11756 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    11757 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    11758 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11759 File
    11760 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11761 packages/chimerax/graphics/drawing.py", line 1108, in
    11762 _first_intercept_excluding_children 
    11763 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    11764 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11765 File
    11766 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11767 packages/chimerax/geometry/place.py", line 201, in inverse 
    11768 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    11769 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11770 File
    11771 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11772 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    11773 rinv[:, :] = matrix_inverse(r) 
    11774 ^^^^^^^^^^^^^^^^^ 
    11775 File
    11776 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11777 packages/numpy/linalg/linalg.py", line 561, in inv 
    11778 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    11779 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11780 File
    11781 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11782 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    11783 raise LinAlgError("Singular matrix") 
    11784 numpy.linalg.LinAlgError: Singular matrix 
    11785  
    11786 numpy.linalg.LinAlgError: Singular matrix 
    11787  
    11788 File
    11789 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11790 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    11791 raise LinAlgError("Singular matrix") 
    11792  
    11793 See log for complete Python traceback. 
    11794  
    11795 Traceback (most recent call last): 
    11796 File
    11797 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11798 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    11799 self.session.ui.mouse_modes.mouse_pause_tracking() 
    11800 File
    11801 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11802 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    11803 mouse_pause_tracking 
    11804 self._mouse_pause() 
    11805 File
    11806 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11807 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    11808 m.pause(self._mouse_pause_position) 
    11809 File
    11810 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11811 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    11812 p = self.view.picked_object(x, y) 
    11813 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11814 File
    11815 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11816 packages/chimerax/graphics/view.py", line 838, in picked_object 
    11817 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    11818 beyond, 
    11819 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11820 File
    11821 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11822 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    11823 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    11824 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11825 File
    11826 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11827 packages/chimerax/core/models.py", line 143, in first_intercept 
    11828 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    11829 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11830 File
    11831 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11832 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    11833 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    11834 exclude=exclude) 
    11835 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11836 File
    11837 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11838 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    11839 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    11840 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11841 File
    11842 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11843 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    11844 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    11845 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11846 File
    11847 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11848 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    11849 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    11850 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11851 File
    11852 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11853 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    11854 p = super().first_intercept(mxyz1, mxyz2) 
    11855 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11856 File
    11857 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11858 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    11859 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    11860 exclude=exclude) 
    11861 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11862 File
    11863 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11864 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    11865 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    11866 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11867 File
    11868 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11869 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    11870 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    11871 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11872 File
    11873 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11874 packages/chimerax/graphics/drawing.py", line 1108, in
    11875 _first_intercept_excluding_children 
    11876 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    11877 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11878 File
    11879 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11880 packages/chimerax/geometry/place.py", line 201, in inverse 
    11881 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    11882 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11883 File
    11884 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11885 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    11886 rinv[:, :] = matrix_inverse(r) 
    11887 ^^^^^^^^^^^^^^^^^ 
    11888 File
    11889 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11890 packages/numpy/linalg/linalg.py", line 561, in inv 
    11891 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    11892 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11893 File
    11894 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11895 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    11896 raise LinAlgError("Singular matrix") 
    11897 numpy.linalg.LinAlgError: Singular matrix 
    11898  
    11899 numpy.linalg.LinAlgError: Singular matrix 
    11900  
    11901 File
    11902 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11903 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    11904 raise LinAlgError("Singular matrix") 
    11905  
    11906 See log for complete Python traceback. 
    11907  
    11908 Traceback (most recent call last): 
    11909 File
    11910 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11911 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    11912 self.session.ui.mouse_modes.mouse_pause_tracking() 
    11913 File
    11914 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11915 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    11916 mouse_pause_tracking 
    11917 self._mouse_pause() 
    11918 File
    11919 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11920 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    11921 m.pause(self._mouse_pause_position) 
    11922 File
    11923 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11924 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    11925 p = self.view.picked_object(x, y) 
    11926 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11927 File
    11928 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11929 packages/chimerax/graphics/view.py", line 838, in picked_object 
    11930 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    11931 beyond, 
    11932 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11933 File
    11934 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11935 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    11936 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    11937 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11938 File
    11939 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11940 packages/chimerax/core/models.py", line 143, in first_intercept 
    11941 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    11942 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11943 File
    11944 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11945 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    11946 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    11947 exclude=exclude) 
    11948 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11949 File
    11950 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11951 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    11952 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    11953 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11954 File
    11955 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11956 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    11957 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    11958 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11959 File
    11960 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11961 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    11962 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    11963 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11964 File
    11965 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11966 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    11967 p = super().first_intercept(mxyz1, mxyz2) 
    11968 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11969 File
    11970 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11971 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    11972 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    11973 exclude=exclude) 
    11974 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11975 File
    11976 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11977 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    11978 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    11979 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11980 File
    11981 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11982 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    11983 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    11984 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11985 File
    11986 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11987 packages/chimerax/graphics/drawing.py", line 1108, in
    11988 _first_intercept_excluding_children 
    11989 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    11990 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11991 File
    11992 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11993 packages/chimerax/geometry/place.py", line 201, in inverse 
    11994 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    11995 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    11996 File
    11997 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    11998 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    11999 rinv[:, :] = matrix_inverse(r) 
    12000 ^^^^^^^^^^^^^^^^^ 
    12001 File
    12002 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12003 packages/numpy/linalg/linalg.py", line 561, in inv 
    12004 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    12005 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12006 File
    12007 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12008 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    12009 raise LinAlgError("Singular matrix") 
    12010 numpy.linalg.LinAlgError: Singular matrix 
    12011  
    12012 numpy.linalg.LinAlgError: Singular matrix 
    12013  
    12014 File
    12015 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12016 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    12017 raise LinAlgError("Singular matrix") 
    12018  
    12019 See log for complete Python traceback. 
    12020  
    12021 Traceback (most recent call last): 
    12022 File
    12023 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12024 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    12025 self.session.ui.mouse_modes.mouse_pause_tracking() 
    12026 File
    12027 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12028 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    12029 mouse_pause_tracking 
    12030 self._mouse_pause() 
    12031 File
    12032 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12033 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    12034 m.pause(self._mouse_pause_position) 
    12035 File
    12036 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12037 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    12038 p = self.view.picked_object(x, y) 
    12039 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12040 File
    12041 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12042 packages/chimerax/graphics/view.py", line 838, in picked_object 
    12043 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    12044 beyond, 
    12045 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12046 File
    12047 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12048 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    12049 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    12050 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12051 File
    12052 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12053 packages/chimerax/core/models.py", line 143, in first_intercept 
    12054 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    12055 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12056 File
    12057 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12058 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    12059 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    12060 exclude=exclude) 
    12061 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12062 File
    12063 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12064 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    12065 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    12066 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12067 File
    12068 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12069 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    12070 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    12071 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12072 File
    12073 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12074 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    12075 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    12076 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12077 File
    12078 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12079 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    12080 p = super().first_intercept(mxyz1, mxyz2) 
    12081 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12082 File
    12083 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12084 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    12085 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    12086 exclude=exclude) 
    12087 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12088 File
    12089 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12090 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    12091 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    12092 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12093 File
    12094 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12095 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    12096 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    12097 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12098 File
    12099 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12100 packages/chimerax/graphics/drawing.py", line 1108, in
    12101 _first_intercept_excluding_children 
    12102 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    12103 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12104 File
    12105 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12106 packages/chimerax/geometry/place.py", line 201, in inverse 
    12107 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    12108 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12109 File
    12110 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12111 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    12112 rinv[:, :] = matrix_inverse(r) 
    12113 ^^^^^^^^^^^^^^^^^ 
    12114 File
    12115 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12116 packages/numpy/linalg/linalg.py", line 561, in inv 
    12117 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    12118 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12119 File
    12120 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12121 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    12122 raise LinAlgError("Singular matrix") 
    12123 numpy.linalg.LinAlgError: Singular matrix 
    12124  
    12125 numpy.linalg.LinAlgError: Singular matrix 
    12126  
    12127 File
    12128 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12129 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    12130 raise LinAlgError("Singular matrix") 
    12131  
    12132 See log for complete Python traceback. 
    12133  
    12134 Traceback (most recent call last): 
    12135 File
    12136 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12137 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    12138 self.session.ui.mouse_modes.mouse_pause_tracking() 
    12139 File
    12140 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12141 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    12142 mouse_pause_tracking 
    12143 self._mouse_pause() 
    12144 File
    12145 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12146 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    12147 m.pause(self._mouse_pause_position) 
    12148 File
    12149 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12150 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    12151 p = self.view.picked_object(x, y) 
    12152 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12153 File
    12154 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12155 packages/chimerax/graphics/view.py", line 838, in picked_object 
    12156 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    12157 beyond, 
    12158 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12159 File
    12160 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12161 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    12162 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    12163 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12164 File
    12165 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12166 packages/chimerax/core/models.py", line 143, in first_intercept 
    12167 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    12168 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12169 File
    12170 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12171 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    12172 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    12173 exclude=exclude) 
    12174 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12175 File
    12176 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12177 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    12178 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    12179 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12180 File
    12181 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12182 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    12183 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    12184 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12185 File
    12186 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12187 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    12188 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    12189 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12190 File
    12191 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12192 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    12193 p = super().first_intercept(mxyz1, mxyz2) 
    12194 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12195 File
    12196 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12197 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    12198 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    12199 exclude=exclude) 
    12200 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12201 File
    12202 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12203 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    12204 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    12205 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12206 File
    12207 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12208 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    12209 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    12210 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12211 File
    12212 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12213 packages/chimerax/graphics/drawing.py", line 1108, in
    12214 _first_intercept_excluding_children 
    12215 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    12216 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12217 File
    12218 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12219 packages/chimerax/geometry/place.py", line 201, in inverse 
    12220 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    12221 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12222 File
    12223 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12224 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    12225 rinv[:, :] = matrix_inverse(r) 
    12226 ^^^^^^^^^^^^^^^^^ 
    12227 File
    12228 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12229 packages/numpy/linalg/linalg.py", line 561, in inv 
    12230 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    12231 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12232 File
    12233 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12234 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    12235 raise LinAlgError("Singular matrix") 
    12236 numpy.linalg.LinAlgError: Singular matrix 
    12237  
    12238 numpy.linalg.LinAlgError: Singular matrix 
    12239  
    12240 File
    12241 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12242 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    12243 raise LinAlgError("Singular matrix") 
    12244  
    12245 See log for complete Python traceback. 
    12246  
    12247 Traceback (most recent call last): 
    12248 File
    12249 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12250 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    12251 self.session.ui.mouse_modes.mouse_pause_tracking() 
    12252 File
    12253 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12254 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    12255 mouse_pause_tracking 
    12256 self._mouse_pause() 
    12257 File
    12258 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12259 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    12260 m.pause(self._mouse_pause_position) 
    12261 File
    12262 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12263 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    12264 p = self.view.picked_object(x, y) 
    12265 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12266 File
    12267 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12268 packages/chimerax/graphics/view.py", line 838, in picked_object 
    12269 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    12270 beyond, 
    12271 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12272 File
    12273 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12274 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    12275 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    12276 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12277 File
    12278 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12279 packages/chimerax/core/models.py", line 143, in first_intercept 
    12280 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    12281 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12282 File
    12283 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12284 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    12285 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    12286 exclude=exclude) 
    12287 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12288 File
    12289 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12290 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    12291 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    12292 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12293 File
    12294 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12295 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    12296 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    12297 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12298 File
    12299 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12300 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    12301 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    12302 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12303 File
    12304 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12305 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    12306 p = super().first_intercept(mxyz1, mxyz2) 
    12307 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12308 File
    12309 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12310 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    12311 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    12312 exclude=exclude) 
    12313 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12314 File
    12315 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12316 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    12317 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    12318 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12319 File
    12320 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12321 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    12322 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    12323 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12324 File
    12325 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12326 packages/chimerax/graphics/drawing.py", line 1108, in
    12327 _first_intercept_excluding_children 
    12328 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    12329 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12330 File
    12331 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12332 packages/chimerax/geometry/place.py", line 201, in inverse 
    12333 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    12334 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12335 File
    12336 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12337 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    12338 rinv[:, :] = matrix_inverse(r) 
    12339 ^^^^^^^^^^^^^^^^^ 
    12340 File
    12341 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12342 packages/numpy/linalg/linalg.py", line 561, in inv 
    12343 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    12344 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12345 File
    12346 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12347 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    12348 raise LinAlgError("Singular matrix") 
    12349 numpy.linalg.LinAlgError: Singular matrix 
    12350  
    12351 numpy.linalg.LinAlgError: Singular matrix 
    12352  
    12353 File
    12354 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12355 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    12356 raise LinAlgError("Singular matrix") 
    12357  
    12358 See log for complete Python traceback. 
    12359  
    12360 Traceback (most recent call last): 
    12361 File
    12362 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12363 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    12364 self.session.ui.mouse_modes.mouse_pause_tracking() 
    12365 File
    12366 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12367 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    12368 mouse_pause_tracking 
    12369 self._mouse_pause() 
    12370 File
    12371 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12372 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    12373 m.pause(self._mouse_pause_position) 
    12374 File
    12375 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12376 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    12377 p = self.view.picked_object(x, y) 
    12378 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12379 File
    12380 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12381 packages/chimerax/graphics/view.py", line 838, in picked_object 
    12382 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    12383 beyond, 
    12384 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12385 File
    12386 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12387 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    12388 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    12389 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12390 File
    12391 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12392 packages/chimerax/core/models.py", line 143, in first_intercept 
    12393 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    12394 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12395 File
    12396 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12397 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    12398 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    12399 exclude=exclude) 
    12400 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12401 File
    12402 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12403 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    12404 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    12405 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12406 File
    12407 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12408 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    12409 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    12410 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12411 File
    12412 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12413 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    12414 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    12415 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12416 File
    12417 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12418 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    12419 p = super().first_intercept(mxyz1, mxyz2) 
    12420 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12421 File
    12422 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12423 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    12424 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    12425 exclude=exclude) 
    12426 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12427 File
    12428 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12429 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    12430 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    12431 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12432 File
    12433 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12434 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    12435 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    12436 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12437 File
    12438 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12439 packages/chimerax/graphics/drawing.py", line 1108, in
    12440 _first_intercept_excluding_children 
    12441 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    12442 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12443 File
    12444 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12445 packages/chimerax/geometry/place.py", line 201, in inverse 
    12446 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    12447 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12448 File
    12449 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12450 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    12451 rinv[:, :] = matrix_inverse(r) 
    12452 ^^^^^^^^^^^^^^^^^ 
    12453 File
    12454 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12455 packages/numpy/linalg/linalg.py", line 561, in inv 
    12456 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    12457 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12458 File
    12459 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12460 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    12461 raise LinAlgError("Singular matrix") 
    12462 numpy.linalg.LinAlgError: Singular matrix 
    12463  
    12464 numpy.linalg.LinAlgError: Singular matrix 
    12465  
    12466 File
    12467 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12468 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    12469 raise LinAlgError("Singular matrix") 
    12470  
    12471 See log for complete Python traceback. 
    12472  
    12473 Traceback (most recent call last): 
    12474 File
    12475 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12476 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    12477 self.session.ui.mouse_modes.mouse_pause_tracking() 
    12478 File
    12479 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12480 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    12481 mouse_pause_tracking 
    12482 self._mouse_pause() 
    12483 File
    12484 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12485 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    12486 m.pause(self._mouse_pause_position) 
    12487 File
    12488 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12489 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    12490 p = self.view.picked_object(x, y) 
    12491 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12492 File
    12493 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12494 packages/chimerax/graphics/view.py", line 838, in picked_object 
    12495 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    12496 beyond, 
    12497 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12498 File
    12499 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12500 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    12501 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    12502 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12503 File
    12504 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12505 packages/chimerax/core/models.py", line 143, in first_intercept 
    12506 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    12507 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12508 File
    12509 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12510 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    12511 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    12512 exclude=exclude) 
    12513 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12514 File
    12515 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12516 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    12517 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    12518 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12519 File
    12520 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12521 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    12522 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    12523 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12524 File
    12525 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12526 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    12527 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    12528 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12529 File
    12530 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12531 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    12532 p = super().first_intercept(mxyz1, mxyz2) 
    12533 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12534 File
    12535 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12536 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    12537 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    12538 exclude=exclude) 
    12539 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12540 File
    12541 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12542 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    12543 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    12544 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12545 File
    12546 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12547 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    12548 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    12549 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12550 File
    12551 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12552 packages/chimerax/graphics/drawing.py", line 1108, in
    12553 _first_intercept_excluding_children 
    12554 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    12555 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12556 File
    12557 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12558 packages/chimerax/geometry/place.py", line 201, in inverse 
    12559 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    12560 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12561 File
    12562 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12563 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    12564 rinv[:, :] = matrix_inverse(r) 
    12565 ^^^^^^^^^^^^^^^^^ 
    12566 File
    12567 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12568 packages/numpy/linalg/linalg.py", line 561, in inv 
    12569 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    12570 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12571 File
    12572 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12573 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    12574 raise LinAlgError("Singular matrix") 
    12575 numpy.linalg.LinAlgError: Singular matrix 
    12576  
    12577 numpy.linalg.LinAlgError: Singular matrix 
    12578  
    12579 File
    12580 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12581 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    12582 raise LinAlgError("Singular matrix") 
    12583  
    12584 See log for complete Python traceback. 
    12585  
    12586 Traceback (most recent call last): 
    12587 File
    12588 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12589 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    12590 self.session.ui.mouse_modes.mouse_pause_tracking() 
    12591 File
    12592 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12593 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    12594 mouse_pause_tracking 
    12595 self._mouse_pause() 
    12596 File
    12597 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12598 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    12599 m.pause(self._mouse_pause_position) 
    12600 File
    12601 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12602 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    12603 p = self.view.picked_object(x, y) 
    12604 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12605 File
    12606 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12607 packages/chimerax/graphics/view.py", line 838, in picked_object 
    12608 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    12609 beyond, 
    12610 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12611 File
    12612 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12613 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    12614 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    12615 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12616 File
    12617 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12618 packages/chimerax/core/models.py", line 143, in first_intercept 
    12619 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    12620 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12621 File
    12622 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12623 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    12624 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    12625 exclude=exclude) 
    12626 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12627 File
    12628 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12629 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    12630 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    12631 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12632 File
    12633 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12634 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    12635 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    12636 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12637 File
    12638 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12639 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    12640 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    12641 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12642 File
    12643 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12644 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    12645 p = super().first_intercept(mxyz1, mxyz2) 
    12646 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12647 File
    12648 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12649 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    12650 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    12651 exclude=exclude) 
    12652 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12653 File
    12654 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12655 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    12656 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    12657 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12658 File
    12659 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12660 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    12661 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    12662 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12663 File
    12664 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12665 packages/chimerax/graphics/drawing.py", line 1108, in
    12666 _first_intercept_excluding_children 
    12667 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    12668 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12669 File
    12670 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12671 packages/chimerax/geometry/place.py", line 201, in inverse 
    12672 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    12673 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12674 File
    12675 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12676 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    12677 rinv[:, :] = matrix_inverse(r) 
    12678 ^^^^^^^^^^^^^^^^^ 
    12679 File
    12680 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12681 packages/numpy/linalg/linalg.py", line 561, in inv 
    12682 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    12683 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12684 File
    12685 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12686 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    12687 raise LinAlgError("Singular matrix") 
    12688 numpy.linalg.LinAlgError: Singular matrix 
    12689  
    12690 numpy.linalg.LinAlgError: Singular matrix 
    12691  
    12692 File
    12693 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12694 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    12695 raise LinAlgError("Singular matrix") 
    12696  
    12697 See log for complete Python traceback. 
    12698  
    12699 Traceback (most recent call last): 
    12700 File
    12701 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12702 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    12703 self.session.ui.mouse_modes.mouse_pause_tracking() 
    12704 File
    12705 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12706 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    12707 mouse_pause_tracking 
    12708 self._mouse_pause() 
    12709 File
    12710 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12711 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    12712 m.pause(self._mouse_pause_position) 
    12713 File
    12714 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12715 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    12716 p = self.view.picked_object(x, y) 
    12717 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12718 File
    12719 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12720 packages/chimerax/graphics/view.py", line 838, in picked_object 
    12721 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    12722 beyond, 
    12723 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12724 File
    12725 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12726 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    12727 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    12728 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12729 File
    12730 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12731 packages/chimerax/core/models.py", line 143, in first_intercept 
    12732 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    12733 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12734 File
    12735 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12736 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    12737 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    12738 exclude=exclude) 
    12739 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12740 File
    12741 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12742 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    12743 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    12744 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12745 File
    12746 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12747 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    12748 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    12749 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12750 File
    12751 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12752 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    12753 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    12754 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12755 File
    12756 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12757 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    12758 p = super().first_intercept(mxyz1, mxyz2) 
    12759 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12760 File
    12761 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12762 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    12763 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    12764 exclude=exclude) 
    12765 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12766 File
    12767 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12768 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    12769 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    12770 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12771 File
    12772 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12773 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    12774 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    12775 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12776 File
    12777 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12778 packages/chimerax/graphics/drawing.py", line 1108, in
    12779 _first_intercept_excluding_children 
    12780 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    12781 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12782 File
    12783 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12784 packages/chimerax/geometry/place.py", line 201, in inverse 
    12785 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    12786 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12787 File
    12788 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12789 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    12790 rinv[:, :] = matrix_inverse(r) 
    12791 ^^^^^^^^^^^^^^^^^ 
    12792 File
    12793 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12794 packages/numpy/linalg/linalg.py", line 561, in inv 
    12795 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    12796 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12797 File
    12798 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12799 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    12800 raise LinAlgError("Singular matrix") 
    12801 numpy.linalg.LinAlgError: Singular matrix 
    12802  
    12803 numpy.linalg.LinAlgError: Singular matrix 
    12804  
    12805 File
    12806 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12807 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    12808 raise LinAlgError("Singular matrix") 
    12809  
    12810 See log for complete Python traceback. 
    12811  
    12812 Traceback (most recent call last): 
    12813 File
    12814 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12815 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    12816 self.session.ui.mouse_modes.mouse_pause_tracking() 
    12817 File
    12818 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12819 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    12820 mouse_pause_tracking 
    12821 self._mouse_pause() 
    12822 File
    12823 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12824 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    12825 m.pause(self._mouse_pause_position) 
    12826 File
    12827 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12828 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    12829 p = self.view.picked_object(x, y) 
    12830 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12831 File
    12832 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12833 packages/chimerax/graphics/view.py", line 838, in picked_object 
    12834 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    12835 beyond, 
    12836 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12837 File
    12838 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12839 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    12840 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    12841 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12842 File
    12843 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12844 packages/chimerax/core/models.py", line 143, in first_intercept 
    12845 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    12846 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12847 File
    12848 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12849 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    12850 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    12851 exclude=exclude) 
    12852 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12853 File
    12854 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12855 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    12856 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    12857 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12858 File
    12859 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12860 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    12861 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    12862 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12863 File
    12864 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12865 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    12866 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    12867 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12868 File
    12869 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12870 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    12871 p = super().first_intercept(mxyz1, mxyz2) 
    12872 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12873 File
    12874 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12875 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    12876 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    12877 exclude=exclude) 
    12878 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12879 File
    12880 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12881 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    12882 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    12883 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12884 File
    12885 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12886 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    12887 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    12888 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12889 File
    12890 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12891 packages/chimerax/graphics/drawing.py", line 1108, in
    12892 _first_intercept_excluding_children 
    12893 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    12894 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12895 File
    12896 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12897 packages/chimerax/geometry/place.py", line 201, in inverse 
    12898 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    12899 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12900 File
    12901 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12902 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    12903 rinv[:, :] = matrix_inverse(r) 
    12904 ^^^^^^^^^^^^^^^^^ 
    12905 File
    12906 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12907 packages/numpy/linalg/linalg.py", line 561, in inv 
    12908 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    12909 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12910 File
    12911 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12912 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    12913 raise LinAlgError("Singular matrix") 
    12914 numpy.linalg.LinAlgError: Singular matrix 
    12915  
    12916 numpy.linalg.LinAlgError: Singular matrix 
    12917  
    12918 File
    12919 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12920 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    12921 raise LinAlgError("Singular matrix") 
    12922  
    12923 See log for complete Python traceback. 
    12924  
    12925 Traceback (most recent call last): 
    12926 File
    12927 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12928 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    12929 self.session.ui.mouse_modes.mouse_pause_tracking() 
    12930 File
    12931 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12932 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    12933 mouse_pause_tracking 
    12934 self._mouse_pause() 
    12935 File
    12936 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12937 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    12938 m.pause(self._mouse_pause_position) 
    12939 File
    12940 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12941 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    12942 p = self.view.picked_object(x, y) 
    12943 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12944 File
    12945 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12946 packages/chimerax/graphics/view.py", line 838, in picked_object 
    12947 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    12948 beyond, 
    12949 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12950 File
    12951 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12952 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    12953 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    12954 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12955 File
    12956 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12957 packages/chimerax/core/models.py", line 143, in first_intercept 
    12958 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    12959 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12960 File
    12961 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12962 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    12963 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    12964 exclude=exclude) 
    12965 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12966 File
    12967 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12968 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    12969 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    12970 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12971 File
    12972 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12973 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    12974 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    12975 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12976 File
    12977 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12978 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    12979 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    12980 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12981 File
    12982 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12983 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    12984 p = super().first_intercept(mxyz1, mxyz2) 
    12985 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12986 File
    12987 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12988 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    12989 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    12990 exclude=exclude) 
    12991 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12992 File
    12993 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12994 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    12995 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    12996 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    12997 File
    12998 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    12999 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    13000 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    13001 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13002 File
    13003 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13004 packages/chimerax/graphics/drawing.py", line 1108, in
    13005 _first_intercept_excluding_children 
    13006 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    13007 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13008 File
    13009 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13010 packages/chimerax/geometry/place.py", line 201, in inverse 
    13011 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    13012 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13013 File
    13014 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13015 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    13016 rinv[:, :] = matrix_inverse(r) 
    13017 ^^^^^^^^^^^^^^^^^ 
    13018 File
    13019 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13020 packages/numpy/linalg/linalg.py", line 561, in inv 
    13021 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    13022 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13023 File
    13024 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13025 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    13026 raise LinAlgError("Singular matrix") 
    13027 numpy.linalg.LinAlgError: Singular matrix 
    13028  
    13029 numpy.linalg.LinAlgError: Singular matrix 
    13030  
    13031 File
    13032 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13033 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    13034 raise LinAlgError("Singular matrix") 
    13035  
    13036 See log for complete Python traceback. 
    13037  
    13038 Traceback (most recent call last): 
    13039 File
    13040 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13041 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    13042 self.session.ui.mouse_modes.mouse_pause_tracking() 
    13043 File
    13044 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13045 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    13046 mouse_pause_tracking 
    13047 self._mouse_pause() 
    13048 File
    13049 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13050 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    13051 m.pause(self._mouse_pause_position) 
    13052 File
    13053 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13054 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    13055 p = self.view.picked_object(x, y) 
    13056 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13057 File
    13058 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13059 packages/chimerax/graphics/view.py", line 838, in picked_object 
    13060 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    13061 beyond, 
    13062 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13063 File
    13064 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13065 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    13066 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    13067 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13068 File
    13069 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13070 packages/chimerax/core/models.py", line 143, in first_intercept 
    13071 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    13072 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13073 File
    13074 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13075 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    13076 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    13077 exclude=exclude) 
    13078 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13079 File
    13080 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13081 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    13082 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    13083 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13084 File
    13085 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13086 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    13087 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    13088 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13089 File
    13090 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13091 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    13092 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    13093 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13094 File
    13095 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13096 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    13097 p = super().first_intercept(mxyz1, mxyz2) 
    13098 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13099 File
    13100 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13101 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    13102 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    13103 exclude=exclude) 
    13104 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13105 File
    13106 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13107 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    13108 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    13109 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13110 File
    13111 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13112 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    13113 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    13114 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13115 File
    13116 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13117 packages/chimerax/graphics/drawing.py", line 1108, in
    13118 _first_intercept_excluding_children 
    13119 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    13120 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13121 File
    13122 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13123 packages/chimerax/geometry/place.py", line 201, in inverse 
    13124 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    13125 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13126 File
    13127 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13128 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    13129 rinv[:, :] = matrix_inverse(r) 
    13130 ^^^^^^^^^^^^^^^^^ 
    13131 File
    13132 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13133 packages/numpy/linalg/linalg.py", line 561, in inv 
    13134 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    13135 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13136 File
    13137 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13138 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    13139 raise LinAlgError("Singular matrix") 
    13140 numpy.linalg.LinAlgError: Singular matrix 
    13141  
    13142 numpy.linalg.LinAlgError: Singular matrix 
    13143  
    13144 File
    13145 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13146 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    13147 raise LinAlgError("Singular matrix") 
    13148  
    13149 See log for complete Python traceback. 
    13150  
    13151 Traceback (most recent call last): 
    13152 File
    13153 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13154 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    13155 self.session.ui.mouse_modes.mouse_pause_tracking() 
    13156 File
    13157 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13158 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    13159 mouse_pause_tracking 
    13160 self._mouse_pause() 
    13161 File
    13162 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13163 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    13164 m.pause(self._mouse_pause_position) 
    13165 File
    13166 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13167 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    13168 p = self.view.picked_object(x, y) 
    13169 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13170 File
    13171 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13172 packages/chimerax/graphics/view.py", line 838, in picked_object 
    13173 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    13174 beyond, 
    13175 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13176 File
    13177 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13178 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    13179 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    13180 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13181 File
    13182 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13183 packages/chimerax/core/models.py", line 143, in first_intercept 
    13184 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    13185 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13186 File
    13187 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13188 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    13189 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    13190 exclude=exclude) 
    13191 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13192 File
    13193 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13194 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    13195 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    13196 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13197 File
    13198 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13199 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    13200 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    13201 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13202 File
    13203 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13204 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    13205 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    13206 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13207 File
    13208 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13209 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    13210 p = super().first_intercept(mxyz1, mxyz2) 
    13211 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13212 File
    13213 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13214 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    13215 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    13216 exclude=exclude) 
    13217 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13218 File
    13219 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13220 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    13221 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    13222 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13223 File
    13224 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13225 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    13226 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    13227 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13228 File
    13229 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13230 packages/chimerax/graphics/drawing.py", line 1108, in
    13231 _first_intercept_excluding_children 
    13232 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    13233 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13234 File
    13235 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13236 packages/chimerax/geometry/place.py", line 201, in inverse 
    13237 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    13238 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13239 File
    13240 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13241 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    13242 rinv[:, :] = matrix_inverse(r) 
    13243 ^^^^^^^^^^^^^^^^^ 
    13244 File
    13245 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13246 packages/numpy/linalg/linalg.py", line 561, in inv 
    13247 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    13248 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13249 File
    13250 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13251 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    13252 raise LinAlgError("Singular matrix") 
    13253 numpy.linalg.LinAlgError: Singular matrix 
    13254  
    13255 numpy.linalg.LinAlgError: Singular matrix 
    13256  
    13257 File
    13258 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13259 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    13260 raise LinAlgError("Singular matrix") 
    13261  
    13262 See log for complete Python traceback. 
    13263  
    13264 Traceback (most recent call last): 
    13265 File
    13266 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13267 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    13268 self.session.ui.mouse_modes.mouse_pause_tracking() 
    13269 File
    13270 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13271 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    13272 mouse_pause_tracking 
    13273 self._mouse_pause() 
    13274 File
    13275 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13276 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    13277 m.pause(self._mouse_pause_position) 
    13278 File
    13279 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13280 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    13281 p = self.view.picked_object(x, y) 
    13282 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13283 File
    13284 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13285 packages/chimerax/graphics/view.py", line 838, in picked_object 
    13286 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    13287 beyond, 
    13288 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13289 File
    13290 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13291 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    13292 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    13293 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13294 File
    13295 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13296 packages/chimerax/core/models.py", line 143, in first_intercept 
    13297 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    13298 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13299 File
    13300 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13301 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    13302 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    13303 exclude=exclude) 
    13304 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13305 File
    13306 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13307 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    13308 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    13309 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13310 File
    13311 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13312 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    13313 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    13314 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13315 File
    13316 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13317 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    13318 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    13319 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13320 File
    13321 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13322 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    13323 p = super().first_intercept(mxyz1, mxyz2) 
    13324 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13325 File
    13326 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13327 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    13328 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    13329 exclude=exclude) 
    13330 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13331 File
    13332 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13333 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    13334 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    13335 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13336 File
    13337 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13338 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    13339 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    13340 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13341 File
    13342 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13343 packages/chimerax/graphics/drawing.py", line 1108, in
    13344 _first_intercept_excluding_children 
    13345 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    13346 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13347 File
    13348 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13349 packages/chimerax/geometry/place.py", line 201, in inverse 
    13350 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    13351 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13352 File
    13353 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13354 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    13355 rinv[:, :] = matrix_inverse(r) 
    13356 ^^^^^^^^^^^^^^^^^ 
    13357 File
    13358 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13359 packages/numpy/linalg/linalg.py", line 561, in inv 
    13360 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    13361 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13362 File
    13363 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13364 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    13365 raise LinAlgError("Singular matrix") 
    13366 numpy.linalg.LinAlgError: Singular matrix 
    13367  
    13368 numpy.linalg.LinAlgError: Singular matrix 
    13369  
    13370 File
    13371 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13372 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    13373 raise LinAlgError("Singular matrix") 
    13374  
    13375 See log for complete Python traceback. 
    13376  
    13377 Traceback (most recent call last): 
    13378 File
    13379 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13380 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    13381 self.session.ui.mouse_modes.mouse_pause_tracking() 
    13382 File
    13383 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13384 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    13385 mouse_pause_tracking 
    13386 self._mouse_pause() 
    13387 File
    13388 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13389 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    13390 m.pause(self._mouse_pause_position) 
    13391 File
    13392 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13393 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    13394 p = self.view.picked_object(x, y) 
    13395 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13396 File
    13397 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13398 packages/chimerax/graphics/view.py", line 838, in picked_object 
    13399 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    13400 beyond, 
    13401 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13402 File
    13403 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13404 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    13405 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    13406 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13407 File
    13408 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13409 packages/chimerax/core/models.py", line 143, in first_intercept 
    13410 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    13411 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13412 File
    13413 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13414 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    13415 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    13416 exclude=exclude) 
    13417 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13418 File
    13419 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13420 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    13421 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    13422 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13423 File
    13424 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13425 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    13426 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    13427 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13428 File
    13429 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13430 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    13431 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    13432 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13433 File
    13434 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13435 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    13436 p = super().first_intercept(mxyz1, mxyz2) 
    13437 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13438 File
    13439 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13440 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    13441 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    13442 exclude=exclude) 
    13443 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13444 File
    13445 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13446 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    13447 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    13448 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13449 File
    13450 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13451 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    13452 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    13453 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13454 File
    13455 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13456 packages/chimerax/graphics/drawing.py", line 1108, in
    13457 _first_intercept_excluding_children 
    13458 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    13459 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13460 File
    13461 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13462 packages/chimerax/geometry/place.py", line 201, in inverse 
    13463 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    13464 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13465 File
    13466 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13467 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    13468 rinv[:, :] = matrix_inverse(r) 
    13469 ^^^^^^^^^^^^^^^^^ 
    13470 File
    13471 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13472 packages/numpy/linalg/linalg.py", line 561, in inv 
    13473 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    13474 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13475 File
    13476 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13477 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    13478 raise LinAlgError("Singular matrix") 
    13479 numpy.linalg.LinAlgError: Singular matrix 
    13480  
    13481 numpy.linalg.LinAlgError: Singular matrix 
    13482  
    13483 File
    13484 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13485 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    13486 raise LinAlgError("Singular matrix") 
    13487  
    13488 See log for complete Python traceback. 
    13489  
    13490 Traceback (most recent call last): 
    13491 File
    13492 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13493 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    13494 self.session.ui.mouse_modes.mouse_pause_tracking() 
    13495 File
    13496 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13497 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    13498 mouse_pause_tracking 
    13499 self._mouse_pause() 
    13500 File
    13501 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13502 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    13503 m.pause(self._mouse_pause_position) 
    13504 File
    13505 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13506 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    13507 p = self.view.picked_object(x, y) 
    13508 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13509 File
    13510 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13511 packages/chimerax/graphics/view.py", line 838, in picked_object 
    13512 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    13513 beyond, 
    13514 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13515 File
    13516 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13517 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    13518 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    13519 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13520 File
    13521 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13522 packages/chimerax/core/models.py", line 143, in first_intercept 
    13523 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    13524 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13525 File
    13526 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13527 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    13528 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    13529 exclude=exclude) 
    13530 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13531 File
    13532 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13533 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    13534 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    13535 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13536 File
    13537 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13538 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    13539 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    13540 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13541 File
    13542 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13543 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    13544 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    13545 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13546 File
    13547 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13548 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    13549 p = super().first_intercept(mxyz1, mxyz2) 
    13550 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13551 File
    13552 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13553 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    13554 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    13555 exclude=exclude) 
    13556 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13557 File
    13558 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13559 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    13560 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    13561 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13562 File
    13563 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13564 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    13565 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    13566 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13567 File
    13568 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13569 packages/chimerax/graphics/drawing.py", line 1108, in
    13570 _first_intercept_excluding_children 
    13571 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    13572 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13573 File
    13574 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13575 packages/chimerax/geometry/place.py", line 201, in inverse 
    13576 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    13577 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13578 File
    13579 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13580 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    13581 rinv[:, :] = matrix_inverse(r) 
    13582 ^^^^^^^^^^^^^^^^^ 
    13583 File
    13584 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13585 packages/numpy/linalg/linalg.py", line 561, in inv 
    13586 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    13587 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13588 File
    13589 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13590 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    13591 raise LinAlgError("Singular matrix") 
    13592 numpy.linalg.LinAlgError: Singular matrix 
    13593  
    13594 numpy.linalg.LinAlgError: Singular matrix 
    13595  
    13596 File
    13597 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13598 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    13599 raise LinAlgError("Singular matrix") 
    13600  
    13601 See log for complete Python traceback. 
    13602  
    13603 Traceback (most recent call last): 
    13604 File
    13605 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13606 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    13607 self.session.ui.mouse_modes.mouse_pause_tracking() 
    13608 File
    13609 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13610 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    13611 mouse_pause_tracking 
    13612 self._mouse_pause() 
    13613 File
    13614 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13615 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    13616 m.pause(self._mouse_pause_position) 
    13617 File
    13618 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13619 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    13620 p = self.view.picked_object(x, y) 
    13621 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13622 File
    13623 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13624 packages/chimerax/graphics/view.py", line 838, in picked_object 
    13625 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    13626 beyond, 
    13627 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13628 File
    13629 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13630 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    13631 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    13632 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13633 File
    13634 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13635 packages/chimerax/core/models.py", line 143, in first_intercept 
    13636 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    13637 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13638 File
    13639 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13640 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    13641 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    13642 exclude=exclude) 
    13643 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13644 File
    13645 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13646 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    13647 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    13648 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13649 File
    13650 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13651 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    13652 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    13653 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13654 File
    13655 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13656 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    13657 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    13658 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13659 File
    13660 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13661 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    13662 p = super().first_intercept(mxyz1, mxyz2) 
    13663 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13664 File
    13665 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13666 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    13667 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    13668 exclude=exclude) 
    13669 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13670 File
    13671 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13672 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    13673 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    13674 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13675 File
    13676 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13677 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    13678 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    13679 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13680 File
    13681 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13682 packages/chimerax/graphics/drawing.py", line 1108, in
    13683 _first_intercept_excluding_children 
    13684 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    13685 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13686 File
    13687 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13688 packages/chimerax/geometry/place.py", line 201, in inverse 
    13689 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    13690 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13691 File
    13692 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13693 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    13694 rinv[:, :] = matrix_inverse(r) 
    13695 ^^^^^^^^^^^^^^^^^ 
    13696 File
    13697 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13698 packages/numpy/linalg/linalg.py", line 561, in inv 
    13699 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    13700 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13701 File
    13702 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13703 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    13704 raise LinAlgError("Singular matrix") 
    13705 numpy.linalg.LinAlgError: Singular matrix 
    13706  
    13707 numpy.linalg.LinAlgError: Singular matrix 
    13708  
    13709 File
    13710 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13711 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    13712 raise LinAlgError("Singular matrix") 
    13713  
    13714 See log for complete Python traceback. 
    13715  
    13716 Traceback (most recent call last): 
    13717 File
    13718 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13719 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    13720 self.session.ui.mouse_modes.mouse_pause_tracking() 
    13721 File
    13722 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13723 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    13724 mouse_pause_tracking 
    13725 self._mouse_pause() 
    13726 File
    13727 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13728 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    13729 m.pause(self._mouse_pause_position) 
    13730 File
    13731 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13732 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    13733 p = self.view.picked_object(x, y) 
    13734 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13735 File
    13736 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13737 packages/chimerax/graphics/view.py", line 838, in picked_object 
    13738 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    13739 beyond, 
    13740 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13741 File
    13742 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13743 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    13744 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    13745 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13746 File
    13747 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13748 packages/chimerax/core/models.py", line 143, in first_intercept 
    13749 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    13750 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13751 File
    13752 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13753 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    13754 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    13755 exclude=exclude) 
    13756 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13757 File
    13758 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13759 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    13760 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    13761 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13762 File
    13763 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13764 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    13765 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    13766 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13767 File
    13768 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13769 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    13770 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    13771 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13772 File
    13773 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13774 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    13775 p = super().first_intercept(mxyz1, mxyz2) 
    13776 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13777 File
    13778 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13779 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    13780 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    13781 exclude=exclude) 
    13782 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13783 File
    13784 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13785 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    13786 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    13787 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13788 File
    13789 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13790 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    13791 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    13792 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13793 File
    13794 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13795 packages/chimerax/graphics/drawing.py", line 1108, in
    13796 _first_intercept_excluding_children 
    13797 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    13798 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13799 File
    13800 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13801 packages/chimerax/geometry/place.py", line 201, in inverse 
    13802 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    13803 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13804 File
    13805 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13806 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    13807 rinv[:, :] = matrix_inverse(r) 
    13808 ^^^^^^^^^^^^^^^^^ 
    13809 File
    13810 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13811 packages/numpy/linalg/linalg.py", line 561, in inv 
    13812 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    13813 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13814 File
    13815 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13816 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    13817 raise LinAlgError("Singular matrix") 
    13818 numpy.linalg.LinAlgError: Singular matrix 
    13819  
    13820 numpy.linalg.LinAlgError: Singular matrix 
    13821  
    13822 File
    13823 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13824 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    13825 raise LinAlgError("Singular matrix") 
    13826  
    13827 See log for complete Python traceback. 
    13828  
    13829 Traceback (most recent call last): 
    13830 File
    13831 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13832 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    13833 self.session.ui.mouse_modes.mouse_pause_tracking() 
    13834 File
    13835 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13836 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    13837 mouse_pause_tracking 
    13838 self._mouse_pause() 
    13839 File
    13840 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13841 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    13842 m.pause(self._mouse_pause_position) 
    13843 File
    13844 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13845 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    13846 p = self.view.picked_object(x, y) 
    13847 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13848 File
    13849 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13850 packages/chimerax/graphics/view.py", line 838, in picked_object 
    13851 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    13852 beyond, 
    13853 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13854 File
    13855 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13856 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    13857 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    13858 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13859 File
    13860 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13861 packages/chimerax/core/models.py", line 143, in first_intercept 
    13862 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    13863 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13864 File
    13865 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13866 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    13867 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    13868 exclude=exclude) 
    13869 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13870 File
    13871 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13872 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    13873 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    13874 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13875 File
    13876 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13877 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    13878 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    13879 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13880 File
    13881 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13882 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    13883 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    13884 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13885 File
    13886 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13887 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    13888 p = super().first_intercept(mxyz1, mxyz2) 
    13889 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13890 File
    13891 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13892 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    13893 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    13894 exclude=exclude) 
    13895 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13896 File
    13897 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13898 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    13899 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    13900 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13901 File
    13902 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13903 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    13904 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    13905 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13906 File
    13907 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13908 packages/chimerax/graphics/drawing.py", line 1108, in
    13909 _first_intercept_excluding_children 
    13910 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    13911 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13912 File
    13913 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13914 packages/chimerax/geometry/place.py", line 201, in inverse 
    13915 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    13916 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13917 File
    13918 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13919 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    13920 rinv[:, :] = matrix_inverse(r) 
    13921 ^^^^^^^^^^^^^^^^^ 
    13922 File
    13923 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13924 packages/numpy/linalg/linalg.py", line 561, in inv 
    13925 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    13926 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13927 File
    13928 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13929 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    13930 raise LinAlgError("Singular matrix") 
    13931 numpy.linalg.LinAlgError: Singular matrix 
    13932  
    13933 numpy.linalg.LinAlgError: Singular matrix 
    13934  
    13935 File
    13936 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13937 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    13938 raise LinAlgError("Singular matrix") 
    13939  
    13940 See log for complete Python traceback. 
    13941  
    13942 Traceback (most recent call last): 
    13943 File
    13944 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13945 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    13946 self.session.ui.mouse_modes.mouse_pause_tracking() 
    13947 File
    13948 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13949 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    13950 mouse_pause_tracking 
    13951 self._mouse_pause() 
    13952 File
    13953 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13954 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    13955 m.pause(self._mouse_pause_position) 
    13956 File
    13957 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13958 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    13959 p = self.view.picked_object(x, y) 
    13960 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13961 File
    13962 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13963 packages/chimerax/graphics/view.py", line 838, in picked_object 
    13964 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    13965 beyond, 
    13966 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13967 File
    13968 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13969 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    13970 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    13971 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13972 File
    13973 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13974 packages/chimerax/core/models.py", line 143, in first_intercept 
    13975 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    13976 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13977 File
    13978 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13979 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    13980 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    13981 exclude=exclude) 
    13982 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13983 File
    13984 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13985 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    13986 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    13987 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13988 File
    13989 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13990 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    13991 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    13992 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13993 File
    13994 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    13995 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    13996 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    13997 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    13998 File
    13999 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14000 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    14001 p = super().first_intercept(mxyz1, mxyz2) 
    14002 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14003 File
    14004 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14005 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    14006 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    14007 exclude=exclude) 
    14008 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14009 File
    14010 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14011 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    14012 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    14013 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14014 File
    14015 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14016 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    14017 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    14018 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14019 File
    14020 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14021 packages/chimerax/graphics/drawing.py", line 1108, in
    14022 _first_intercept_excluding_children 
    14023 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    14024 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14025 File
    14026 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14027 packages/chimerax/geometry/place.py", line 201, in inverse 
    14028 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    14029 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14030 File
    14031 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14032 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    14033 rinv[:, :] = matrix_inverse(r) 
    14034 ^^^^^^^^^^^^^^^^^ 
    14035 File
    14036 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14037 packages/numpy/linalg/linalg.py", line 561, in inv 
    14038 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    14039 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14040 File
    14041 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14042 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    14043 raise LinAlgError("Singular matrix") 
    14044 numpy.linalg.LinAlgError: Singular matrix 
    14045  
    14046 numpy.linalg.LinAlgError: Singular matrix 
    14047  
    14048 File
    14049 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14050 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    14051 raise LinAlgError("Singular matrix") 
    14052  
    14053 See log for complete Python traceback. 
    14054  
    14055 Traceback (most recent call last): 
    14056 File
    14057 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14058 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    14059 self.session.ui.mouse_modes.mouse_pause_tracking() 
    14060 File
    14061 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14062 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    14063 mouse_pause_tracking 
    14064 self._mouse_pause() 
    14065 File
    14066 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14067 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    14068 m.pause(self._mouse_pause_position) 
    14069 File
    14070 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14071 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    14072 p = self.view.picked_object(x, y) 
    14073 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14074 File
    14075 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14076 packages/chimerax/graphics/view.py", line 838, in picked_object 
    14077 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    14078 beyond, 
    14079 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14080 File
    14081 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14082 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    14083 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    14084 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14085 File
    14086 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14087 packages/chimerax/core/models.py", line 143, in first_intercept 
    14088 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    14089 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14090 File
    14091 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14092 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    14093 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    14094 exclude=exclude) 
    14095 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14096 File
    14097 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14098 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    14099 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    14100 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14101 File
    14102 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14103 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    14104 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    14105 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14106 File
    14107 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14108 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    14109 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    14110 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14111 File
    14112 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14113 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    14114 p = super().first_intercept(mxyz1, mxyz2) 
    14115 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14116 File
    14117 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14118 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    14119 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    14120 exclude=exclude) 
    14121 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14122 File
    14123 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14124 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    14125 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    14126 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14127 File
    14128 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14129 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    14130 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    14131 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14132 File
    14133 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14134 packages/chimerax/graphics/drawing.py", line 1108, in
    14135 _first_intercept_excluding_children 
    14136 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    14137 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14138 File
    14139 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14140 packages/chimerax/geometry/place.py", line 201, in inverse 
    14141 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    14142 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14143 File
    14144 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14145 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    14146 rinv[:, :] = matrix_inverse(r) 
    14147 ^^^^^^^^^^^^^^^^^ 
    14148 File
    14149 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14150 packages/numpy/linalg/linalg.py", line 561, in inv 
    14151 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    14152 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14153 File
    14154 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14155 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    14156 raise LinAlgError("Singular matrix") 
    14157 numpy.linalg.LinAlgError: Singular matrix 
    14158  
    14159 numpy.linalg.LinAlgError: Singular matrix 
    14160  
    14161 File
    14162 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14163 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    14164 raise LinAlgError("Singular matrix") 
    14165  
    14166 See log for complete Python traceback. 
    14167  
    14168 Traceback (most recent call last): 
    14169 File
    14170 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14171 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    14172 self.session.ui.mouse_modes.mouse_pause_tracking() 
    14173 File
    14174 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14175 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    14176 mouse_pause_tracking 
    14177 self._mouse_pause() 
    14178 File
    14179 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14180 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    14181 m.pause(self._mouse_pause_position) 
    14182 File
    14183 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14184 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    14185 p = self.view.picked_object(x, y) 
    14186 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14187 File
    14188 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14189 packages/chimerax/graphics/view.py", line 838, in picked_object 
    14190 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    14191 beyond, 
    14192 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14193 File
    14194 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14195 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    14196 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    14197 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14198 File
    14199 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14200 packages/chimerax/core/models.py", line 143, in first_intercept 
    14201 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    14202 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14203 File
    14204 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14205 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    14206 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    14207 exclude=exclude) 
    14208 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14209 File
    14210 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14211 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    14212 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    14213 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14214 File
    14215 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14216 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    14217 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    14218 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14219 File
    14220 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14221 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    14222 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    14223 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14224 File
    14225 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14226 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    14227 p = super().first_intercept(mxyz1, mxyz2) 
    14228 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14229 File
    14230 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14231 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    14232 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    14233 exclude=exclude) 
    14234 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14235 File
    14236 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14237 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    14238 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    14239 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14240 File
    14241 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14242 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    14243 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    14244 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14245 File
    14246 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14247 packages/chimerax/graphics/drawing.py", line 1108, in
    14248 _first_intercept_excluding_children 
    14249 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    14250 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14251 File
    14252 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14253 packages/chimerax/geometry/place.py", line 201, in inverse 
    14254 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    14255 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14256 File
    14257 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14258 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    14259 rinv[:, :] = matrix_inverse(r) 
    14260 ^^^^^^^^^^^^^^^^^ 
    14261 File
    14262 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14263 packages/numpy/linalg/linalg.py", line 561, in inv 
    14264 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    14265 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14266 File
    14267 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14268 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    14269 raise LinAlgError("Singular matrix") 
    14270 numpy.linalg.LinAlgError: Singular matrix 
    14271  
    14272 numpy.linalg.LinAlgError: Singular matrix 
    14273  
    14274 File
    14275 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14276 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    14277 raise LinAlgError("Singular matrix") 
    14278  
    14279 See log for complete Python traceback. 
    14280  
    14281 Traceback (most recent call last): 
    14282 File
    14283 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14284 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    14285 self.session.ui.mouse_modes.mouse_pause_tracking() 
    14286 File
    14287 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14288 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    14289 mouse_pause_tracking 
    14290 self._mouse_pause() 
    14291 File
    14292 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14293 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    14294 m.pause(self._mouse_pause_position) 
    14295 File
    14296 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14297 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    14298 p = self.view.picked_object(x, y) 
    14299 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14300 File
    14301 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14302 packages/chimerax/graphics/view.py", line 838, in picked_object 
    14303 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    14304 beyond, 
    14305 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14306 File
    14307 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14308 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    14309 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    14310 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14311 File
    14312 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14313 packages/chimerax/core/models.py", line 143, in first_intercept 
    14314 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    14315 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14316 File
    14317 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14318 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    14319 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    14320 exclude=exclude) 
    14321 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14322 File
    14323 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14324 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    14325 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    14326 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14327 File
    14328 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14329 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    14330 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    14331 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14332 File
    14333 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14334 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    14335 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    14336 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14337 File
    14338 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14339 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    14340 p = super().first_intercept(mxyz1, mxyz2) 
    14341 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14342 File
    14343 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14344 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    14345 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    14346 exclude=exclude) 
    14347 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14348 File
    14349 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14350 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    14351 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    14352 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14353 File
    14354 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14355 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    14356 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    14357 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14358 File
    14359 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14360 packages/chimerax/graphics/drawing.py", line 1108, in
    14361 _first_intercept_excluding_children 
    14362 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    14363 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14364 File
    14365 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14366 packages/chimerax/geometry/place.py", line 201, in inverse 
    14367 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    14368 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14369 File
    14370 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14371 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    14372 rinv[:, :] = matrix_inverse(r) 
    14373 ^^^^^^^^^^^^^^^^^ 
    14374 File
    14375 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14376 packages/numpy/linalg/linalg.py", line 561, in inv 
    14377 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    14378 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14379 File
    14380 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14381 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    14382 raise LinAlgError("Singular matrix") 
    14383 numpy.linalg.LinAlgError: Singular matrix 
    14384  
    14385 numpy.linalg.LinAlgError: Singular matrix 
    14386  
    14387 File
    14388 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14389 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    14390 raise LinAlgError("Singular matrix") 
    14391  
    14392 See log for complete Python traceback. 
    14393  
    14394 Traceback (most recent call last): 
    14395 File
    14396 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14397 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    14398 self.session.ui.mouse_modes.mouse_pause_tracking() 
    14399 File
    14400 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14401 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    14402 mouse_pause_tracking 
    14403 self._mouse_pause() 
    14404 File
    14405 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14406 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    14407 m.pause(self._mouse_pause_position) 
    14408 File
    14409 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14410 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    14411 p = self.view.picked_object(x, y) 
    14412 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14413 File
    14414 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14415 packages/chimerax/graphics/view.py", line 838, in picked_object 
    14416 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    14417 beyond, 
    14418 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14419 File
    14420 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14421 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    14422 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    14423 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14424 File
    14425 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14426 packages/chimerax/core/models.py", line 143, in first_intercept 
    14427 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    14428 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14429 File
    14430 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14431 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    14432 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    14433 exclude=exclude) 
    14434 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14435 File
    14436 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14437 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    14438 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    14439 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14440 File
    14441 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14442 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    14443 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    14444 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14445 File
    14446 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14447 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    14448 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    14449 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14450 File
    14451 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14452 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    14453 p = super().first_intercept(mxyz1, mxyz2) 
    14454 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14455 File
    14456 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14457 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    14458 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    14459 exclude=exclude) 
    14460 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14461 File
    14462 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14463 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    14464 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    14465 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14466 File
    14467 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14468 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    14469 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    14470 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14471 File
    14472 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14473 packages/chimerax/graphics/drawing.py", line 1108, in
    14474 _first_intercept_excluding_children 
    14475 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    14476 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14477 File
    14478 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14479 packages/chimerax/geometry/place.py", line 201, in inverse 
    14480 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    14481 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14482 File
    14483 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14484 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    14485 rinv[:, :] = matrix_inverse(r) 
    14486 ^^^^^^^^^^^^^^^^^ 
    14487 File
    14488 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14489 packages/numpy/linalg/linalg.py", line 561, in inv 
    14490 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    14491 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14492 File
    14493 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14494 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    14495 raise LinAlgError("Singular matrix") 
    14496 numpy.linalg.LinAlgError: Singular matrix 
    14497  
    14498 numpy.linalg.LinAlgError: Singular matrix 
    14499  
    14500 File
    14501 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14502 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    14503 raise LinAlgError("Singular matrix") 
    14504  
    14505 See log for complete Python traceback. 
    14506  
    14507 Traceback (most recent call last): 
    14508 File
    14509 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14510 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    14511 self.session.ui.mouse_modes.mouse_pause_tracking() 
    14512 File
    14513 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14514 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    14515 mouse_pause_tracking 
    14516 self._mouse_pause() 
    14517 File
    14518 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14519 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    14520 m.pause(self._mouse_pause_position) 
    14521 File
    14522 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14523 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    14524 p = self.view.picked_object(x, y) 
    14525 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14526 File
    14527 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14528 packages/chimerax/graphics/view.py", line 838, in picked_object 
    14529 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    14530 beyond, 
    14531 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14532 File
    14533 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14534 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    14535 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    14536 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14537 File
    14538 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14539 packages/chimerax/core/models.py", line 143, in first_intercept 
    14540 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    14541 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14542 File
    14543 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14544 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    14545 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    14546 exclude=exclude) 
    14547 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14548 File
    14549 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14550 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    14551 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    14552 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14553 File
    14554 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14555 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    14556 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    14557 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14558 File
    14559 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14560 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    14561 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    14562 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14563 File
    14564 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14565 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    14566 p = super().first_intercept(mxyz1, mxyz2) 
    14567 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14568 File
    14569 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14570 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    14571 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    14572 exclude=exclude) 
    14573 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14574 File
    14575 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14576 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    14577 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    14578 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14579 File
    14580 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14581 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    14582 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    14583 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14584 File
    14585 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14586 packages/chimerax/graphics/drawing.py", line 1108, in
    14587 _first_intercept_excluding_children 
    14588 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    14589 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14590 File
    14591 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14592 packages/chimerax/geometry/place.py", line 201, in inverse 
    14593 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    14594 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14595 File
    14596 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14597 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    14598 rinv[:, :] = matrix_inverse(r) 
    14599 ^^^^^^^^^^^^^^^^^ 
    14600 File
    14601 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14602 packages/numpy/linalg/linalg.py", line 561, in inv 
    14603 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    14604 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14605 File
    14606 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14607 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    14608 raise LinAlgError("Singular matrix") 
    14609 numpy.linalg.LinAlgError: Singular matrix 
    14610  
    14611 numpy.linalg.LinAlgError: Singular matrix 
    14612  
    14613 File
    14614 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14615 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    14616 raise LinAlgError("Singular matrix") 
    14617  
    14618 See log for complete Python traceback. 
    14619  
    14620 Traceback (most recent call last): 
    14621 File
    14622 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14623 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    14624 self.session.ui.mouse_modes.mouse_pause_tracking() 
    14625 File
    14626 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14627 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    14628 mouse_pause_tracking 
    14629 self._mouse_pause() 
    14630 File
    14631 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14632 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    14633 m.pause(self._mouse_pause_position) 
    14634 File
    14635 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14636 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    14637 p = self.view.picked_object(x, y) 
    14638 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14639 File
    14640 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14641 packages/chimerax/graphics/view.py", line 838, in picked_object 
    14642 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    14643 beyond, 
    14644 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14645 File
    14646 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14647 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    14648 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    14649 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14650 File
    14651 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14652 packages/chimerax/core/models.py", line 143, in first_intercept 
    14653 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    14654 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14655 File
    14656 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14657 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    14658 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    14659 exclude=exclude) 
    14660 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14661 File
    14662 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14663 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    14664 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    14665 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14666 File
    14667 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14668 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    14669 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    14670 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14671 File
    14672 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14673 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    14674 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    14675 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14676 File
    14677 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14678 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    14679 p = super().first_intercept(mxyz1, mxyz2) 
    14680 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14681 File
    14682 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14683 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    14684 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    14685 exclude=exclude) 
    14686 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14687 File
    14688 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14689 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    14690 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    14691 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14692 File
    14693 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14694 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    14695 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    14696 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14697 File
    14698 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14699 packages/chimerax/graphics/drawing.py", line 1108, in
    14700 _first_intercept_excluding_children 
    14701 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    14702 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14703 File
    14704 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14705 packages/chimerax/geometry/place.py", line 201, in inverse 
    14706 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    14707 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14708 File
    14709 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14710 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    14711 rinv[:, :] = matrix_inverse(r) 
    14712 ^^^^^^^^^^^^^^^^^ 
    14713 File
    14714 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14715 packages/numpy/linalg/linalg.py", line 561, in inv 
    14716 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    14717 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14718 File
    14719 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14720 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    14721 raise LinAlgError("Singular matrix") 
    14722 numpy.linalg.LinAlgError: Singular matrix 
    14723  
    14724 numpy.linalg.LinAlgError: Singular matrix 
    14725  
    14726 File
    14727 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14728 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    14729 raise LinAlgError("Singular matrix") 
    14730  
    14731 See log for complete Python traceback. 
    14732  
    14733 Traceback (most recent call last): 
    14734 File
    14735 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14736 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    14737 self.session.ui.mouse_modes.mouse_pause_tracking() 
    14738 File
    14739 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14740 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    14741 mouse_pause_tracking 
    14742 self._mouse_pause() 
    14743 File
    14744 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14745 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    14746 m.pause(self._mouse_pause_position) 
    14747 File
    14748 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14749 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    14750 p = self.view.picked_object(x, y) 
    14751 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14752 File
    14753 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14754 packages/chimerax/graphics/view.py", line 838, in picked_object 
    14755 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    14756 beyond, 
    14757 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14758 File
    14759 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14760 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    14761 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    14762 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14763 File
    14764 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14765 packages/chimerax/core/models.py", line 143, in first_intercept 
    14766 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    14767 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14768 File
    14769 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14770 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    14771 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    14772 exclude=exclude) 
    14773 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14774 File
    14775 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14776 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    14777 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    14778 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14779 File
    14780 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14781 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    14782 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    14783 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14784 File
    14785 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14786 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    14787 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    14788 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14789 File
    14790 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14791 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    14792 p = super().first_intercept(mxyz1, mxyz2) 
    14793 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14794 File
    14795 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14796 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    14797 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    14798 exclude=exclude) 
    14799 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14800 File
    14801 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14802 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    14803 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    14804 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14805 File
    14806 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14807 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    14808 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    14809 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14810 File
    14811 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14812 packages/chimerax/graphics/drawing.py", line 1108, in
    14813 _first_intercept_excluding_children 
    14814 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    14815 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14816 File
    14817 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14818 packages/chimerax/geometry/place.py", line 201, in inverse 
    14819 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    14820 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14821 File
    14822 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14823 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    14824 rinv[:, :] = matrix_inverse(r) 
    14825 ^^^^^^^^^^^^^^^^^ 
    14826 File
    14827 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14828 packages/numpy/linalg/linalg.py", line 561, in inv 
    14829 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    14830 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14831 File
    14832 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14833 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    14834 raise LinAlgError("Singular matrix") 
    14835 numpy.linalg.LinAlgError: Singular matrix 
    14836  
    14837 numpy.linalg.LinAlgError: Singular matrix 
    14838  
    14839 File
    14840 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14841 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    14842 raise LinAlgError("Singular matrix") 
    14843  
    14844 See log for complete Python traceback. 
    14845  
    14846 Traceback (most recent call last): 
    14847 File
    14848 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14849 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    14850 self.session.ui.mouse_modes.mouse_pause_tracking() 
    14851 File
    14852 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14853 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    14854 mouse_pause_tracking 
    14855 self._mouse_pause() 
    14856 File
    14857 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14858 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    14859 m.pause(self._mouse_pause_position) 
    14860 File
    14861 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14862 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    14863 p = self.view.picked_object(x, y) 
    14864 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14865 File
    14866 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14867 packages/chimerax/graphics/view.py", line 838, in picked_object 
    14868 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    14869 beyond, 
    14870 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14871 File
    14872 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14873 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    14874 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    14875 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14876 File
    14877 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14878 packages/chimerax/core/models.py", line 143, in first_intercept 
    14879 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    14880 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14881 File
    14882 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14883 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    14884 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    14885 exclude=exclude) 
    14886 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14887 File
    14888 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14889 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    14890 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    14891 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14892 File
    14893 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14894 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    14895 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    14896 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14897 File
    14898 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14899 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    14900 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    14901 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14902 File
    14903 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14904 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    14905 p = super().first_intercept(mxyz1, mxyz2) 
    14906 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14907 File
    14908 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14909 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    14910 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    14911 exclude=exclude) 
    14912 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14913 File
    14914 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14915 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    14916 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    14917 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14918 File
    14919 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14920 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    14921 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    14922 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14923 File
    14924 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14925 packages/chimerax/graphics/drawing.py", line 1108, in
    14926 _first_intercept_excluding_children 
    14927 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    14928 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14929 File
    14930 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14931 packages/chimerax/geometry/place.py", line 201, in inverse 
    14932 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    14933 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14934 File
    14935 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14936 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    14937 rinv[:, :] = matrix_inverse(r) 
    14938 ^^^^^^^^^^^^^^^^^ 
    14939 File
    14940 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14941 packages/numpy/linalg/linalg.py", line 561, in inv 
    14942 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    14943 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14944 File
    14945 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14946 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    14947 raise LinAlgError("Singular matrix") 
    14948 numpy.linalg.LinAlgError: Singular matrix 
    14949  
    14950 numpy.linalg.LinAlgError: Singular matrix 
    14951  
    14952 File
    14953 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14954 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    14955 raise LinAlgError("Singular matrix") 
    14956  
    14957 See log for complete Python traceback. 
    14958  
    14959 Traceback (most recent call last): 
    14960 File
    14961 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14962 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    14963 self.session.ui.mouse_modes.mouse_pause_tracking() 
    14964 File
    14965 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14966 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    14967 mouse_pause_tracking 
    14968 self._mouse_pause() 
    14969 File
    14970 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14971 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    14972 m.pause(self._mouse_pause_position) 
    14973 File
    14974 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14975 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    14976 p = self.view.picked_object(x, y) 
    14977 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14978 File
    14979 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14980 packages/chimerax/graphics/view.py", line 838, in picked_object 
    14981 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    14982 beyond, 
    14983 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14984 File
    14985 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14986 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    14987 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    14988 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14989 File
    14990 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14991 packages/chimerax/core/models.py", line 143, in first_intercept 
    14992 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    14993 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    14994 File
    14995 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    14996 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    14997 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    14998 exclude=exclude) 
    14999 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15000 File
    15001 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15002 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    15003 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    15004 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15005 File
    15006 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15007 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    15008 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    15009 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15010 File
    15011 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15012 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    15013 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    15014 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15015 File
    15016 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15017 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    15018 p = super().first_intercept(mxyz1, mxyz2) 
    15019 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15020 File
    15021 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15022 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    15023 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    15024 exclude=exclude) 
    15025 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15026 File
    15027 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15028 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    15029 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    15030 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15031 File
    15032 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15033 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    15034 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    15035 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15036 File
    15037 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15038 packages/chimerax/graphics/drawing.py", line 1108, in
    15039 _first_intercept_excluding_children 
    15040 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    15041 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15042 File
    15043 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15044 packages/chimerax/geometry/place.py", line 201, in inverse 
    15045 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    15046 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15047 File
    15048 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15049 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    15050 rinv[:, :] = matrix_inverse(r) 
    15051 ^^^^^^^^^^^^^^^^^ 
    15052 File
    15053 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15054 packages/numpy/linalg/linalg.py", line 561, in inv 
    15055 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    15056 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15057 File
    15058 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15059 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    15060 raise LinAlgError("Singular matrix") 
    15061 numpy.linalg.LinAlgError: Singular matrix 
    15062  
    15063 numpy.linalg.LinAlgError: Singular matrix 
    15064  
    15065 File
    15066 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15067 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    15068 raise LinAlgError("Singular matrix") 
    15069  
    15070 See log for complete Python traceback. 
    15071  
    15072 Traceback (most recent call last): 
    15073 File
    15074 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15075 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    15076 self.session.ui.mouse_modes.mouse_pause_tracking() 
    15077 File
    15078 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15079 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    15080 mouse_pause_tracking 
    15081 self._mouse_pause() 
    15082 File
    15083 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15084 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    15085 m.pause(self._mouse_pause_position) 
    15086 File
    15087 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15088 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    15089 p = self.view.picked_object(x, y) 
    15090 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15091 File
    15092 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15093 packages/chimerax/graphics/view.py", line 838, in picked_object 
    15094 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    15095 beyond, 
    15096 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15097 File
    15098 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15099 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    15100 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    15101 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15102 File
    15103 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15104 packages/chimerax/core/models.py", line 143, in first_intercept 
    15105 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    15106 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15107 File
    15108 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15109 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    15110 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    15111 exclude=exclude) 
    15112 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15113 File
    15114 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15115 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    15116 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    15117 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15118 File
    15119 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15120 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    15121 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    15122 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15123 File
    15124 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15125 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    15126 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    15127 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15128 File
    15129 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15130 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    15131 p = super().first_intercept(mxyz1, mxyz2) 
    15132 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15133 File
    15134 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15135 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    15136 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    15137 exclude=exclude) 
    15138 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15139 File
    15140 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15141 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    15142 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    15143 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15144 File
    15145 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15146 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    15147 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    15148 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15149 File
    15150 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15151 packages/chimerax/graphics/drawing.py", line 1108, in
    15152 _first_intercept_excluding_children 
    15153 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    15154 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15155 File
    15156 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15157 packages/chimerax/geometry/place.py", line 201, in inverse 
    15158 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    15159 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15160 File
    15161 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15162 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    15163 rinv[:, :] = matrix_inverse(r) 
    15164 ^^^^^^^^^^^^^^^^^ 
    15165 File
    15166 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15167 packages/numpy/linalg/linalg.py", line 561, in inv 
    15168 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    15169 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15170 File
    15171 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15172 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    15173 raise LinAlgError("Singular matrix") 
    15174 numpy.linalg.LinAlgError: Singular matrix 
    15175  
    15176 numpy.linalg.LinAlgError: Singular matrix 
    15177  
    15178 File
    15179 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15180 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    15181 raise LinAlgError("Singular matrix") 
    15182  
    15183 See log for complete Python traceback. 
    15184  
    15185 Traceback (most recent call last): 
    15186 File
    15187 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15188 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    15189 self.session.ui.mouse_modes.mouse_pause_tracking() 
    15190 File
    15191 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15192 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    15193 mouse_pause_tracking 
    15194 self._mouse_pause() 
    15195 File
    15196 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15197 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    15198 m.pause(self._mouse_pause_position) 
    15199 File
    15200 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15201 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    15202 p = self.view.picked_object(x, y) 
    15203 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15204 File
    15205 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15206 packages/chimerax/graphics/view.py", line 838, in picked_object 
    15207 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    15208 beyond, 
    15209 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15210 File
    15211 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15212 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    15213 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    15214 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15215 File
    15216 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15217 packages/chimerax/core/models.py", line 143, in first_intercept 
    15218 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    15219 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15220 File
    15221 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15222 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    15223 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    15224 exclude=exclude) 
    15225 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15226 File
    15227 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15228 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    15229 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    15230 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15231 File
    15232 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15233 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    15234 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    15235 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15236 File
    15237 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15238 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    15239 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    15240 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15241 File
    15242 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15243 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    15244 p = super().first_intercept(mxyz1, mxyz2) 
    15245 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15246 File
    15247 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15248 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    15249 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    15250 exclude=exclude) 
    15251 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15252 File
    15253 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15254 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    15255 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    15256 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15257 File
    15258 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15259 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    15260 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    15261 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15262 File
    15263 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15264 packages/chimerax/graphics/drawing.py", line 1108, in
    15265 _first_intercept_excluding_children 
    15266 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    15267 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15268 File
    15269 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15270 packages/chimerax/geometry/place.py", line 201, in inverse 
    15271 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    15272 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15273 File
    15274 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15275 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    15276 rinv[:, :] = matrix_inverse(r) 
    15277 ^^^^^^^^^^^^^^^^^ 
    15278 File
    15279 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15280 packages/numpy/linalg/linalg.py", line 561, in inv 
    15281 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    15282 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15283 File
    15284 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15285 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    15286 raise LinAlgError("Singular matrix") 
    15287 numpy.linalg.LinAlgError: Singular matrix 
    15288  
    15289 numpy.linalg.LinAlgError: Singular matrix 
    15290  
    15291 File
    15292 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15293 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    15294 raise LinAlgError("Singular matrix") 
    15295  
    15296 See log for complete Python traceback. 
    15297  
    15298 Traceback (most recent call last): 
    15299 File
    15300 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15301 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    15302 self.session.ui.mouse_modes.mouse_pause_tracking() 
    15303 File
    15304 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15305 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    15306 mouse_pause_tracking 
    15307 self._mouse_pause() 
    15308 File
    15309 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15310 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    15311 m.pause(self._mouse_pause_position) 
    15312 File
    15313 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15314 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    15315 p = self.view.picked_object(x, y) 
    15316 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15317 File
    15318 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15319 packages/chimerax/graphics/view.py", line 838, in picked_object 
    15320 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    15321 beyond, 
    15322 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15323 File
    15324 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15325 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    15326 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    15327 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15328 File
    15329 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15330 packages/chimerax/core/models.py", line 143, in first_intercept 
    15331 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    15332 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15333 File
    15334 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15335 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    15336 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    15337 exclude=exclude) 
    15338 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15339 File
    15340 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15341 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    15342 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    15343 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15344 File
    15345 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15346 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    15347 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    15348 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15349 File
    15350 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15351 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    15352 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    15353 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15354 File
    15355 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15356 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    15357 p = super().first_intercept(mxyz1, mxyz2) 
    15358 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15359 File
    15360 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15361 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    15362 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    15363 exclude=exclude) 
    15364 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15365 File
    15366 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15367 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    15368 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    15369 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15370 File
    15371 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15372 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    15373 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    15374 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15375 File
    15376 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15377 packages/chimerax/graphics/drawing.py", line 1108, in
    15378 _first_intercept_excluding_children 
    15379 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    15380 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15381 File
    15382 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15383 packages/chimerax/geometry/place.py", line 201, in inverse 
    15384 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    15385 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15386 File
    15387 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15388 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    15389 rinv[:, :] = matrix_inverse(r) 
    15390 ^^^^^^^^^^^^^^^^^ 
    15391 File
    15392 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15393 packages/numpy/linalg/linalg.py", line 561, in inv 
    15394 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    15395 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15396 File
    15397 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15398 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    15399 raise LinAlgError("Singular matrix") 
    15400 numpy.linalg.LinAlgError: Singular matrix 
    15401  
    15402 numpy.linalg.LinAlgError: Singular matrix 
    15403  
    15404 File
    15405 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15406 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    15407 raise LinAlgError("Singular matrix") 
    15408  
    15409 See log for complete Python traceback. 
    15410  
    15411 Traceback (most recent call last): 
    15412 File
    15413 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15414 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    15415 self.session.ui.mouse_modes.mouse_pause_tracking() 
    15416 File
    15417 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15418 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    15419 mouse_pause_tracking 
    15420 self._mouse_pause() 
    15421 File
    15422 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15423 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    15424 m.pause(self._mouse_pause_position) 
    15425 File
    15426 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15427 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    15428 p = self.view.picked_object(x, y) 
    15429 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15430 File
    15431 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15432 packages/chimerax/graphics/view.py", line 838, in picked_object 
    15433 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    15434 beyond, 
    15435 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15436 File
    15437 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15438 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    15439 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    15440 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15441 File
    15442 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15443 packages/chimerax/core/models.py", line 143, in first_intercept 
    15444 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    15445 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15446 File
    15447 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15448 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    15449 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    15450 exclude=exclude) 
    15451 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15452 File
    15453 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15454 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    15455 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    15456 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15457 File
    15458 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15459 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    15460 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    15461 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15462 File
    15463 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15464 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    15465 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    15466 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15467 File
    15468 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15469 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    15470 p = super().first_intercept(mxyz1, mxyz2) 
    15471 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15472 File
    15473 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15474 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    15475 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    15476 exclude=exclude) 
    15477 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15478 File
    15479 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15480 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    15481 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    15482 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15483 File
    15484 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15485 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    15486 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    15487 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15488 File
    15489 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15490 packages/chimerax/graphics/drawing.py", line 1108, in
    15491 _first_intercept_excluding_children 
    15492 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    15493 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15494 File
    15495 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15496 packages/chimerax/geometry/place.py", line 201, in inverse 
    15497 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    15498 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15499 File
    15500 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15501 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    15502 rinv[:, :] = matrix_inverse(r) 
    15503 ^^^^^^^^^^^^^^^^^ 
    15504 File
    15505 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15506 packages/numpy/linalg/linalg.py", line 561, in inv 
    15507 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    15508 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15509 File
    15510 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15511 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    15512 raise LinAlgError("Singular matrix") 
    15513 numpy.linalg.LinAlgError: Singular matrix 
    15514  
    15515 numpy.linalg.LinAlgError: Singular matrix 
    15516  
    15517 File
    15518 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15519 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    15520 raise LinAlgError("Singular matrix") 
    15521  
    15522 See log for complete Python traceback. 
    15523  
    15524 Traceback (most recent call last): 
    15525 File
    15526 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15527 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    15528 self.session.ui.mouse_modes.mouse_pause_tracking() 
    15529 File
    15530 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15531 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    15532 mouse_pause_tracking 
    15533 self._mouse_pause() 
    15534 File
    15535 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15536 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    15537 m.pause(self._mouse_pause_position) 
    15538 File
    15539 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15540 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    15541 p = self.view.picked_object(x, y) 
    15542 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15543 File
    15544 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15545 packages/chimerax/graphics/view.py", line 838, in picked_object 
    15546 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    15547 beyond, 
    15548 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15549 File
    15550 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15551 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    15552 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    15553 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15554 File
    15555 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15556 packages/chimerax/core/models.py", line 143, in first_intercept 
    15557 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    15558 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15559 File
    15560 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15561 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    15562 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    15563 exclude=exclude) 
    15564 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15565 File
    15566 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15567 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    15568 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    15569 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15570 File
    15571 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15572 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    15573 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    15574 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15575 File
    15576 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15577 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    15578 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    15579 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15580 File
    15581 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15582 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    15583 p = super().first_intercept(mxyz1, mxyz2) 
    15584 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15585 File
    15586 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15587 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    15588 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    15589 exclude=exclude) 
    15590 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15591 File
    15592 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15593 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    15594 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    15595 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15596 File
    15597 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15598 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    15599 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    15600 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15601 File
    15602 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15603 packages/chimerax/graphics/drawing.py", line 1108, in
    15604 _first_intercept_excluding_children 
    15605 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    15606 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15607 File
    15608 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15609 packages/chimerax/geometry/place.py", line 201, in inverse 
    15610 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    15611 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15612 File
    15613 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15614 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    15615 rinv[:, :] = matrix_inverse(r) 
    15616 ^^^^^^^^^^^^^^^^^ 
    15617 File
    15618 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15619 packages/numpy/linalg/linalg.py", line 561, in inv 
    15620 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    15621 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15622 File
    15623 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15624 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    15625 raise LinAlgError("Singular matrix") 
    15626 numpy.linalg.LinAlgError: Singular matrix 
    15627  
    15628 numpy.linalg.LinAlgError: Singular matrix 
    15629  
    15630 File
    15631 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15632 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    15633 raise LinAlgError("Singular matrix") 
    15634  
    15635 See log for complete Python traceback. 
    15636  
    15637 Traceback (most recent call last): 
    15638 File
    15639 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15640 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    15641 self.session.ui.mouse_modes.mouse_pause_tracking() 
    15642 File
    15643 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15644 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    15645 mouse_pause_tracking 
    15646 self._mouse_pause() 
    15647 File
    15648 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15649 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    15650 m.pause(self._mouse_pause_position) 
    15651 File
    15652 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15653 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    15654 p = self.view.picked_object(x, y) 
    15655 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15656 File
    15657 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15658 packages/chimerax/graphics/view.py", line 838, in picked_object 
    15659 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    15660 beyond, 
    15661 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15662 File
    15663 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15664 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    15665 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    15666 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15667 File
    15668 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15669 packages/chimerax/core/models.py", line 143, in first_intercept 
    15670 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    15671 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15672 File
    15673 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15674 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    15675 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    15676 exclude=exclude) 
    15677 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15678 File
    15679 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15680 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    15681 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    15682 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15683 File
    15684 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15685 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    15686 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    15687 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15688 File
    15689 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15690 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    15691 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    15692 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15693 File
    15694 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15695 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    15696 p = super().first_intercept(mxyz1, mxyz2) 
    15697 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15698 File
    15699 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15700 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    15701 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    15702 exclude=exclude) 
    15703 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15704 File
    15705 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15706 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    15707 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    15708 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15709 File
    15710 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15711 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    15712 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    15713 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15714 File
    15715 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15716 packages/chimerax/graphics/drawing.py", line 1108, in
    15717 _first_intercept_excluding_children 
    15718 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    15719 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15720 File
    15721 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15722 packages/chimerax/geometry/place.py", line 201, in inverse 
    15723 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    15724 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15725 File
    15726 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15727 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    15728 rinv[:, :] = matrix_inverse(r) 
    15729 ^^^^^^^^^^^^^^^^^ 
    15730 File
    15731 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15732 packages/numpy/linalg/linalg.py", line 561, in inv 
    15733 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    15734 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15735 File
    15736 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15737 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    15738 raise LinAlgError("Singular matrix") 
    15739 numpy.linalg.LinAlgError: Singular matrix 
    15740  
    15741 numpy.linalg.LinAlgError: Singular matrix 
    15742  
    15743 File
    15744 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15745 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    15746 raise LinAlgError("Singular matrix") 
    15747  
    15748 See log for complete Python traceback. 
    15749  
    15750 Traceback (most recent call last): 
    15751 File
    15752 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15753 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    15754 self.session.ui.mouse_modes.mouse_pause_tracking() 
    15755 File
    15756 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15757 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    15758 mouse_pause_tracking 
    15759 self._mouse_pause() 
    15760 File
    15761 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15762 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    15763 m.pause(self._mouse_pause_position) 
    15764 File
    15765 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15766 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    15767 p = self.view.picked_object(x, y) 
    15768 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15769 File
    15770 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15771 packages/chimerax/graphics/view.py", line 838, in picked_object 
    15772 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    15773 beyond, 
    15774 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15775 File
    15776 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15777 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    15778 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    15779 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15780 File
    15781 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15782 packages/chimerax/core/models.py", line 143, in first_intercept 
    15783 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    15784 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15785 File
    15786 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15787 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    15788 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    15789 exclude=exclude) 
    15790 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15791 File
    15792 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15793 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    15794 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    15795 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15796 File
    15797 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15798 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    15799 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    15800 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15801 File
    15802 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15803 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    15804 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    15805 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15806 File
    15807 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15808 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    15809 p = super().first_intercept(mxyz1, mxyz2) 
    15810 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15811 File
    15812 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15813 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    15814 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    15815 exclude=exclude) 
    15816 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15817 File
    15818 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15819 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    15820 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    15821 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15822 File
    15823 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15824 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    15825 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    15826 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15827 File
    15828 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15829 packages/chimerax/graphics/drawing.py", line 1108, in
    15830 _first_intercept_excluding_children 
    15831 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    15832 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15833 File
    15834 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15835 packages/chimerax/geometry/place.py", line 201, in inverse 
    15836 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    15837 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15838 File
    15839 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15840 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    15841 rinv[:, :] = matrix_inverse(r) 
    15842 ^^^^^^^^^^^^^^^^^ 
    15843 File
    15844 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15845 packages/numpy/linalg/linalg.py", line 561, in inv 
    15846 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    15847 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15848 File
    15849 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15850 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    15851 raise LinAlgError("Singular matrix") 
    15852 numpy.linalg.LinAlgError: Singular matrix 
    15853  
    15854 numpy.linalg.LinAlgError: Singular matrix 
    15855  
    15856 File
    15857 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15858 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    15859 raise LinAlgError("Singular matrix") 
    15860  
    15861 See log for complete Python traceback. 
    15862  
    15863 Traceback (most recent call last): 
    15864 File
    15865 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15866 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    15867 self.session.ui.mouse_modes.mouse_pause_tracking() 
    15868 File
    15869 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15870 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    15871 mouse_pause_tracking 
    15872 self._mouse_pause() 
    15873 File
    15874 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15875 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    15876 m.pause(self._mouse_pause_position) 
    15877 File
    15878 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15879 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    15880 p = self.view.picked_object(x, y) 
    15881 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15882 File
    15883 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15884 packages/chimerax/graphics/view.py", line 838, in picked_object 
    15885 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    15886 beyond, 
    15887 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15888 File
    15889 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15890 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    15891 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    15892 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15893 File
    15894 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15895 packages/chimerax/core/models.py", line 143, in first_intercept 
    15896 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    15897 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15898 File
    15899 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15900 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    15901 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    15902 exclude=exclude) 
    15903 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15904 File
    15905 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15906 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    15907 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    15908 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15909 File
    15910 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15911 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    15912 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    15913 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15914 File
    15915 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15916 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    15917 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    15918 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15919 File
    15920 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15921 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    15922 p = super().first_intercept(mxyz1, mxyz2) 
    15923 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15924 File
    15925 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15926 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    15927 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    15928 exclude=exclude) 
    15929 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15930 File
    15931 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15932 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    15933 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    15934 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15935 File
    15936 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15937 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    15938 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    15939 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15940 File
    15941 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15942 packages/chimerax/graphics/drawing.py", line 1108, in
    15943 _first_intercept_excluding_children 
    15944 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    15945 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15946 File
    15947 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15948 packages/chimerax/geometry/place.py", line 201, in inverse 
    15949 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    15950 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15951 File
    15952 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15953 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    15954 rinv[:, :] = matrix_inverse(r) 
    15955 ^^^^^^^^^^^^^^^^^ 
    15956 File
    15957 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15958 packages/numpy/linalg/linalg.py", line 561, in inv 
    15959 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    15960 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15961 File
    15962 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15963 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    15964 raise LinAlgError("Singular matrix") 
    15965 numpy.linalg.LinAlgError: Singular matrix 
    15966  
    15967 numpy.linalg.LinAlgError: Singular matrix 
    15968  
    15969 File
    15970 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15971 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    15972 raise LinAlgError("Singular matrix") 
    15973  
    15974 See log for complete Python traceback. 
    15975  
    15976 Traceback (most recent call last): 
    15977 File
    15978 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15979 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    15980 self.session.ui.mouse_modes.mouse_pause_tracking() 
    15981 File
    15982 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15983 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    15984 mouse_pause_tracking 
    15985 self._mouse_pause() 
    15986 File
    15987 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15988 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    15989 m.pause(self._mouse_pause_position) 
    15990 File
    15991 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15992 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    15993 p = self.view.picked_object(x, y) 
    15994 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    15995 File
    15996 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    15997 packages/chimerax/graphics/view.py", line 838, in picked_object 
    15998 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    15999 beyond, 
    16000 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16001 File
    16002 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16003 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    16004 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    16005 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16006 File
    16007 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16008 packages/chimerax/core/models.py", line 143, in first_intercept 
    16009 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    16010 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16011 File
    16012 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16013 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    16014 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    16015 exclude=exclude) 
    16016 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16017 File
    16018 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16019 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    16020 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    16021 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16022 File
    16023 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16024 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    16025 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    16026 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16027 File
    16028 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16029 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    16030 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    16031 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16032 File
    16033 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16034 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    16035 p = super().first_intercept(mxyz1, mxyz2) 
    16036 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16037 File
    16038 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16039 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    16040 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    16041 exclude=exclude) 
    16042 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16043 File
    16044 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16045 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    16046 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    16047 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16048 File
    16049 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16050 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    16051 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    16052 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16053 File
    16054 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16055 packages/chimerax/graphics/drawing.py", line 1108, in
    16056 _first_intercept_excluding_children 
    16057 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    16058 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16059 File
    16060 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16061 packages/chimerax/geometry/place.py", line 201, in inverse 
    16062 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    16063 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16064 File
    16065 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16066 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    16067 rinv[:, :] = matrix_inverse(r) 
    16068 ^^^^^^^^^^^^^^^^^ 
    16069 File
    16070 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16071 packages/numpy/linalg/linalg.py", line 561, in inv 
    16072 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    16073 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16074 File
    16075 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16076 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    16077 raise LinAlgError("Singular matrix") 
    16078 numpy.linalg.LinAlgError: Singular matrix 
    16079  
    16080 numpy.linalg.LinAlgError: Singular matrix 
    16081  
    16082 File
    16083 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16084 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    16085 raise LinAlgError("Singular matrix") 
    16086  
    16087 See log for complete Python traceback. 
    16088  
    16089 Traceback (most recent call last): 
    16090 File
    16091 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16092 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    16093 self.session.ui.mouse_modes.mouse_pause_tracking() 
    16094 File
    16095 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16096 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    16097 mouse_pause_tracking 
    16098 self._mouse_pause() 
    16099 File
    16100 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16101 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    16102 m.pause(self._mouse_pause_position) 
    16103 File
    16104 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16105 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    16106 p = self.view.picked_object(x, y) 
    16107 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16108 File
    16109 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16110 packages/chimerax/graphics/view.py", line 838, in picked_object 
    16111 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    16112 beyond, 
    16113 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16114 File
    16115 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16116 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    16117 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    16118 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16119 File
    16120 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16121 packages/chimerax/core/models.py", line 143, in first_intercept 
    16122 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    16123 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16124 File
    16125 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16126 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    16127 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    16128 exclude=exclude) 
    16129 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16130 File
    16131 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16132 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    16133 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    16134 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16135 File
    16136 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16137 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    16138 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    16139 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16140 File
    16141 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16142 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    16143 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    16144 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16145 File
    16146 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16147 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    16148 p = super().first_intercept(mxyz1, mxyz2) 
    16149 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16150 File
    16151 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16152 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    16153 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    16154 exclude=exclude) 
    16155 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16156 File
    16157 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16158 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    16159 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    16160 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16161 File
    16162 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16163 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    16164 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    16165 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16166 File
    16167 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16168 packages/chimerax/graphics/drawing.py", line 1108, in
    16169 _first_intercept_excluding_children 
    16170 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    16171 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16172 File
    16173 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16174 packages/chimerax/geometry/place.py", line 201, in inverse 
    16175 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    16176 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16177 File
    16178 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16179 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    16180 rinv[:, :] = matrix_inverse(r) 
    16181 ^^^^^^^^^^^^^^^^^ 
    16182 File
    16183 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16184 packages/numpy/linalg/linalg.py", line 561, in inv 
    16185 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    16186 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16187 File
    16188 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16189 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    16190 raise LinAlgError("Singular matrix") 
    16191 numpy.linalg.LinAlgError: Singular matrix 
    16192  
    16193 numpy.linalg.LinAlgError: Singular matrix 
    16194  
    16195 File
    16196 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16197 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    16198 raise LinAlgError("Singular matrix") 
    16199  
    16200 See log for complete Python traceback. 
    16201  
    16202 Traceback (most recent call last): 
    16203 File
    16204 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16205 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    16206 self.session.ui.mouse_modes.mouse_pause_tracking() 
    16207 File
    16208 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16209 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    16210 mouse_pause_tracking 
    16211 self._mouse_pause() 
    16212 File
    16213 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16214 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    16215 m.pause(self._mouse_pause_position) 
    16216 File
    16217 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16218 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    16219 p = self.view.picked_object(x, y) 
    16220 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16221 File
    16222 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16223 packages/chimerax/graphics/view.py", line 838, in picked_object 
    16224 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    16225 beyond, 
    16226 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16227 File
    16228 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16229 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    16230 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    16231 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16232 File
    16233 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16234 packages/chimerax/core/models.py", line 143, in first_intercept 
    16235 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    16236 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16237 File
    16238 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16239 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    16240 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    16241 exclude=exclude) 
    16242 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16243 File
    16244 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16245 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    16246 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    16247 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16248 File
    16249 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16250 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    16251 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    16252 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16253 File
    16254 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16255 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    16256 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    16257 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16258 File
    16259 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16260 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    16261 p = super().first_intercept(mxyz1, mxyz2) 
    16262 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16263 File
    16264 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16265 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    16266 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    16267 exclude=exclude) 
    16268 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16269 File
    16270 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16271 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    16272 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    16273 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16274 File
    16275 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16276 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    16277 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    16278 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16279 File
    16280 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16281 packages/chimerax/graphics/drawing.py", line 1108, in
    16282 _first_intercept_excluding_children 
    16283 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    16284 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16285 File
    16286 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16287 packages/chimerax/geometry/place.py", line 201, in inverse 
    16288 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    16289 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16290 File
    16291 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16292 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    16293 rinv[:, :] = matrix_inverse(r) 
    16294 ^^^^^^^^^^^^^^^^^ 
    16295 File
    16296 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16297 packages/numpy/linalg/linalg.py", line 561, in inv 
    16298 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    16299 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16300 File
    16301 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16302 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    16303 raise LinAlgError("Singular matrix") 
    16304 numpy.linalg.LinAlgError: Singular matrix 
    16305  
    16306 numpy.linalg.LinAlgError: Singular matrix 
    16307  
    16308 File
    16309 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16310 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    16311 raise LinAlgError("Singular matrix") 
    16312  
    16313 See log for complete Python traceback. 
    16314  
    16315 Traceback (most recent call last): 
    16316 File
    16317 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16318 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    16319 self.session.ui.mouse_modes.mouse_pause_tracking() 
    16320 File
    16321 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16322 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    16323 mouse_pause_tracking 
    16324 self._mouse_pause() 
    16325 File
    16326 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16327 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    16328 m.pause(self._mouse_pause_position) 
    16329 File
    16330 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16331 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    16332 p = self.view.picked_object(x, y) 
    16333 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16334 File
    16335 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16336 packages/chimerax/graphics/view.py", line 838, in picked_object 
    16337 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    16338 beyond, 
    16339 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16340 File
    16341 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16342 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    16343 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    16344 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16345 File
    16346 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16347 packages/chimerax/core/models.py", line 143, in first_intercept 
    16348 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    16349 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16350 File
    16351 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16352 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    16353 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    16354 exclude=exclude) 
    16355 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16356 File
    16357 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16358 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    16359 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    16360 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16361 File
    16362 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16363 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    16364 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    16365 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16366 File
    16367 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16368 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    16369 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    16370 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16371 File
    16372 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16373 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    16374 p = super().first_intercept(mxyz1, mxyz2) 
    16375 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16376 File
    16377 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16378 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    16379 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    16380 exclude=exclude) 
    16381 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16382 File
    16383 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16384 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    16385 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    16386 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16387 File
    16388 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16389 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    16390 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    16391 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16392 File
    16393 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16394 packages/chimerax/graphics/drawing.py", line 1108, in
    16395 _first_intercept_excluding_children 
    16396 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    16397 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16398 File
    16399 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16400 packages/chimerax/geometry/place.py", line 201, in inverse 
    16401 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    16402 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16403 File
    16404 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16405 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    16406 rinv[:, :] = matrix_inverse(r) 
    16407 ^^^^^^^^^^^^^^^^^ 
    16408 File
    16409 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16410 packages/numpy/linalg/linalg.py", line 561, in inv 
    16411 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    16412 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16413 File
    16414 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16415 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    16416 raise LinAlgError("Singular matrix") 
    16417 numpy.linalg.LinAlgError: Singular matrix 
    16418  
    16419 numpy.linalg.LinAlgError: Singular matrix 
    16420  
    16421 File
    16422 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16423 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    16424 raise LinAlgError("Singular matrix") 
    16425  
    16426 See log for complete Python traceback. 
    16427  
    16428 Traceback (most recent call last): 
    16429 File
    16430 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16431 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    16432 self.session.ui.mouse_modes.mouse_pause_tracking() 
    16433 File
    16434 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16435 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    16436 mouse_pause_tracking 
    16437 self._mouse_pause() 
    16438 File
    16439 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16440 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    16441 m.pause(self._mouse_pause_position) 
    16442 File
    16443 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16444 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    16445 p = self.view.picked_object(x, y) 
    16446 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16447 File
    16448 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16449 packages/chimerax/graphics/view.py", line 838, in picked_object 
    16450 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    16451 beyond, 
    16452 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16453 File
    16454 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16455 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    16456 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    16457 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16458 File
    16459 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16460 packages/chimerax/core/models.py", line 143, in first_intercept 
    16461 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    16462 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16463 File
    16464 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16465 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    16466 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    16467 exclude=exclude) 
    16468 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16469 File
    16470 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16471 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    16472 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    16473 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16474 File
    16475 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16476 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    16477 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    16478 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16479 File
    16480 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16481 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    16482 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    16483 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16484 File
    16485 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16486 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    16487 p = super().first_intercept(mxyz1, mxyz2) 
    16488 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16489 File
    16490 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16491 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    16492 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    16493 exclude=exclude) 
    16494 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16495 File
    16496 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16497 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    16498 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    16499 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16500 File
    16501 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16502 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    16503 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    16504 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16505 File
    16506 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16507 packages/chimerax/graphics/drawing.py", line 1108, in
    16508 _first_intercept_excluding_children 
    16509 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    16510 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16511 File
    16512 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16513 packages/chimerax/geometry/place.py", line 201, in inverse 
    16514 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    16515 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16516 File
    16517 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16518 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    16519 rinv[:, :] = matrix_inverse(r) 
    16520 ^^^^^^^^^^^^^^^^^ 
    16521 File
    16522 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16523 packages/numpy/linalg/linalg.py", line 561, in inv 
    16524 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    16525 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16526 File
    16527 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16528 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    16529 raise LinAlgError("Singular matrix") 
    16530 numpy.linalg.LinAlgError: Singular matrix 
    16531  
    16532 numpy.linalg.LinAlgError: Singular matrix 
    16533  
    16534 File
    16535 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16536 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    16537 raise LinAlgError("Singular matrix") 
    16538  
    16539 See log for complete Python traceback. 
    16540  
    16541 Traceback (most recent call last): 
    16542 File
    16543 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16544 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    16545 self.session.ui.mouse_modes.mouse_pause_tracking() 
    16546 File
    16547 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16548 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    16549 mouse_pause_tracking 
    16550 self._mouse_pause() 
    16551 File
    16552 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16553 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    16554 m.pause(self._mouse_pause_position) 
    16555 File
    16556 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16557 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    16558 p = self.view.picked_object(x, y) 
    16559 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16560 File
    16561 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16562 packages/chimerax/graphics/view.py", line 838, in picked_object 
    16563 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    16564 beyond, 
    16565 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16566 File
    16567 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16568 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    16569 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    16570 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16571 File
    16572 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16573 packages/chimerax/core/models.py", line 143, in first_intercept 
    16574 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    16575 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16576 File
    16577 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16578 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    16579 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    16580 exclude=exclude) 
    16581 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16582 File
    16583 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16584 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    16585 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    16586 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16587 File
    16588 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16589 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    16590 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    16591 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16592 File
    16593 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16594 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    16595 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    16596 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16597 File
    16598 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16599 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    16600 p = super().first_intercept(mxyz1, mxyz2) 
    16601 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16602 File
    16603 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16604 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    16605 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    16606 exclude=exclude) 
    16607 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16608 File
    16609 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16610 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    16611 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    16612 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16613 File
    16614 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16615 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    16616 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    16617 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16618 File
    16619 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16620 packages/chimerax/graphics/drawing.py", line 1108, in
    16621 _first_intercept_excluding_children 
    16622 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    16623 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16624 File
    16625 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16626 packages/chimerax/geometry/place.py", line 201, in inverse 
    16627 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    16628 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16629 File
    16630 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16631 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    16632 rinv[:, :] = matrix_inverse(r) 
    16633 ^^^^^^^^^^^^^^^^^ 
    16634 File
    16635 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16636 packages/numpy/linalg/linalg.py", line 561, in inv 
    16637 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    16638 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16639 File
    16640 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16641 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    16642 raise LinAlgError("Singular matrix") 
    16643 numpy.linalg.LinAlgError: Singular matrix 
    16644  
    16645 numpy.linalg.LinAlgError: Singular matrix 
    16646  
    16647 File
    16648 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16649 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    16650 raise LinAlgError("Singular matrix") 
    16651  
    16652 See log for complete Python traceback. 
    16653  
    16654 Traceback (most recent call last): 
    16655 File
    16656 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16657 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    16658 self.session.ui.mouse_modes.mouse_pause_tracking() 
    16659 File
    16660 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16661 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    16662 mouse_pause_tracking 
    16663 self._mouse_pause() 
    16664 File
    16665 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16666 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    16667 m.pause(self._mouse_pause_position) 
    16668 File
    16669 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16670 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    16671 p = self.view.picked_object(x, y) 
    16672 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16673 File
    16674 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16675 packages/chimerax/graphics/view.py", line 838, in picked_object 
    16676 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    16677 beyond, 
    16678 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16679 File
    16680 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16681 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    16682 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    16683 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16684 File
    16685 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16686 packages/chimerax/core/models.py", line 143, in first_intercept 
    16687 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    16688 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16689 File
    16690 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16691 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    16692 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    16693 exclude=exclude) 
    16694 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16695 File
    16696 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16697 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    16698 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    16699 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16700 File
    16701 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16702 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    16703 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    16704 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16705 File
    16706 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16707 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    16708 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    16709 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16710 File
    16711 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16712 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    16713 p = super().first_intercept(mxyz1, mxyz2) 
    16714 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16715 File
    16716 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16717 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    16718 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    16719 exclude=exclude) 
    16720 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16721 File
    16722 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16723 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    16724 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    16725 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16726 File
    16727 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16728 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    16729 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    16730 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16731 File
    16732 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16733 packages/chimerax/graphics/drawing.py", line 1108, in
    16734 _first_intercept_excluding_children 
    16735 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    16736 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16737 File
    16738 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16739 packages/chimerax/geometry/place.py", line 201, in inverse 
    16740 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    16741 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16742 File
    16743 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16744 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    16745 rinv[:, :] = matrix_inverse(r) 
    16746 ^^^^^^^^^^^^^^^^^ 
    16747 File
    16748 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16749 packages/numpy/linalg/linalg.py", line 561, in inv 
    16750 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    16751 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16752 File
    16753 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16754 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    16755 raise LinAlgError("Singular matrix") 
    16756 numpy.linalg.LinAlgError: Singular matrix 
    16757  
    16758 numpy.linalg.LinAlgError: Singular matrix 
    16759  
    16760 File
    16761 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16762 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    16763 raise LinAlgError("Singular matrix") 
    16764  
    16765 See log for complete Python traceback. 
    16766  
    16767 Traceback (most recent call last): 
    16768 File
    16769 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16770 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    16771 self.session.ui.mouse_modes.mouse_pause_tracking() 
    16772 File
    16773 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16774 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    16775 mouse_pause_tracking 
    16776 self._mouse_pause() 
    16777 File
    16778 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16779 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    16780 m.pause(self._mouse_pause_position) 
    16781 File
    16782 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16783 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    16784 p = self.view.picked_object(x, y) 
    16785 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16786 File
    16787 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16788 packages/chimerax/graphics/view.py", line 838, in picked_object 
    16789 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    16790 beyond, 
    16791 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16792 File
    16793 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16794 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    16795 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    16796 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16797 File
    16798 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16799 packages/chimerax/core/models.py", line 143, in first_intercept 
    16800 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    16801 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16802 File
    16803 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16804 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    16805 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    16806 exclude=exclude) 
    16807 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16808 File
    16809 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16810 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    16811 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    16812 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16813 File
    16814 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16815 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    16816 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    16817 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16818 File
    16819 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16820 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    16821 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    16822 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16823 File
    16824 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16825 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    16826 p = super().first_intercept(mxyz1, mxyz2) 
    16827 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16828 File
    16829 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16830 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    16831 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    16832 exclude=exclude) 
    16833 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16834 File
    16835 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16836 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    16837 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    16838 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16839 File
    16840 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16841 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    16842 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    16843 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16844 File
    16845 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16846 packages/chimerax/graphics/drawing.py", line 1108, in
    16847 _first_intercept_excluding_children 
    16848 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    16849 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16850 File
    16851 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16852 packages/chimerax/geometry/place.py", line 201, in inverse 
    16853 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    16854 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16855 File
    16856 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16857 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    16858 rinv[:, :] = matrix_inverse(r) 
    16859 ^^^^^^^^^^^^^^^^^ 
    16860 File
    16861 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16862 packages/numpy/linalg/linalg.py", line 561, in inv 
    16863 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    16864 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16865 File
    16866 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16867 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    16868 raise LinAlgError("Singular matrix") 
    16869 numpy.linalg.LinAlgError: Singular matrix 
    16870  
    16871 numpy.linalg.LinAlgError: Singular matrix 
    16872  
    16873 File
    16874 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16875 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    16876 raise LinAlgError("Singular matrix") 
    16877  
    16878 See log for complete Python traceback. 
    16879  
    16880 Traceback (most recent call last): 
    16881 File
    16882 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16883 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    16884 self.session.ui.mouse_modes.mouse_pause_tracking() 
    16885 File
    16886 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16887 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    16888 mouse_pause_tracking 
    16889 self._mouse_pause() 
    16890 File
    16891 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16892 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    16893 m.pause(self._mouse_pause_position) 
    16894 File
    16895 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16896 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    16897 p = self.view.picked_object(x, y) 
    16898 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16899 File
    16900 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16901 packages/chimerax/graphics/view.py", line 838, in picked_object 
    16902 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    16903 beyond, 
    16904 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16905 File
    16906 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16907 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    16908 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    16909 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16910 File
    16911 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16912 packages/chimerax/core/models.py", line 143, in first_intercept 
    16913 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    16914 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16915 File
    16916 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16917 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    16918 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    16919 exclude=exclude) 
    16920 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16921 File
    16922 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16923 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    16924 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    16925 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16926 File
    16927 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16928 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    16929 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    16930 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16931 File
    16932 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16933 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    16934 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    16935 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16936 File
    16937 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16938 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    16939 p = super().first_intercept(mxyz1, mxyz2) 
    16940 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16941 File
    16942 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16943 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    16944 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    16945 exclude=exclude) 
    16946 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16947 File
    16948 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16949 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    16950 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    16951 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16952 File
    16953 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16954 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    16955 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    16956 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16957 File
    16958 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16959 packages/chimerax/graphics/drawing.py", line 1108, in
    16960 _first_intercept_excluding_children 
    16961 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    16962 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16963 File
    16964 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16965 packages/chimerax/geometry/place.py", line 201, in inverse 
    16966 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    16967 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16968 File
    16969 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16970 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    16971 rinv[:, :] = matrix_inverse(r) 
    16972 ^^^^^^^^^^^^^^^^^ 
    16973 File
    16974 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16975 packages/numpy/linalg/linalg.py", line 561, in inv 
    16976 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    16977 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    16978 File
    16979 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16980 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    16981 raise LinAlgError("Singular matrix") 
    16982 numpy.linalg.LinAlgError: Singular matrix 
    16983  
    16984 numpy.linalg.LinAlgError: Singular matrix 
    16985  
    16986 File
    16987 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16988 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    16989 raise LinAlgError("Singular matrix") 
    16990  
    16991 See log for complete Python traceback. 
    16992  
    16993 Traceback (most recent call last): 
    16994 File
    16995 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    16996 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    16997 self.session.ui.mouse_modes.mouse_pause_tracking() 
    16998 File
    16999 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17000 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    17001 mouse_pause_tracking 
    17002 self._mouse_pause() 
    17003 File
    17004 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17005 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    17006 m.pause(self._mouse_pause_position) 
    17007 File
    17008 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17009 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    17010 p = self.view.picked_object(x, y) 
    17011 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17012 File
    17013 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17014 packages/chimerax/graphics/view.py", line 838, in picked_object 
    17015 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    17016 beyond, 
    17017 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17018 File
    17019 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17020 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    17021 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    17022 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17023 File
    17024 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17025 packages/chimerax/core/models.py", line 143, in first_intercept 
    17026 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    17027 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17028 File
    17029 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17030 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    17031 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    17032 exclude=exclude) 
    17033 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17034 File
    17035 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17036 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    17037 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    17038 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17039 File
    17040 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17041 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    17042 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    17043 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17044 File
    17045 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17046 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    17047 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    17048 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17049 File
    17050 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17051 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    17052 p = super().first_intercept(mxyz1, mxyz2) 
    17053 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17054 File
    17055 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17056 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    17057 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    17058 exclude=exclude) 
    17059 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17060 File
    17061 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17062 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    17063 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    17064 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17065 File
    17066 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17067 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    17068 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    17069 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17070 File
    17071 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17072 packages/chimerax/graphics/drawing.py", line 1108, in
    17073 _first_intercept_excluding_children 
    17074 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    17075 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17076 File
    17077 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17078 packages/chimerax/geometry/place.py", line 201, in inverse 
    17079 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    17080 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17081 File
    17082 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17083 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    17084 rinv[:, :] = matrix_inverse(r) 
    17085 ^^^^^^^^^^^^^^^^^ 
    17086 File
    17087 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17088 packages/numpy/linalg/linalg.py", line 561, in inv 
    17089 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    17090 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17091 File
    17092 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17093 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    17094 raise LinAlgError("Singular matrix") 
    17095 numpy.linalg.LinAlgError: Singular matrix 
    17096  
    17097 numpy.linalg.LinAlgError: Singular matrix 
    17098  
    17099 File
    17100 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17101 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    17102 raise LinAlgError("Singular matrix") 
    17103  
    17104 See log for complete Python traceback. 
    17105  
    17106 Traceback (most recent call last): 
    17107 File
    17108 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17109 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    17110 self.session.ui.mouse_modes.mouse_pause_tracking() 
    17111 File
    17112 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17113 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    17114 mouse_pause_tracking 
    17115 self._mouse_pause() 
    17116 File
    17117 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17118 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    17119 m.pause(self._mouse_pause_position) 
    17120 File
    17121 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17122 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    17123 p = self.view.picked_object(x, y) 
    17124 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17125 File
    17126 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17127 packages/chimerax/graphics/view.py", line 838, in picked_object 
    17128 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    17129 beyond, 
    17130 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17131 File
    17132 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17133 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    17134 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    17135 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17136 File
    17137 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17138 packages/chimerax/core/models.py", line 143, in first_intercept 
    17139 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    17140 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17141 File
    17142 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17143 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    17144 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    17145 exclude=exclude) 
    17146 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17147 File
    17148 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17149 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    17150 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    17151 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17152 File
    17153 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17154 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    17155 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    17156 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17157 File
    17158 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17159 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    17160 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    17161 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17162 File
    17163 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17164 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    17165 p = super().first_intercept(mxyz1, mxyz2) 
    17166 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17167 File
    17168 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17169 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    17170 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    17171 exclude=exclude) 
    17172 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17173 File
    17174 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17175 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    17176 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    17177 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17178 File
    17179 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17180 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    17181 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    17182 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17183 File
    17184 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17185 packages/chimerax/graphics/drawing.py", line 1108, in
    17186 _first_intercept_excluding_children 
    17187 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    17188 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17189 File
    17190 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17191 packages/chimerax/geometry/place.py", line 201, in inverse 
    17192 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    17193 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17194 File
    17195 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17196 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    17197 rinv[:, :] = matrix_inverse(r) 
    17198 ^^^^^^^^^^^^^^^^^ 
    17199 File
    17200 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17201 packages/numpy/linalg/linalg.py", line 561, in inv 
    17202 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    17203 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17204 File
    17205 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17206 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    17207 raise LinAlgError("Singular matrix") 
    17208 numpy.linalg.LinAlgError: Singular matrix 
    17209  
    17210 numpy.linalg.LinAlgError: Singular matrix 
    17211  
    17212 File
    17213 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17214 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    17215 raise LinAlgError("Singular matrix") 
    17216  
    17217 See log for complete Python traceback. 
    17218  
    17219 Traceback (most recent call last): 
    17220 File
    17221 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17222 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    17223 self.session.ui.mouse_modes.mouse_pause_tracking() 
    17224 File
    17225 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17226 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    17227 mouse_pause_tracking 
    17228 self._mouse_pause() 
    17229 File
    17230 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17231 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    17232 m.pause(self._mouse_pause_position) 
    17233 File
    17234 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17235 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    17236 p = self.view.picked_object(x, y) 
    17237 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17238 File
    17239 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17240 packages/chimerax/graphics/view.py", line 838, in picked_object 
    17241 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    17242 beyond, 
    17243 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17244 File
    17245 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17246 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    17247 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    17248 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17249 File
    17250 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17251 packages/chimerax/core/models.py", line 143, in first_intercept 
    17252 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    17253 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17254 File
    17255 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17256 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    17257 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    17258 exclude=exclude) 
    17259 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17260 File
    17261 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17262 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    17263 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    17264 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17265 File
    17266 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17267 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    17268 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    17269 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17270 File
    17271 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17272 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    17273 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    17274 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17275 File
    17276 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17277 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    17278 p = super().first_intercept(mxyz1, mxyz2) 
    17279 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17280 File
    17281 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17282 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    17283 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    17284 exclude=exclude) 
    17285 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17286 File
    17287 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17288 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    17289 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    17290 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17291 File
    17292 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17293 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    17294 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    17295 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17296 File
    17297 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17298 packages/chimerax/graphics/drawing.py", line 1108, in
    17299 _first_intercept_excluding_children 
    17300 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    17301 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17302 File
    17303 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17304 packages/chimerax/geometry/place.py", line 201, in inverse 
    17305 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    17306 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17307 File
    17308 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17309 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    17310 rinv[:, :] = matrix_inverse(r) 
    17311 ^^^^^^^^^^^^^^^^^ 
    17312 File
    17313 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17314 packages/numpy/linalg/linalg.py", line 561, in inv 
    17315 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    17316 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17317 File
    17318 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17319 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    17320 raise LinAlgError("Singular matrix") 
    17321 numpy.linalg.LinAlgError: Singular matrix 
    17322  
    17323 numpy.linalg.LinAlgError: Singular matrix 
    17324  
    17325 File
    17326 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17327 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    17328 raise LinAlgError("Singular matrix") 
    17329  
    17330 See log for complete Python traceback. 
    17331  
    17332 Traceback (most recent call last): 
    17333 File
    17334 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17335 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    17336 self.session.ui.mouse_modes.mouse_pause_tracking() 
    17337 File
    17338 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17339 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    17340 mouse_pause_tracking 
    17341 self._mouse_pause() 
    17342 File
    17343 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17344 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    17345 m.pause(self._mouse_pause_position) 
    17346 File
    17347 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17348 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    17349 p = self.view.picked_object(x, y) 
    17350 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17351 File
    17352 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17353 packages/chimerax/graphics/view.py", line 838, in picked_object 
    17354 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    17355 beyond, 
    17356 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17357 File
    17358 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17359 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    17360 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    17361 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17362 File
    17363 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17364 packages/chimerax/core/models.py", line 143, in first_intercept 
    17365 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    17366 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17367 File
    17368 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17369 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    17370 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    17371 exclude=exclude) 
    17372 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17373 File
    17374 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17375 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    17376 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    17377 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17378 File
    17379 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17380 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    17381 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    17382 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17383 File
    17384 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17385 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    17386 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    17387 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17388 File
    17389 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17390 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    17391 p = super().first_intercept(mxyz1, mxyz2) 
    17392 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17393 File
    17394 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17395 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    17396 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    17397 exclude=exclude) 
    17398 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17399 File
    17400 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17401 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    17402 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    17403 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17404 File
    17405 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17406 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    17407 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    17408 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17409 File
    17410 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17411 packages/chimerax/graphics/drawing.py", line 1108, in
    17412 _first_intercept_excluding_children 
    17413 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    17414 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17415 File
    17416 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17417 packages/chimerax/geometry/place.py", line 201, in inverse 
    17418 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    17419 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17420 File
    17421 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17422 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    17423 rinv[:, :] = matrix_inverse(r) 
    17424 ^^^^^^^^^^^^^^^^^ 
    17425 File
    17426 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17427 packages/numpy/linalg/linalg.py", line 561, in inv 
    17428 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    17429 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17430 File
    17431 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17432 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    17433 raise LinAlgError("Singular matrix") 
    17434 numpy.linalg.LinAlgError: Singular matrix 
    17435  
    17436 numpy.linalg.LinAlgError: Singular matrix 
    17437  
    17438 File
    17439 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17440 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    17441 raise LinAlgError("Singular matrix") 
    17442  
    17443 See log for complete Python traceback. 
    17444  
    17445 Traceback (most recent call last): 
    17446 File
    17447 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17448 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    17449 self.session.ui.mouse_modes.mouse_pause_tracking() 
    17450 File
    17451 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17452 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    17453 mouse_pause_tracking 
    17454 self._mouse_pause() 
    17455 File
    17456 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17457 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    17458 m.pause(self._mouse_pause_position) 
    17459 File
    17460 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17461 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    17462 p = self.view.picked_object(x, y) 
    17463 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17464 File
    17465 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17466 packages/chimerax/graphics/view.py", line 838, in picked_object 
    17467 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    17468 beyond, 
    17469 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17470 File
    17471 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17472 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    17473 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    17474 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17475 File
    17476 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17477 packages/chimerax/core/models.py", line 143, in first_intercept 
    17478 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    17479 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17480 File
    17481 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17482 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    17483 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    17484 exclude=exclude) 
    17485 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17486 File
    17487 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17488 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    17489 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    17490 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17491 File
    17492 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17493 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    17494 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    17495 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17496 File
    17497 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17498 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    17499 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    17500 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17501 File
    17502 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17503 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    17504 p = super().first_intercept(mxyz1, mxyz2) 
    17505 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17506 File
    17507 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17508 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    17509 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    17510 exclude=exclude) 
    17511 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17512 File
    17513 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17514 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    17515 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    17516 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17517 File
    17518 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17519 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    17520 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    17521 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17522 File
    17523 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17524 packages/chimerax/graphics/drawing.py", line 1108, in
    17525 _first_intercept_excluding_children 
    17526 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    17527 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17528 File
    17529 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17530 packages/chimerax/geometry/place.py", line 201, in inverse 
    17531 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    17532 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17533 File
    17534 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17535 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    17536 rinv[:, :] = matrix_inverse(r) 
    17537 ^^^^^^^^^^^^^^^^^ 
    17538 File
    17539 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17540 packages/numpy/linalg/linalg.py", line 561, in inv 
    17541 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    17542 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17543 File
    17544 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17545 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    17546 raise LinAlgError("Singular matrix") 
    17547 numpy.linalg.LinAlgError: Singular matrix 
    17548  
    17549 numpy.linalg.LinAlgError: Singular matrix 
    17550  
    17551 File
    17552 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17553 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    17554 raise LinAlgError("Singular matrix") 
    17555  
    17556 See log for complete Python traceback. 
    17557  
    17558 Traceback (most recent call last): 
    17559 File
    17560 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17561 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    17562 self.session.ui.mouse_modes.mouse_pause_tracking() 
    17563 File
    17564 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17565 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    17566 mouse_pause_tracking 
    17567 self._mouse_pause() 
    17568 File
    17569 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17570 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    17571 m.pause(self._mouse_pause_position) 
    17572 File
    17573 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17574 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    17575 p = self.view.picked_object(x, y) 
    17576 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17577 File
    17578 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17579 packages/chimerax/graphics/view.py", line 838, in picked_object 
    17580 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    17581 beyond, 
    17582 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17583 File
    17584 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17585 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    17586 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    17587 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17588 File
    17589 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17590 packages/chimerax/core/models.py", line 143, in first_intercept 
    17591 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    17592 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17593 File
    17594 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17595 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    17596 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    17597 exclude=exclude) 
    17598 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17599 File
    17600 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17601 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    17602 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    17603 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17604 File
    17605 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17606 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    17607 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    17608 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17609 File
    17610 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17611 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    17612 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    17613 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17614 File
    17615 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17616 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    17617 p = super().first_intercept(mxyz1, mxyz2) 
    17618 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17619 File
    17620 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17621 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    17622 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    17623 exclude=exclude) 
    17624 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17625 File
    17626 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17627 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    17628 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    17629 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17630 File
    17631 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17632 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    17633 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    17634 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17635 File
    17636 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17637 packages/chimerax/graphics/drawing.py", line 1108, in
    17638 _first_intercept_excluding_children 
    17639 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    17640 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17641 File
    17642 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17643 packages/chimerax/geometry/place.py", line 201, in inverse 
    17644 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    17645 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17646 File
    17647 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17648 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    17649 rinv[:, :] = matrix_inverse(r) 
    17650 ^^^^^^^^^^^^^^^^^ 
    17651 File
    17652 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17653 packages/numpy/linalg/linalg.py", line 561, in inv 
    17654 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    17655 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17656 File
    17657 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17658 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    17659 raise LinAlgError("Singular matrix") 
    17660 numpy.linalg.LinAlgError: Singular matrix 
    17661  
    17662 numpy.linalg.LinAlgError: Singular matrix 
    17663  
    17664 File
    17665 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17666 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    17667 raise LinAlgError("Singular matrix") 
    17668  
    17669 See log for complete Python traceback. 
    17670  
    17671 Traceback (most recent call last): 
    17672 File
    17673 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17674 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    17675 self.session.ui.mouse_modes.mouse_pause_tracking() 
    17676 File
    17677 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17678 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    17679 mouse_pause_tracking 
    17680 self._mouse_pause() 
    17681 File
    17682 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17683 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    17684 m.pause(self._mouse_pause_position) 
    17685 File
    17686 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17687 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    17688 p = self.view.picked_object(x, y) 
    17689 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17690 File
    17691 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17692 packages/chimerax/graphics/view.py", line 838, in picked_object 
    17693 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    17694 beyond, 
    17695 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17696 File
    17697 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17698 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    17699 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    17700 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17701 File
    17702 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17703 packages/chimerax/core/models.py", line 143, in first_intercept 
    17704 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    17705 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17706 File
    17707 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17708 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    17709 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    17710 exclude=exclude) 
    17711 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17712 File
    17713 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17714 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    17715 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    17716 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17717 File
    17718 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17719 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    17720 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    17721 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17722 File
    17723 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17724 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    17725 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    17726 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17727 File
    17728 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17729 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    17730 p = super().first_intercept(mxyz1, mxyz2) 
    17731 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17732 File
    17733 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17734 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    17735 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    17736 exclude=exclude) 
    17737 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17738 File
    17739 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17740 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    17741 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    17742 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17743 File
    17744 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17745 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    17746 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    17747 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17748 File
    17749 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17750 packages/chimerax/graphics/drawing.py", line 1108, in
    17751 _first_intercept_excluding_children 
    17752 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    17753 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17754 File
    17755 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17756 packages/chimerax/geometry/place.py", line 201, in inverse 
    17757 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    17758 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17759 File
    17760 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17761 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    17762 rinv[:, :] = matrix_inverse(r) 
    17763 ^^^^^^^^^^^^^^^^^ 
    17764 File
    17765 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17766 packages/numpy/linalg/linalg.py", line 561, in inv 
    17767 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    17768 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17769 File
    17770 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17771 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    17772 raise LinAlgError("Singular matrix") 
    17773 numpy.linalg.LinAlgError: Singular matrix 
    17774  
    17775 numpy.linalg.LinAlgError: Singular matrix 
    17776  
    17777 File
    17778 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17779 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    17780 raise LinAlgError("Singular matrix") 
    17781  
    17782 See log for complete Python traceback. 
    17783  
    17784 Traceback (most recent call last): 
    17785 File
    17786 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17787 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    17788 self.session.ui.mouse_modes.mouse_pause_tracking() 
    17789 File
    17790 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17791 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    17792 mouse_pause_tracking 
    17793 self._mouse_pause() 
    17794 File
    17795 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17796 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    17797 m.pause(self._mouse_pause_position) 
    17798 File
    17799 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17800 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    17801 p = self.view.picked_object(x, y) 
    17802 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17803 File
    17804 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17805 packages/chimerax/graphics/view.py", line 838, in picked_object 
    17806 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    17807 beyond, 
    17808 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17809 File
    17810 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17811 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    17812 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    17813 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17814 File
    17815 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17816 packages/chimerax/core/models.py", line 143, in first_intercept 
    17817 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    17818 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17819 File
    17820 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17821 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    17822 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    17823 exclude=exclude) 
    17824 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17825 File
    17826 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17827 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    17828 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    17829 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17830 File
    17831 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17832 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    17833 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    17834 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17835 File
    17836 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17837 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    17838 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    17839 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17840 File
    17841 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17842 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    17843 p = super().first_intercept(mxyz1, mxyz2) 
    17844 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17845 File
    17846 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17847 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    17848 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    17849 exclude=exclude) 
    17850 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17851 File
    17852 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17853 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    17854 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    17855 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17856 File
    17857 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17858 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    17859 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    17860 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17861 File
    17862 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17863 packages/chimerax/graphics/drawing.py", line 1108, in
    17864 _first_intercept_excluding_children 
    17865 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    17866 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17867 File
    17868 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17869 packages/chimerax/geometry/place.py", line 201, in inverse 
    17870 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    17871 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17872 File
    17873 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17874 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    17875 rinv[:, :] = matrix_inverse(r) 
    17876 ^^^^^^^^^^^^^^^^^ 
    17877 File
    17878 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17879 packages/numpy/linalg/linalg.py", line 561, in inv 
    17880 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    17881 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17882 File
    17883 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17884 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    17885 raise LinAlgError("Singular matrix") 
    17886 numpy.linalg.LinAlgError: Singular matrix 
    17887  
    17888 numpy.linalg.LinAlgError: Singular matrix 
    17889  
    17890 File
    17891 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17892 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    17893 raise LinAlgError("Singular matrix") 
    17894  
    17895 See log for complete Python traceback. 
    17896  
    17897 Traceback (most recent call last): 
    17898 File
    17899 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17900 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    17901 self.session.ui.mouse_modes.mouse_pause_tracking() 
    17902 File
    17903 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17904 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    17905 mouse_pause_tracking 
    17906 self._mouse_pause() 
    17907 File
    17908 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17909 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    17910 m.pause(self._mouse_pause_position) 
    17911 File
    17912 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17913 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    17914 p = self.view.picked_object(x, y) 
    17915 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17916 File
    17917 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17918 packages/chimerax/graphics/view.py", line 838, in picked_object 
    17919 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    17920 beyond, 
    17921 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17922 File
    17923 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17924 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    17925 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    17926 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17927 File
    17928 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17929 packages/chimerax/core/models.py", line 143, in first_intercept 
    17930 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    17931 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17932 File
    17933 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17934 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    17935 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    17936 exclude=exclude) 
    17937 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17938 File
    17939 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17940 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    17941 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    17942 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17943 File
    17944 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17945 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    17946 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    17947 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17948 File
    17949 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17950 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    17951 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    17952 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17953 File
    17954 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17955 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    17956 p = super().first_intercept(mxyz1, mxyz2) 
    17957 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17958 File
    17959 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17960 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    17961 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    17962 exclude=exclude) 
    17963 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17964 File
    17965 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17966 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    17967 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    17968 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17969 File
    17970 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17971 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    17972 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    17973 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17974 File
    17975 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17976 packages/chimerax/graphics/drawing.py", line 1108, in
    17977 _first_intercept_excluding_children 
    17978 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    17979 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17980 File
    17981 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17982 packages/chimerax/geometry/place.py", line 201, in inverse 
    17983 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    17984 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17985 File
    17986 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17987 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    17988 rinv[:, :] = matrix_inverse(r) 
    17989 ^^^^^^^^^^^^^^^^^ 
    17990 File
    17991 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17992 packages/numpy/linalg/linalg.py", line 561, in inv 
    17993 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    17994 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    17995 File
    17996 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    17997 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    17998 raise LinAlgError("Singular matrix") 
    17999 numpy.linalg.LinAlgError: Singular matrix 
    18000  
    18001 numpy.linalg.LinAlgError: Singular matrix 
    18002  
    18003 File
    18004 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18005 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    18006 raise LinAlgError("Singular matrix") 
    18007  
    18008 See log for complete Python traceback. 
    18009  
    18010 Traceback (most recent call last): 
    18011 File
    18012 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18013 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    18014 self.session.ui.mouse_modes.mouse_pause_tracking() 
    18015 File
    18016 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18017 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    18018 mouse_pause_tracking 
    18019 self._mouse_pause() 
    18020 File
    18021 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18022 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    18023 m.pause(self._mouse_pause_position) 
    18024 File
    18025 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18026 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    18027 p = self.view.picked_object(x, y) 
    18028 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18029 File
    18030 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18031 packages/chimerax/graphics/view.py", line 838, in picked_object 
    18032 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    18033 beyond, 
    18034 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18035 File
    18036 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18037 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    18038 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    18039 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18040 File
    18041 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18042 packages/chimerax/core/models.py", line 143, in first_intercept 
    18043 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    18044 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18045 File
    18046 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18047 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    18048 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    18049 exclude=exclude) 
    18050 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18051 File
    18052 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18053 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    18054 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    18055 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18056 File
    18057 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18058 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    18059 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    18060 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18061 File
    18062 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18063 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    18064 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    18065 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18066 File
    18067 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18068 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    18069 p = super().first_intercept(mxyz1, mxyz2) 
    18070 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18071 File
    18072 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18073 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    18074 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    18075 exclude=exclude) 
    18076 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18077 File
    18078 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18079 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    18080 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    18081 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18082 File
    18083 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18084 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    18085 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    18086 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18087 File
    18088 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18089 packages/chimerax/graphics/drawing.py", line 1108, in
    18090 _first_intercept_excluding_children 
    18091 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    18092 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18093 File
    18094 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18095 packages/chimerax/geometry/place.py", line 201, in inverse 
    18096 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    18097 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18098 File
    18099 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18100 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    18101 rinv[:, :] = matrix_inverse(r) 
    18102 ^^^^^^^^^^^^^^^^^ 
    18103 File
    18104 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18105 packages/numpy/linalg/linalg.py", line 561, in inv 
    18106 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    18107 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18108 File
    18109 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18110 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    18111 raise LinAlgError("Singular matrix") 
    18112 numpy.linalg.LinAlgError: Singular matrix 
    18113  
    18114 numpy.linalg.LinAlgError: Singular matrix 
    18115  
    18116 File
    18117 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18118 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    18119 raise LinAlgError("Singular matrix") 
    18120  
    18121 See log for complete Python traceback. 
    18122  
    18123 Traceback (most recent call last): 
    18124 File
    18125 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18126 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    18127 self.session.ui.mouse_modes.mouse_pause_tracking() 
    18128 File
    18129 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18130 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    18131 mouse_pause_tracking 
    18132 self._mouse_pause() 
    18133 File
    18134 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18135 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    18136 m.pause(self._mouse_pause_position) 
    18137 File
    18138 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18139 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    18140 p = self.view.picked_object(x, y) 
    18141 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18142 File
    18143 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18144 packages/chimerax/graphics/view.py", line 838, in picked_object 
    18145 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    18146 beyond, 
    18147 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18148 File
    18149 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18150 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    18151 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    18152 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18153 File
    18154 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18155 packages/chimerax/core/models.py", line 143, in first_intercept 
    18156 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    18157 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18158 File
    18159 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18160 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    18161 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    18162 exclude=exclude) 
    18163 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18164 File
    18165 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18166 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    18167 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    18168 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18169 File
    18170 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18171 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    18172 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    18173 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18174 File
    18175 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18176 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    18177 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    18178 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18179 File
    18180 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18181 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    18182 p = super().first_intercept(mxyz1, mxyz2) 
    18183 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18184 File
    18185 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18186 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    18187 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    18188 exclude=exclude) 
    18189 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18190 File
    18191 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18192 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    18193 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    18194 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18195 File
    18196 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18197 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    18198 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    18199 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18200 File
    18201 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18202 packages/chimerax/graphics/drawing.py", line 1108, in
    18203 _first_intercept_excluding_children 
    18204 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    18205 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18206 File
    18207 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18208 packages/chimerax/geometry/place.py", line 201, in inverse 
    18209 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    18210 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18211 File
    18212 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18213 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    18214 rinv[:, :] = matrix_inverse(r) 
    18215 ^^^^^^^^^^^^^^^^^ 
    18216 File
    18217 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18218 packages/numpy/linalg/linalg.py", line 561, in inv 
    18219 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    18220 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18221 File
    18222 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18223 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    18224 raise LinAlgError("Singular matrix") 
    18225 numpy.linalg.LinAlgError: Singular matrix 
    18226  
    18227 numpy.linalg.LinAlgError: Singular matrix 
    18228  
    18229 File
    18230 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18231 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    18232 raise LinAlgError("Singular matrix") 
    18233  
    18234 See log for complete Python traceback. 
    18235  
    18236 Traceback (most recent call last): 
    18237 File
    18238 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18239 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    18240 self.session.ui.mouse_modes.mouse_pause_tracking() 
    18241 File
    18242 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18243 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    18244 mouse_pause_tracking 
    18245 self._mouse_pause() 
    18246 File
    18247 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18248 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    18249 m.pause(self._mouse_pause_position) 
    18250 File
    18251 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18252 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    18253 p = self.view.picked_object(x, y) 
    18254 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18255 File
    18256 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18257 packages/chimerax/graphics/view.py", line 838, in picked_object 
    18258 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    18259 beyond, 
    18260 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18261 File
    18262 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18263 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    18264 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    18265 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18266 File
    18267 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18268 packages/chimerax/core/models.py", line 143, in first_intercept 
    18269 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    18270 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18271 File
    18272 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18273 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    18274 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    18275 exclude=exclude) 
    18276 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18277 File
    18278 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18279 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    18280 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    18281 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18282 File
    18283 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18284 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    18285 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    18286 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18287 File
    18288 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18289 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    18290 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    18291 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18292 File
    18293 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18294 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    18295 p = super().first_intercept(mxyz1, mxyz2) 
    18296 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18297 File
    18298 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18299 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    18300 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    18301 exclude=exclude) 
    18302 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18303 File
    18304 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18305 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    18306 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    18307 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18308 File
    18309 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18310 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    18311 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    18312 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18313 File
    18314 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18315 packages/chimerax/graphics/drawing.py", line 1108, in
    18316 _first_intercept_excluding_children 
    18317 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    18318 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18319 File
    18320 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18321 packages/chimerax/geometry/place.py", line 201, in inverse 
    18322 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    18323 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18324 File
    18325 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18326 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    18327 rinv[:, :] = matrix_inverse(r) 
    18328 ^^^^^^^^^^^^^^^^^ 
    18329 File
    18330 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18331 packages/numpy/linalg/linalg.py", line 561, in inv 
    18332 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    18333 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18334 File
    18335 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18336 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    18337 raise LinAlgError("Singular matrix") 
    18338 numpy.linalg.LinAlgError: Singular matrix 
    18339  
    18340 numpy.linalg.LinAlgError: Singular matrix 
    18341  
    18342 File
    18343 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18344 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    18345 raise LinAlgError("Singular matrix") 
    18346  
    18347 See log for complete Python traceback. 
    18348  
    18349 Traceback (most recent call last): 
    18350 File
    18351 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18352 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    18353 self.session.ui.mouse_modes.mouse_pause_tracking() 
    18354 File
    18355 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18356 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    18357 mouse_pause_tracking 
    18358 self._mouse_pause() 
    18359 File
    18360 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18361 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    18362 m.pause(self._mouse_pause_position) 
    18363 File
    18364 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18365 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    18366 p = self.view.picked_object(x, y) 
    18367 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18368 File
    18369 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18370 packages/chimerax/graphics/view.py", line 838, in picked_object 
    18371 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    18372 beyond, 
    18373 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18374 File
    18375 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18376 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    18377 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    18378 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18379 File
    18380 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18381 packages/chimerax/core/models.py", line 143, in first_intercept 
    18382 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    18383 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18384 File
    18385 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18386 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    18387 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    18388 exclude=exclude) 
    18389 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18390 File
    18391 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18392 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    18393 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    18394 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18395 File
    18396 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18397 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    18398 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    18399 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18400 File
    18401 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18402 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    18403 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    18404 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18405 File
    18406 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18407 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    18408 p = super().first_intercept(mxyz1, mxyz2) 
    18409 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18410 File
    18411 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18412 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    18413 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    18414 exclude=exclude) 
    18415 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18416 File
    18417 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18418 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    18419 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    18420 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18421 File
    18422 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18423 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    18424 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    18425 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18426 File
    18427 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18428 packages/chimerax/graphics/drawing.py", line 1108, in
    18429 _first_intercept_excluding_children 
    18430 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    18431 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18432 File
    18433 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18434 packages/chimerax/geometry/place.py", line 201, in inverse 
    18435 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    18436 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18437 File
    18438 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18439 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    18440 rinv[:, :] = matrix_inverse(r) 
    18441 ^^^^^^^^^^^^^^^^^ 
    18442 File
    18443 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18444 packages/numpy/linalg/linalg.py", line 561, in inv 
    18445 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    18446 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18447 File
    18448 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18449 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    18450 raise LinAlgError("Singular matrix") 
    18451 numpy.linalg.LinAlgError: Singular matrix 
    18452  
    18453 numpy.linalg.LinAlgError: Singular matrix 
    18454  
    18455 File
    18456 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18457 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    18458 raise LinAlgError("Singular matrix") 
    18459  
    18460 See log for complete Python traceback. 
    18461  
    18462 Traceback (most recent call last): 
    18463 File
    18464 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18465 packages/chimerax/mouse_modes/mousemodes.py", line 656, in <lambda> 
    18466 gw.mouseReleaseEvent = lambda e, s=self: s._dispatch_mouse_event(e,
    18467 "mouse_up") 
    18468 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18469 File
    18470 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18471 packages/chimerax/mouse_modes/mousemodes.py", line 556, in
    18472 _dispatch_mouse_event 
    18473 f(MouseEvent(event, modifiers=modifiers)) 
    18474 File
    18475 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18476 packages/chimerax/mouse_modes/std_modes.py", line 70, in mouse_up 
    18477 mouse_select(event, mode, self.session, self.view) 
    18478 File
    18479 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18480 packages/chimerax/mouse_modes/std_modes.py", line 209, in mouse_select 
    18481 pick = view.picked_object(x, y) 
    18482 ^^^^^^^^^^^^^^^^^^^^^^^^ 
    18483 File
    18484 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18485 packages/chimerax/graphics/view.py", line 838, in picked_object 
    18486 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    18487 beyond, 
    18488 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18489 File
    18490 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18491 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    18492 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    18493 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18494 File
    18495 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18496 packages/chimerax/core/models.py", line 143, in first_intercept 
    18497 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    18498 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18499 File
    18500 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18501 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    18502 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    18503 exclude=exclude) 
    18504 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18505 File
    18506 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18507 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    18508 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    18509 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18510 File
    18511 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18512 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    18513 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    18514 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18515 File
    18516 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18517 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    18518 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    18519 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18520 File
    18521 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18522 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    18523 p = super().first_intercept(mxyz1, mxyz2) 
    18524 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18525 File
    18526 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18527 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    18528 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    18529 exclude=exclude) 
    18530 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18531 File
    18532 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18533 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    18534 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    18535 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18536 File
    18537 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18538 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    18539 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    18540 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18541 File
    18542 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18543 packages/chimerax/graphics/drawing.py", line 1108, in
    18544 _first_intercept_excluding_children 
    18545 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    18546 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18547 File
    18548 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18549 packages/chimerax/geometry/place.py", line 201, in inverse 
    18550 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    18551 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18552 File
    18553 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18554 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    18555 rinv[:, :] = matrix_inverse(r) 
    18556 ^^^^^^^^^^^^^^^^^ 
    18557 File
    18558 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18559 packages/numpy/linalg/linalg.py", line 561, in inv 
    18560 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    18561 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18562 File
    18563 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18564 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    18565 raise LinAlgError("Singular matrix") 
    18566 numpy.linalg.LinAlgError: Singular matrix 
    18567  
    18568 numpy.linalg.LinAlgError: Singular matrix 
    18569  
    18570 File
    18571 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18572 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    18573 raise LinAlgError("Singular matrix") 
    18574  
    18575 See log for complete Python traceback. 
    18576  
    18577 Traceback (most recent call last): 
    18578 File
    18579 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18580 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    18581 self.session.ui.mouse_modes.mouse_pause_tracking() 
    18582 File
    18583 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18584 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    18585 mouse_pause_tracking 
    18586 self._mouse_pause() 
    18587 File
    18588 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18589 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    18590 m.pause(self._mouse_pause_position) 
    18591 File
    18592 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18593 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    18594 p = self.view.picked_object(x, y) 
    18595 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18596 File
    18597 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18598 packages/chimerax/graphics/view.py", line 838, in picked_object 
    18599 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    18600 beyond, 
    18601 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18602 File
    18603 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18604 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    18605 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    18606 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18607 File
    18608 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18609 packages/chimerax/core/models.py", line 143, in first_intercept 
    18610 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    18611 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18612 File
    18613 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18614 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    18615 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    18616 exclude=exclude) 
    18617 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18618 File
    18619 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18620 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    18621 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    18622 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18623 File
    18624 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18625 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    18626 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    18627 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18628 File
    18629 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18630 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    18631 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    18632 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18633 File
    18634 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18635 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    18636 p = super().first_intercept(mxyz1, mxyz2) 
    18637 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18638 File
    18639 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18640 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    18641 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    18642 exclude=exclude) 
    18643 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18644 File
    18645 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18646 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    18647 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    18648 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18649 File
    18650 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18651 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    18652 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    18653 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18654 File
    18655 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18656 packages/chimerax/graphics/drawing.py", line 1108, in
    18657 _first_intercept_excluding_children 
    18658 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    18659 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18660 File
    18661 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18662 packages/chimerax/geometry/place.py", line 201, in inverse 
    18663 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    18664 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18665 File
    18666 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18667 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    18668 rinv[:, :] = matrix_inverse(r) 
    18669 ^^^^^^^^^^^^^^^^^ 
    18670 File
    18671 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18672 packages/numpy/linalg/linalg.py", line 561, in inv 
    18673 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    18674 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18675 File
    18676 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18677 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    18678 raise LinAlgError("Singular matrix") 
    18679 numpy.linalg.LinAlgError: Singular matrix 
    18680  
    18681 numpy.linalg.LinAlgError: Singular matrix 
    18682  
    18683 File
    18684 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18685 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    18686 raise LinAlgError("Singular matrix") 
    18687  
    18688 See log for complete Python traceback. 
    18689  
    18690 Traceback (most recent call last): 
    18691 File
    18692 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18693 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    18694 self.session.ui.mouse_modes.mouse_pause_tracking() 
    18695 File
    18696 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18697 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    18698 mouse_pause_tracking 
    18699 self._mouse_pause() 
    18700 File
    18701 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18702 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    18703 m.pause(self._mouse_pause_position) 
    18704 File
    18705 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18706 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    18707 p = self.view.picked_object(x, y) 
    18708 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18709 File
    18710 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18711 packages/chimerax/graphics/view.py", line 838, in picked_object 
    18712 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    18713 beyond, 
    18714 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18715 File
    18716 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18717 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    18718 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    18719 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18720 File
    18721 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18722 packages/chimerax/core/models.py", line 143, in first_intercept 
    18723 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    18724 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18725 File
    18726 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18727 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    18728 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    18729 exclude=exclude) 
    18730 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18731 File
    18732 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18733 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    18734 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    18735 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18736 File
    18737 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18738 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    18739 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    18740 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18741 File
    18742 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18743 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    18744 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    18745 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18746 File
    18747 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18748 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    18749 p = super().first_intercept(mxyz1, mxyz2) 
    18750 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18751 File
    18752 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18753 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    18754 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    18755 exclude=exclude) 
    18756 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18757 File
    18758 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18759 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    18760 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    18761 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18762 File
    18763 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18764 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    18765 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    18766 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18767 File
    18768 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18769 packages/chimerax/graphics/drawing.py", line 1108, in
    18770 _first_intercept_excluding_children 
    18771 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    18772 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18773 File
    18774 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18775 packages/chimerax/geometry/place.py", line 201, in inverse 
    18776 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    18777 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18778 File
    18779 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18780 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    18781 rinv[:, :] = matrix_inverse(r) 
    18782 ^^^^^^^^^^^^^^^^^ 
    18783 File
    18784 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18785 packages/numpy/linalg/linalg.py", line 561, in inv 
    18786 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    18787 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18788 File
    18789 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18790 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    18791 raise LinAlgError("Singular matrix") 
    18792 numpy.linalg.LinAlgError: Singular matrix 
    18793  
    18794 numpy.linalg.LinAlgError: Singular matrix 
    18795  
    18796 File
    18797 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18798 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    18799 raise LinAlgError("Singular matrix") 
    18800  
    18801 See log for complete Python traceback. 
    18802  
    18803 Traceback (most recent call last): 
    18804 File
    18805 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18806 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    18807 self.session.ui.mouse_modes.mouse_pause_tracking() 
    18808 File
    18809 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18810 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    18811 mouse_pause_tracking 
    18812 self._mouse_pause() 
    18813 File
    18814 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18815 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    18816 m.pause(self._mouse_pause_position) 
    18817 File
    18818 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18819 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    18820 p = self.view.picked_object(x, y) 
    18821 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18822 File
    18823 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18824 packages/chimerax/graphics/view.py", line 838, in picked_object 
    18825 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    18826 beyond, 
    18827 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18828 File
    18829 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18830 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    18831 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    18832 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18833 File
    18834 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18835 packages/chimerax/core/models.py", line 143, in first_intercept 
    18836 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    18837 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18838 File
    18839 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18840 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    18841 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    18842 exclude=exclude) 
    18843 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18844 File
    18845 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18846 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    18847 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    18848 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18849 File
    18850 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18851 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    18852 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    18853 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18854 File
    18855 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18856 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    18857 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    18858 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18859 File
    18860 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18861 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    18862 p = super().first_intercept(mxyz1, mxyz2) 
    18863 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18864 File
    18865 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18866 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    18867 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    18868 exclude=exclude) 
    18869 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18870 File
    18871 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18872 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    18873 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    18874 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18875 File
    18876 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18877 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    18878 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    18879 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18880 File
    18881 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18882 packages/chimerax/graphics/drawing.py", line 1108, in
    18883 _first_intercept_excluding_children 
    18884 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    18885 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18886 File
    18887 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18888 packages/chimerax/geometry/place.py", line 201, in inverse 
    18889 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    18890 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18891 File
    18892 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18893 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    18894 rinv[:, :] = matrix_inverse(r) 
    18895 ^^^^^^^^^^^^^^^^^ 
    18896 File
    18897 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18898 packages/numpy/linalg/linalg.py", line 561, in inv 
    18899 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    18900 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18901 File
    18902 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18903 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    18904 raise LinAlgError("Singular matrix") 
    18905 numpy.linalg.LinAlgError: Singular matrix 
    18906  
    18907 numpy.linalg.LinAlgError: Singular matrix 
    18908  
    18909 File
    18910 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18911 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    18912 raise LinAlgError("Singular matrix") 
    18913  
    18914 See log for complete Python traceback. 
    18915  
    18916 Traceback (most recent call last): 
    18917 File
    18918 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18919 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    18920 self.session.ui.mouse_modes.mouse_pause_tracking() 
    18921 File
    18922 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18923 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    18924 mouse_pause_tracking 
    18925 self._mouse_pause() 
    18926 File
    18927 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18928 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    18929 m.pause(self._mouse_pause_position) 
    18930 File
    18931 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18932 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    18933 p = self.view.picked_object(x, y) 
    18934 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18935 File
    18936 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18937 packages/chimerax/graphics/view.py", line 838, in picked_object 
    18938 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    18939 beyond, 
    18940 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18941 File
    18942 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18943 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    18944 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    18945 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18946 File
    18947 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18948 packages/chimerax/core/models.py", line 143, in first_intercept 
    18949 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    18950 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18951 File
    18952 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18953 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    18954 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    18955 exclude=exclude) 
    18956 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18957 File
    18958 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18959 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    18960 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    18961 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18962 File
    18963 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18964 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    18965 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    18966 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18967 File
    18968 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18969 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    18970 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    18971 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18972 File
    18973 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18974 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    18975 p = super().first_intercept(mxyz1, mxyz2) 
    18976 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18977 File
    18978 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18979 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    18980 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    18981 exclude=exclude) 
    18982 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18983 File
    18984 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18985 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    18986 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    18987 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18988 File
    18989 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18990 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    18991 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    18992 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18993 File
    18994 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    18995 packages/chimerax/graphics/drawing.py", line 1108, in
    18996 _first_intercept_excluding_children 
    18997 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    18998 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    18999 File
    19000 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19001 packages/chimerax/geometry/place.py", line 201, in inverse 
    19002 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    19003 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19004 File
    19005 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19006 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    19007 rinv[:, :] = matrix_inverse(r) 
    19008 ^^^^^^^^^^^^^^^^^ 
    19009 File
    19010 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19011 packages/numpy/linalg/linalg.py", line 561, in inv 
    19012 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    19013 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19014 File
    19015 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19016 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    19017 raise LinAlgError("Singular matrix") 
    19018 numpy.linalg.LinAlgError: Singular matrix 
    19019  
    19020 numpy.linalg.LinAlgError: Singular matrix 
    19021  
    19022 File
    19023 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19024 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    19025 raise LinAlgError("Singular matrix") 
    19026  
    19027 See log for complete Python traceback. 
    19028  
    19029 Traceback (most recent call last): 
    19030 File
    19031 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19032 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    19033 self.session.ui.mouse_modes.mouse_pause_tracking() 
    19034 File
    19035 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19036 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    19037 mouse_pause_tracking 
    19038 self._mouse_pause() 
    19039 File
    19040 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19041 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    19042 m.pause(self._mouse_pause_position) 
    19043 File
    19044 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19045 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    19046 p = self.view.picked_object(x, y) 
    19047 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19048 File
    19049 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19050 packages/chimerax/graphics/view.py", line 838, in picked_object 
    19051 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    19052 beyond, 
    19053 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19054 File
    19055 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19056 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    19057 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    19058 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19059 File
    19060 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19061 packages/chimerax/core/models.py", line 143, in first_intercept 
    19062 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    19063 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19064 File
    19065 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19066 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    19067 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    19068 exclude=exclude) 
    19069 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19070 File
    19071 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19072 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    19073 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    19074 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19075 File
    19076 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19077 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    19078 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    19079 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19080 File
    19081 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19082 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    19083 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    19084 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19085 File
    19086 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19087 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    19088 p = super().first_intercept(mxyz1, mxyz2) 
    19089 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19090 File
    19091 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19092 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    19093 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    19094 exclude=exclude) 
    19095 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19096 File
    19097 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19098 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    19099 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    19100 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19101 File
    19102 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19103 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    19104 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    19105 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19106 File
    19107 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19108 packages/chimerax/graphics/drawing.py", line 1108, in
    19109 _first_intercept_excluding_children 
    19110 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    19111 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19112 File
    19113 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19114 packages/chimerax/geometry/place.py", line 201, in inverse 
    19115 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    19116 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19117 File
    19118 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19119 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    19120 rinv[:, :] = matrix_inverse(r) 
    19121 ^^^^^^^^^^^^^^^^^ 
    19122 File
    19123 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19124 packages/numpy/linalg/linalg.py", line 561, in inv 
    19125 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    19126 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19127 File
    19128 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19129 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    19130 raise LinAlgError("Singular matrix") 
    19131 numpy.linalg.LinAlgError: Singular matrix 
    19132  
    19133 numpy.linalg.LinAlgError: Singular matrix 
    19134  
    19135 File
    19136 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19137 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    19138 raise LinAlgError("Singular matrix") 
    19139  
    19140 See log for complete Python traceback. 
    19141  
    19142 Traceback (most recent call last): 
    19143 File
    19144 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19145 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    19146 self.session.ui.mouse_modes.mouse_pause_tracking() 
    19147 File
    19148 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19149 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    19150 mouse_pause_tracking 
    19151 self._mouse_pause() 
    19152 File
    19153 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19154 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    19155 m.pause(self._mouse_pause_position) 
    19156 File
    19157 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19158 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    19159 p = self.view.picked_object(x, y) 
    19160 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19161 File
    19162 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19163 packages/chimerax/graphics/view.py", line 838, in picked_object 
    19164 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    19165 beyond, 
    19166 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19167 File
    19168 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19169 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    19170 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    19171 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19172 File
    19173 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19174 packages/chimerax/core/models.py", line 143, in first_intercept 
    19175 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    19176 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19177 File
    19178 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19179 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    19180 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    19181 exclude=exclude) 
    19182 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19183 File
    19184 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19185 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    19186 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    19187 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19188 File
    19189 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19190 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    19191 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    19192 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19193 File
    19194 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19195 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    19196 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    19197 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19198 File
    19199 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19200 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    19201 p = super().first_intercept(mxyz1, mxyz2) 
    19202 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19203 File
    19204 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19205 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    19206 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    19207 exclude=exclude) 
    19208 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19209 File
    19210 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19211 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    19212 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    19213 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19214 File
    19215 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19216 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    19217 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    19218 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19219 File
    19220 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19221 packages/chimerax/graphics/drawing.py", line 1108, in
    19222 _first_intercept_excluding_children 
    19223 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    19224 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19225 File
    19226 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19227 packages/chimerax/geometry/place.py", line 201, in inverse 
    19228 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    19229 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19230 File
    19231 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19232 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    19233 rinv[:, :] = matrix_inverse(r) 
    19234 ^^^^^^^^^^^^^^^^^ 
    19235 File
    19236 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19237 packages/numpy/linalg/linalg.py", line 561, in inv 
    19238 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    19239 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19240 File
    19241 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19242 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    19243 raise LinAlgError("Singular matrix") 
    19244 numpy.linalg.LinAlgError: Singular matrix 
    19245  
    19246 numpy.linalg.LinAlgError: Singular matrix 
    19247  
    19248 File
    19249 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19250 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    19251 raise LinAlgError("Singular matrix") 
    19252  
    19253 See log for complete Python traceback. 
    19254  
    19255 Traceback (most recent call last): 
    19256 File
    19257 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19258 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    19259 self.session.ui.mouse_modes.mouse_pause_tracking() 
    19260 File
    19261 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19262 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    19263 mouse_pause_tracking 
    19264 self._mouse_pause() 
    19265 File
    19266 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19267 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    19268 m.pause(self._mouse_pause_position) 
    19269 File
    19270 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19271 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    19272 p = self.view.picked_object(x, y) 
    19273 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19274 File
    19275 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19276 packages/chimerax/graphics/view.py", line 838, in picked_object 
    19277 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    19278 beyond, 
    19279 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19280 File
    19281 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19282 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    19283 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    19284 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19285 File
    19286 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19287 packages/chimerax/core/models.py", line 143, in first_intercept 
    19288 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    19289 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19290 File
    19291 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19292 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    19293 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    19294 exclude=exclude) 
    19295 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19296 File
    19297 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19298 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    19299 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    19300 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19301 File
    19302 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19303 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    19304 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    19305 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19306 File
    19307 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19308 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    19309 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    19310 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19311 File
    19312 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19313 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    19314 p = super().first_intercept(mxyz1, mxyz2) 
    19315 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19316 File
    19317 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19318 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    19319 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    19320 exclude=exclude) 
    19321 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19322 File
    19323 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19324 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    19325 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    19326 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19327 File
    19328 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19329 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    19330 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    19331 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19332 File
    19333 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19334 packages/chimerax/graphics/drawing.py", line 1108, in
    19335 _first_intercept_excluding_children 
    19336 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    19337 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19338 File
    19339 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19340 packages/chimerax/geometry/place.py", line 201, in inverse 
    19341 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    19342 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19343 File
    19344 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19345 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    19346 rinv[:, :] = matrix_inverse(r) 
    19347 ^^^^^^^^^^^^^^^^^ 
    19348 File
    19349 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19350 packages/numpy/linalg/linalg.py", line 561, in inv 
    19351 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    19352 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19353 File
    19354 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19355 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    19356 raise LinAlgError("Singular matrix") 
    19357 numpy.linalg.LinAlgError: Singular matrix 
    19358  
    19359 numpy.linalg.LinAlgError: Singular matrix 
    19360  
    19361 File
    19362 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19363 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    19364 raise LinAlgError("Singular matrix") 
    19365  
    19366 See log for complete Python traceback. 
    19367  
    19368 Traceback (most recent call last): 
    19369 File
    19370 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19371 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    19372 self.session.ui.mouse_modes.mouse_pause_tracking() 
    19373 File
    19374 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19375 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    19376 mouse_pause_tracking 
    19377 self._mouse_pause() 
    19378 File
    19379 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19380 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    19381 m.pause(self._mouse_pause_position) 
    19382 File
    19383 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19384 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    19385 p = self.view.picked_object(x, y) 
    19386 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19387 File
    19388 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19389 packages/chimerax/graphics/view.py", line 838, in picked_object 
    19390 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    19391 beyond, 
    19392 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19393 File
    19394 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19395 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    19396 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    19397 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19398 File
    19399 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19400 packages/chimerax/core/models.py", line 143, in first_intercept 
    19401 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    19402 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19403 File
    19404 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19405 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    19406 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    19407 exclude=exclude) 
    19408 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19409 File
    19410 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19411 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    19412 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    19413 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19414 File
    19415 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19416 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    19417 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    19418 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19419 File
    19420 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19421 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    19422 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    19423 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19424 File
    19425 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19426 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    19427 p = super().first_intercept(mxyz1, mxyz2) 
    19428 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19429 File
    19430 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19431 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    19432 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    19433 exclude=exclude) 
    19434 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19435 File
    19436 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19437 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    19438 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    19439 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19440 File
    19441 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19442 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    19443 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    19444 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19445 File
    19446 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19447 packages/chimerax/graphics/drawing.py", line 1108, in
    19448 _first_intercept_excluding_children 
    19449 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    19450 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19451 File
    19452 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19453 packages/chimerax/geometry/place.py", line 201, in inverse 
    19454 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    19455 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19456 File
    19457 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19458 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    19459 rinv[:, :] = matrix_inverse(r) 
    19460 ^^^^^^^^^^^^^^^^^ 
    19461 File
    19462 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19463 packages/numpy/linalg/linalg.py", line 561, in inv 
    19464 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    19465 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19466 File
    19467 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19468 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    19469 raise LinAlgError("Singular matrix") 
    19470 numpy.linalg.LinAlgError: Singular matrix 
    19471  
    19472 numpy.linalg.LinAlgError: Singular matrix 
    19473  
    19474 File
    19475 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19476 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    19477 raise LinAlgError("Singular matrix") 
    19478  
    19479 See log for complete Python traceback. 
    19480  
    19481 Traceback (most recent call last): 
    19482 File
    19483 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19484 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    19485 self.session.ui.mouse_modes.mouse_pause_tracking() 
    19486 File
    19487 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19488 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    19489 mouse_pause_tracking 
    19490 self._mouse_pause() 
    19491 File
    19492 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19493 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    19494 m.pause(self._mouse_pause_position) 
    19495 File
    19496 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19497 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    19498 p = self.view.picked_object(x, y) 
    19499 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19500 File
    19501 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19502 packages/chimerax/graphics/view.py", line 838, in picked_object 
    19503 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    19504 beyond, 
    19505 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19506 File
    19507 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19508 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    19509 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    19510 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19511 File
    19512 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19513 packages/chimerax/core/models.py", line 143, in first_intercept 
    19514 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    19515 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19516 File
    19517 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19518 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    19519 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    19520 exclude=exclude) 
    19521 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19522 File
    19523 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19524 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    19525 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    19526 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19527 File
    19528 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19529 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    19530 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    19531 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19532 File
    19533 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19534 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    19535 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    19536 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19537 File
    19538 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19539 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    19540 p = super().first_intercept(mxyz1, mxyz2) 
    19541 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19542 File
    19543 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19544 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    19545 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    19546 exclude=exclude) 
    19547 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19548 File
    19549 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19550 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    19551 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    19552 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19553 File
    19554 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19555 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    19556 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    19557 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19558 File
    19559 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19560 packages/chimerax/graphics/drawing.py", line 1108, in
    19561 _first_intercept_excluding_children 
    19562 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    19563 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19564 File
    19565 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19566 packages/chimerax/geometry/place.py", line 201, in inverse 
    19567 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    19568 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19569 File
    19570 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19571 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    19572 rinv[:, :] = matrix_inverse(r) 
    19573 ^^^^^^^^^^^^^^^^^ 
    19574 File
    19575 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19576 packages/numpy/linalg/linalg.py", line 561, in inv 
    19577 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    19578 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19579 File
    19580 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19581 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    19582 raise LinAlgError("Singular matrix") 
    19583 numpy.linalg.LinAlgError: Singular matrix 
    19584  
    19585 numpy.linalg.LinAlgError: Singular matrix 
    19586  
    19587 File
    19588 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19589 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    19590 raise LinAlgError("Singular matrix") 
    19591  
    19592 See log for complete Python traceback. 
    19593  
    19594 Traceback (most recent call last): 
    19595 File
    19596 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19597 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    19598 self.session.ui.mouse_modes.mouse_pause_tracking() 
    19599 File
    19600 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19601 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    19602 mouse_pause_tracking 
    19603 self._mouse_pause() 
    19604 File
    19605 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19606 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    19607 m.pause(self._mouse_pause_position) 
    19608 File
    19609 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19610 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    19611 p = self.view.picked_object(x, y) 
    19612 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19613 File
    19614 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19615 packages/chimerax/graphics/view.py", line 838, in picked_object 
    19616 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    19617 beyond, 
    19618 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19619 File
    19620 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19621 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    19622 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    19623 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19624 File
    19625 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19626 packages/chimerax/core/models.py", line 143, in first_intercept 
    19627 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    19628 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19629 File
    19630 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19631 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    19632 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    19633 exclude=exclude) 
    19634 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19635 File
    19636 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19637 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    19638 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    19639 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19640 File
    19641 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19642 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    19643 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    19644 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19645 File
    19646 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19647 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    19648 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    19649 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19650 File
    19651 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19652 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    19653 p = super().first_intercept(mxyz1, mxyz2) 
    19654 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19655 File
    19656 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19657 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    19658 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    19659 exclude=exclude) 
    19660 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19661 File
    19662 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19663 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    19664 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    19665 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19666 File
    19667 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19668 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    19669 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    19670 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19671 File
    19672 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19673 packages/chimerax/graphics/drawing.py", line 1108, in
    19674 _first_intercept_excluding_children 
    19675 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    19676 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19677 File
    19678 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19679 packages/chimerax/geometry/place.py", line 201, in inverse 
    19680 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    19681 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19682 File
    19683 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19684 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    19685 rinv[:, :] = matrix_inverse(r) 
    19686 ^^^^^^^^^^^^^^^^^ 
    19687 File
    19688 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19689 packages/numpy/linalg/linalg.py", line 561, in inv 
    19690 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    19691 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19692 File
    19693 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19694 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    19695 raise LinAlgError("Singular matrix") 
    19696 numpy.linalg.LinAlgError: Singular matrix 
    19697  
    19698 numpy.linalg.LinAlgError: Singular matrix 
    19699  
    19700 File
    19701 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19702 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    19703 raise LinAlgError("Singular matrix") 
    19704  
    19705 See log for complete Python traceback. 
    19706  
    19707 Traceback (most recent call last): 
    19708 File
    19709 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19710 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    19711 self.session.ui.mouse_modes.mouse_pause_tracking() 
    19712 File
    19713 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19714 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    19715 mouse_pause_tracking 
    19716 self._mouse_pause() 
    19717 File
    19718 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19719 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    19720 m.pause(self._mouse_pause_position) 
    19721 File
    19722 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19723 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    19724 p = self.view.picked_object(x, y) 
    19725 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19726 File
    19727 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19728 packages/chimerax/graphics/view.py", line 838, in picked_object 
    19729 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    19730 beyond, 
    19731 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19732 File
    19733 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19734 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    19735 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    19736 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19737 File
    19738 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19739 packages/chimerax/core/models.py", line 143, in first_intercept 
    19740 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    19741 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19742 File
    19743 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19744 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    19745 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    19746 exclude=exclude) 
    19747 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19748 File
    19749 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19750 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    19751 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    19752 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19753 File
    19754 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19755 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    19756 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    19757 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19758 File
    19759 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19760 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    19761 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    19762 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19763 File
    19764 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19765 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    19766 p = super().first_intercept(mxyz1, mxyz2) 
    19767 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19768 File
    19769 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19770 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    19771 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    19772 exclude=exclude) 
    19773 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19774 File
    19775 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19776 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    19777 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    19778 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19779 File
    19780 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19781 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    19782 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    19783 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19784 File
    19785 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19786 packages/chimerax/graphics/drawing.py", line 1108, in
    19787 _first_intercept_excluding_children 
    19788 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    19789 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19790 File
    19791 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19792 packages/chimerax/geometry/place.py", line 201, in inverse 
    19793 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    19794 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19795 File
    19796 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19797 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    19798 rinv[:, :] = matrix_inverse(r) 
    19799 ^^^^^^^^^^^^^^^^^ 
    19800 File
    19801 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19802 packages/numpy/linalg/linalg.py", line 561, in inv 
    19803 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    19804 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19805 File
    19806 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19807 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    19808 raise LinAlgError("Singular matrix") 
    19809 numpy.linalg.LinAlgError: Singular matrix 
    19810  
    19811 numpy.linalg.LinAlgError: Singular matrix 
    19812  
    19813 File
    19814 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19815 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    19816 raise LinAlgError("Singular matrix") 
    19817  
    19818 See log for complete Python traceback. 
    19819  
    19820 Traceback (most recent call last): 
    19821 File
    19822 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19823 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    19824 self.session.ui.mouse_modes.mouse_pause_tracking() 
    19825 File
    19826 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19827 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    19828 mouse_pause_tracking 
    19829 self._mouse_pause() 
    19830 File
    19831 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19832 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    19833 m.pause(self._mouse_pause_position) 
    19834 File
    19835 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19836 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    19837 p = self.view.picked_object(x, y) 
    19838 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19839 File
    19840 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19841 packages/chimerax/graphics/view.py", line 838, in picked_object 
    19842 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    19843 beyond, 
    19844 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19845 File
    19846 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19847 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    19848 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    19849 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19850 File
    19851 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19852 packages/chimerax/core/models.py", line 143, in first_intercept 
    19853 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    19854 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19855 File
    19856 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19857 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    19858 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    19859 exclude=exclude) 
    19860 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19861 File
    19862 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19863 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    19864 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    19865 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19866 File
    19867 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19868 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    19869 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    19870 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19871 File
    19872 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19873 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    19874 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    19875 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19876 File
    19877 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19878 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    19879 p = super().first_intercept(mxyz1, mxyz2) 
    19880 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19881 File
    19882 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19883 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    19884 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    19885 exclude=exclude) 
    19886 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19887 File
    19888 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19889 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    19890 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    19891 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19892 File
    19893 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19894 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    19895 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    19896 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19897 File
    19898 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19899 packages/chimerax/graphics/drawing.py", line 1108, in
    19900 _first_intercept_excluding_children 
    19901 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    19902 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19903 File
    19904 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19905 packages/chimerax/geometry/place.py", line 201, in inverse 
    19906 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    19907 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19908 File
    19909 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19910 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    19911 rinv[:, :] = matrix_inverse(r) 
    19912 ^^^^^^^^^^^^^^^^^ 
    19913 File
    19914 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19915 packages/numpy/linalg/linalg.py", line 561, in inv 
    19916 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    19917 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19918 File
    19919 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19920 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    19921 raise LinAlgError("Singular matrix") 
    19922 numpy.linalg.LinAlgError: Singular matrix 
    19923  
    19924 numpy.linalg.LinAlgError: Singular matrix 
    19925  
    19926 File
    19927 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19928 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    19929 raise LinAlgError("Singular matrix") 
    19930  
    19931 See log for complete Python traceback. 
    19932  
    19933 Traceback (most recent call last): 
    19934 File
    19935 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19936 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    19937 self.session.ui.mouse_modes.mouse_pause_tracking() 
    19938 File
    19939 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19940 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    19941 mouse_pause_tracking 
    19942 self._mouse_pause() 
    19943 File
    19944 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19945 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    19946 m.pause(self._mouse_pause_position) 
    19947 File
    19948 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19949 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    19950 p = self.view.picked_object(x, y) 
    19951 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19952 File
    19953 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19954 packages/chimerax/graphics/view.py", line 838, in picked_object 
    19955 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    19956 beyond, 
    19957 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19958 File
    19959 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19960 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    19961 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    19962 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19963 File
    19964 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19965 packages/chimerax/core/models.py", line 143, in first_intercept 
    19966 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    19967 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19968 File
    19969 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19970 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    19971 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    19972 exclude=exclude) 
    19973 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19974 File
    19975 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19976 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    19977 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    19978 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19979 File
    19980 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19981 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    19982 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    19983 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19984 File
    19985 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19986 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    19987 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    19988 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19989 File
    19990 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19991 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    19992 p = super().first_intercept(mxyz1, mxyz2) 
    19993 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    19994 File
    19995 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    19996 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    19997 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    19998 exclude=exclude) 
    19999 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20000 File
    20001 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20002 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    20003 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    20004 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20005 File
    20006 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20007 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    20008 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    20009 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20010 File
    20011 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20012 packages/chimerax/graphics/drawing.py", line 1108, in
    20013 _first_intercept_excluding_children 
    20014 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    20015 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20016 File
    20017 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20018 packages/chimerax/geometry/place.py", line 201, in inverse 
    20019 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    20020 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20021 File
    20022 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20023 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    20024 rinv[:, :] = matrix_inverse(r) 
    20025 ^^^^^^^^^^^^^^^^^ 
    20026 File
    20027 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20028 packages/numpy/linalg/linalg.py", line 561, in inv 
    20029 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    20030 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20031 File
    20032 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20033 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    20034 raise LinAlgError("Singular matrix") 
    20035 numpy.linalg.LinAlgError: Singular matrix 
    20036  
    20037 numpy.linalg.LinAlgError: Singular matrix 
    20038  
    20039 File
    20040 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20041 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    20042 raise LinAlgError("Singular matrix") 
    20043  
    20044 See log for complete Python traceback. 
    20045  
    20046 Traceback (most recent call last): 
    20047 File
    20048 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20049 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    20050 self.session.ui.mouse_modes.mouse_pause_tracking() 
    20051 File
    20052 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20053 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    20054 mouse_pause_tracking 
    20055 self._mouse_pause() 
    20056 File
    20057 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20058 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    20059 m.pause(self._mouse_pause_position) 
    20060 File
    20061 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20062 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    20063 p = self.view.picked_object(x, y) 
    20064 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20065 File
    20066 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20067 packages/chimerax/graphics/view.py", line 838, in picked_object 
    20068 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    20069 beyond, 
    20070 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20071 File
    20072 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20073 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    20074 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    20075 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20076 File
    20077 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20078 packages/chimerax/core/models.py", line 143, in first_intercept 
    20079 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    20080 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20081 File
    20082 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20083 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    20084 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    20085 exclude=exclude) 
    20086 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20087 File
    20088 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20089 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    20090 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    20091 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20092 File
    20093 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20094 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    20095 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    20096 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20097 File
    20098 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20099 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    20100 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    20101 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20102 File
    20103 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20104 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    20105 p = super().first_intercept(mxyz1, mxyz2) 
    20106 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20107 File
    20108 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20109 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    20110 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    20111 exclude=exclude) 
    20112 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20113 File
    20114 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20115 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    20116 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    20117 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20118 File
    20119 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20120 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    20121 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    20122 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20123 File
    20124 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20125 packages/chimerax/graphics/drawing.py", line 1108, in
    20126 _first_intercept_excluding_children 
    20127 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    20128 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20129 File
    20130 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20131 packages/chimerax/geometry/place.py", line 201, in inverse 
    20132 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    20133 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20134 File
    20135 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20136 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    20137 rinv[:, :] = matrix_inverse(r) 
    20138 ^^^^^^^^^^^^^^^^^ 
    20139 File
    20140 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20141 packages/numpy/linalg/linalg.py", line 561, in inv 
    20142 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    20143 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20144 File
    20145 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20146 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    20147 raise LinAlgError("Singular matrix") 
    20148 numpy.linalg.LinAlgError: Singular matrix 
    20149  
    20150 numpy.linalg.LinAlgError: Singular matrix 
    20151  
    20152 File
    20153 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20154 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    20155 raise LinAlgError("Singular matrix") 
    20156  
    20157 See log for complete Python traceback. 
    20158  
    20159 Traceback (most recent call last): 
    20160 File
    20161 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20162 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    20163 self.session.ui.mouse_modes.mouse_pause_tracking() 
    20164 File
    20165 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20166 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    20167 mouse_pause_tracking 
    20168 self._mouse_pause() 
    20169 File
    20170 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20171 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    20172 m.pause(self._mouse_pause_position) 
    20173 File
    20174 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20175 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    20176 p = self.view.picked_object(x, y) 
    20177 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20178 File
    20179 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20180 packages/chimerax/graphics/view.py", line 838, in picked_object 
    20181 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    20182 beyond, 
    20183 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20184 File
    20185 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20186 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    20187 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    20188 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20189 File
    20190 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20191 packages/chimerax/core/models.py", line 143, in first_intercept 
    20192 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    20193 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20194 File
    20195 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20196 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    20197 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    20198 exclude=exclude) 
    20199 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20200 File
    20201 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20202 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    20203 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    20204 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20205 File
    20206 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20207 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    20208 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    20209 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20210 File
    20211 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20212 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    20213 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    20214 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20215 File
    20216 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20217 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    20218 p = super().first_intercept(mxyz1, mxyz2) 
    20219 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20220 File
    20221 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20222 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    20223 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    20224 exclude=exclude) 
    20225 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20226 File
    20227 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20228 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    20229 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    20230 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20231 File
    20232 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20233 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    20234 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    20235 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20236 File
    20237 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20238 packages/chimerax/graphics/drawing.py", line 1108, in
    20239 _first_intercept_excluding_children 
    20240 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    20241 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20242 File
    20243 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20244 packages/chimerax/geometry/place.py", line 201, in inverse 
    20245 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    20246 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20247 File
    20248 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20249 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    20250 rinv[:, :] = matrix_inverse(r) 
    20251 ^^^^^^^^^^^^^^^^^ 
    20252 File
    20253 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20254 packages/numpy/linalg/linalg.py", line 561, in inv 
    20255 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    20256 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20257 File
    20258 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20259 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    20260 raise LinAlgError("Singular matrix") 
    20261 numpy.linalg.LinAlgError: Singular matrix 
    20262  
    20263 numpy.linalg.LinAlgError: Singular matrix 
    20264  
    20265 File
    20266 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20267 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    20268 raise LinAlgError("Singular matrix") 
    20269  
    20270 See log for complete Python traceback. 
    20271  
    20272 Traceback (most recent call last): 
    20273 File
    20274 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20275 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    20276 self.session.ui.mouse_modes.mouse_pause_tracking() 
    20277 File
    20278 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20279 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    20280 mouse_pause_tracking 
    20281 self._mouse_pause() 
    20282 File
    20283 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20284 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    20285 m.pause(self._mouse_pause_position) 
    20286 File
    20287 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20288 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    20289 p = self.view.picked_object(x, y) 
    20290 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20291 File
    20292 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20293 packages/chimerax/graphics/view.py", line 838, in picked_object 
    20294 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    20295 beyond, 
    20296 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20297 File
    20298 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20299 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    20300 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    20301 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20302 File
    20303 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20304 packages/chimerax/core/models.py", line 143, in first_intercept 
    20305 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    20306 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20307 File
    20308 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20309 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    20310 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    20311 exclude=exclude) 
    20312 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20313 File
    20314 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20315 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    20316 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    20317 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20318 File
    20319 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20320 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    20321 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    20322 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20323 File
    20324 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20325 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    20326 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    20327 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20328 File
    20329 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20330 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    20331 p = super().first_intercept(mxyz1, mxyz2) 
    20332 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20333 File
    20334 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20335 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    20336 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    20337 exclude=exclude) 
    20338 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20339 File
    20340 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20341 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    20342 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    20343 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20344 File
    20345 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20346 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    20347 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    20348 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20349 File
    20350 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20351 packages/chimerax/graphics/drawing.py", line 1108, in
    20352 _first_intercept_excluding_children 
    20353 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    20354 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20355 File
    20356 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20357 packages/chimerax/geometry/place.py", line 201, in inverse 
    20358 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    20359 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20360 File
    20361 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20362 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    20363 rinv[:, :] = matrix_inverse(r) 
    20364 ^^^^^^^^^^^^^^^^^ 
    20365 File
    20366 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20367 packages/numpy/linalg/linalg.py", line 561, in inv 
    20368 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    20369 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20370 File
    20371 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20372 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    20373 raise LinAlgError("Singular matrix") 
    20374 numpy.linalg.LinAlgError: Singular matrix 
    20375  
    20376 numpy.linalg.LinAlgError: Singular matrix 
    20377  
    20378 File
    20379 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20380 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    20381 raise LinAlgError("Singular matrix") 
    20382  
    20383 See log for complete Python traceback. 
    20384  
    20385 Traceback (most recent call last): 
    20386 File
    20387 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20388 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    20389 self.session.ui.mouse_modes.mouse_pause_tracking() 
    20390 File
    20391 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20392 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    20393 mouse_pause_tracking 
    20394 self._mouse_pause() 
    20395 File
    20396 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20397 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    20398 m.pause(self._mouse_pause_position) 
    20399 File
    20400 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20401 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    20402 p = self.view.picked_object(x, y) 
    20403 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20404 File
    20405 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20406 packages/chimerax/graphics/view.py", line 838, in picked_object 
    20407 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    20408 beyond, 
    20409 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20410 File
    20411 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20412 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    20413 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    20414 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20415 File
    20416 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20417 packages/chimerax/core/models.py", line 143, in first_intercept 
    20418 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    20419 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20420 File
    20421 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20422 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    20423 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    20424 exclude=exclude) 
    20425 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20426 File
    20427 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20428 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    20429 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    20430 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20431 File
    20432 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20433 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    20434 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    20435 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20436 File
    20437 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20438 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    20439 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    20440 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20441 File
    20442 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20443 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    20444 p = super().first_intercept(mxyz1, mxyz2) 
    20445 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20446 File
    20447 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20448 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    20449 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    20450 exclude=exclude) 
    20451 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20452 File
    20453 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20454 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    20455 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    20456 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20457 File
    20458 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20459 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    20460 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    20461 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20462 File
    20463 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20464 packages/chimerax/graphics/drawing.py", line 1108, in
    20465 _first_intercept_excluding_children 
    20466 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    20467 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20468 File
    20469 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20470 packages/chimerax/geometry/place.py", line 201, in inverse 
    20471 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    20472 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20473 File
    20474 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20475 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    20476 rinv[:, :] = matrix_inverse(r) 
    20477 ^^^^^^^^^^^^^^^^^ 
    20478 File
    20479 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20480 packages/numpy/linalg/linalg.py", line 561, in inv 
    20481 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    20482 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20483 File
    20484 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20485 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    20486 raise LinAlgError("Singular matrix") 
    20487 numpy.linalg.LinAlgError: Singular matrix 
    20488  
    20489 numpy.linalg.LinAlgError: Singular matrix 
    20490  
    20491 File
    20492 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20493 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    20494 raise LinAlgError("Singular matrix") 
    20495  
    20496 See log for complete Python traceback. 
    20497  
    20498 Traceback (most recent call last): 
    20499 File
    20500 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20501 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    20502 self.session.ui.mouse_modes.mouse_pause_tracking() 
    20503 File
    20504 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20505 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    20506 mouse_pause_tracking 
    20507 self._mouse_pause() 
    20508 File
    20509 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20510 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    20511 m.pause(self._mouse_pause_position) 
    20512 File
    20513 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20514 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    20515 p = self.view.picked_object(x, y) 
    20516 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20517 File
    20518 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20519 packages/chimerax/graphics/view.py", line 838, in picked_object 
    20520 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    20521 beyond, 
    20522 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20523 File
    20524 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20525 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    20526 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    20527 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20528 File
    20529 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20530 packages/chimerax/core/models.py", line 143, in first_intercept 
    20531 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    20532 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20533 File
    20534 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20535 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    20536 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    20537 exclude=exclude) 
    20538 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20539 File
    20540 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20541 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    20542 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    20543 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20544 File
    20545 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20546 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    20547 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    20548 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20549 File
    20550 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20551 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    20552 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    20553 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20554 File
    20555 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20556 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    20557 p = super().first_intercept(mxyz1, mxyz2) 
    20558 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20559 File
    20560 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20561 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    20562 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    20563 exclude=exclude) 
    20564 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20565 File
    20566 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20567 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    20568 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    20569 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20570 File
    20571 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20572 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    20573 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    20574 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20575 File
    20576 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20577 packages/chimerax/graphics/drawing.py", line 1108, in
    20578 _first_intercept_excluding_children 
    20579 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    20580 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20581 File
    20582 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20583 packages/chimerax/geometry/place.py", line 201, in inverse 
    20584 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    20585 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20586 File
    20587 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20588 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    20589 rinv[:, :] = matrix_inverse(r) 
    20590 ^^^^^^^^^^^^^^^^^ 
    20591 File
    20592 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20593 packages/numpy/linalg/linalg.py", line 561, in inv 
    20594 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    20595 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20596 File
    20597 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20598 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    20599 raise LinAlgError("Singular matrix") 
    20600 numpy.linalg.LinAlgError: Singular matrix 
    20601  
    20602 numpy.linalg.LinAlgError: Singular matrix 
    20603  
    20604 File
    20605 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20606 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    20607 raise LinAlgError("Singular matrix") 
    20608  
    20609 See log for complete Python traceback. 
    20610  
    20611 Traceback (most recent call last): 
    20612 File
    20613 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20614 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    20615 self.session.ui.mouse_modes.mouse_pause_tracking() 
    20616 File
    20617 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20618 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    20619 mouse_pause_tracking 
    20620 self._mouse_pause() 
    20621 File
    20622 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20623 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    20624 m.pause(self._mouse_pause_position) 
    20625 File
    20626 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20627 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    20628 p = self.view.picked_object(x, y) 
    20629 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20630 File
    20631 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20632 packages/chimerax/graphics/view.py", line 838, in picked_object 
    20633 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    20634 beyond, 
    20635 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20636 File
    20637 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20638 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    20639 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    20640 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20641 File
    20642 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20643 packages/chimerax/core/models.py", line 143, in first_intercept 
    20644 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    20645 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20646 File
    20647 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20648 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    20649 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    20650 exclude=exclude) 
    20651 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20652 File
    20653 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20654 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    20655 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    20656 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20657 File
    20658 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20659 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    20660 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    20661 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20662 File
    20663 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20664 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    20665 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    20666 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20667 File
    20668 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20669 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    20670 p = super().first_intercept(mxyz1, mxyz2) 
    20671 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20672 File
    20673 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20674 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    20675 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    20676 exclude=exclude) 
    20677 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20678 File
    20679 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20680 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    20681 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    20682 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20683 File
    20684 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20685 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    20686 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    20687 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20688 File
    20689 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20690 packages/chimerax/graphics/drawing.py", line 1108, in
    20691 _first_intercept_excluding_children 
    20692 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    20693 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20694 File
    20695 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20696 packages/chimerax/geometry/place.py", line 201, in inverse 
    20697 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    20698 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20699 File
    20700 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20701 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    20702 rinv[:, :] = matrix_inverse(r) 
    20703 ^^^^^^^^^^^^^^^^^ 
    20704 File
    20705 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20706 packages/numpy/linalg/linalg.py", line 561, in inv 
    20707 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    20708 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20709 File
    20710 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20711 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    20712 raise LinAlgError("Singular matrix") 
    20713 numpy.linalg.LinAlgError: Singular matrix 
    20714  
    20715 numpy.linalg.LinAlgError: Singular matrix 
    20716  
    20717 File
    20718 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20719 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    20720 raise LinAlgError("Singular matrix") 
    20721  
    20722 See log for complete Python traceback. 
    20723  
    20724 Traceback (most recent call last): 
    20725 File
    20726 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20727 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    20728 self.session.ui.mouse_modes.mouse_pause_tracking() 
    20729 File
    20730 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20731 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    20732 mouse_pause_tracking 
    20733 self._mouse_pause() 
    20734 File
    20735 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20736 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    20737 m.pause(self._mouse_pause_position) 
    20738 File
    20739 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20740 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    20741 p = self.view.picked_object(x, y) 
    20742 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20743 File
    20744 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20745 packages/chimerax/graphics/view.py", line 838, in picked_object 
    20746 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    20747 beyond, 
    20748 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20749 File
    20750 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20751 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    20752 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    20753 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20754 File
    20755 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20756 packages/chimerax/core/models.py", line 143, in first_intercept 
    20757 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    20758 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20759 File
    20760 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20761 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    20762 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    20763 exclude=exclude) 
    20764 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20765 File
    20766 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20767 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    20768 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    20769 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20770 File
    20771 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20772 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    20773 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    20774 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20775 File
    20776 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20777 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    20778 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    20779 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20780 File
    20781 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20782 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    20783 p = super().first_intercept(mxyz1, mxyz2) 
    20784 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20785 File
    20786 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20787 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    20788 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    20789 exclude=exclude) 
    20790 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20791 File
    20792 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20793 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    20794 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    20795 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20796 File
    20797 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20798 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    20799 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    20800 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20801 File
    20802 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20803 packages/chimerax/graphics/drawing.py", line 1108, in
    20804 _first_intercept_excluding_children 
    20805 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    20806 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20807 File
    20808 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20809 packages/chimerax/geometry/place.py", line 201, in inverse 
    20810 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    20811 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20812 File
    20813 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20814 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    20815 rinv[:, :] = matrix_inverse(r) 
    20816 ^^^^^^^^^^^^^^^^^ 
    20817 File
    20818 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20819 packages/numpy/linalg/linalg.py", line 561, in inv 
    20820 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    20821 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20822 File
    20823 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20824 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    20825 raise LinAlgError("Singular matrix") 
    20826 numpy.linalg.LinAlgError: Singular matrix 
    20827  
    20828 numpy.linalg.LinAlgError: Singular matrix 
    20829  
    20830 File
    20831 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20832 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    20833 raise LinAlgError("Singular matrix") 
    20834  
    20835 See log for complete Python traceback. 
    20836  
    20837 Traceback (most recent call last): 
    20838 File
    20839 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20840 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    20841 self.session.ui.mouse_modes.mouse_pause_tracking() 
    20842 File
    20843 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20844 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    20845 mouse_pause_tracking 
    20846 self._mouse_pause() 
    20847 File
    20848 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20849 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    20850 m.pause(self._mouse_pause_position) 
    20851 File
    20852 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20853 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    20854 p = self.view.picked_object(x, y) 
    20855 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20856 File
    20857 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20858 packages/chimerax/graphics/view.py", line 838, in picked_object 
    20859 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    20860 beyond, 
    20861 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20862 File
    20863 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20864 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    20865 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    20866 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20867 File
    20868 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20869 packages/chimerax/core/models.py", line 143, in first_intercept 
    20870 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    20871 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20872 File
    20873 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20874 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    20875 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    20876 exclude=exclude) 
    20877 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20878 File
    20879 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20880 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    20881 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    20882 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20883 File
    20884 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20885 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    20886 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    20887 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20888 File
    20889 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20890 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    20891 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    20892 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20893 File
    20894 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20895 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    20896 p = super().first_intercept(mxyz1, mxyz2) 
    20897 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20898 File
    20899 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20900 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    20901 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    20902 exclude=exclude) 
    20903 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20904 File
    20905 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20906 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    20907 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    20908 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20909 File
    20910 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20911 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    20912 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    20913 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20914 File
    20915 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20916 packages/chimerax/graphics/drawing.py", line 1108, in
    20917 _first_intercept_excluding_children 
    20918 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    20919 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20920 File
    20921 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20922 packages/chimerax/geometry/place.py", line 201, in inverse 
    20923 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    20924 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20925 File
    20926 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20927 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    20928 rinv[:, :] = matrix_inverse(r) 
    20929 ^^^^^^^^^^^^^^^^^ 
    20930 File
    20931 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20932 packages/numpy/linalg/linalg.py", line 561, in inv 
    20933 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    20934 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20935 File
    20936 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20937 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    20938 raise LinAlgError("Singular matrix") 
    20939 numpy.linalg.LinAlgError: Singular matrix 
    20940  
    20941 numpy.linalg.LinAlgError: Singular matrix 
    20942  
    20943 File
    20944 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20945 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    20946 raise LinAlgError("Singular matrix") 
    20947  
    20948 See log for complete Python traceback. 
    20949  
    20950 Traceback (most recent call last): 
    20951 File
    20952 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20953 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    20954 self.session.ui.mouse_modes.mouse_pause_tracking() 
    20955 File
    20956 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20957 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    20958 mouse_pause_tracking 
    20959 self._mouse_pause() 
    20960 File
    20961 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20962 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    20963 m.pause(self._mouse_pause_position) 
    20964 File
    20965 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20966 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    20967 p = self.view.picked_object(x, y) 
    20968 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20969 File
    20970 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20971 packages/chimerax/graphics/view.py", line 838, in picked_object 
    20972 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    20973 beyond, 
    20974 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20975 File
    20976 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20977 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    20978 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    20979 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20980 File
    20981 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20982 packages/chimerax/core/models.py", line 143, in first_intercept 
    20983 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    20984 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20985 File
    20986 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20987 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    20988 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    20989 exclude=exclude) 
    20990 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20991 File
    20992 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20993 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    20994 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    20995 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    20996 File
    20997 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    20998 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    20999 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    21000 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21001 File
    21002 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21003 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    21004 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    21005 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21006 File
    21007 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21008 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    21009 p = super().first_intercept(mxyz1, mxyz2) 
    21010 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21011 File
    21012 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21013 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    21014 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    21015 exclude=exclude) 
    21016 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21017 File
    21018 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21019 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    21020 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    21021 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21022 File
    21023 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21024 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    21025 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    21026 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21027 File
    21028 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21029 packages/chimerax/graphics/drawing.py", line 1108, in
    21030 _first_intercept_excluding_children 
    21031 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    21032 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21033 File
    21034 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21035 packages/chimerax/geometry/place.py", line 201, in inverse 
    21036 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    21037 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21038 File
    21039 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21040 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    21041 rinv[:, :] = matrix_inverse(r) 
    21042 ^^^^^^^^^^^^^^^^^ 
    21043 File
    21044 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21045 packages/numpy/linalg/linalg.py", line 561, in inv 
    21046 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    21047 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21048 File
    21049 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21050 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    21051 raise LinAlgError("Singular matrix") 
    21052 numpy.linalg.LinAlgError: Singular matrix 
    21053  
    21054 numpy.linalg.LinAlgError: Singular matrix 
    21055  
    21056 File
    21057 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21058 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    21059 raise LinAlgError("Singular matrix") 
    21060  
    21061 See log for complete Python traceback. 
    21062  
    21063 Traceback (most recent call last): 
    21064 File
    21065 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21066 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    21067 self.session.ui.mouse_modes.mouse_pause_tracking() 
    21068 File
    21069 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21070 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    21071 mouse_pause_tracking 
    21072 self._mouse_pause() 
    21073 File
    21074 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21075 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    21076 m.pause(self._mouse_pause_position) 
    21077 File
    21078 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21079 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    21080 p = self.view.picked_object(x, y) 
    21081 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21082 File
    21083 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21084 packages/chimerax/graphics/view.py", line 838, in picked_object 
    21085 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    21086 beyond, 
    21087 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21088 File
    21089 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21090 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    21091 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    21092 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21093 File
    21094 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21095 packages/chimerax/core/models.py", line 143, in first_intercept 
    21096 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    21097 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21098 File
    21099 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21100 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    21101 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    21102 exclude=exclude) 
    21103 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21104 File
    21105 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21106 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    21107 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    21108 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21109 File
    21110 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21111 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    21112 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    21113 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21114 File
    21115 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21116 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    21117 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    21118 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21119 File
    21120 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21121 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    21122 p = super().first_intercept(mxyz1, mxyz2) 
    21123 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21124 File
    21125 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21126 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    21127 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    21128 exclude=exclude) 
    21129 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21130 File
    21131 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21132 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    21133 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    21134 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21135 File
    21136 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21137 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    21138 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    21139 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21140 File
    21141 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21142 packages/chimerax/graphics/drawing.py", line 1108, in
    21143 _first_intercept_excluding_children 
    21144 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    21145 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21146 File
    21147 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21148 packages/chimerax/geometry/place.py", line 201, in inverse 
    21149 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    21150 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21151 File
    21152 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21153 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    21154 rinv[:, :] = matrix_inverse(r) 
    21155 ^^^^^^^^^^^^^^^^^ 
    21156 File
    21157 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21158 packages/numpy/linalg/linalg.py", line 561, in inv 
    21159 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    21160 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21161 File
    21162 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21163 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    21164 raise LinAlgError("Singular matrix") 
    21165 numpy.linalg.LinAlgError: Singular matrix 
    21166  
    21167 numpy.linalg.LinAlgError: Singular matrix 
    21168  
    21169 File
    21170 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21171 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    21172 raise LinAlgError("Singular matrix") 
    21173  
    21174 See log for complete Python traceback. 
    21175  
    21176 Traceback (most recent call last): 
    21177 File
    21178 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21179 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    21180 self.session.ui.mouse_modes.mouse_pause_tracking() 
    21181 File
    21182 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21183 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    21184 mouse_pause_tracking 
    21185 self._mouse_pause() 
    21186 File
    21187 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21188 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    21189 m.pause(self._mouse_pause_position) 
    21190 File
    21191 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21192 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    21193 p = self.view.picked_object(x, y) 
    21194 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21195 File
    21196 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21197 packages/chimerax/graphics/view.py", line 838, in picked_object 
    21198 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    21199 beyond, 
    21200 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21201 File
    21202 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21203 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    21204 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    21205 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21206 File
    21207 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21208 packages/chimerax/core/models.py", line 143, in first_intercept 
    21209 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    21210 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21211 File
    21212 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21213 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    21214 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    21215 exclude=exclude) 
    21216 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21217 File
    21218 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21219 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    21220 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    21221 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21222 File
    21223 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21224 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    21225 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    21226 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21227 File
    21228 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21229 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    21230 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    21231 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21232 File
    21233 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21234 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    21235 p = super().first_intercept(mxyz1, mxyz2) 
    21236 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21237 File
    21238 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21239 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    21240 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    21241 exclude=exclude) 
    21242 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21243 File
    21244 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21245 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    21246 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    21247 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21248 File
    21249 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21250 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    21251 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    21252 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21253 File
    21254 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21255 packages/chimerax/graphics/drawing.py", line 1108, in
    21256 _first_intercept_excluding_children 
    21257 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    21258 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21259 File
    21260 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21261 packages/chimerax/geometry/place.py", line 201, in inverse 
    21262 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    21263 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21264 File
    21265 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21266 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    21267 rinv[:, :] = matrix_inverse(r) 
    21268 ^^^^^^^^^^^^^^^^^ 
    21269 File
    21270 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21271 packages/numpy/linalg/linalg.py", line 561, in inv 
    21272 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    21273 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21274 File
    21275 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21276 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    21277 raise LinAlgError("Singular matrix") 
    21278 numpy.linalg.LinAlgError: Singular matrix 
    21279  
    21280 numpy.linalg.LinAlgError: Singular matrix 
    21281  
    21282 File
    21283 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21284 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    21285 raise LinAlgError("Singular matrix") 
    21286  
    21287 See log for complete Python traceback. 
    21288  
    21289 Traceback (most recent call last): 
    21290 File
    21291 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21292 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    21293 self.session.ui.mouse_modes.mouse_pause_tracking() 
    21294 File
    21295 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21296 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    21297 mouse_pause_tracking 
    21298 self._mouse_pause() 
    21299 File
    21300 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21301 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    21302 m.pause(self._mouse_pause_position) 
    21303 File
    21304 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21305 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    21306 p = self.view.picked_object(x, y) 
    21307 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21308 File
    21309 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21310 packages/chimerax/graphics/view.py", line 838, in picked_object 
    21311 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    21312 beyond, 
    21313 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21314 File
    21315 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21316 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    21317 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    21318 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21319 File
    21320 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21321 packages/chimerax/core/models.py", line 143, in first_intercept 
    21322 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    21323 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21324 File
    21325 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21326 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    21327 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    21328 exclude=exclude) 
    21329 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21330 File
    21331 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21332 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    21333 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    21334 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21335 File
    21336 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21337 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    21338 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    21339 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21340 File
    21341 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21342 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    21343 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    21344 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21345 File
    21346 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21347 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    21348 p = super().first_intercept(mxyz1, mxyz2) 
    21349 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21350 File
    21351 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21352 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    21353 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    21354 exclude=exclude) 
    21355 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21356 File
    21357 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21358 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    21359 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    21360 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21361 File
    21362 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21363 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    21364 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    21365 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21366 File
    21367 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21368 packages/chimerax/graphics/drawing.py", line 1108, in
    21369 _first_intercept_excluding_children 
    21370 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    21371 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21372 File
    21373 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21374 packages/chimerax/geometry/place.py", line 201, in inverse 
    21375 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    21376 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21377 File
    21378 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21379 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    21380 rinv[:, :] = matrix_inverse(r) 
    21381 ^^^^^^^^^^^^^^^^^ 
    21382 File
    21383 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21384 packages/numpy/linalg/linalg.py", line 561, in inv 
    21385 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    21386 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21387 File
    21388 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21389 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    21390 raise LinAlgError("Singular matrix") 
    21391 numpy.linalg.LinAlgError: Singular matrix 
    21392  
    21393 numpy.linalg.LinAlgError: Singular matrix 
    21394  
    21395 File
    21396 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21397 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    21398 raise LinAlgError("Singular matrix") 
    21399  
    21400 See log for complete Python traceback. 
    21401  
    21402 Traceback (most recent call last): 
    21403 File
    21404 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21405 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    21406 self.session.ui.mouse_modes.mouse_pause_tracking() 
    21407 File
    21408 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21409 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    21410 mouse_pause_tracking 
    21411 self._mouse_pause() 
    21412 File
    21413 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21414 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    21415 m.pause(self._mouse_pause_position) 
    21416 File
    21417 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21418 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    21419 p = self.view.picked_object(x, y) 
    21420 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21421 File
    21422 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21423 packages/chimerax/graphics/view.py", line 838, in picked_object 
    21424 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    21425 beyond, 
    21426 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21427 File
    21428 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21429 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    21430 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    21431 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21432 File
    21433 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21434 packages/chimerax/core/models.py", line 143, in first_intercept 
    21435 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    21436 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21437 File
    21438 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21439 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    21440 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    21441 exclude=exclude) 
    21442 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21443 File
    21444 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21445 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    21446 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    21447 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21448 File
    21449 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21450 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    21451 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    21452 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21453 File
    21454 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21455 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    21456 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    21457 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21458 File
    21459 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21460 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    21461 p = super().first_intercept(mxyz1, mxyz2) 
    21462 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21463 File
    21464 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21465 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    21466 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    21467 exclude=exclude) 
    21468 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21469 File
    21470 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21471 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    21472 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    21473 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21474 File
    21475 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21476 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    21477 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    21478 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21479 File
    21480 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21481 packages/chimerax/graphics/drawing.py", line 1108, in
    21482 _first_intercept_excluding_children 
    21483 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    21484 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21485 File
    21486 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21487 packages/chimerax/geometry/place.py", line 201, in inverse 
    21488 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    21489 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21490 File
    21491 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21492 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    21493 rinv[:, :] = matrix_inverse(r) 
    21494 ^^^^^^^^^^^^^^^^^ 
    21495 File
    21496 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21497 packages/numpy/linalg/linalg.py", line 561, in inv 
    21498 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    21499 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21500 File
    21501 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21502 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    21503 raise LinAlgError("Singular matrix") 
    21504 numpy.linalg.LinAlgError: Singular matrix 
    21505  
    21506 numpy.linalg.LinAlgError: Singular matrix 
    21507  
    21508 File
    21509 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21510 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    21511 raise LinAlgError("Singular matrix") 
    21512  
    21513 See log for complete Python traceback. 
    21514  
    21515 Traceback (most recent call last): 
    21516 File
    21517 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21518 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    21519 self.session.ui.mouse_modes.mouse_pause_tracking() 
    21520 File
    21521 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21522 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    21523 mouse_pause_tracking 
    21524 self._mouse_pause() 
    21525 File
    21526 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21527 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    21528 m.pause(self._mouse_pause_position) 
    21529 File
    21530 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21531 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    21532 p = self.view.picked_object(x, y) 
    21533 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21534 File
    21535 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21536 packages/chimerax/graphics/view.py", line 838, in picked_object 
    21537 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    21538 beyond, 
    21539 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21540 File
    21541 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21542 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    21543 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    21544 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21545 File
    21546 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21547 packages/chimerax/core/models.py", line 143, in first_intercept 
    21548 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    21549 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21550 File
    21551 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21552 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    21553 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    21554 exclude=exclude) 
    21555 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21556 File
    21557 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21558 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    21559 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    21560 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21561 File
    21562 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21563 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    21564 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    21565 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21566 File
    21567 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21568 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    21569 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    21570 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21571 File
    21572 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21573 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    21574 p = super().first_intercept(mxyz1, mxyz2) 
    21575 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21576 File
    21577 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21578 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    21579 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    21580 exclude=exclude) 
    21581 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21582 File
    21583 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21584 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    21585 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    21586 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21587 File
    21588 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21589 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    21590 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    21591 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21592 File
    21593 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21594 packages/chimerax/graphics/drawing.py", line 1108, in
    21595 _first_intercept_excluding_children 
    21596 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    21597 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21598 File
    21599 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21600 packages/chimerax/geometry/place.py", line 201, in inverse 
    21601 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    21602 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21603 File
    21604 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21605 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    21606 rinv[:, :] = matrix_inverse(r) 
    21607 ^^^^^^^^^^^^^^^^^ 
    21608 File
    21609 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21610 packages/numpy/linalg/linalg.py", line 561, in inv 
    21611 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    21612 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21613 File
    21614 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21615 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    21616 raise LinAlgError("Singular matrix") 
    21617 numpy.linalg.LinAlgError: Singular matrix 
    21618  
    21619 numpy.linalg.LinAlgError: Singular matrix 
    21620  
    21621 File
    21622 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21623 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    21624 raise LinAlgError("Singular matrix") 
    21625  
    21626 See log for complete Python traceback. 
    21627  
    21628 Traceback (most recent call last): 
    21629 File
    21630 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21631 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    21632 self.session.ui.mouse_modes.mouse_pause_tracking() 
    21633 File
    21634 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21635 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    21636 mouse_pause_tracking 
    21637 self._mouse_pause() 
    21638 File
    21639 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21640 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    21641 m.pause(self._mouse_pause_position) 
    21642 File
    21643 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21644 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    21645 p = self.view.picked_object(x, y) 
    21646 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21647 File
    21648 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21649 packages/chimerax/graphics/view.py", line 838, in picked_object 
    21650 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    21651 beyond, 
    21652 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21653 File
    21654 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21655 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    21656 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    21657 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21658 File
    21659 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21660 packages/chimerax/core/models.py", line 143, in first_intercept 
    21661 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    21662 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21663 File
    21664 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21665 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    21666 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    21667 exclude=exclude) 
    21668 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21669 File
    21670 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21671 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    21672 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    21673 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21674 File
    21675 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21676 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    21677 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    21678 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21679 File
    21680 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21681 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    21682 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    21683 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21684 File
    21685 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21686 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    21687 p = super().first_intercept(mxyz1, mxyz2) 
    21688 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21689 File
    21690 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21691 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    21692 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    21693 exclude=exclude) 
    21694 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21695 File
    21696 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21697 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    21698 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    21699 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21700 File
    21701 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21702 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    21703 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    21704 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21705 File
    21706 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21707 packages/chimerax/graphics/drawing.py", line 1108, in
    21708 _first_intercept_excluding_children 
    21709 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    21710 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21711 File
    21712 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21713 packages/chimerax/geometry/place.py", line 201, in inverse 
    21714 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    21715 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21716 File
    21717 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21718 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    21719 rinv[:, :] = matrix_inverse(r) 
    21720 ^^^^^^^^^^^^^^^^^ 
    21721 File
    21722 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21723 packages/numpy/linalg/linalg.py", line 561, in inv 
    21724 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    21725 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21726 File
    21727 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21728 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    21729 raise LinAlgError("Singular matrix") 
    21730 numpy.linalg.LinAlgError: Singular matrix 
    21731  
    21732 numpy.linalg.LinAlgError: Singular matrix 
    21733  
    21734 File
    21735 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21736 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    21737 raise LinAlgError("Singular matrix") 
    21738  
    21739 See log for complete Python traceback. 
    21740  
    21741 Traceback (most recent call last): 
    21742 File
    21743 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21744 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    21745 self.session.ui.mouse_modes.mouse_pause_tracking() 
    21746 File
    21747 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21748 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    21749 mouse_pause_tracking 
    21750 self._mouse_pause() 
    21751 File
    21752 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21753 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    21754 m.pause(self._mouse_pause_position) 
    21755 File
    21756 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21757 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    21758 p = self.view.picked_object(x, y) 
    21759 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21760 File
    21761 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21762 packages/chimerax/graphics/view.py", line 838, in picked_object 
    21763 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    21764 beyond, 
    21765 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21766 File
    21767 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21768 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    21769 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    21770 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21771 File
    21772 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21773 packages/chimerax/core/models.py", line 143, in first_intercept 
    21774 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    21775 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21776 File
    21777 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21778 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    21779 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    21780 exclude=exclude) 
    21781 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21782 File
    21783 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21784 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    21785 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    21786 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21787 File
    21788 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21789 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    21790 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    21791 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21792 File
    21793 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21794 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    21795 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    21796 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21797 File
    21798 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21799 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    21800 p = super().first_intercept(mxyz1, mxyz2) 
    21801 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21802 File
    21803 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21804 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    21805 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    21806 exclude=exclude) 
    21807 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21808 File
    21809 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21810 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    21811 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    21812 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21813 File
    21814 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21815 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    21816 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    21817 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21818 File
    21819 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21820 packages/chimerax/graphics/drawing.py", line 1108, in
    21821 _first_intercept_excluding_children 
    21822 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    21823 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21824 File
    21825 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21826 packages/chimerax/geometry/place.py", line 201, in inverse 
    21827 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    21828 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21829 File
    21830 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21831 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    21832 rinv[:, :] = matrix_inverse(r) 
    21833 ^^^^^^^^^^^^^^^^^ 
    21834 File
    21835 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21836 packages/numpy/linalg/linalg.py", line 561, in inv 
    21837 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    21838 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21839 File
    21840 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21841 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    21842 raise LinAlgError("Singular matrix") 
    21843 numpy.linalg.LinAlgError: Singular matrix 
    21844  
    21845 numpy.linalg.LinAlgError: Singular matrix 
    21846  
    21847 File
    21848 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21849 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    21850 raise LinAlgError("Singular matrix") 
    21851  
    21852 See log for complete Python traceback. 
    21853  
    21854 Traceback (most recent call last): 
    21855 File
    21856 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21857 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    21858 self.session.ui.mouse_modes.mouse_pause_tracking() 
    21859 File
    21860 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21861 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    21862 mouse_pause_tracking 
    21863 self._mouse_pause() 
    21864 File
    21865 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21866 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    21867 m.pause(self._mouse_pause_position) 
    21868 File
    21869 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21870 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    21871 p = self.view.picked_object(x, y) 
    21872 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21873 File
    21874 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21875 packages/chimerax/graphics/view.py", line 838, in picked_object 
    21876 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    21877 beyond, 
    21878 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21879 File
    21880 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21881 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    21882 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    21883 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21884 File
    21885 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21886 packages/chimerax/core/models.py", line 143, in first_intercept 
    21887 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    21888 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21889 File
    21890 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21891 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    21892 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    21893 exclude=exclude) 
    21894 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21895 File
    21896 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21897 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    21898 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    21899 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21900 File
    21901 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21902 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    21903 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    21904 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21905 File
    21906 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21907 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    21908 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    21909 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21910 File
    21911 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21912 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    21913 p = super().first_intercept(mxyz1, mxyz2) 
    21914 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21915 File
    21916 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21917 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    21918 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    21919 exclude=exclude) 
    21920 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21921 File
    21922 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21923 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    21924 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    21925 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21926 File
    21927 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21928 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    21929 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    21930 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21931 File
    21932 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21933 packages/chimerax/graphics/drawing.py", line 1108, in
    21934 _first_intercept_excluding_children 
    21935 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    21936 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21937 File
    21938 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21939 packages/chimerax/geometry/place.py", line 201, in inverse 
    21940 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    21941 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21942 File
    21943 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21944 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    21945 rinv[:, :] = matrix_inverse(r) 
    21946 ^^^^^^^^^^^^^^^^^ 
    21947 File
    21948 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21949 packages/numpy/linalg/linalg.py", line 561, in inv 
    21950 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    21951 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21952 File
    21953 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21954 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    21955 raise LinAlgError("Singular matrix") 
    21956 numpy.linalg.LinAlgError: Singular matrix 
    21957  
    21958 numpy.linalg.LinAlgError: Singular matrix 
    21959  
    21960 File
    21961 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21962 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    21963 raise LinAlgError("Singular matrix") 
    21964  
    21965 See log for complete Python traceback. 
    21966  
    21967 Traceback (most recent call last): 
    21968 File
    21969 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21970 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    21971 self.session.ui.mouse_modes.mouse_pause_tracking() 
    21972 File
    21973 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21974 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    21975 mouse_pause_tracking 
    21976 self._mouse_pause() 
    21977 File
    21978 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21979 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    21980 m.pause(self._mouse_pause_position) 
    21981 File
    21982 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21983 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    21984 p = self.view.picked_object(x, y) 
    21985 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21986 File
    21987 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21988 packages/chimerax/graphics/view.py", line 838, in picked_object 
    21989 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    21990 beyond, 
    21991 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21992 File
    21993 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21994 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    21995 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    21996 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    21997 File
    21998 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    21999 packages/chimerax/core/models.py", line 143, in first_intercept 
    22000 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    22001 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22002 File
    22003 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22004 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    22005 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    22006 exclude=exclude) 
    22007 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22008 File
    22009 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22010 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    22011 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    22012 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22013 File
    22014 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22015 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    22016 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    22017 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22018 File
    22019 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22020 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    22021 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    22022 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22023 File
    22024 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22025 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    22026 p = super().first_intercept(mxyz1, mxyz2) 
    22027 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22028 File
    22029 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22030 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    22031 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    22032 exclude=exclude) 
    22033 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22034 File
    22035 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22036 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    22037 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    22038 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22039 File
    22040 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22041 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    22042 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    22043 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22044 File
    22045 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22046 packages/chimerax/graphics/drawing.py", line 1108, in
    22047 _first_intercept_excluding_children 
    22048 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    22049 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22050 File
    22051 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22052 packages/chimerax/geometry/place.py", line 201, in inverse 
    22053 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    22054 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22055 File
    22056 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22057 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    22058 rinv[:, :] = matrix_inverse(r) 
    22059 ^^^^^^^^^^^^^^^^^ 
    22060 File
    22061 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22062 packages/numpy/linalg/linalg.py", line 561, in inv 
    22063 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    22064 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22065 File
    22066 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22067 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    22068 raise LinAlgError("Singular matrix") 
    22069 numpy.linalg.LinAlgError: Singular matrix 
    22070  
    22071 numpy.linalg.LinAlgError: Singular matrix 
    22072  
    22073 File
    22074 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22075 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    22076 raise LinAlgError("Singular matrix") 
    22077  
    22078 See log for complete Python traceback. 
    22079  
    22080 Traceback (most recent call last): 
    22081 File
    22082 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22083 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    22084 self.session.ui.mouse_modes.mouse_pause_tracking() 
    22085 File
    22086 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22087 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    22088 mouse_pause_tracking 
    22089 self._mouse_pause() 
    22090 File
    22091 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22092 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    22093 m.pause(self._mouse_pause_position) 
    22094 File
    22095 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22096 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    22097 p = self.view.picked_object(x, y) 
    22098 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22099 File
    22100 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22101 packages/chimerax/graphics/view.py", line 838, in picked_object 
    22102 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    22103 beyond, 
    22104 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22105 File
    22106 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22107 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    22108 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    22109 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22110 File
    22111 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22112 packages/chimerax/core/models.py", line 143, in first_intercept 
    22113 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    22114 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22115 File
    22116 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22117 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    22118 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    22119 exclude=exclude) 
    22120 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22121 File
    22122 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22123 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    22124 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    22125 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22126 File
    22127 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22128 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    22129 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    22130 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22131 File
    22132 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22133 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    22134 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    22135 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22136 File
    22137 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22138 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    22139 p = super().first_intercept(mxyz1, mxyz2) 
    22140 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22141 File
    22142 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22143 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    22144 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    22145 exclude=exclude) 
    22146 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22147 File
    22148 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22149 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    22150 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    22151 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22152 File
    22153 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22154 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    22155 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    22156 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22157 File
    22158 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22159 packages/chimerax/graphics/drawing.py", line 1108, in
    22160 _first_intercept_excluding_children 
    22161 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    22162 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22163 File
    22164 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22165 packages/chimerax/geometry/place.py", line 201, in inverse 
    22166 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    22167 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22168 File
    22169 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22170 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    22171 rinv[:, :] = matrix_inverse(r) 
    22172 ^^^^^^^^^^^^^^^^^ 
    22173 File
    22174 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22175 packages/numpy/linalg/linalg.py", line 561, in inv 
    22176 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    22177 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22178 File
    22179 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22180 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    22181 raise LinAlgError("Singular matrix") 
    22182 numpy.linalg.LinAlgError: Singular matrix 
    22183  
    22184 numpy.linalg.LinAlgError: Singular matrix 
    22185  
    22186 File
    22187 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22188 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    22189 raise LinAlgError("Singular matrix") 
    22190  
    22191 See log for complete Python traceback. 
    22192  
    22193 Traceback (most recent call last): 
    22194 File
    22195 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22196 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    22197 self.session.ui.mouse_modes.mouse_pause_tracking() 
    22198 File
    22199 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22200 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    22201 mouse_pause_tracking 
    22202 self._mouse_pause() 
    22203 File
    22204 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22205 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    22206 m.pause(self._mouse_pause_position) 
    22207 File
    22208 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22209 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    22210 p = self.view.picked_object(x, y) 
    22211 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22212 File
    22213 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22214 packages/chimerax/graphics/view.py", line 838, in picked_object 
    22215 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    22216 beyond, 
    22217 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22218 File
    22219 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22220 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    22221 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    22222 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22223 File
    22224 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22225 packages/chimerax/core/models.py", line 143, in first_intercept 
    22226 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    22227 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22228 File
    22229 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22230 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    22231 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    22232 exclude=exclude) 
    22233 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22234 File
    22235 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22236 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    22237 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    22238 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22239 File
    22240 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22241 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    22242 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    22243 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22244 File
    22245 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22246 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    22247 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    22248 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22249 File
    22250 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22251 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    22252 p = super().first_intercept(mxyz1, mxyz2) 
    22253 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22254 File
    22255 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22256 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    22257 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    22258 exclude=exclude) 
    22259 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22260 File
    22261 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22262 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    22263 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    22264 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22265 File
    22266 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22267 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    22268 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    22269 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22270 File
    22271 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22272 packages/chimerax/graphics/drawing.py", line 1108, in
    22273 _first_intercept_excluding_children 
    22274 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    22275 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22276 File
    22277 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22278 packages/chimerax/geometry/place.py", line 201, in inverse 
    22279 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    22280 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22281 File
    22282 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22283 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    22284 rinv[:, :] = matrix_inverse(r) 
    22285 ^^^^^^^^^^^^^^^^^ 
    22286 File
    22287 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22288 packages/numpy/linalg/linalg.py", line 561, in inv 
    22289 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    22290 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22291 File
    22292 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22293 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    22294 raise LinAlgError("Singular matrix") 
    22295 numpy.linalg.LinAlgError: Singular matrix 
    22296  
    22297 numpy.linalg.LinAlgError: Singular matrix 
    22298  
    22299 File
    22300 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22301 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    22302 raise LinAlgError("Singular matrix") 
    22303  
    22304 See log for complete Python traceback. 
    22305  
    22306 Traceback (most recent call last): 
    22307 File
    22308 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22309 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    22310 self.session.ui.mouse_modes.mouse_pause_tracking() 
    22311 File
    22312 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22313 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    22314 mouse_pause_tracking 
    22315 self._mouse_pause() 
    22316 File
    22317 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22318 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    22319 m.pause(self._mouse_pause_position) 
    22320 File
    22321 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22322 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    22323 p = self.view.picked_object(x, y) 
    22324 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22325 File
    22326 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22327 packages/chimerax/graphics/view.py", line 838, in picked_object 
    22328 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    22329 beyond, 
    22330 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22331 File
    22332 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22333 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    22334 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    22335 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22336 File
    22337 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22338 packages/chimerax/core/models.py", line 143, in first_intercept 
    22339 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    22340 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22341 File
    22342 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22343 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    22344 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    22345 exclude=exclude) 
    22346 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22347 File
    22348 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22349 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    22350 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    22351 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22352 File
    22353 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22354 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    22355 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    22356 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22357 File
    22358 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22359 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    22360 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    22361 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22362 File
    22363 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22364 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    22365 p = super().first_intercept(mxyz1, mxyz2) 
    22366 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22367 File
    22368 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22369 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    22370 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    22371 exclude=exclude) 
    22372 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22373 File
    22374 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22375 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    22376 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    22377 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22378 File
    22379 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22380 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    22381 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    22382 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22383 File
    22384 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22385 packages/chimerax/graphics/drawing.py", line 1108, in
    22386 _first_intercept_excluding_children 
    22387 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    22388 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22389 File
    22390 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22391 packages/chimerax/geometry/place.py", line 201, in inverse 
    22392 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    22393 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22394 File
    22395 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22396 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    22397 rinv[:, :] = matrix_inverse(r) 
    22398 ^^^^^^^^^^^^^^^^^ 
    22399 File
    22400 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22401 packages/numpy/linalg/linalg.py", line 561, in inv 
    22402 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    22403 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22404 File
    22405 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22406 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    22407 raise LinAlgError("Singular matrix") 
    22408 numpy.linalg.LinAlgError: Singular matrix 
    22409  
    22410 numpy.linalg.LinAlgError: Singular matrix 
    22411  
    22412 File
    22413 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22414 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    22415 raise LinAlgError("Singular matrix") 
    22416  
    22417 See log for complete Python traceback. 
    22418  
    22419 Traceback (most recent call last): 
    22420 File
    22421 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22422 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    22423 self.session.ui.mouse_modes.mouse_pause_tracking() 
    22424 File
    22425 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22426 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    22427 mouse_pause_tracking 
    22428 self._mouse_pause() 
    22429 File
    22430 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22431 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    22432 m.pause(self._mouse_pause_position) 
    22433 File
    22434 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22435 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    22436 p = self.view.picked_object(x, y) 
    22437 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22438 File
    22439 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22440 packages/chimerax/graphics/view.py", line 838, in picked_object 
    22441 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    22442 beyond, 
    22443 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22444 File
    22445 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22446 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    22447 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    22448 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22449 File
    22450 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22451 packages/chimerax/core/models.py", line 143, in first_intercept 
    22452 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    22453 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22454 File
    22455 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22456 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    22457 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    22458 exclude=exclude) 
    22459 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22460 File
    22461 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22462 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    22463 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    22464 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22465 File
    22466 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22467 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    22468 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    22469 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22470 File
    22471 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22472 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    22473 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    22474 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22475 File
    22476 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22477 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    22478 p = super().first_intercept(mxyz1, mxyz2) 
    22479 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22480 File
    22481 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22482 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    22483 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    22484 exclude=exclude) 
    22485 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22486 File
    22487 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22488 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    22489 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    22490 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22491 File
    22492 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22493 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    22494 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    22495 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22496 File
    22497 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22498 packages/chimerax/graphics/drawing.py", line 1108, in
    22499 _first_intercept_excluding_children 
    22500 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    22501 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22502 File
    22503 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22504 packages/chimerax/geometry/place.py", line 201, in inverse 
    22505 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    22506 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22507 File
    22508 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22509 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    22510 rinv[:, :] = matrix_inverse(r) 
    22511 ^^^^^^^^^^^^^^^^^ 
    22512 File
    22513 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22514 packages/numpy/linalg/linalg.py", line 561, in inv 
    22515 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    22516 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22517 File
    22518 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22519 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    22520 raise LinAlgError("Singular matrix") 
    22521 numpy.linalg.LinAlgError: Singular matrix 
    22522  
    22523 numpy.linalg.LinAlgError: Singular matrix 
    22524  
    22525 File
    22526 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22527 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    22528 raise LinAlgError("Singular matrix") 
    22529  
    22530 See log for complete Python traceback. 
    22531  
    22532 Traceback (most recent call last): 
    22533 File
    22534 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22535 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    22536 self.session.ui.mouse_modes.mouse_pause_tracking() 
    22537 File
    22538 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22539 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    22540 mouse_pause_tracking 
    22541 self._mouse_pause() 
    22542 File
    22543 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22544 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    22545 m.pause(self._mouse_pause_position) 
    22546 File
    22547 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22548 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    22549 p = self.view.picked_object(x, y) 
    22550 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22551 File
    22552 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22553 packages/chimerax/graphics/view.py", line 838, in picked_object 
    22554 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    22555 beyond, 
    22556 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22557 File
    22558 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22559 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    22560 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    22561 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22562 File
    22563 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22564 packages/chimerax/core/models.py", line 143, in first_intercept 
    22565 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    22566 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22567 File
    22568 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22569 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    22570 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    22571 exclude=exclude) 
    22572 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22573 File
    22574 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22575 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    22576 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    22577 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22578 File
    22579 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22580 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    22581 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    22582 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22583 File
    22584 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22585 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    22586 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    22587 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22588 File
    22589 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22590 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    22591 p = super().first_intercept(mxyz1, mxyz2) 
    22592 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22593 File
    22594 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22595 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    22596 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    22597 exclude=exclude) 
    22598 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22599 File
    22600 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22601 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    22602 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    22603 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22604 File
    22605 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22606 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    22607 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    22608 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22609 File
    22610 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22611 packages/chimerax/graphics/drawing.py", line 1108, in
    22612 _first_intercept_excluding_children 
    22613 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    22614 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22615 File
    22616 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22617 packages/chimerax/geometry/place.py", line 201, in inverse 
    22618 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    22619 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22620 File
    22621 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22622 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    22623 rinv[:, :] = matrix_inverse(r) 
    22624 ^^^^^^^^^^^^^^^^^ 
    22625 File
    22626 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22627 packages/numpy/linalg/linalg.py", line 561, in inv 
    22628 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    22629 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22630 File
    22631 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22632 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    22633 raise LinAlgError("Singular matrix") 
    22634 numpy.linalg.LinAlgError: Singular matrix 
    22635  
    22636 numpy.linalg.LinAlgError: Singular matrix 
    22637  
    22638 File
    22639 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22640 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    22641 raise LinAlgError("Singular matrix") 
    22642  
    22643 See log for complete Python traceback. 
    22644  
    22645 Traceback (most recent call last): 
    22646 File
    22647 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22648 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    22649 self.session.ui.mouse_modes.mouse_pause_tracking() 
    22650 File
    22651 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22652 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    22653 mouse_pause_tracking 
    22654 self._mouse_pause() 
    22655 File
    22656 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22657 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    22658 m.pause(self._mouse_pause_position) 
    22659 File
    22660 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22661 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    22662 p = self.view.picked_object(x, y) 
    22663 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22664 File
    22665 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22666 packages/chimerax/graphics/view.py", line 838, in picked_object 
    22667 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    22668 beyond, 
    22669 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22670 File
    22671 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22672 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    22673 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    22674 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22675 File
    22676 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22677 packages/chimerax/core/models.py", line 143, in first_intercept 
    22678 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    22679 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22680 File
    22681 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22682 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    22683 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    22684 exclude=exclude) 
    22685 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22686 File
    22687 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22688 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    22689 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    22690 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22691 File
    22692 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22693 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    22694 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    22695 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22696 File
    22697 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22698 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    22699 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    22700 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22701 File
    22702 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22703 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    22704 p = super().first_intercept(mxyz1, mxyz2) 
    22705 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22706 File
    22707 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22708 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    22709 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    22710 exclude=exclude) 
    22711 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22712 File
    22713 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22714 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    22715 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    22716 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22717 File
    22718 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22719 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    22720 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    22721 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22722 File
    22723 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22724 packages/chimerax/graphics/drawing.py", line 1108, in
    22725 _first_intercept_excluding_children 
    22726 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    22727 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22728 File
    22729 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22730 packages/chimerax/geometry/place.py", line 201, in inverse 
    22731 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    22732 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22733 File
    22734 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22735 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    22736 rinv[:, :] = matrix_inverse(r) 
    22737 ^^^^^^^^^^^^^^^^^ 
    22738 File
    22739 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22740 packages/numpy/linalg/linalg.py", line 561, in inv 
    22741 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    22742 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22743 File
    22744 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22745 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    22746 raise LinAlgError("Singular matrix") 
    22747 numpy.linalg.LinAlgError: Singular matrix 
    22748  
    22749 numpy.linalg.LinAlgError: Singular matrix 
    22750  
    22751 File
    22752 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22753 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    22754 raise LinAlgError("Singular matrix") 
    22755  
    22756 See log for complete Python traceback. 
    22757  
    22758 Traceback (most recent call last): 
    22759 File
    22760 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22761 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    22762 self.session.ui.mouse_modes.mouse_pause_tracking() 
    22763 File
    22764 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22765 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    22766 mouse_pause_tracking 
    22767 self._mouse_pause() 
    22768 File
    22769 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22770 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    22771 m.pause(self._mouse_pause_position) 
    22772 File
    22773 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22774 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    22775 p = self.view.picked_object(x, y) 
    22776 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22777 File
    22778 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22779 packages/chimerax/graphics/view.py", line 838, in picked_object 
    22780 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    22781 beyond, 
    22782 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22783 File
    22784 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22785 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    22786 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    22787 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22788 File
    22789 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22790 packages/chimerax/core/models.py", line 143, in first_intercept 
    22791 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    22792 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22793 File
    22794 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22795 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    22796 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    22797 exclude=exclude) 
    22798 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22799 File
    22800 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22801 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    22802 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    22803 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22804 File
    22805 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22806 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    22807 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    22808 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22809 File
    22810 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22811 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    22812 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    22813 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22814 File
    22815 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22816 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    22817 p = super().first_intercept(mxyz1, mxyz2) 
    22818 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22819 File
    22820 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22821 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    22822 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    22823 exclude=exclude) 
    22824 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22825 File
    22826 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22827 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    22828 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    22829 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22830 File
    22831 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22832 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    22833 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    22834 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22835 File
    22836 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22837 packages/chimerax/graphics/drawing.py", line 1108, in
    22838 _first_intercept_excluding_children 
    22839 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    22840 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22841 File
    22842 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22843 packages/chimerax/geometry/place.py", line 201, in inverse 
    22844 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    22845 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22846 File
    22847 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22848 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    22849 rinv[:, :] = matrix_inverse(r) 
    22850 ^^^^^^^^^^^^^^^^^ 
    22851 File
    22852 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22853 packages/numpy/linalg/linalg.py", line 561, in inv 
    22854 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    22855 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22856 File
    22857 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22858 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    22859 raise LinAlgError("Singular matrix") 
    22860 numpy.linalg.LinAlgError: Singular matrix 
    22861  
    22862 numpy.linalg.LinAlgError: Singular matrix 
    22863  
    22864 File
    22865 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22866 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    22867 raise LinAlgError("Singular matrix") 
    22868  
    22869 See log for complete Python traceback. 
    22870  
    22871 Traceback (most recent call last): 
    22872 File
    22873 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22874 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    22875 self.session.ui.mouse_modes.mouse_pause_tracking() 
    22876 File
    22877 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22878 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    22879 mouse_pause_tracking 
    22880 self._mouse_pause() 
    22881 File
    22882 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22883 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    22884 m.pause(self._mouse_pause_position) 
    22885 File
    22886 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22887 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    22888 p = self.view.picked_object(x, y) 
    22889 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22890 File
    22891 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22892 packages/chimerax/graphics/view.py", line 838, in picked_object 
    22893 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    22894 beyond, 
    22895 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22896 File
    22897 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22898 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    22899 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    22900 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22901 File
    22902 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22903 packages/chimerax/core/models.py", line 143, in first_intercept 
    22904 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    22905 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22906 File
    22907 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22908 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    22909 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    22910 exclude=exclude) 
    22911 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22912 File
    22913 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22914 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    22915 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    22916 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22917 File
    22918 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22919 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    22920 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    22921 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22922 File
    22923 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22924 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    22925 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    22926 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22927 File
    22928 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22929 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    22930 p = super().first_intercept(mxyz1, mxyz2) 
    22931 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22932 File
    22933 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22934 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    22935 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    22936 exclude=exclude) 
    22937 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22938 File
    22939 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22940 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    22941 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    22942 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22943 File
    22944 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22945 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    22946 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    22947 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22948 File
    22949 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22950 packages/chimerax/graphics/drawing.py", line 1108, in
    22951 _first_intercept_excluding_children 
    22952 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    22953 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22954 File
    22955 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22956 packages/chimerax/geometry/place.py", line 201, in inverse 
    22957 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    22958 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22959 File
    22960 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22961 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    22962 rinv[:, :] = matrix_inverse(r) 
    22963 ^^^^^^^^^^^^^^^^^ 
    22964 File
    22965 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22966 packages/numpy/linalg/linalg.py", line 561, in inv 
    22967 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    22968 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    22969 File
    22970 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22971 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    22972 raise LinAlgError("Singular matrix") 
    22973 numpy.linalg.LinAlgError: Singular matrix 
    22974  
    22975 numpy.linalg.LinAlgError: Singular matrix 
    22976  
    22977 File
    22978 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22979 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    22980 raise LinAlgError("Singular matrix") 
    22981  
    22982 See log for complete Python traceback. 
    22983  
    22984 Traceback (most recent call last): 
    22985 File
    22986 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22987 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    22988 self.session.ui.mouse_modes.mouse_pause_tracking() 
    22989 File
    22990 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22991 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    22992 mouse_pause_tracking 
    22993 self._mouse_pause() 
    22994 File
    22995 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    22996 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    22997 m.pause(self._mouse_pause_position) 
    22998 File
    22999 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23000 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    23001 p = self.view.picked_object(x, y) 
    23002 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23003 File
    23004 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23005 packages/chimerax/graphics/view.py", line 838, in picked_object 
    23006 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    23007 beyond, 
    23008 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23009 File
    23010 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23011 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    23012 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    23013 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23014 File
    23015 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23016 packages/chimerax/core/models.py", line 143, in first_intercept 
    23017 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    23018 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23019 File
    23020 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23021 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    23022 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    23023 exclude=exclude) 
    23024 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23025 File
    23026 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23027 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    23028 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    23029 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23030 File
    23031 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23032 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    23033 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    23034 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23035 File
    23036 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23037 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    23038 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    23039 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23040 File
    23041 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23042 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    23043 p = super().first_intercept(mxyz1, mxyz2) 
    23044 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23045 File
    23046 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23047 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    23048 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    23049 exclude=exclude) 
    23050 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23051 File
    23052 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23053 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    23054 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    23055 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23056 File
    23057 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23058 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    23059 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    23060 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23061 File
    23062 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23063 packages/chimerax/graphics/drawing.py", line 1108, in
    23064 _first_intercept_excluding_children 
    23065 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    23066 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23067 File
    23068 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23069 packages/chimerax/geometry/place.py", line 201, in inverse 
    23070 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    23071 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23072 File
    23073 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23074 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    23075 rinv[:, :] = matrix_inverse(r) 
    23076 ^^^^^^^^^^^^^^^^^ 
    23077 File
    23078 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23079 packages/numpy/linalg/linalg.py", line 561, in inv 
    23080 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    23081 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23082 File
    23083 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23084 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    23085 raise LinAlgError("Singular matrix") 
    23086 numpy.linalg.LinAlgError: Singular matrix 
    23087  
    23088 numpy.linalg.LinAlgError: Singular matrix 
    23089  
    23090 File
    23091 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23092 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    23093 raise LinAlgError("Singular matrix") 
    23094  
    23095 See log for complete Python traceback. 
    23096  
    23097 Traceback (most recent call last): 
    23098 File
    23099 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23100 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    23101 self.session.ui.mouse_modes.mouse_pause_tracking() 
    23102 File
    23103 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23104 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    23105 mouse_pause_tracking 
    23106 self._mouse_pause() 
    23107 File
    23108 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23109 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    23110 m.pause(self._mouse_pause_position) 
    23111 File
    23112 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23113 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    23114 p = self.view.picked_object(x, y) 
    23115 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23116 File
    23117 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23118 packages/chimerax/graphics/view.py", line 838, in picked_object 
    23119 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    23120 beyond, 
    23121 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23122 File
    23123 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23124 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    23125 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    23126 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23127 File
    23128 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23129 packages/chimerax/core/models.py", line 143, in first_intercept 
    23130 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    23131 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23132 File
    23133 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23134 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    23135 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    23136 exclude=exclude) 
    23137 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23138 File
    23139 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23140 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    23141 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    23142 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23143 File
    23144 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23145 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    23146 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    23147 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23148 File
    23149 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23150 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    23151 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    23152 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23153 File
    23154 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23155 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    23156 p = super().first_intercept(mxyz1, mxyz2) 
    23157 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23158 File
    23159 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23160 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    23161 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    23162 exclude=exclude) 
    23163 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23164 File
    23165 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23166 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    23167 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    23168 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23169 File
    23170 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23171 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    23172 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    23173 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23174 File
    23175 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23176 packages/chimerax/graphics/drawing.py", line 1108, in
    23177 _first_intercept_excluding_children 
    23178 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    23179 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23180 File
    23181 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23182 packages/chimerax/geometry/place.py", line 201, in inverse 
    23183 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    23184 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23185 File
    23186 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23187 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    23188 rinv[:, :] = matrix_inverse(r) 
    23189 ^^^^^^^^^^^^^^^^^ 
    23190 File
    23191 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23192 packages/numpy/linalg/linalg.py", line 561, in inv 
    23193 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    23194 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23195 File
    23196 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23197 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    23198 raise LinAlgError("Singular matrix") 
    23199 numpy.linalg.LinAlgError: Singular matrix 
    23200  
    23201 numpy.linalg.LinAlgError: Singular matrix 
    23202  
    23203 File
    23204 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23205 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    23206 raise LinAlgError("Singular matrix") 
    23207  
    23208 See log for complete Python traceback. 
    23209  
    23210 Traceback (most recent call last): 
    23211 File
    23212 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23213 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    23214 self.session.ui.mouse_modes.mouse_pause_tracking() 
    23215 File
    23216 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23217 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    23218 mouse_pause_tracking 
    23219 self._mouse_pause() 
    23220 File
    23221 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23222 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    23223 m.pause(self._mouse_pause_position) 
    23224 File
    23225 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23226 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    23227 p = self.view.picked_object(x, y) 
    23228 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23229 File
    23230 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23231 packages/chimerax/graphics/view.py", line 838, in picked_object 
    23232 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    23233 beyond, 
    23234 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23235 File
    23236 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23237 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    23238 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    23239 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23240 File
    23241 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23242 packages/chimerax/core/models.py", line 143, in first_intercept 
    23243 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    23244 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23245 File
    23246 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23247 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    23248 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    23249 exclude=exclude) 
    23250 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23251 File
    23252 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23253 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    23254 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    23255 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23256 File
    23257 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23258 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    23259 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    23260 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23261 File
    23262 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23263 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    23264 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    23265 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23266 File
    23267 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23268 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    23269 p = super().first_intercept(mxyz1, mxyz2) 
    23270 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23271 File
    23272 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23273 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    23274 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    23275 exclude=exclude) 
    23276 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23277 File
    23278 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23279 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    23280 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    23281 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23282 File
    23283 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23284 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    23285 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    23286 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23287 File
    23288 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23289 packages/chimerax/graphics/drawing.py", line 1108, in
    23290 _first_intercept_excluding_children 
    23291 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    23292 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23293 File
    23294 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23295 packages/chimerax/geometry/place.py", line 201, in inverse 
    23296 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    23297 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23298 File
    23299 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23300 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    23301 rinv[:, :] = matrix_inverse(r) 
    23302 ^^^^^^^^^^^^^^^^^ 
    23303 File
    23304 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23305 packages/numpy/linalg/linalg.py", line 561, in inv 
    23306 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    23307 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23308 File
    23309 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23310 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    23311 raise LinAlgError("Singular matrix") 
    23312 numpy.linalg.LinAlgError: Singular matrix 
    23313  
    23314 numpy.linalg.LinAlgError: Singular matrix 
    23315  
    23316 File
    23317 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23318 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    23319 raise LinAlgError("Singular matrix") 
    23320  
    23321 See log for complete Python traceback. 
    23322  
    23323 Traceback (most recent call last): 
    23324 File
    23325 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23326 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    23327 self.session.ui.mouse_modes.mouse_pause_tracking() 
    23328 File
    23329 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23330 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    23331 mouse_pause_tracking 
    23332 self._mouse_pause() 
    23333 File
    23334 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23335 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    23336 m.pause(self._mouse_pause_position) 
    23337 File
    23338 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23339 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    23340 p = self.view.picked_object(x, y) 
    23341 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23342 File
    23343 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23344 packages/chimerax/graphics/view.py", line 838, in picked_object 
    23345 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    23346 beyond, 
    23347 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23348 File
    23349 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23350 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    23351 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    23352 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23353 File
    23354 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23355 packages/chimerax/core/models.py", line 143, in first_intercept 
    23356 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    23357 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23358 File
    23359 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23360 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    23361 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    23362 exclude=exclude) 
    23363 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23364 File
    23365 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23366 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    23367 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    23368 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23369 File
    23370 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23371 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    23372 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    23373 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23374 File
    23375 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23376 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    23377 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    23378 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23379 File
    23380 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23381 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    23382 p = super().first_intercept(mxyz1, mxyz2) 
    23383 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23384 File
    23385 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23386 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    23387 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    23388 exclude=exclude) 
    23389 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23390 File
    23391 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23392 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    23393 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    23394 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23395 File
    23396 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23397 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    23398 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    23399 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23400 File
    23401 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23402 packages/chimerax/graphics/drawing.py", line 1108, in
    23403 _first_intercept_excluding_children 
    23404 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    23405 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23406 File
    23407 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23408 packages/chimerax/geometry/place.py", line 201, in inverse 
    23409 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    23410 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23411 File
    23412 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23413 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    23414 rinv[:, :] = matrix_inverse(r) 
    23415 ^^^^^^^^^^^^^^^^^ 
    23416 File
    23417 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23418 packages/numpy/linalg/linalg.py", line 561, in inv 
    23419 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    23420 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23421 File
    23422 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23423 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    23424 raise LinAlgError("Singular matrix") 
    23425 numpy.linalg.LinAlgError: Singular matrix 
    23426  
    23427 numpy.linalg.LinAlgError: Singular matrix 
    23428  
    23429 File
    23430 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23431 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    23432 raise LinAlgError("Singular matrix") 
    23433  
    23434 See log for complete Python traceback. 
    23435  
    23436 Traceback (most recent call last): 
    23437 File
    23438 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23439 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    23440 self.session.ui.mouse_modes.mouse_pause_tracking() 
    23441 File
    23442 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23443 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    23444 mouse_pause_tracking 
    23445 self._mouse_pause() 
    23446 File
    23447 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23448 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    23449 m.pause(self._mouse_pause_position) 
    23450 File
    23451 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23452 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    23453 p = self.view.picked_object(x, y) 
    23454 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23455 File
    23456 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23457 packages/chimerax/graphics/view.py", line 838, in picked_object 
    23458 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    23459 beyond, 
    23460 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23461 File
    23462 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23463 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    23464 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    23465 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23466 File
    23467 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23468 packages/chimerax/core/models.py", line 143, in first_intercept 
    23469 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    23470 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23471 File
    23472 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23473 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    23474 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    23475 exclude=exclude) 
    23476 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23477 File
    23478 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23479 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    23480 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    23481 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23482 File
    23483 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23484 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    23485 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    23486 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23487 File
    23488 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23489 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    23490 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    23491 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23492 File
    23493 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23494 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    23495 p = super().first_intercept(mxyz1, mxyz2) 
    23496 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23497 File
    23498 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23499 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    23500 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    23501 exclude=exclude) 
    23502 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23503 File
    23504 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23505 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    23506 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    23507 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23508 File
    23509 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23510 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    23511 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    23512 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23513 File
    23514 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23515 packages/chimerax/graphics/drawing.py", line 1108, in
    23516 _first_intercept_excluding_children 
    23517 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    23518 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23519 File
    23520 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23521 packages/chimerax/geometry/place.py", line 201, in inverse 
    23522 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    23523 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23524 File
    23525 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23526 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    23527 rinv[:, :] = matrix_inverse(r) 
    23528 ^^^^^^^^^^^^^^^^^ 
    23529 File
    23530 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23531 packages/numpy/linalg/linalg.py", line 561, in inv 
    23532 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    23533 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23534 File
    23535 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23536 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    23537 raise LinAlgError("Singular matrix") 
    23538 numpy.linalg.LinAlgError: Singular matrix 
    23539  
    23540 numpy.linalg.LinAlgError: Singular matrix 
    23541  
    23542 File
    23543 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23544 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    23545 raise LinAlgError("Singular matrix") 
    23546  
    23547 See log for complete Python traceback. 
    23548  
    23549 Traceback (most recent call last): 
    23550 File
    23551 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23552 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    23553 self.session.ui.mouse_modes.mouse_pause_tracking() 
    23554 File
    23555 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23556 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    23557 mouse_pause_tracking 
    23558 self._mouse_pause() 
    23559 File
    23560 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23561 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    23562 m.pause(self._mouse_pause_position) 
    23563 File
    23564 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23565 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    23566 p = self.view.picked_object(x, y) 
    23567 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23568 File
    23569 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23570 packages/chimerax/graphics/view.py", line 838, in picked_object 
    23571 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    23572 beyond, 
    23573 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23574 File
    23575 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23576 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    23577 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    23578 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23579 File
    23580 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23581 packages/chimerax/core/models.py", line 143, in first_intercept 
    23582 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    23583 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23584 File
    23585 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23586 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    23587 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    23588 exclude=exclude) 
    23589 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23590 File
    23591 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23592 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    23593 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    23594 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23595 File
    23596 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23597 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    23598 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    23599 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23600 File
    23601 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23602 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    23603 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    23604 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23605 File
    23606 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23607 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    23608 p = super().first_intercept(mxyz1, mxyz2) 
    23609 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23610 File
    23611 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23612 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    23613 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    23614 exclude=exclude) 
    23615 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23616 File
    23617 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23618 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    23619 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    23620 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23621 File
    23622 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23623 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    23624 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    23625 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23626 File
    23627 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23628 packages/chimerax/graphics/drawing.py", line 1108, in
    23629 _first_intercept_excluding_children 
    23630 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    23631 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23632 File
    23633 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23634 packages/chimerax/geometry/place.py", line 201, in inverse 
    23635 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    23636 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23637 File
    23638 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23639 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    23640 rinv[:, :] = matrix_inverse(r) 
    23641 ^^^^^^^^^^^^^^^^^ 
    23642 File
    23643 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23644 packages/numpy/linalg/linalg.py", line 561, in inv 
    23645 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    23646 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23647 File
    23648 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23649 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    23650 raise LinAlgError("Singular matrix") 
    23651 numpy.linalg.LinAlgError: Singular matrix 
    23652  
    23653 numpy.linalg.LinAlgError: Singular matrix 
    23654  
    23655 File
    23656 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23657 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    23658 raise LinAlgError("Singular matrix") 
    23659  
    23660 See log for complete Python traceback. 
    23661  
    23662 Traceback (most recent call last): 
    23663 File
    23664 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23665 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    23666 self.session.ui.mouse_modes.mouse_pause_tracking() 
    23667 File
    23668 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23669 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    23670 mouse_pause_tracking 
    23671 self._mouse_pause() 
    23672 File
    23673 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23674 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    23675 m.pause(self._mouse_pause_position) 
    23676 File
    23677 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23678 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    23679 p = self.view.picked_object(x, y) 
    23680 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23681 File
    23682 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23683 packages/chimerax/graphics/view.py", line 838, in picked_object 
    23684 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    23685 beyond, 
    23686 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23687 File
    23688 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23689 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    23690 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    23691 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23692 File
    23693 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23694 packages/chimerax/core/models.py", line 143, in first_intercept 
    23695 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    23696 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23697 File
    23698 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23699 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    23700 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    23701 exclude=exclude) 
    23702 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23703 File
    23704 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23705 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    23706 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    23707 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23708 File
    23709 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23710 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    23711 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    23712 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23713 File
    23714 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23715 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    23716 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    23717 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23718 File
    23719 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23720 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    23721 p = super().first_intercept(mxyz1, mxyz2) 
    23722 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23723 File
    23724 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23725 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    23726 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    23727 exclude=exclude) 
    23728 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23729 File
    23730 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23731 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    23732 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    23733 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23734 File
    23735 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23736 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    23737 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    23738 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23739 File
    23740 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23741 packages/chimerax/graphics/drawing.py", line 1108, in
    23742 _first_intercept_excluding_children 
    23743 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    23744 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23745 File
    23746 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23747 packages/chimerax/geometry/place.py", line 201, in inverse 
    23748 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    23749 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23750 File
    23751 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23752 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    23753 rinv[:, :] = matrix_inverse(r) 
    23754 ^^^^^^^^^^^^^^^^^ 
    23755 File
    23756 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23757 packages/numpy/linalg/linalg.py", line 561, in inv 
    23758 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    23759 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23760 File
    23761 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23762 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    23763 raise LinAlgError("Singular matrix") 
    23764 numpy.linalg.LinAlgError: Singular matrix 
    23765  
    23766 numpy.linalg.LinAlgError: Singular matrix 
    23767  
    23768 File
    23769 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23770 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    23771 raise LinAlgError("Singular matrix") 
    23772  
    23773 See log for complete Python traceback. 
    23774  
    23775 Traceback (most recent call last): 
    23776 File
    23777 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23778 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    23779 self.session.ui.mouse_modes.mouse_pause_tracking() 
    23780 File
    23781 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23782 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    23783 mouse_pause_tracking 
    23784 self._mouse_pause() 
    23785 File
    23786 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23787 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    23788 m.pause(self._mouse_pause_position) 
    23789 File
    23790 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23791 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    23792 p = self.view.picked_object(x, y) 
    23793 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23794 File
    23795 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23796 packages/chimerax/graphics/view.py", line 838, in picked_object 
    23797 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    23798 beyond, 
    23799 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23800 File
    23801 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23802 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    23803 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    23804 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23805 File
    23806 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23807 packages/chimerax/core/models.py", line 143, in first_intercept 
    23808 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    23809 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23810 File
    23811 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23812 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    23813 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    23814 exclude=exclude) 
    23815 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23816 File
    23817 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23818 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    23819 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    23820 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23821 File
    23822 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23823 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    23824 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    23825 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23826 File
    23827 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23828 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    23829 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    23830 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23831 File
    23832 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23833 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    23834 p = super().first_intercept(mxyz1, mxyz2) 
    23835 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23836 File
    23837 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23838 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    23839 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    23840 exclude=exclude) 
    23841 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23842 File
    23843 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23844 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    23845 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    23846 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23847 File
    23848 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23849 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    23850 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    23851 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23852 File
    23853 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23854 packages/chimerax/graphics/drawing.py", line 1108, in
    23855 _first_intercept_excluding_children 
    23856 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    23857 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23858 File
    23859 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23860 packages/chimerax/geometry/place.py", line 201, in inverse 
    23861 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    23862 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23863 File
    23864 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23865 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    23866 rinv[:, :] = matrix_inverse(r) 
    23867 ^^^^^^^^^^^^^^^^^ 
    23868 File
    23869 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23870 packages/numpy/linalg/linalg.py", line 561, in inv 
    23871 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    23872 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23873 File
    23874 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23875 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    23876 raise LinAlgError("Singular matrix") 
    23877 numpy.linalg.LinAlgError: Singular matrix 
    23878  
    23879 numpy.linalg.LinAlgError: Singular matrix 
    23880  
    23881 File
    23882 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23883 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    23884 raise LinAlgError("Singular matrix") 
    23885  
    23886 See log for complete Python traceback. 
    23887  
    23888 Traceback (most recent call last): 
    23889 File
    23890 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23891 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    23892 self.session.ui.mouse_modes.mouse_pause_tracking() 
    23893 File
    23894 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23895 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    23896 mouse_pause_tracking 
    23897 self._mouse_pause() 
    23898 File
    23899 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23900 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    23901 m.pause(self._mouse_pause_position) 
    23902 File
    23903 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23904 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    23905 p = self.view.picked_object(x, y) 
    23906 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23907 File
    23908 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23909 packages/chimerax/graphics/view.py", line 838, in picked_object 
    23910 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    23911 beyond, 
    23912 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23913 File
    23914 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23915 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    23916 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    23917 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23918 File
    23919 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23920 packages/chimerax/core/models.py", line 143, in first_intercept 
    23921 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    23922 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23923 File
    23924 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23925 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    23926 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    23927 exclude=exclude) 
    23928 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23929 File
    23930 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23931 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    23932 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    23933 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23934 File
    23935 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23936 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    23937 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    23938 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23939 File
    23940 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23941 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    23942 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    23943 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23944 File
    23945 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23946 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    23947 p = super().first_intercept(mxyz1, mxyz2) 
    23948 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23949 File
    23950 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23951 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    23952 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    23953 exclude=exclude) 
    23954 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23955 File
    23956 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23957 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    23958 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    23959 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23960 File
    23961 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23962 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    23963 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    23964 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23965 File
    23966 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23967 packages/chimerax/graphics/drawing.py", line 1108, in
    23968 _first_intercept_excluding_children 
    23969 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    23970 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23971 File
    23972 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23973 packages/chimerax/geometry/place.py", line 201, in inverse 
    23974 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    23975 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23976 File
    23977 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23978 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    23979 rinv[:, :] = matrix_inverse(r) 
    23980 ^^^^^^^^^^^^^^^^^ 
    23981 File
    23982 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23983 packages/numpy/linalg/linalg.py", line 561, in inv 
    23984 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    23985 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    23986 File
    23987 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23988 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    23989 raise LinAlgError("Singular matrix") 
    23990 numpy.linalg.LinAlgError: Singular matrix 
    23991  
    23992 numpy.linalg.LinAlgError: Singular matrix 
    23993  
    23994 File
    23995 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    23996 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    23997 raise LinAlgError("Singular matrix") 
    23998  
    23999 See log for complete Python traceback. 
    24000  
    24001 Traceback (most recent call last): 
    24002 File
    24003 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24004 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    24005 self.session.ui.mouse_modes.mouse_pause_tracking() 
    24006 File
    24007 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24008 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    24009 mouse_pause_tracking 
    24010 self._mouse_pause() 
    24011 File
    24012 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24013 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    24014 m.pause(self._mouse_pause_position) 
    24015 File
    24016 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24017 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    24018 p = self.view.picked_object(x, y) 
    24019 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24020 File
    24021 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24022 packages/chimerax/graphics/view.py", line 838, in picked_object 
    24023 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    24024 beyond, 
    24025 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24026 File
    24027 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24028 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    24029 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    24030 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24031 File
    24032 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24033 packages/chimerax/core/models.py", line 143, in first_intercept 
    24034 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    24035 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24036 File
    24037 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24038 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    24039 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    24040 exclude=exclude) 
    24041 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24042 File
    24043 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24044 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    24045 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    24046 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24047 File
    24048 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24049 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    24050 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    24051 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24052 File
    24053 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24054 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    24055 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    24056 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24057 File
    24058 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24059 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    24060 p = super().first_intercept(mxyz1, mxyz2) 
    24061 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24062 File
    24063 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24064 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    24065 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    24066 exclude=exclude) 
    24067 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24068 File
    24069 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24070 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    24071 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    24072 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24073 File
    24074 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24075 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    24076 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    24077 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24078 File
    24079 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24080 packages/chimerax/graphics/drawing.py", line 1108, in
    24081 _first_intercept_excluding_children 
    24082 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    24083 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24084 File
    24085 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24086 packages/chimerax/geometry/place.py", line 201, in inverse 
    24087 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    24088 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24089 File
    24090 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24091 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    24092 rinv[:, :] = matrix_inverse(r) 
    24093 ^^^^^^^^^^^^^^^^^ 
    24094 File
    24095 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24096 packages/numpy/linalg/linalg.py", line 561, in inv 
    24097 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    24098 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24099 File
    24100 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24101 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    24102 raise LinAlgError("Singular matrix") 
    24103 numpy.linalg.LinAlgError: Singular matrix 
    24104  
    24105 numpy.linalg.LinAlgError: Singular matrix 
    24106  
    24107 File
    24108 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24109 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    24110 raise LinAlgError("Singular matrix") 
    24111  
    24112 See log for complete Python traceback. 
    24113  
    24114 Traceback (most recent call last): 
    24115 File
    24116 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24117 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    24118 self.session.ui.mouse_modes.mouse_pause_tracking() 
    24119 File
    24120 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24121 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    24122 mouse_pause_tracking 
    24123 self._mouse_pause() 
    24124 File
    24125 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24126 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    24127 m.pause(self._mouse_pause_position) 
    24128 File
    24129 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24130 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    24131 p = self.view.picked_object(x, y) 
    24132 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24133 File
    24134 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24135 packages/chimerax/graphics/view.py", line 838, in picked_object 
    24136 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    24137 beyond, 
    24138 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24139 File
    24140 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24141 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    24142 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    24143 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24144 File
    24145 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24146 packages/chimerax/core/models.py", line 143, in first_intercept 
    24147 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    24148 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24149 File
    24150 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24151 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    24152 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    24153 exclude=exclude) 
    24154 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24155 File
    24156 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24157 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    24158 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    24159 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24160 File
    24161 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24162 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    24163 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    24164 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24165 File
    24166 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24167 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    24168 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    24169 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24170 File
    24171 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24172 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    24173 p = super().first_intercept(mxyz1, mxyz2) 
    24174 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24175 File
    24176 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24177 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    24178 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    24179 exclude=exclude) 
    24180 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24181 File
    24182 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24183 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    24184 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    24185 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24186 File
    24187 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24188 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    24189 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    24190 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24191 File
    24192 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24193 packages/chimerax/graphics/drawing.py", line 1108, in
    24194 _first_intercept_excluding_children 
    24195 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    24196 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24197 File
    24198 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24199 packages/chimerax/geometry/place.py", line 201, in inverse 
    24200 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    24201 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24202 File
    24203 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24204 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    24205 rinv[:, :] = matrix_inverse(r) 
    24206 ^^^^^^^^^^^^^^^^^ 
    24207 File
    24208 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24209 packages/numpy/linalg/linalg.py", line 561, in inv 
    24210 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    24211 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24212 File
    24213 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24214 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    24215 raise LinAlgError("Singular matrix") 
    24216 numpy.linalg.LinAlgError: Singular matrix 
    24217  
    24218 numpy.linalg.LinAlgError: Singular matrix 
    24219  
    24220 File
    24221 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24222 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    24223 raise LinAlgError("Singular matrix") 
    24224  
    24225 See log for complete Python traceback. 
    24226  
    24227 Traceback (most recent call last): 
    24228 File
    24229 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24230 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    24231 self.session.ui.mouse_modes.mouse_pause_tracking() 
    24232 File
    24233 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24234 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    24235 mouse_pause_tracking 
    24236 self._mouse_pause() 
    24237 File
    24238 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24239 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    24240 m.pause(self._mouse_pause_position) 
    24241 File
    24242 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24243 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    24244 p = self.view.picked_object(x, y) 
    24245 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24246 File
    24247 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24248 packages/chimerax/graphics/view.py", line 838, in picked_object 
    24249 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    24250 beyond, 
    24251 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24252 File
    24253 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24254 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    24255 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    24256 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24257 File
    24258 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24259 packages/chimerax/core/models.py", line 143, in first_intercept 
    24260 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    24261 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24262 File
    24263 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24264 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    24265 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    24266 exclude=exclude) 
    24267 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24268 File
    24269 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24270 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    24271 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    24272 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24273 File
    24274 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24275 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    24276 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    24277 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24278 File
    24279 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24280 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    24281 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    24282 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24283 File
    24284 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24285 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    24286 p = super().first_intercept(mxyz1, mxyz2) 
    24287 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24288 File
    24289 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24290 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    24291 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    24292 exclude=exclude) 
    24293 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24294 File
    24295 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24296 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    24297 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    24298 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24299 File
    24300 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24301 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    24302 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    24303 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24304 File
    24305 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24306 packages/chimerax/graphics/drawing.py", line 1108, in
    24307 _first_intercept_excluding_children 
    24308 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    24309 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24310 File
    24311 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24312 packages/chimerax/geometry/place.py", line 201, in inverse 
    24313 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    24314 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24315 File
    24316 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24317 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    24318 rinv[:, :] = matrix_inverse(r) 
    24319 ^^^^^^^^^^^^^^^^^ 
    24320 File
    24321 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24322 packages/numpy/linalg/linalg.py", line 561, in inv 
    24323 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    24324 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24325 File
    24326 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24327 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    24328 raise LinAlgError("Singular matrix") 
    24329 numpy.linalg.LinAlgError: Singular matrix 
    24330  
    24331 numpy.linalg.LinAlgError: Singular matrix 
    24332  
    24333 File
    24334 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24335 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    24336 raise LinAlgError("Singular matrix") 
    24337  
    24338 See log for complete Python traceback. 
    24339  
    24340 Traceback (most recent call last): 
    24341 File
    24342 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24343 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    24344 self.session.ui.mouse_modes.mouse_pause_tracking() 
    24345 File
    24346 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24347 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    24348 mouse_pause_tracking 
    24349 self._mouse_pause() 
    24350 File
    24351 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24352 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    24353 m.pause(self._mouse_pause_position) 
    24354 File
    24355 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24356 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    24357 p = self.view.picked_object(x, y) 
    24358 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24359 File
    24360 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24361 packages/chimerax/graphics/view.py", line 838, in picked_object 
    24362 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    24363 beyond, 
    24364 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24365 File
    24366 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24367 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    24368 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    24369 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24370 File
    24371 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24372 packages/chimerax/core/models.py", line 143, in first_intercept 
    24373 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    24374 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24375 File
    24376 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24377 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    24378 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    24379 exclude=exclude) 
    24380 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24381 File
    24382 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24383 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    24384 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    24385 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24386 File
    24387 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24388 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    24389 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    24390 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24391 File
    24392 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24393 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    24394 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    24395 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24396 File
    24397 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24398 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    24399 p = super().first_intercept(mxyz1, mxyz2) 
    24400 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24401 File
    24402 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24403 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    24404 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    24405 exclude=exclude) 
    24406 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24407 File
    24408 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24409 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    24410 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    24411 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24412 File
    24413 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24414 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    24415 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    24416 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24417 File
    24418 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24419 packages/chimerax/graphics/drawing.py", line 1108, in
    24420 _first_intercept_excluding_children 
    24421 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    24422 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24423 File
    24424 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24425 packages/chimerax/geometry/place.py", line 201, in inverse 
    24426 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    24427 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24428 File
    24429 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24430 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    24431 rinv[:, :] = matrix_inverse(r) 
    24432 ^^^^^^^^^^^^^^^^^ 
    24433 File
    24434 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24435 packages/numpy/linalg/linalg.py", line 561, in inv 
    24436 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    24437 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24438 File
    24439 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24440 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    24441 raise LinAlgError("Singular matrix") 
    24442 numpy.linalg.LinAlgError: Singular matrix 
    24443  
    24444 numpy.linalg.LinAlgError: Singular matrix 
    24445  
    24446 File
    24447 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24448 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    24449 raise LinAlgError("Singular matrix") 
    24450  
    24451 See log for complete Python traceback. 
    24452  
    24453 Traceback (most recent call last): 
    24454 File
    24455 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24456 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    24457 self.session.ui.mouse_modes.mouse_pause_tracking() 
    24458 File
    24459 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24460 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    24461 mouse_pause_tracking 
    24462 self._mouse_pause() 
    24463 File
    24464 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24465 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    24466 m.pause(self._mouse_pause_position) 
    24467 File
    24468 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24469 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    24470 p = self.view.picked_object(x, y) 
    24471 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24472 File
    24473 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24474 packages/chimerax/graphics/view.py", line 838, in picked_object 
    24475 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    24476 beyond, 
    24477 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24478 File
    24479 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24480 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    24481 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    24482 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24483 File
    24484 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24485 packages/chimerax/core/models.py", line 143, in first_intercept 
    24486 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    24487 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24488 File
    24489 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24490 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    24491 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    24492 exclude=exclude) 
    24493 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24494 File
    24495 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24496 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    24497 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    24498 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24499 File
    24500 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24501 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    24502 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    24503 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24504 File
    24505 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24506 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    24507 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    24508 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24509 File
    24510 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24511 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    24512 p = super().first_intercept(mxyz1, mxyz2) 
    24513 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24514 File
    24515 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24516 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    24517 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    24518 exclude=exclude) 
    24519 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24520 File
    24521 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24522 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    24523 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    24524 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24525 File
    24526 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24527 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    24528 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    24529 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24530 File
    24531 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24532 packages/chimerax/graphics/drawing.py", line 1108, in
    24533 _first_intercept_excluding_children 
    24534 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    24535 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24536 File
    24537 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24538 packages/chimerax/geometry/place.py", line 201, in inverse 
    24539 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    24540 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24541 File
    24542 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24543 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    24544 rinv[:, :] = matrix_inverse(r) 
    24545 ^^^^^^^^^^^^^^^^^ 
    24546 File
    24547 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24548 packages/numpy/linalg/linalg.py", line 561, in inv 
    24549 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    24550 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24551 File
    24552 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24553 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    24554 raise LinAlgError("Singular matrix") 
    24555 numpy.linalg.LinAlgError: Singular matrix 
    24556  
    24557 numpy.linalg.LinAlgError: Singular matrix 
    24558  
    24559 File
    24560 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24561 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    24562 raise LinAlgError("Singular matrix") 
    24563  
    24564 See log for complete Python traceback. 
    24565  
    24566 Traceback (most recent call last): 
    24567 File
    24568 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24569 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    24570 self.session.ui.mouse_modes.mouse_pause_tracking() 
    24571 File
    24572 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24573 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    24574 mouse_pause_tracking 
    24575 self._mouse_pause() 
    24576 File
    24577 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24578 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    24579 m.pause(self._mouse_pause_position) 
    24580 File
    24581 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24582 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    24583 p = self.view.picked_object(x, y) 
    24584 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24585 File
    24586 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24587 packages/chimerax/graphics/view.py", line 838, in picked_object 
    24588 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    24589 beyond, 
    24590 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24591 File
    24592 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24593 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    24594 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    24595 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24596 File
    24597 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24598 packages/chimerax/core/models.py", line 143, in first_intercept 
    24599 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    24600 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24601 File
    24602 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24603 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    24604 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    24605 exclude=exclude) 
    24606 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24607 File
    24608 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24609 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    24610 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    24611 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24612 File
    24613 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24614 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    24615 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    24616 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24617 File
    24618 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24619 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    24620 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    24621 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24622 File
    24623 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24624 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    24625 p = super().first_intercept(mxyz1, mxyz2) 
    24626 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24627 File
    24628 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24629 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    24630 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    24631 exclude=exclude) 
    24632 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24633 File
    24634 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24635 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    24636 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    24637 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24638 File
    24639 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24640 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    24641 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    24642 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24643 File
    24644 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24645 packages/chimerax/graphics/drawing.py", line 1108, in
    24646 _first_intercept_excluding_children 
    24647 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    24648 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24649 File
    24650 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24651 packages/chimerax/geometry/place.py", line 201, in inverse 
    24652 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    24653 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24654 File
    24655 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24656 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    24657 rinv[:, :] = matrix_inverse(r) 
    24658 ^^^^^^^^^^^^^^^^^ 
    24659 File
    24660 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24661 packages/numpy/linalg/linalg.py", line 561, in inv 
    24662 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    24663 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24664 File
    24665 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24666 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    24667 raise LinAlgError("Singular matrix") 
    24668 numpy.linalg.LinAlgError: Singular matrix 
    24669  
    24670 numpy.linalg.LinAlgError: Singular matrix 
    24671  
    24672 File
    24673 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24674 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    24675 raise LinAlgError("Singular matrix") 
    24676  
    24677 See log for complete Python traceback. 
    24678  
    24679 Traceback (most recent call last): 
    24680 File
    24681 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24682 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    24683 self.session.ui.mouse_modes.mouse_pause_tracking() 
    24684 File
    24685 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24686 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    24687 mouse_pause_tracking 
    24688 self._mouse_pause() 
    24689 File
    24690 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24691 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    24692 m.pause(self._mouse_pause_position) 
    24693 File
    24694 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24695 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    24696 p = self.view.picked_object(x, y) 
    24697 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24698 File
    24699 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24700 packages/chimerax/graphics/view.py", line 838, in picked_object 
    24701 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    24702 beyond, 
    24703 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24704 File
    24705 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24706 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    24707 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    24708 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24709 File
    24710 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24711 packages/chimerax/core/models.py", line 143, in first_intercept 
    24712 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    24713 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24714 File
    24715 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24716 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    24717 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    24718 exclude=exclude) 
    24719 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24720 File
    24721 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24722 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    24723 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    24724 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24725 File
    24726 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24727 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    24728 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    24729 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24730 File
    24731 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24732 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    24733 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    24734 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24735 File
    24736 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24737 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    24738 p = super().first_intercept(mxyz1, mxyz2) 
    24739 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24740 File
    24741 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24742 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    24743 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    24744 exclude=exclude) 
    24745 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24746 File
    24747 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24748 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    24749 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    24750 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24751 File
    24752 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24753 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    24754 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    24755 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24756 File
    24757 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24758 packages/chimerax/graphics/drawing.py", line 1108, in
    24759 _first_intercept_excluding_children 
    24760 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    24761 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24762 File
    24763 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24764 packages/chimerax/geometry/place.py", line 201, in inverse 
    24765 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    24766 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24767 File
    24768 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24769 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    24770 rinv[:, :] = matrix_inverse(r) 
    24771 ^^^^^^^^^^^^^^^^^ 
    24772 File
    24773 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24774 packages/numpy/linalg/linalg.py", line 561, in inv 
    24775 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    24776 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24777 File
    24778 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24779 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    24780 raise LinAlgError("Singular matrix") 
    24781 numpy.linalg.LinAlgError: Singular matrix 
    24782  
    24783 numpy.linalg.LinAlgError: Singular matrix 
    24784  
    24785 File
    24786 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24787 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    24788 raise LinAlgError("Singular matrix") 
    24789  
    24790 See log for complete Python traceback. 
    24791  
    24792 Traceback (most recent call last): 
    24793 File
    24794 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24795 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    24796 self.session.ui.mouse_modes.mouse_pause_tracking() 
    24797 File
    24798 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24799 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    24800 mouse_pause_tracking 
    24801 self._mouse_pause() 
    24802 File
    24803 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24804 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    24805 m.pause(self._mouse_pause_position) 
    24806 File
    24807 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24808 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    24809 p = self.view.picked_object(x, y) 
    24810 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24811 File
    24812 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24813 packages/chimerax/graphics/view.py", line 838, in picked_object 
    24814 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    24815 beyond, 
    24816 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24817 File
    24818 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24819 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    24820 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    24821 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24822 File
    24823 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24824 packages/chimerax/core/models.py", line 143, in first_intercept 
    24825 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    24826 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24827 File
    24828 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24829 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    24830 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    24831 exclude=exclude) 
    24832 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24833 File
    24834 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24835 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    24836 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    24837 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24838 File
    24839 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24840 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    24841 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    24842 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24843 File
    24844 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24845 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    24846 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    24847 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24848 File
    24849 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24850 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    24851 p = super().first_intercept(mxyz1, mxyz2) 
    24852 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24853 File
    24854 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24855 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    24856 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    24857 exclude=exclude) 
    24858 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24859 File
    24860 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24861 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    24862 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    24863 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24864 File
    24865 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24866 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    24867 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    24868 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24869 File
    24870 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24871 packages/chimerax/graphics/drawing.py", line 1108, in
    24872 _first_intercept_excluding_children 
    24873 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    24874 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24875 File
    24876 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24877 packages/chimerax/geometry/place.py", line 201, in inverse 
    24878 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    24879 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24880 File
    24881 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24882 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    24883 rinv[:, :] = matrix_inverse(r) 
    24884 ^^^^^^^^^^^^^^^^^ 
    24885 File
    24886 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24887 packages/numpy/linalg/linalg.py", line 561, in inv 
    24888 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    24889 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24890 File
    24891 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24892 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    24893 raise LinAlgError("Singular matrix") 
    24894 numpy.linalg.LinAlgError: Singular matrix 
    24895  
    24896 numpy.linalg.LinAlgError: Singular matrix 
    24897  
    24898 File
    24899 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24900 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    24901 raise LinAlgError("Singular matrix") 
    24902  
    24903 See log for complete Python traceback. 
    24904  
    24905 Traceback (most recent call last): 
    24906 File
    24907 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24908 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    24909 self.session.ui.mouse_modes.mouse_pause_tracking() 
    24910 File
    24911 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24912 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    24913 mouse_pause_tracking 
    24914 self._mouse_pause() 
    24915 File
    24916 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24917 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    24918 m.pause(self._mouse_pause_position) 
    24919 File
    24920 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24921 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    24922 p = self.view.picked_object(x, y) 
    24923 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24924 File
    24925 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24926 packages/chimerax/graphics/view.py", line 838, in picked_object 
    24927 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    24928 beyond, 
    24929 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24930 File
    24931 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24932 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    24933 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    24934 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24935 File
    24936 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24937 packages/chimerax/core/models.py", line 143, in first_intercept 
    24938 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    24939 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24940 File
    24941 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24942 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    24943 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    24944 exclude=exclude) 
    24945 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24946 File
    24947 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24948 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    24949 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    24950 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24951 File
    24952 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24953 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    24954 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    24955 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24956 File
    24957 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24958 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    24959 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    24960 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24961 File
    24962 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24963 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    24964 p = super().first_intercept(mxyz1, mxyz2) 
    24965 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24966 File
    24967 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24968 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    24969 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    24970 exclude=exclude) 
    24971 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24972 File
    24973 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24974 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    24975 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    24976 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24977 File
    24978 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24979 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    24980 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    24981 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24982 File
    24983 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24984 packages/chimerax/graphics/drawing.py", line 1108, in
    24985 _first_intercept_excluding_children 
    24986 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    24987 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24988 File
    24989 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24990 packages/chimerax/geometry/place.py", line 201, in inverse 
    24991 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    24992 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    24993 File
    24994 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    24995 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    24996 rinv[:, :] = matrix_inverse(r) 
    24997 ^^^^^^^^^^^^^^^^^ 
    24998 File
    24999 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25000 packages/numpy/linalg/linalg.py", line 561, in inv 
    25001 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    25002 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25003 File
    25004 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25005 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    25006 raise LinAlgError("Singular matrix") 
    25007 numpy.linalg.LinAlgError: Singular matrix 
    25008  
    25009 numpy.linalg.LinAlgError: Singular matrix 
    25010  
    25011 File
    25012 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25013 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    25014 raise LinAlgError("Singular matrix") 
    25015  
    25016 See log for complete Python traceback. 
    25017  
    25018 Traceback (most recent call last): 
    25019 File
    25020 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25021 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    25022 self.session.ui.mouse_modes.mouse_pause_tracking() 
    25023 File
    25024 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25025 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    25026 mouse_pause_tracking 
    25027 self._mouse_pause() 
    25028 File
    25029 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25030 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    25031 m.pause(self._mouse_pause_position) 
    25032 File
    25033 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25034 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    25035 p = self.view.picked_object(x, y) 
    25036 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25037 File
    25038 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25039 packages/chimerax/graphics/view.py", line 838, in picked_object 
    25040 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    25041 beyond, 
    25042 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25043 File
    25044 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25045 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    25046 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    25047 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25048 File
    25049 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25050 packages/chimerax/core/models.py", line 143, in first_intercept 
    25051 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    25052 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25053 File
    25054 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25055 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    25056 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    25057 exclude=exclude) 
    25058 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25059 File
    25060 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25061 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    25062 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    25063 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25064 File
    25065 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25066 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    25067 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    25068 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25069 File
    25070 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25071 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    25072 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    25073 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25074 File
    25075 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25076 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    25077 p = super().first_intercept(mxyz1, mxyz2) 
    25078 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25079 File
    25080 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25081 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    25082 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    25083 exclude=exclude) 
    25084 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25085 File
    25086 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25087 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    25088 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    25089 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25090 File
    25091 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25092 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    25093 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    25094 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25095 File
    25096 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25097 packages/chimerax/graphics/drawing.py", line 1108, in
    25098 _first_intercept_excluding_children 
    25099 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    25100 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25101 File
    25102 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25103 packages/chimerax/geometry/place.py", line 201, in inverse 
    25104 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    25105 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25106 File
    25107 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25108 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    25109 rinv[:, :] = matrix_inverse(r) 
    25110 ^^^^^^^^^^^^^^^^^ 
    25111 File
    25112 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25113 packages/numpy/linalg/linalg.py", line 561, in inv 
    25114 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    25115 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25116 File
    25117 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25118 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    25119 raise LinAlgError("Singular matrix") 
    25120 numpy.linalg.LinAlgError: Singular matrix 
    25121  
    25122 numpy.linalg.LinAlgError: Singular matrix 
    25123  
    25124 File
    25125 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25126 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    25127 raise LinAlgError("Singular matrix") 
    25128  
    25129 See log for complete Python traceback. 
    25130  
    25131 Traceback (most recent call last): 
    25132 File
    25133 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25134 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    25135 self.session.ui.mouse_modes.mouse_pause_tracking() 
    25136 File
    25137 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25138 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    25139 mouse_pause_tracking 
    25140 self._mouse_pause() 
    25141 File
    25142 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25143 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    25144 m.pause(self._mouse_pause_position) 
    25145 File
    25146 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25147 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    25148 p = self.view.picked_object(x, y) 
    25149 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25150 File
    25151 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25152 packages/chimerax/graphics/view.py", line 838, in picked_object 
    25153 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    25154 beyond, 
    25155 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25156 File
    25157 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25158 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    25159 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    25160 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25161 File
    25162 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25163 packages/chimerax/core/models.py", line 143, in first_intercept 
    25164 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    25165 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25166 File
    25167 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25168 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    25169 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    25170 exclude=exclude) 
    25171 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25172 File
    25173 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25174 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    25175 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    25176 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25177 File
    25178 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25179 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    25180 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    25181 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25182 File
    25183 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25184 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    25185 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    25186 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25187 File
    25188 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25189 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    25190 p = super().first_intercept(mxyz1, mxyz2) 
    25191 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25192 File
    25193 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25194 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    25195 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    25196 exclude=exclude) 
    25197 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25198 File
    25199 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25200 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    25201 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    25202 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25203 File
    25204 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25205 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    25206 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    25207 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25208 File
    25209 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25210 packages/chimerax/graphics/drawing.py", line 1108, in
    25211 _first_intercept_excluding_children 
    25212 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    25213 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25214 File
    25215 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25216 packages/chimerax/geometry/place.py", line 201, in inverse 
    25217 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    25218 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25219 File
    25220 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25221 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    25222 rinv[:, :] = matrix_inverse(r) 
    25223 ^^^^^^^^^^^^^^^^^ 
    25224 File
    25225 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25226 packages/numpy/linalg/linalg.py", line 561, in inv 
    25227 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    25228 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25229 File
    25230 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25231 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    25232 raise LinAlgError("Singular matrix") 
    25233 numpy.linalg.LinAlgError: Singular matrix 
    25234  
    25235 numpy.linalg.LinAlgError: Singular matrix 
    25236  
    25237 File
    25238 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25239 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    25240 raise LinAlgError("Singular matrix") 
    25241  
    25242 See log for complete Python traceback. 
    25243  
    25244 Traceback (most recent call last): 
    25245 File
    25246 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25247 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    25248 self.session.ui.mouse_modes.mouse_pause_tracking() 
    25249 File
    25250 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25251 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    25252 mouse_pause_tracking 
    25253 self._mouse_pause() 
    25254 File
    25255 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25256 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    25257 m.pause(self._mouse_pause_position) 
    25258 File
    25259 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25260 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    25261 p = self.view.picked_object(x, y) 
    25262 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25263 File
    25264 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25265 packages/chimerax/graphics/view.py", line 838, in picked_object 
    25266 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    25267 beyond, 
    25268 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25269 File
    25270 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25271 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    25272 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    25273 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25274 File
    25275 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25276 packages/chimerax/core/models.py", line 143, in first_intercept 
    25277 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    25278 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25279 File
    25280 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25281 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    25282 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    25283 exclude=exclude) 
    25284 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25285 File
    25286 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25287 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    25288 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    25289 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25290 File
    25291 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25292 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    25293 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    25294 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25295 File
    25296 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25297 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    25298 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    25299 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25300 File
    25301 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25302 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    25303 p = super().first_intercept(mxyz1, mxyz2) 
    25304 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25305 File
    25306 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25307 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    25308 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    25309 exclude=exclude) 
    25310 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25311 File
    25312 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25313 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    25314 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    25315 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25316 File
    25317 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25318 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    25319 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    25320 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25321 File
    25322 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25323 packages/chimerax/graphics/drawing.py", line 1108, in
    25324 _first_intercept_excluding_children 
    25325 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    25326 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25327 File
    25328 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25329 packages/chimerax/geometry/place.py", line 201, in inverse 
    25330 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    25331 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25332 File
    25333 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25334 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    25335 rinv[:, :] = matrix_inverse(r) 
    25336 ^^^^^^^^^^^^^^^^^ 
    25337 File
    25338 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25339 packages/numpy/linalg/linalg.py", line 561, in inv 
    25340 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    25341 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25342 File
    25343 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25344 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    25345 raise LinAlgError("Singular matrix") 
    25346 numpy.linalg.LinAlgError: Singular matrix 
    25347  
    25348 numpy.linalg.LinAlgError: Singular matrix 
    25349  
    25350 File
    25351 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25352 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    25353 raise LinAlgError("Singular matrix") 
    25354  
    25355 See log for complete Python traceback. 
    25356  
    25357 Traceback (most recent call last): 
    25358 File
    25359 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25360 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    25361 self.session.ui.mouse_modes.mouse_pause_tracking() 
    25362 File
    25363 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25364 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    25365 mouse_pause_tracking 
    25366 self._mouse_pause() 
    25367 File
    25368 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25369 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    25370 m.pause(self._mouse_pause_position) 
    25371 File
    25372 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25373 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    25374 p = self.view.picked_object(x, y) 
    25375 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25376 File
    25377 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25378 packages/chimerax/graphics/view.py", line 838, in picked_object 
    25379 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    25380 beyond, 
    25381 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25382 File
    25383 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25384 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    25385 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    25386 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25387 File
    25388 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25389 packages/chimerax/core/models.py", line 143, in first_intercept 
    25390 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    25391 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25392 File
    25393 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25394 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    25395 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    25396 exclude=exclude) 
    25397 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25398 File
    25399 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25400 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    25401 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    25402 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25403 File
    25404 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25405 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    25406 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    25407 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25408 File
    25409 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25410 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    25411 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    25412 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25413 File
    25414 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25415 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    25416 p = super().first_intercept(mxyz1, mxyz2) 
    25417 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25418 File
    25419 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25420 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    25421 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    25422 exclude=exclude) 
    25423 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25424 File
    25425 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25426 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    25427 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    25428 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25429 File
    25430 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25431 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    25432 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    25433 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25434 File
    25435 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25436 packages/chimerax/graphics/drawing.py", line 1108, in
    25437 _first_intercept_excluding_children 
    25438 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    25439 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25440 File
    25441 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25442 packages/chimerax/geometry/place.py", line 201, in inverse 
    25443 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    25444 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25445 File
    25446 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25447 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    25448 rinv[:, :] = matrix_inverse(r) 
    25449 ^^^^^^^^^^^^^^^^^ 
    25450 File
    25451 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25452 packages/numpy/linalg/linalg.py", line 561, in inv 
    25453 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    25454 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25455 File
    25456 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25457 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    25458 raise LinAlgError("Singular matrix") 
    25459 numpy.linalg.LinAlgError: Singular matrix 
    25460  
    25461 numpy.linalg.LinAlgError: Singular matrix 
    25462  
    25463 File
    25464 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25465 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    25466 raise LinAlgError("Singular matrix") 
    25467  
    25468 See log for complete Python traceback. 
    25469  
    25470 Traceback (most recent call last): 
    25471 File
    25472 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25473 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    25474 self.session.ui.mouse_modes.mouse_pause_tracking() 
    25475 File
    25476 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25477 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    25478 mouse_pause_tracking 
    25479 self._mouse_pause() 
    25480 File
    25481 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25482 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    25483 m.pause(self._mouse_pause_position) 
    25484 File
    25485 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25486 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    25487 p = self.view.picked_object(x, y) 
    25488 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25489 File
    25490 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25491 packages/chimerax/graphics/view.py", line 838, in picked_object 
    25492 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    25493 beyond, 
    25494 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25495 File
    25496 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25497 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    25498 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    25499 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25500 File
    25501 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25502 packages/chimerax/core/models.py", line 143, in first_intercept 
    25503 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    25504 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25505 File
    25506 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25507 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    25508 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    25509 exclude=exclude) 
    25510 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25511 File
    25512 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25513 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    25514 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    25515 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25516 File
    25517 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25518 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    25519 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    25520 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25521 File
    25522 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25523 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    25524 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    25525 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25526 File
    25527 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25528 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    25529 p = super().first_intercept(mxyz1, mxyz2) 
    25530 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25531 File
    25532 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25533 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    25534 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    25535 exclude=exclude) 
    25536 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25537 File
    25538 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25539 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    25540 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    25541 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25542 File
    25543 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25544 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    25545 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    25546 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25547 File
    25548 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25549 packages/chimerax/graphics/drawing.py", line 1108, in
    25550 _first_intercept_excluding_children 
    25551 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    25552 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25553 File
    25554 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25555 packages/chimerax/geometry/place.py", line 201, in inverse 
    25556 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    25557 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25558 File
    25559 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25560 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    25561 rinv[:, :] = matrix_inverse(r) 
    25562 ^^^^^^^^^^^^^^^^^ 
    25563 File
    25564 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25565 packages/numpy/linalg/linalg.py", line 561, in inv 
    25566 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    25567 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25568 File
    25569 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25570 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    25571 raise LinAlgError("Singular matrix") 
    25572 numpy.linalg.LinAlgError: Singular matrix 
    25573  
    25574 numpy.linalg.LinAlgError: Singular matrix 
    25575  
    25576 File
    25577 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25578 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    25579 raise LinAlgError("Singular matrix") 
    25580  
    25581 See log for complete Python traceback. 
    25582  
    25583 Traceback (most recent call last): 
    25584 File
    25585 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25586 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    25587 self.session.ui.mouse_modes.mouse_pause_tracking() 
    25588 File
    25589 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25590 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    25591 mouse_pause_tracking 
    25592 self._mouse_pause() 
    25593 File
    25594 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25595 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    25596 m.pause(self._mouse_pause_position) 
    25597 File
    25598 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25599 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    25600 p = self.view.picked_object(x, y) 
    25601 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25602 File
    25603 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25604 packages/chimerax/graphics/view.py", line 838, in picked_object 
    25605 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    25606 beyond, 
    25607 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25608 File
    25609 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25610 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    25611 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    25612 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25613 File
    25614 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25615 packages/chimerax/core/models.py", line 143, in first_intercept 
    25616 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    25617 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25618 File
    25619 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25620 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    25621 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    25622 exclude=exclude) 
    25623 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25624 File
    25625 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25626 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    25627 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    25628 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25629 File
    25630 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25631 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    25632 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    25633 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25634 File
    25635 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25636 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    25637 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    25638 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25639 File
    25640 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25641 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    25642 p = super().first_intercept(mxyz1, mxyz2) 
    25643 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25644 File
    25645 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25646 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    25647 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    25648 exclude=exclude) 
    25649 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25650 File
    25651 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25652 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    25653 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    25654 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25655 File
    25656 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25657 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    25658 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    25659 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25660 File
    25661 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25662 packages/chimerax/graphics/drawing.py", line 1108, in
    25663 _first_intercept_excluding_children 
    25664 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    25665 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25666 File
    25667 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25668 packages/chimerax/geometry/place.py", line 201, in inverse 
    25669 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    25670 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25671 File
    25672 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25673 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    25674 rinv[:, :] = matrix_inverse(r) 
    25675 ^^^^^^^^^^^^^^^^^ 
    25676 File
    25677 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25678 packages/numpy/linalg/linalg.py", line 561, in inv 
    25679 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    25680 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25681 File
    25682 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25683 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    25684 raise LinAlgError("Singular matrix") 
    25685 numpy.linalg.LinAlgError: Singular matrix 
    25686  
    25687 numpy.linalg.LinAlgError: Singular matrix 
    25688  
    25689 File
    25690 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25691 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    25692 raise LinAlgError("Singular matrix") 
    25693  
    25694 See log for complete Python traceback. 
    25695  
    25696 Traceback (most recent call last): 
    25697 File
    25698 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25699 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    25700 self.session.ui.mouse_modes.mouse_pause_tracking() 
    25701 File
    25702 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25703 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    25704 mouse_pause_tracking 
    25705 self._mouse_pause() 
    25706 File
    25707 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25708 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    25709 m.pause(self._mouse_pause_position) 
    25710 File
    25711 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25712 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    25713 p = self.view.picked_object(x, y) 
    25714 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25715 File
    25716 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25717 packages/chimerax/graphics/view.py", line 838, in picked_object 
    25718 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    25719 beyond, 
    25720 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25721 File
    25722 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25723 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    25724 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    25725 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25726 File
    25727 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25728 packages/chimerax/core/models.py", line 143, in first_intercept 
    25729 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    25730 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25731 File
    25732 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25733 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    25734 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    25735 exclude=exclude) 
    25736 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25737 File
    25738 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25739 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    25740 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    25741 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25742 File
    25743 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25744 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    25745 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    25746 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25747 File
    25748 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25749 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    25750 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    25751 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25752 File
    25753 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25754 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    25755 p = super().first_intercept(mxyz1, mxyz2) 
    25756 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25757 File
    25758 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25759 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    25760 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    25761 exclude=exclude) 
    25762 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25763 File
    25764 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25765 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    25766 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    25767 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25768 File
    25769 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25770 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    25771 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    25772 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25773 File
    25774 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25775 packages/chimerax/graphics/drawing.py", line 1108, in
    25776 _first_intercept_excluding_children 
    25777 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    25778 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25779 File
    25780 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25781 packages/chimerax/geometry/place.py", line 201, in inverse 
    25782 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    25783 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25784 File
    25785 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25786 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    25787 rinv[:, :] = matrix_inverse(r) 
    25788 ^^^^^^^^^^^^^^^^^ 
    25789 File
    25790 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25791 packages/numpy/linalg/linalg.py", line 561, in inv 
    25792 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    25793 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25794 File
    25795 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25796 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    25797 raise LinAlgError("Singular matrix") 
    25798 numpy.linalg.LinAlgError: Singular matrix 
    25799  
    25800 numpy.linalg.LinAlgError: Singular matrix 
    25801  
    25802 File
    25803 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25804 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    25805 raise LinAlgError("Singular matrix") 
    25806  
    25807 See log for complete Python traceback. 
    25808  
    25809 Traceback (most recent call last): 
    25810 File
    25811 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25812 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    25813 self.session.ui.mouse_modes.mouse_pause_tracking() 
    25814 File
    25815 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25816 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    25817 mouse_pause_tracking 
    25818 self._mouse_pause() 
    25819 File
    25820 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25821 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    25822 m.pause(self._mouse_pause_position) 
    25823 File
    25824 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25825 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    25826 p = self.view.picked_object(x, y) 
    25827 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25828 File
    25829 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25830 packages/chimerax/graphics/view.py", line 838, in picked_object 
    25831 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    25832 beyond, 
    25833 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25834 File
    25835 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25836 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    25837 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    25838 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25839 File
    25840 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25841 packages/chimerax/core/models.py", line 143, in first_intercept 
    25842 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    25843 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25844 File
    25845 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25846 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    25847 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    25848 exclude=exclude) 
    25849 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25850 File
    25851 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25852 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    25853 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    25854 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25855 File
    25856 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25857 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    25858 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    25859 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25860 File
    25861 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25862 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    25863 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    25864 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25865 File
    25866 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25867 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    25868 p = super().first_intercept(mxyz1, mxyz2) 
    25869 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25870 File
    25871 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25872 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    25873 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    25874 exclude=exclude) 
    25875 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25876 File
    25877 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25878 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    25879 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    25880 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25881 File
    25882 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25883 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    25884 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    25885 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25886 File
    25887 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25888 packages/chimerax/graphics/drawing.py", line 1108, in
    25889 _first_intercept_excluding_children 
    25890 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    25891 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25892 File
    25893 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25894 packages/chimerax/geometry/place.py", line 201, in inverse 
    25895 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    25896 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25897 File
    25898 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25899 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    25900 rinv[:, :] = matrix_inverse(r) 
    25901 ^^^^^^^^^^^^^^^^^ 
    25902 File
    25903 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25904 packages/numpy/linalg/linalg.py", line 561, in inv 
    25905 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    25906 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25907 File
    25908 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25909 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    25910 raise LinAlgError("Singular matrix") 
    25911 numpy.linalg.LinAlgError: Singular matrix 
    25912  
    25913 numpy.linalg.LinAlgError: Singular matrix 
    25914  
    25915 File
    25916 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25917 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    25918 raise LinAlgError("Singular matrix") 
    25919  
    25920 See log for complete Python traceback. 
    25921  
    25922 Traceback (most recent call last): 
    25923 File
    25924 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25925 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    25926 self.session.ui.mouse_modes.mouse_pause_tracking() 
    25927 File
    25928 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25929 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    25930 mouse_pause_tracking 
    25931 self._mouse_pause() 
    25932 File
    25933 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25934 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    25935 m.pause(self._mouse_pause_position) 
    25936 File
    25937 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25938 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    25939 p = self.view.picked_object(x, y) 
    25940 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25941 File
    25942 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25943 packages/chimerax/graphics/view.py", line 838, in picked_object 
    25944 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    25945 beyond, 
    25946 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25947 File
    25948 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25949 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    25950 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    25951 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25952 File
    25953 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25954 packages/chimerax/core/models.py", line 143, in first_intercept 
    25955 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    25956 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25957 File
    25958 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25959 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    25960 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    25961 exclude=exclude) 
    25962 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25963 File
    25964 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25965 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    25966 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    25967 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25968 File
    25969 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25970 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    25971 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    25972 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25973 File
    25974 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25975 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    25976 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    25977 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25978 File
    25979 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25980 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    25981 p = super().first_intercept(mxyz1, mxyz2) 
    25982 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25983 File
    25984 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25985 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    25986 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    25987 exclude=exclude) 
    25988 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25989 File
    25990 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25991 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    25992 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    25993 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25994 File
    25995 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    25996 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    25997 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    25998 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    25999 File
    26000 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26001 packages/chimerax/graphics/drawing.py", line 1108, in
    26002 _first_intercept_excluding_children 
    26003 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    26004 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26005 File
    26006 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26007 packages/chimerax/geometry/place.py", line 201, in inverse 
    26008 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    26009 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26010 File
    26011 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26012 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    26013 rinv[:, :] = matrix_inverse(r) 
    26014 ^^^^^^^^^^^^^^^^^ 
    26015 File
    26016 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26017 packages/numpy/linalg/linalg.py", line 561, in inv 
    26018 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    26019 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26020 File
    26021 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26022 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    26023 raise LinAlgError("Singular matrix") 
    26024 numpy.linalg.LinAlgError: Singular matrix 
    26025  
    26026 numpy.linalg.LinAlgError: Singular matrix 
    26027  
    26028 File
    26029 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26030 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    26031 raise LinAlgError("Singular matrix") 
    26032  
    26033 See log for complete Python traceback. 
    26034  
    26035 Traceback (most recent call last): 
    26036 File
    26037 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26038 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    26039 self.session.ui.mouse_modes.mouse_pause_tracking() 
    26040 File
    26041 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26042 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    26043 mouse_pause_tracking 
    26044 self._mouse_pause() 
    26045 File
    26046 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26047 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    26048 m.pause(self._mouse_pause_position) 
    26049 File
    26050 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26051 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    26052 p = self.view.picked_object(x, y) 
    26053 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26054 File
    26055 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26056 packages/chimerax/graphics/view.py", line 838, in picked_object 
    26057 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    26058 beyond, 
    26059 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26060 File
    26061 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26062 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    26063 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    26064 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26065 File
    26066 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26067 packages/chimerax/core/models.py", line 143, in first_intercept 
    26068 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    26069 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26070 File
    26071 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26072 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    26073 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    26074 exclude=exclude) 
    26075 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26076 File
    26077 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26078 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    26079 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    26080 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26081 File
    26082 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26083 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    26084 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    26085 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26086 File
    26087 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26088 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    26089 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    26090 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26091 File
    26092 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26093 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    26094 p = super().first_intercept(mxyz1, mxyz2) 
    26095 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26096 File
    26097 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26098 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    26099 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    26100 exclude=exclude) 
    26101 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26102 File
    26103 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26104 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    26105 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    26106 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26107 File
    26108 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26109 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    26110 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    26111 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26112 File
    26113 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26114 packages/chimerax/graphics/drawing.py", line 1108, in
    26115 _first_intercept_excluding_children 
    26116 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    26117 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26118 File
    26119 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26120 packages/chimerax/geometry/place.py", line 201, in inverse 
    26121 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    26122 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26123 File
    26124 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26125 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    26126 rinv[:, :] = matrix_inverse(r) 
    26127 ^^^^^^^^^^^^^^^^^ 
    26128 File
    26129 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26130 packages/numpy/linalg/linalg.py", line 561, in inv 
    26131 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    26132 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26133 File
    26134 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26135 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    26136 raise LinAlgError("Singular matrix") 
    26137 numpy.linalg.LinAlgError: Singular matrix 
    26138  
    26139 numpy.linalg.LinAlgError: Singular matrix 
    26140  
    26141 File
    26142 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26143 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    26144 raise LinAlgError("Singular matrix") 
    26145  
    26146 See log for complete Python traceback. 
    26147  
    26148 Traceback (most recent call last): 
    26149 File
    26150 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26151 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    26152 self.session.ui.mouse_modes.mouse_pause_tracking() 
    26153 File
    26154 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26155 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    26156 mouse_pause_tracking 
    26157 self._mouse_pause() 
    26158 File
    26159 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26160 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    26161 m.pause(self._mouse_pause_position) 
    26162 File
    26163 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26164 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    26165 p = self.view.picked_object(x, y) 
    26166 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26167 File
    26168 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26169 packages/chimerax/graphics/view.py", line 838, in picked_object 
    26170 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    26171 beyond, 
    26172 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26173 File
    26174 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26175 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    26176 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    26177 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26178 File
    26179 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26180 packages/chimerax/core/models.py", line 143, in first_intercept 
    26181 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    26182 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26183 File
    26184 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26185 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    26186 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    26187 exclude=exclude) 
    26188 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26189 File
    26190 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26191 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    26192 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    26193 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26194 File
    26195 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26196 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    26197 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    26198 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26199 File
    26200 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26201 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    26202 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    26203 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26204 File
    26205 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26206 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    26207 p = super().first_intercept(mxyz1, mxyz2) 
    26208 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26209 File
    26210 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26211 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    26212 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    26213 exclude=exclude) 
    26214 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26215 File
    26216 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26217 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    26218 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    26219 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26220 File
    26221 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26222 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    26223 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    26224 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26225 File
    26226 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26227 packages/chimerax/graphics/drawing.py", line 1108, in
    26228 _first_intercept_excluding_children 
    26229 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    26230 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26231 File
    26232 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26233 packages/chimerax/geometry/place.py", line 201, in inverse 
    26234 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    26235 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26236 File
    26237 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26238 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    26239 rinv[:, :] = matrix_inverse(r) 
    26240 ^^^^^^^^^^^^^^^^^ 
    26241 File
    26242 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26243 packages/numpy/linalg/linalg.py", line 561, in inv 
    26244 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    26245 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26246 File
    26247 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26248 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    26249 raise LinAlgError("Singular matrix") 
    26250 numpy.linalg.LinAlgError: Singular matrix 
    26251  
    26252 numpy.linalg.LinAlgError: Singular matrix 
    26253  
    26254 File
    26255 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26256 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    26257 raise LinAlgError("Singular matrix") 
    26258  
    26259 See log for complete Python traceback. 
    26260  
    26261 Traceback (most recent call last): 
    26262 File
    26263 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26264 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    26265 self.session.ui.mouse_modes.mouse_pause_tracking() 
    26266 File
    26267 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26268 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    26269 mouse_pause_tracking 
    26270 self._mouse_pause() 
    26271 File
    26272 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26273 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    26274 m.pause(self._mouse_pause_position) 
    26275 File
    26276 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26277 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    26278 p = self.view.picked_object(x, y) 
    26279 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26280 File
    26281 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26282 packages/chimerax/graphics/view.py", line 838, in picked_object 
    26283 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    26284 beyond, 
    26285 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26286 File
    26287 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26288 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    26289 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    26290 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26291 File
    26292 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26293 packages/chimerax/core/models.py", line 143, in first_intercept 
    26294 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    26295 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26296 File
    26297 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26298 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    26299 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    26300 exclude=exclude) 
    26301 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26302 File
    26303 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26304 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    26305 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    26306 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26307 File
    26308 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26309 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    26310 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    26311 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26312 File
    26313 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26314 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    26315 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    26316 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26317 File
    26318 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26319 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    26320 p = super().first_intercept(mxyz1, mxyz2) 
    26321 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26322 File
    26323 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26324 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    26325 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    26326 exclude=exclude) 
    26327 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26328 File
    26329 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26330 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    26331 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    26332 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26333 File
    26334 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26335 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    26336 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    26337 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26338 File
    26339 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26340 packages/chimerax/graphics/drawing.py", line 1108, in
    26341 _first_intercept_excluding_children 
    26342 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    26343 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26344 File
    26345 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26346 packages/chimerax/geometry/place.py", line 201, in inverse 
    26347 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    26348 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26349 File
    26350 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26351 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    26352 rinv[:, :] = matrix_inverse(r) 
    26353 ^^^^^^^^^^^^^^^^^ 
    26354 File
    26355 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26356 packages/numpy/linalg/linalg.py", line 561, in inv 
    26357 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    26358 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26359 File
    26360 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26361 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    26362 raise LinAlgError("Singular matrix") 
    26363 numpy.linalg.LinAlgError: Singular matrix 
    26364  
    26365 numpy.linalg.LinAlgError: Singular matrix 
    26366  
    26367 File
    26368 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26369 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    26370 raise LinAlgError("Singular matrix") 
    26371  
    26372 See log for complete Python traceback. 
    26373  
    26374 Traceback (most recent call last): 
    26375 File
    26376 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26377 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    26378 self.session.ui.mouse_modes.mouse_pause_tracking() 
    26379 File
    26380 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26381 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    26382 mouse_pause_tracking 
    26383 self._mouse_pause() 
    26384 File
    26385 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26386 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    26387 m.pause(self._mouse_pause_position) 
    26388 File
    26389 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26390 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    26391 p = self.view.picked_object(x, y) 
    26392 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26393 File
    26394 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26395 packages/chimerax/graphics/view.py", line 838, in picked_object 
    26396 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    26397 beyond, 
    26398 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26399 File
    26400 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26401 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    26402 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    26403 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26404 File
    26405 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26406 packages/chimerax/core/models.py", line 143, in first_intercept 
    26407 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    26408 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26409 File
    26410 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26411 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    26412 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    26413 exclude=exclude) 
    26414 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26415 File
    26416 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26417 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    26418 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    26419 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26420 File
    26421 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26422 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    26423 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    26424 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26425 File
    26426 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26427 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    26428 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    26429 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26430 File
    26431 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26432 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    26433 p = super().first_intercept(mxyz1, mxyz2) 
    26434 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26435 File
    26436 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26437 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    26438 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    26439 exclude=exclude) 
    26440 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26441 File
    26442 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26443 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    26444 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    26445 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26446 File
    26447 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26448 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    26449 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    26450 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26451 File
    26452 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26453 packages/chimerax/graphics/drawing.py", line 1108, in
    26454 _first_intercept_excluding_children 
    26455 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    26456 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26457 File
    26458 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26459 packages/chimerax/geometry/place.py", line 201, in inverse 
    26460 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    26461 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26462 File
    26463 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26464 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    26465 rinv[:, :] = matrix_inverse(r) 
    26466 ^^^^^^^^^^^^^^^^^ 
    26467 File
    26468 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26469 packages/numpy/linalg/linalg.py", line 561, in inv 
    26470 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    26471 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26472 File
    26473 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26474 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    26475 raise LinAlgError("Singular matrix") 
    26476 numpy.linalg.LinAlgError: Singular matrix 
    26477  
    26478 numpy.linalg.LinAlgError: Singular matrix 
    26479  
    26480 File
    26481 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26482 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    26483 raise LinAlgError("Singular matrix") 
    26484  
    26485 See log for complete Python traceback. 
    26486  
    26487 Traceback (most recent call last): 
    26488 File
    26489 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26490 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    26491 self.session.ui.mouse_modes.mouse_pause_tracking() 
    26492 File
    26493 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26494 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    26495 mouse_pause_tracking 
    26496 self._mouse_pause() 
    26497 File
    26498 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26499 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    26500 m.pause(self._mouse_pause_position) 
    26501 File
    26502 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26503 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    26504 p = self.view.picked_object(x, y) 
    26505 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26506 File
    26507 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26508 packages/chimerax/graphics/view.py", line 838, in picked_object 
    26509 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    26510 beyond, 
    26511 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26512 File
    26513 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26514 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    26515 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    26516 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26517 File
    26518 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26519 packages/chimerax/core/models.py", line 143, in first_intercept 
    26520 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    26521 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26522 File
    26523 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26524 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    26525 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    26526 exclude=exclude) 
    26527 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26528 File
    26529 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26530 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    26531 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    26532 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26533 File
    26534 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26535 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    26536 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    26537 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26538 File
    26539 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26540 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    26541 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    26542 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26543 File
    26544 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26545 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    26546 p = super().first_intercept(mxyz1, mxyz2) 
    26547 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26548 File
    26549 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26550 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    26551 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    26552 exclude=exclude) 
    26553 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26554 File
    26555 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26556 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    26557 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    26558 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26559 File
    26560 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26561 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    26562 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    26563 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26564 File
    26565 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26566 packages/chimerax/graphics/drawing.py", line 1108, in
    26567 _first_intercept_excluding_children 
    26568 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    26569 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26570 File
    26571 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26572 packages/chimerax/geometry/place.py", line 201, in inverse 
    26573 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    26574 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26575 File
    26576 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26577 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    26578 rinv[:, :] = matrix_inverse(r) 
    26579 ^^^^^^^^^^^^^^^^^ 
    26580 File
    26581 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26582 packages/numpy/linalg/linalg.py", line 561, in inv 
    26583 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    26584 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26585 File
    26586 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26587 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    26588 raise LinAlgError("Singular matrix") 
    26589 numpy.linalg.LinAlgError: Singular matrix 
    26590  
    26591 numpy.linalg.LinAlgError: Singular matrix 
    26592  
    26593 File
    26594 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26595 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    26596 raise LinAlgError("Singular matrix") 
    26597  
    26598 See log for complete Python traceback. 
    26599  
    26600 Traceback (most recent call last): 
    26601 File
    26602 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26603 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    26604 self.session.ui.mouse_modes.mouse_pause_tracking() 
    26605 File
    26606 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26607 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    26608 mouse_pause_tracking 
    26609 self._mouse_pause() 
    26610 File
    26611 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26612 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    26613 m.pause(self._mouse_pause_position) 
    26614 File
    26615 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26616 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    26617 p = self.view.picked_object(x, y) 
    26618 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26619 File
    26620 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26621 packages/chimerax/graphics/view.py", line 838, in picked_object 
    26622 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    26623 beyond, 
    26624 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26625 File
    26626 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26627 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    26628 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    26629 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26630 File
    26631 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26632 packages/chimerax/core/models.py", line 143, in first_intercept 
    26633 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    26634 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26635 File
    26636 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26637 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    26638 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    26639 exclude=exclude) 
    26640 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26641 File
    26642 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26643 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    26644 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    26645 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26646 File
    26647 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26648 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    26649 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    26650 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26651 File
    26652 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26653 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    26654 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    26655 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26656 File
    26657 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26658 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    26659 p = super().first_intercept(mxyz1, mxyz2) 
    26660 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26661 File
    26662 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26663 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    26664 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    26665 exclude=exclude) 
    26666 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26667 File
    26668 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26669 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    26670 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    26671 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26672 File
    26673 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26674 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    26675 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    26676 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26677 File
    26678 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26679 packages/chimerax/graphics/drawing.py", line 1108, in
    26680 _first_intercept_excluding_children 
    26681 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    26682 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26683 File
    26684 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26685 packages/chimerax/geometry/place.py", line 201, in inverse 
    26686 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    26687 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26688 File
    26689 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26690 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    26691 rinv[:, :] = matrix_inverse(r) 
    26692 ^^^^^^^^^^^^^^^^^ 
    26693 File
    26694 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26695 packages/numpy/linalg/linalg.py", line 561, in inv 
    26696 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    26697 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26698 File
    26699 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26700 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    26701 raise LinAlgError("Singular matrix") 
    26702 numpy.linalg.LinAlgError: Singular matrix 
    26703  
    26704 numpy.linalg.LinAlgError: Singular matrix 
    26705  
    26706 File
    26707 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26708 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    26709 raise LinAlgError("Singular matrix") 
    26710  
    26711 See log for complete Python traceback. 
    26712  
    26713 Traceback (most recent call last): 
    26714 File
    26715 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26716 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    26717 self.session.ui.mouse_modes.mouse_pause_tracking() 
    26718 File
    26719 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26720 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    26721 mouse_pause_tracking 
    26722 self._mouse_pause() 
    26723 File
    26724 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26725 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    26726 m.pause(self._mouse_pause_position) 
    26727 File
    26728 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26729 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    26730 p = self.view.picked_object(x, y) 
    26731 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26732 File
    26733 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26734 packages/chimerax/graphics/view.py", line 838, in picked_object 
    26735 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    26736 beyond, 
    26737 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26738 File
    26739 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26740 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    26741 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    26742 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26743 File
    26744 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26745 packages/chimerax/core/models.py", line 143, in first_intercept 
    26746 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    26747 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26748 File
    26749 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26750 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    26751 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    26752 exclude=exclude) 
    26753 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26754 File
    26755 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26756 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    26757 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    26758 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26759 File
    26760 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26761 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    26762 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    26763 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26764 File
    26765 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26766 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    26767 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    26768 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26769 File
    26770 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26771 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    26772 p = super().first_intercept(mxyz1, mxyz2) 
    26773 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26774 File
    26775 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26776 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    26777 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    26778 exclude=exclude) 
    26779 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26780 File
    26781 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26782 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    26783 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    26784 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26785 File
    26786 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26787 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    26788 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    26789 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26790 File
    26791 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26792 packages/chimerax/graphics/drawing.py", line 1108, in
    26793 _first_intercept_excluding_children 
    26794 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    26795 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26796 File
    26797 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26798 packages/chimerax/geometry/place.py", line 201, in inverse 
    26799 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    26800 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26801 File
    26802 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26803 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    26804 rinv[:, :] = matrix_inverse(r) 
    26805 ^^^^^^^^^^^^^^^^^ 
    26806 File
    26807 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26808 packages/numpy/linalg/linalg.py", line 561, in inv 
    26809 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    26810 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26811 File
    26812 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26813 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    26814 raise LinAlgError("Singular matrix") 
    26815 numpy.linalg.LinAlgError: Singular matrix 
    26816  
    26817 numpy.linalg.LinAlgError: Singular matrix 
    26818  
    26819 File
    26820 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26821 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    26822 raise LinAlgError("Singular matrix") 
    26823  
    26824 See log for complete Python traceback. 
    26825  
    26826 Traceback (most recent call last): 
    26827 File
    26828 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26829 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    26830 self.session.ui.mouse_modes.mouse_pause_tracking() 
    26831 File
    26832 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26833 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    26834 mouse_pause_tracking 
    26835 self._mouse_pause() 
    26836 File
    26837 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26838 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    26839 m.pause(self._mouse_pause_position) 
    26840 File
    26841 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26842 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    26843 p = self.view.picked_object(x, y) 
    26844 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26845 File
    26846 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26847 packages/chimerax/graphics/view.py", line 838, in picked_object 
    26848 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    26849 beyond, 
    26850 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26851 File
    26852 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26853 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    26854 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    26855 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26856 File
    26857 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26858 packages/chimerax/core/models.py", line 143, in first_intercept 
    26859 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    26860 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26861 File
    26862 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26863 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    26864 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    26865 exclude=exclude) 
    26866 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26867 File
    26868 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26869 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    26870 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    26871 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26872 File
    26873 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26874 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    26875 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    26876 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26877 File
    26878 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26879 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    26880 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    26881 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26882 File
    26883 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26884 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    26885 p = super().first_intercept(mxyz1, mxyz2) 
    26886 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26887 File
    26888 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26889 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    26890 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    26891 exclude=exclude) 
    26892 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26893 File
    26894 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26895 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    26896 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    26897 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26898 File
    26899 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26900 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    26901 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    26902 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26903 File
    26904 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26905 packages/chimerax/graphics/drawing.py", line 1108, in
    26906 _first_intercept_excluding_children 
    26907 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    26908 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26909 File
    26910 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26911 packages/chimerax/geometry/place.py", line 201, in inverse 
    26912 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    26913 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26914 File
    26915 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26916 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    26917 rinv[:, :] = matrix_inverse(r) 
    26918 ^^^^^^^^^^^^^^^^^ 
    26919 File
    26920 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26921 packages/numpy/linalg/linalg.py", line 561, in inv 
    26922 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    26923 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26924 File
    26925 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26926 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    26927 raise LinAlgError("Singular matrix") 
    26928 numpy.linalg.LinAlgError: Singular matrix 
    26929  
    26930 numpy.linalg.LinAlgError: Singular matrix 
    26931  
    26932 File
    26933 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26934 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    26935 raise LinAlgError("Singular matrix") 
    26936  
    26937 See log for complete Python traceback. 
    26938  
    26939 Traceback (most recent call last): 
    26940 File
    26941 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26942 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    26943 self.session.ui.mouse_modes.mouse_pause_tracking() 
    26944 File
    26945 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26946 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    26947 mouse_pause_tracking 
    26948 self._mouse_pause() 
    26949 File
    26950 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26951 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    26952 m.pause(self._mouse_pause_position) 
    26953 File
    26954 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26955 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    26956 p = self.view.picked_object(x, y) 
    26957 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26958 File
    26959 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26960 packages/chimerax/graphics/view.py", line 838, in picked_object 
    26961 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    26962 beyond, 
    26963 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26964 File
    26965 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26966 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    26967 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    26968 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26969 File
    26970 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26971 packages/chimerax/core/models.py", line 143, in first_intercept 
    26972 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    26973 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26974 File
    26975 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26976 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    26977 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    26978 exclude=exclude) 
    26979 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26980 File
    26981 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26982 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    26983 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    26984 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26985 File
    26986 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26987 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    26988 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    26989 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26990 File
    26991 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26992 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    26993 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    26994 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    26995 File
    26996 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    26997 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    26998 p = super().first_intercept(mxyz1, mxyz2) 
    26999 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27000 File
    27001 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27002 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    27003 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    27004 exclude=exclude) 
    27005 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27006 File
    27007 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27008 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    27009 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    27010 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27011 File
    27012 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27013 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    27014 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    27015 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27016 File
    27017 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27018 packages/chimerax/graphics/drawing.py", line 1108, in
    27019 _first_intercept_excluding_children 
    27020 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    27021 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27022 File
    27023 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27024 packages/chimerax/geometry/place.py", line 201, in inverse 
    27025 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    27026 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27027 File
    27028 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27029 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    27030 rinv[:, :] = matrix_inverse(r) 
    27031 ^^^^^^^^^^^^^^^^^ 
    27032 File
    27033 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27034 packages/numpy/linalg/linalg.py", line 561, in inv 
    27035 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    27036 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27037 File
    27038 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27039 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    27040 raise LinAlgError("Singular matrix") 
    27041 numpy.linalg.LinAlgError: Singular matrix 
    27042  
    27043 numpy.linalg.LinAlgError: Singular matrix 
    27044  
    27045 File
    27046 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27047 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    27048 raise LinAlgError("Singular matrix") 
    27049  
    27050 See log for complete Python traceback. 
    27051  
    27052 Traceback (most recent call last): 
    27053 File
    27054 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27055 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    27056 self.session.ui.mouse_modes.mouse_pause_tracking() 
    27057 File
    27058 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27059 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    27060 mouse_pause_tracking 
    27061 self._mouse_pause() 
    27062 File
    27063 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27064 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    27065 m.pause(self._mouse_pause_position) 
    27066 File
    27067 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27068 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    27069 p = self.view.picked_object(x, y) 
    27070 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27071 File
    27072 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27073 packages/chimerax/graphics/view.py", line 838, in picked_object 
    27074 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    27075 beyond, 
    27076 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27077 File
    27078 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27079 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    27080 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    27081 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27082 File
    27083 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27084 packages/chimerax/core/models.py", line 143, in first_intercept 
    27085 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    27086 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27087 File
    27088 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27089 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    27090 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    27091 exclude=exclude) 
    27092 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27093 File
    27094 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27095 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    27096 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    27097 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27098 File
    27099 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27100 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    27101 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    27102 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27103 File
    27104 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27105 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    27106 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    27107 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27108 File
    27109 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27110 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    27111 p = super().first_intercept(mxyz1, mxyz2) 
    27112 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27113 File
    27114 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27115 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    27116 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    27117 exclude=exclude) 
    27118 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27119 File
    27120 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27121 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    27122 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    27123 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27124 File
    27125 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27126 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    27127 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    27128 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27129 File
    27130 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27131 packages/chimerax/graphics/drawing.py", line 1108, in
    27132 _first_intercept_excluding_children 
    27133 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    27134 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27135 File
    27136 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27137 packages/chimerax/geometry/place.py", line 201, in inverse 
    27138 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    27139 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27140 File
    27141 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27142 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    27143 rinv[:, :] = matrix_inverse(r) 
    27144 ^^^^^^^^^^^^^^^^^ 
    27145 File
    27146 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27147 packages/numpy/linalg/linalg.py", line 561, in inv 
    27148 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    27149 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27150 File
    27151 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27152 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    27153 raise LinAlgError("Singular matrix") 
    27154 numpy.linalg.LinAlgError: Singular matrix 
    27155  
    27156 numpy.linalg.LinAlgError: Singular matrix 
    27157  
    27158 File
    27159 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27160 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    27161 raise LinAlgError("Singular matrix") 
    27162  
    27163 See log for complete Python traceback. 
    27164  
    27165 Traceback (most recent call last): 
    27166 File
    27167 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27168 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    27169 self.session.ui.mouse_modes.mouse_pause_tracking() 
    27170 File
    27171 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27172 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    27173 mouse_pause_tracking 
    27174 self._mouse_pause() 
    27175 File
    27176 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27177 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    27178 m.pause(self._mouse_pause_position) 
    27179 File
    27180 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27181 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    27182 p = self.view.picked_object(x, y) 
    27183 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27184 File
    27185 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27186 packages/chimerax/graphics/view.py", line 838, in picked_object 
    27187 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    27188 beyond, 
    27189 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27190 File
    27191 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27192 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    27193 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    27194 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27195 File
    27196 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27197 packages/chimerax/core/models.py", line 143, in first_intercept 
    27198 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    27199 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27200 File
    27201 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27202 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    27203 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    27204 exclude=exclude) 
    27205 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27206 File
    27207 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27208 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    27209 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    27210 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27211 File
    27212 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27213 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    27214 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    27215 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27216 File
    27217 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27218 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    27219 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    27220 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27221 File
    27222 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27223 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    27224 p = super().first_intercept(mxyz1, mxyz2) 
    27225 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27226 File
    27227 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27228 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    27229 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    27230 exclude=exclude) 
    27231 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27232 File
    27233 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27234 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    27235 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    27236 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27237 File
    27238 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27239 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    27240 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    27241 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27242 File
    27243 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27244 packages/chimerax/graphics/drawing.py", line 1108, in
    27245 _first_intercept_excluding_children 
    27246 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    27247 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27248 File
    27249 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27250 packages/chimerax/geometry/place.py", line 201, in inverse 
    27251 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    27252 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27253 File
    27254 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27255 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    27256 rinv[:, :] = matrix_inverse(r) 
    27257 ^^^^^^^^^^^^^^^^^ 
    27258 File
    27259 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27260 packages/numpy/linalg/linalg.py", line 561, in inv 
    27261 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    27262 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27263 File
    27264 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27265 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    27266 raise LinAlgError("Singular matrix") 
    27267 numpy.linalg.LinAlgError: Singular matrix 
    27268  
    27269 numpy.linalg.LinAlgError: Singular matrix 
    27270  
    27271 File
    27272 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27273 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    27274 raise LinAlgError("Singular matrix") 
    27275  
    27276 See log for complete Python traceback. 
    27277  
    27278 Traceback (most recent call last): 
    27279 File
    27280 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27281 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    27282 self.session.ui.mouse_modes.mouse_pause_tracking() 
    27283 File
    27284 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27285 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    27286 mouse_pause_tracking 
    27287 self._mouse_pause() 
    27288 File
    27289 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27290 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    27291 m.pause(self._mouse_pause_position) 
    27292 File
    27293 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27294 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    27295 p = self.view.picked_object(x, y) 
    27296 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27297 File
    27298 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27299 packages/chimerax/graphics/view.py", line 838, in picked_object 
    27300 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    27301 beyond, 
    27302 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27303 File
    27304 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27305 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    27306 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    27307 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27308 File
    27309 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27310 packages/chimerax/core/models.py", line 143, in first_intercept 
    27311 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    27312 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27313 File
    27314 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27315 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    27316 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    27317 exclude=exclude) 
    27318 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27319 File
    27320 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27321 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    27322 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    27323 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27324 File
    27325 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27326 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    27327 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    27328 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27329 File
    27330 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27331 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    27332 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    27333 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27334 File
    27335 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27336 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    27337 p = super().first_intercept(mxyz1, mxyz2) 
    27338 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27339 File
    27340 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27341 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    27342 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    27343 exclude=exclude) 
    27344 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27345 File
    27346 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27347 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    27348 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    27349 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27350 File
    27351 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27352 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    27353 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    27354 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27355 File
    27356 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27357 packages/chimerax/graphics/drawing.py", line 1108, in
    27358 _first_intercept_excluding_children 
    27359 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    27360 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27361 File
    27362 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27363 packages/chimerax/geometry/place.py", line 201, in inverse 
    27364 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    27365 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27366 File
    27367 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27368 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    27369 rinv[:, :] = matrix_inverse(r) 
    27370 ^^^^^^^^^^^^^^^^^ 
    27371 File
    27372 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27373 packages/numpy/linalg/linalg.py", line 561, in inv 
    27374 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    27375 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27376 File
    27377 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27378 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    27379 raise LinAlgError("Singular matrix") 
    27380 numpy.linalg.LinAlgError: Singular matrix 
    27381  
    27382 numpy.linalg.LinAlgError: Singular matrix 
    27383  
    27384 File
    27385 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27386 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    27387 raise LinAlgError("Singular matrix") 
    27388  
    27389 See log for complete Python traceback. 
    27390  
    27391 Traceback (most recent call last): 
    27392 File
    27393 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27394 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    27395 self.session.ui.mouse_modes.mouse_pause_tracking() 
    27396 File
    27397 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27398 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    27399 mouse_pause_tracking 
    27400 self._mouse_pause() 
    27401 File
    27402 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27403 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    27404 m.pause(self._mouse_pause_position) 
    27405 File
    27406 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27407 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    27408 p = self.view.picked_object(x, y) 
    27409 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27410 File
    27411 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27412 packages/chimerax/graphics/view.py", line 838, in picked_object 
    27413 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    27414 beyond, 
    27415 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27416 File
    27417 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27418 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    27419 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    27420 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27421 File
    27422 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27423 packages/chimerax/core/models.py", line 143, in first_intercept 
    27424 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    27425 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27426 File
    27427 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27428 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    27429 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    27430 exclude=exclude) 
    27431 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27432 File
    27433 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27434 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    27435 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    27436 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27437 File
    27438 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27439 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    27440 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    27441 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27442 File
    27443 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27444 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    27445 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    27446 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27447 File
    27448 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27449 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    27450 p = super().first_intercept(mxyz1, mxyz2) 
    27451 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27452 File
    27453 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27454 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    27455 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    27456 exclude=exclude) 
    27457 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27458 File
    27459 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27460 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    27461 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    27462 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27463 File
    27464 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27465 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    27466 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    27467 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27468 File
    27469 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27470 packages/chimerax/graphics/drawing.py", line 1108, in
    27471 _first_intercept_excluding_children 
    27472 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    27473 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27474 File
    27475 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27476 packages/chimerax/geometry/place.py", line 201, in inverse 
    27477 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    27478 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27479 File
    27480 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27481 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    27482 rinv[:, :] = matrix_inverse(r) 
    27483 ^^^^^^^^^^^^^^^^^ 
    27484 File
    27485 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27486 packages/numpy/linalg/linalg.py", line 561, in inv 
    27487 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    27488 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27489 File
    27490 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27491 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    27492 raise LinAlgError("Singular matrix") 
    27493 numpy.linalg.LinAlgError: Singular matrix 
    27494  
    27495 numpy.linalg.LinAlgError: Singular matrix 
    27496  
    27497 File
    27498 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27499 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    27500 raise LinAlgError("Singular matrix") 
    27501  
    27502 See log for complete Python traceback. 
    27503  
    27504 Traceback (most recent call last): 
    27505 File
    27506 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27507 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    27508 self.session.ui.mouse_modes.mouse_pause_tracking() 
    27509 File
    27510 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27511 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    27512 mouse_pause_tracking 
    27513 self._mouse_pause() 
    27514 File
    27515 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27516 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    27517 m.pause(self._mouse_pause_position) 
    27518 File
    27519 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27520 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    27521 p = self.view.picked_object(x, y) 
    27522 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27523 File
    27524 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27525 packages/chimerax/graphics/view.py", line 838, in picked_object 
    27526 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    27527 beyond, 
    27528 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27529 File
    27530 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27531 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    27532 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    27533 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27534 File
    27535 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27536 packages/chimerax/core/models.py", line 143, in first_intercept 
    27537 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    27538 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27539 File
    27540 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27541 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    27542 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    27543 exclude=exclude) 
    27544 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27545 File
    27546 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27547 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    27548 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    27549 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27550 File
    27551 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27552 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    27553 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    27554 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27555 File
    27556 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27557 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    27558 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    27559 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27560 File
    27561 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27562 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    27563 p = super().first_intercept(mxyz1, mxyz2) 
    27564 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27565 File
    27566 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27567 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    27568 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    27569 exclude=exclude) 
    27570 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27571 File
    27572 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27573 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    27574 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    27575 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27576 File
    27577 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27578 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    27579 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    27580 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27581 File
    27582 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27583 packages/chimerax/graphics/drawing.py", line 1108, in
    27584 _first_intercept_excluding_children 
    27585 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    27586 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27587 File
    27588 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27589 packages/chimerax/geometry/place.py", line 201, in inverse 
    27590 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    27591 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27592 File
    27593 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27594 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    27595 rinv[:, :] = matrix_inverse(r) 
    27596 ^^^^^^^^^^^^^^^^^ 
    27597 File
    27598 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27599 packages/numpy/linalg/linalg.py", line 561, in inv 
    27600 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    27601 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27602 File
    27603 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27604 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    27605 raise LinAlgError("Singular matrix") 
    27606 numpy.linalg.LinAlgError: Singular matrix 
    27607  
    27608 numpy.linalg.LinAlgError: Singular matrix 
    27609  
    27610 File
    27611 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27612 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    27613 raise LinAlgError("Singular matrix") 
    27614  
    27615 See log for complete Python traceback. 
    27616  
    27617 Traceback (most recent call last): 
    27618 File
    27619 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27620 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    27621 self.session.ui.mouse_modes.mouse_pause_tracking() 
    27622 File
    27623 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27624 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    27625 mouse_pause_tracking 
    27626 self._mouse_pause() 
    27627 File
    27628 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27629 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    27630 m.pause(self._mouse_pause_position) 
    27631 File
    27632 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27633 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    27634 p = self.view.picked_object(x, y) 
    27635 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27636 File
    27637 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27638 packages/chimerax/graphics/view.py", line 838, in picked_object 
    27639 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    27640 beyond, 
    27641 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27642 File
    27643 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27644 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    27645 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    27646 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27647 File
    27648 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27649 packages/chimerax/core/models.py", line 143, in first_intercept 
    27650 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    27651 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27652 File
    27653 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27654 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    27655 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    27656 exclude=exclude) 
    27657 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27658 File
    27659 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27660 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    27661 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    27662 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27663 File
    27664 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27665 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    27666 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    27667 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27668 File
    27669 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27670 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    27671 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    27672 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27673 File
    27674 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27675 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    27676 p = super().first_intercept(mxyz1, mxyz2) 
    27677 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27678 File
    27679 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27680 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    27681 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    27682 exclude=exclude) 
    27683 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27684 File
    27685 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27686 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    27687 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    27688 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27689 File
    27690 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27691 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    27692 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    27693 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27694 File
    27695 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27696 packages/chimerax/graphics/drawing.py", line 1108, in
    27697 _first_intercept_excluding_children 
    27698 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    27699 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27700 File
    27701 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27702 packages/chimerax/geometry/place.py", line 201, in inverse 
    27703 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    27704 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27705 File
    27706 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27707 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    27708 rinv[:, :] = matrix_inverse(r) 
    27709 ^^^^^^^^^^^^^^^^^ 
    27710 File
    27711 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27712 packages/numpy/linalg/linalg.py", line 561, in inv 
    27713 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    27714 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27715 File
    27716 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27717 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    27718 raise LinAlgError("Singular matrix") 
    27719 numpy.linalg.LinAlgError: Singular matrix 
    27720  
    27721 numpy.linalg.LinAlgError: Singular matrix 
    27722  
    27723 File
    27724 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27725 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    27726 raise LinAlgError("Singular matrix") 
    27727  
    27728 See log for complete Python traceback. 
    27729  
    27730 Traceback (most recent call last): 
    27731 File
    27732 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27733 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    27734 self.session.ui.mouse_modes.mouse_pause_tracking() 
    27735 File
    27736 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27737 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    27738 mouse_pause_tracking 
    27739 self._mouse_pause() 
    27740 File
    27741 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27742 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    27743 m.pause(self._mouse_pause_position) 
    27744 File
    27745 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27746 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    27747 p = self.view.picked_object(x, y) 
    27748 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27749 File
    27750 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27751 packages/chimerax/graphics/view.py", line 838, in picked_object 
    27752 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    27753 beyond, 
    27754 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27755 File
    27756 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27757 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    27758 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    27759 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27760 File
    27761 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27762 packages/chimerax/core/models.py", line 143, in first_intercept 
    27763 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    27764 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27765 File
    27766 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27767 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    27768 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    27769 exclude=exclude) 
    27770 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27771 File
    27772 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27773 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    27774 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    27775 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27776 File
    27777 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27778 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    27779 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    27780 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27781 File
    27782 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27783 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    27784 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    27785 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27786 File
    27787 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27788 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    27789 p = super().first_intercept(mxyz1, mxyz2) 
    27790 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27791 File
    27792 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27793 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    27794 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    27795 exclude=exclude) 
    27796 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27797 File
    27798 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27799 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    27800 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    27801 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27802 File
    27803 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27804 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    27805 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    27806 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27807 File
    27808 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27809 packages/chimerax/graphics/drawing.py", line 1108, in
    27810 _first_intercept_excluding_children 
    27811 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    27812 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27813 File
    27814 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27815 packages/chimerax/geometry/place.py", line 201, in inverse 
    27816 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    27817 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27818 File
    27819 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27820 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    27821 rinv[:, :] = matrix_inverse(r) 
    27822 ^^^^^^^^^^^^^^^^^ 
    27823 File
    27824 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27825 packages/numpy/linalg/linalg.py", line 561, in inv 
    27826 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    27827 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27828 File
    27829 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27830 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    27831 raise LinAlgError("Singular matrix") 
    27832 numpy.linalg.LinAlgError: Singular matrix 
    27833  
    27834 numpy.linalg.LinAlgError: Singular matrix 
    27835  
    27836 File
    27837 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27838 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    27839 raise LinAlgError("Singular matrix") 
    27840  
    27841 See log for complete Python traceback. 
    27842  
    27843 Traceback (most recent call last): 
    27844 File
    27845 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27846 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    27847 self.session.ui.mouse_modes.mouse_pause_tracking() 
    27848 File
    27849 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27850 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    27851 mouse_pause_tracking 
    27852 self._mouse_pause() 
    27853 File
    27854 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27855 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    27856 m.pause(self._mouse_pause_position) 
    27857 File
    27858 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27859 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    27860 p = self.view.picked_object(x, y) 
    27861 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27862 File
    27863 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27864 packages/chimerax/graphics/view.py", line 838, in picked_object 
    27865 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    27866 beyond, 
    27867 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27868 File
    27869 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27870 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    27871 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    27872 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27873 File
    27874 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27875 packages/chimerax/core/models.py", line 143, in first_intercept 
    27876 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    27877 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27878 File
    27879 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27880 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    27881 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    27882 exclude=exclude) 
    27883 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27884 File
    27885 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27886 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    27887 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    27888 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27889 File
    27890 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27891 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    27892 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    27893 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27894 File
    27895 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27896 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    27897 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    27898 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27899 File
    27900 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27901 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    27902 p = super().first_intercept(mxyz1, mxyz2) 
    27903 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27904 File
    27905 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27906 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    27907 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    27908 exclude=exclude) 
    27909 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27910 File
    27911 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27912 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    27913 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    27914 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27915 File
    27916 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27917 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    27918 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    27919 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27920 File
    27921 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27922 packages/chimerax/graphics/drawing.py", line 1108, in
    27923 _first_intercept_excluding_children 
    27924 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    27925 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27926 File
    27927 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27928 packages/chimerax/geometry/place.py", line 201, in inverse 
    27929 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    27930 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27931 File
    27932 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27933 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    27934 rinv[:, :] = matrix_inverse(r) 
    27935 ^^^^^^^^^^^^^^^^^ 
    27936 File
    27937 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27938 packages/numpy/linalg/linalg.py", line 561, in inv 
    27939 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    27940 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27941 File
    27942 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27943 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    27944 raise LinAlgError("Singular matrix") 
    27945 numpy.linalg.LinAlgError: Singular matrix 
    27946  
    27947 numpy.linalg.LinAlgError: Singular matrix 
    27948  
    27949 File
    27950 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27951 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    27952 raise LinAlgError("Singular matrix") 
    27953  
    27954 See log for complete Python traceback. 
    27955  
    27956 Traceback (most recent call last): 
    27957 File
    27958 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27959 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    27960 self.session.ui.mouse_modes.mouse_pause_tracking() 
    27961 File
    27962 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27963 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    27964 mouse_pause_tracking 
    27965 self._mouse_pause() 
    27966 File
    27967 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27968 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    27969 m.pause(self._mouse_pause_position) 
    27970 File
    27971 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27972 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    27973 p = self.view.picked_object(x, y) 
    27974 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27975 File
    27976 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27977 packages/chimerax/graphics/view.py", line 838, in picked_object 
    27978 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    27979 beyond, 
    27980 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27981 File
    27982 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27983 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    27984 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    27985 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27986 File
    27987 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27988 packages/chimerax/core/models.py", line 143, in first_intercept 
    27989 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    27990 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27991 File
    27992 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27993 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    27994 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    27995 exclude=exclude) 
    27996 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    27997 File
    27998 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    27999 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    28000 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    28001 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28002 File
    28003 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28004 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    28005 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    28006 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28007 File
    28008 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28009 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    28010 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    28011 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28012 File
    28013 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28014 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    28015 p = super().first_intercept(mxyz1, mxyz2) 
    28016 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28017 File
    28018 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28019 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    28020 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    28021 exclude=exclude) 
    28022 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28023 File
    28024 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28025 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    28026 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    28027 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28028 File
    28029 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28030 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    28031 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    28032 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28033 File
    28034 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28035 packages/chimerax/graphics/drawing.py", line 1108, in
    28036 _first_intercept_excluding_children 
    28037 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    28038 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28039 File
    28040 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28041 packages/chimerax/geometry/place.py", line 201, in inverse 
    28042 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    28043 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28044 File
    28045 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28046 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    28047 rinv[:, :] = matrix_inverse(r) 
    28048 ^^^^^^^^^^^^^^^^^ 
    28049 File
    28050 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28051 packages/numpy/linalg/linalg.py", line 561, in inv 
    28052 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    28053 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28054 File
    28055 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28056 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    28057 raise LinAlgError("Singular matrix") 
    28058 numpy.linalg.LinAlgError: Singular matrix 
    28059  
    28060 numpy.linalg.LinAlgError: Singular matrix 
    28061  
    28062 File
    28063 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28064 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    28065 raise LinAlgError("Singular matrix") 
    28066  
    28067 See log for complete Python traceback. 
    28068  
    28069 Traceback (most recent call last): 
    28070 File
    28071 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28072 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    28073 self.session.ui.mouse_modes.mouse_pause_tracking() 
    28074 File
    28075 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28076 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    28077 mouse_pause_tracking 
    28078 self._mouse_pause() 
    28079 File
    28080 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28081 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    28082 m.pause(self._mouse_pause_position) 
    28083 File
    28084 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28085 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    28086 p = self.view.picked_object(x, y) 
    28087 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28088 File
    28089 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28090 packages/chimerax/graphics/view.py", line 838, in picked_object 
    28091 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    28092 beyond, 
    28093 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28094 File
    28095 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28096 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    28097 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    28098 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28099 File
    28100 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28101 packages/chimerax/core/models.py", line 143, in first_intercept 
    28102 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    28103 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28104 File
    28105 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28106 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    28107 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    28108 exclude=exclude) 
    28109 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28110 File
    28111 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28112 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    28113 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    28114 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28115 File
    28116 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28117 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    28118 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    28119 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28120 File
    28121 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28122 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    28123 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    28124 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28125 File
    28126 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28127 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    28128 p = super().first_intercept(mxyz1, mxyz2) 
    28129 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28130 File
    28131 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28132 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    28133 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    28134 exclude=exclude) 
    28135 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28136 File
    28137 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28138 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    28139 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    28140 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28141 File
    28142 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28143 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    28144 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    28145 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28146 File
    28147 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28148 packages/chimerax/graphics/drawing.py", line 1108, in
    28149 _first_intercept_excluding_children 
    28150 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    28151 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28152 File
    28153 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28154 packages/chimerax/geometry/place.py", line 201, in inverse 
    28155 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    28156 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28157 File
    28158 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28159 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    28160 rinv[:, :] = matrix_inverse(r) 
    28161 ^^^^^^^^^^^^^^^^^ 
    28162 File
    28163 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28164 packages/numpy/linalg/linalg.py", line 561, in inv 
    28165 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    28166 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28167 File
    28168 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28169 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    28170 raise LinAlgError("Singular matrix") 
    28171 numpy.linalg.LinAlgError: Singular matrix 
    28172  
    28173 numpy.linalg.LinAlgError: Singular matrix 
    28174  
    28175 File
    28176 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28177 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    28178 raise LinAlgError("Singular matrix") 
    28179  
    28180 See log for complete Python traceback. 
    28181  
    28182 Traceback (most recent call last): 
    28183 File
    28184 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28185 packages/chimerax/mouse_modes/mousemodes.py", line 656, in <lambda> 
    28186 gw.mouseReleaseEvent = lambda e, s=self: s._dispatch_mouse_event(e,
    28187 "mouse_up") 
    28188 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28189 File
    28190 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28191 packages/chimerax/mouse_modes/mousemodes.py", line 556, in
    28192 _dispatch_mouse_event 
    28193 f(MouseEvent(event, modifiers=modifiers)) 
    28194 File
    28195 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28196 packages/chimerax/mouse_modes/std_modes.py", line 70, in mouse_up 
    28197 mouse_select(event, mode, self.session, self.view) 
    28198 File
    28199 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28200 packages/chimerax/mouse_modes/std_modes.py", line 209, in mouse_select 
    28201 pick = view.picked_object(x, y) 
    28202 ^^^^^^^^^^^^^^^^^^^^^^^^ 
    28203 File
    28204 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28205 packages/chimerax/graphics/view.py", line 838, in picked_object 
    28206 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    28207 beyond, 
    28208 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28209 File
    28210 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28211 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    28212 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    28213 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28214 File
    28215 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28216 packages/chimerax/core/models.py", line 143, in first_intercept 
    28217 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    28218 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28219 File
    28220 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28221 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    28222 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    28223 exclude=exclude) 
    28224 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28225 File
    28226 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28227 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    28228 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    28229 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28230 File
    28231 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28232 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    28233 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    28234 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28235 File
    28236 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28237 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    28238 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    28239 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28240 File
    28241 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28242 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    28243 p = super().first_intercept(mxyz1, mxyz2) 
    28244 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28245 File
    28246 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28247 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    28248 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    28249 exclude=exclude) 
    28250 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28251 File
    28252 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28253 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    28254 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    28255 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28256 File
    28257 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28258 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    28259 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    28260 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28261 File
    28262 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28263 packages/chimerax/graphics/drawing.py", line 1108, in
    28264 _first_intercept_excluding_children 
    28265 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    28266 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28267 File
    28268 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28269 packages/chimerax/geometry/place.py", line 201, in inverse 
    28270 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    28271 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28272 File
    28273 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28274 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    28275 rinv[:, :] = matrix_inverse(r) 
    28276 ^^^^^^^^^^^^^^^^^ 
    28277 File
    28278 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28279 packages/numpy/linalg/linalg.py", line 561, in inv 
    28280 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    28281 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28282 File
    28283 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28284 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    28285 raise LinAlgError("Singular matrix") 
    28286 numpy.linalg.LinAlgError: Singular matrix 
    28287  
    28288 numpy.linalg.LinAlgError: Singular matrix 
    28289  
    28290 File
    28291 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28292 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    28293 raise LinAlgError("Singular matrix") 
    28294  
    28295 See log for complete Python traceback. 
    28296  
    28297 Traceback (most recent call last): 
    28298 File
    28299 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28300 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    28301 self.session.ui.mouse_modes.mouse_pause_tracking() 
    28302 File
    28303 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28304 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    28305 mouse_pause_tracking 
    28306 self._mouse_pause() 
    28307 File
    28308 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28309 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    28310 m.pause(self._mouse_pause_position) 
    28311 File
    28312 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28313 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    28314 p = self.view.picked_object(x, y) 
    28315 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28316 File
    28317 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28318 packages/chimerax/graphics/view.py", line 838, in picked_object 
    28319 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    28320 beyond, 
    28321 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28322 File
    28323 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28324 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    28325 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    28326 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28327 File
    28328 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28329 packages/chimerax/core/models.py", line 143, in first_intercept 
    28330 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    28331 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28332 File
    28333 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28334 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    28335 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    28336 exclude=exclude) 
    28337 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28338 File
    28339 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28340 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    28341 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    28342 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28343 File
    28344 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28345 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    28346 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    28347 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28348 File
    28349 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28350 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    28351 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    28352 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28353 File
    28354 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28355 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    28356 p = super().first_intercept(mxyz1, mxyz2) 
    28357 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28358 File
    28359 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28360 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    28361 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    28362 exclude=exclude) 
    28363 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28364 File
    28365 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28366 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    28367 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    28368 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28369 File
    28370 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28371 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    28372 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    28373 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28374 File
    28375 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28376 packages/chimerax/graphics/drawing.py", line 1108, in
    28377 _first_intercept_excluding_children 
    28378 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    28379 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28380 File
    28381 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28382 packages/chimerax/geometry/place.py", line 201, in inverse 
    28383 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    28384 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28385 File
    28386 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28387 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    28388 rinv[:, :] = matrix_inverse(r) 
    28389 ^^^^^^^^^^^^^^^^^ 
    28390 File
    28391 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28392 packages/numpy/linalg/linalg.py", line 561, in inv 
    28393 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    28394 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28395 File
    28396 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28397 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    28398 raise LinAlgError("Singular matrix") 
    28399 numpy.linalg.LinAlgError: Singular matrix 
    28400  
    28401 numpy.linalg.LinAlgError: Singular matrix 
    28402  
    28403 File
    28404 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28405 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    28406 raise LinAlgError("Singular matrix") 
    28407  
    28408 See log for complete Python traceback. 
    28409  
    28410 Traceback (most recent call last): 
    28411 File
    28412 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28413 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    28414 self.session.ui.mouse_modes.mouse_pause_tracking() 
    28415 File
    28416 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28417 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    28418 mouse_pause_tracking 
    28419 self._mouse_pause() 
    28420 File
    28421 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28422 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    28423 m.pause(self._mouse_pause_position) 
    28424 File
    28425 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28426 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    28427 p = self.view.picked_object(x, y) 
    28428 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28429 File
    28430 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28431 packages/chimerax/graphics/view.py", line 838, in picked_object 
    28432 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    28433 beyond, 
    28434 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28435 File
    28436 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28437 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    28438 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    28439 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28440 File
    28441 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28442 packages/chimerax/core/models.py", line 143, in first_intercept 
    28443 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    28444 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28445 File
    28446 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28447 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    28448 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    28449 exclude=exclude) 
    28450 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28451 File
    28452 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28453 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    28454 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    28455 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28456 File
    28457 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28458 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    28459 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    28460 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28461 File
    28462 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28463 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    28464 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    28465 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28466 File
    28467 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28468 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    28469 p = super().first_intercept(mxyz1, mxyz2) 
    28470 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28471 File
    28472 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28473 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    28474 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    28475 exclude=exclude) 
    28476 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28477 File
    28478 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28479 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    28480 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    28481 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28482 File
    28483 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28484 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    28485 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    28486 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28487 File
    28488 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28489 packages/chimerax/graphics/drawing.py", line 1108, in
    28490 _first_intercept_excluding_children 
    28491 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    28492 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28493 File
    28494 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28495 packages/chimerax/geometry/place.py", line 201, in inverse 
    28496 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    28497 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28498 File
    28499 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28500 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    28501 rinv[:, :] = matrix_inverse(r) 
    28502 ^^^^^^^^^^^^^^^^^ 
    28503 File
    28504 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28505 packages/numpy/linalg/linalg.py", line 561, in inv 
    28506 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    28507 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28508 File
    28509 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28510 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    28511 raise LinAlgError("Singular matrix") 
    28512 numpy.linalg.LinAlgError: Singular matrix 
    28513  
    28514 numpy.linalg.LinAlgError: Singular matrix 
    28515  
    28516 File
    28517 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28518 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    28519 raise LinAlgError("Singular matrix") 
    28520  
    28521 See log for complete Python traceback. 
    28522  
    28523 Traceback (most recent call last): 
    28524 File
    28525 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28526 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    28527 self.session.ui.mouse_modes.mouse_pause_tracking() 
    28528 File
    28529 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28530 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    28531 mouse_pause_tracking 
    28532 self._mouse_pause() 
    28533 File
    28534 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28535 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    28536 m.pause(self._mouse_pause_position) 
    28537 File
    28538 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28539 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    28540 p = self.view.picked_object(x, y) 
    28541 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28542 File
    28543 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28544 packages/chimerax/graphics/view.py", line 838, in picked_object 
    28545 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    28546 beyond, 
    28547 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28548 File
    28549 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28550 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    28551 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    28552 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28553 File
    28554 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28555 packages/chimerax/core/models.py", line 143, in first_intercept 
    28556 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    28557 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28558 File
    28559 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28560 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    28561 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    28562 exclude=exclude) 
    28563 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28564 File
    28565 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28566 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    28567 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    28568 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28569 File
    28570 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28571 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    28572 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    28573 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28574 File
    28575 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28576 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    28577 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    28578 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28579 File
    28580 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28581 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    28582 p = super().first_intercept(mxyz1, mxyz2) 
    28583 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28584 File
    28585 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28586 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    28587 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    28588 exclude=exclude) 
    28589 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28590 File
    28591 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28592 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    28593 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    28594 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28595 File
    28596 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28597 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    28598 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    28599 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28600 File
    28601 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28602 packages/chimerax/graphics/drawing.py", line 1108, in
    28603 _first_intercept_excluding_children 
    28604 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    28605 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28606 File
    28607 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28608 packages/chimerax/geometry/place.py", line 201, in inverse 
    28609 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    28610 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28611 File
    28612 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28613 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    28614 rinv[:, :] = matrix_inverse(r) 
    28615 ^^^^^^^^^^^^^^^^^ 
    28616 File
    28617 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28618 packages/numpy/linalg/linalg.py", line 561, in inv 
    28619 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    28620 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28621 File
    28622 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28623 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    28624 raise LinAlgError("Singular matrix") 
    28625 numpy.linalg.LinAlgError: Singular matrix 
    28626  
    28627 numpy.linalg.LinAlgError: Singular matrix 
    28628  
    28629 File
    28630 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28631 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    28632 raise LinAlgError("Singular matrix") 
    28633  
    28634 See log for complete Python traceback. 
    28635  
    28636 Traceback (most recent call last): 
    28637 File
    28638 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28639 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    28640 self.session.ui.mouse_modes.mouse_pause_tracking() 
    28641 File
    28642 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28643 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    28644 mouse_pause_tracking 
    28645 self._mouse_pause() 
    28646 File
    28647 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28648 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    28649 m.pause(self._mouse_pause_position) 
    28650 File
    28651 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28652 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    28653 p = self.view.picked_object(x, y) 
    28654 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28655 File
    28656 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28657 packages/chimerax/graphics/view.py", line 838, in picked_object 
    28658 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    28659 beyond, 
    28660 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28661 File
    28662 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28663 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    28664 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    28665 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28666 File
    28667 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28668 packages/chimerax/core/models.py", line 143, in first_intercept 
    28669 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    28670 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28671 File
    28672 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28673 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    28674 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    28675 exclude=exclude) 
    28676 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28677 File
    28678 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28679 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    28680 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    28681 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28682 File
    28683 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28684 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    28685 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    28686 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28687 File
    28688 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28689 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    28690 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    28691 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28692 File
    28693 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28694 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    28695 p = super().first_intercept(mxyz1, mxyz2) 
    28696 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28697 File
    28698 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28699 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    28700 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    28701 exclude=exclude) 
    28702 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28703 File
    28704 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28705 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    28706 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    28707 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28708 File
    28709 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28710 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    28711 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    28712 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28713 File
    28714 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28715 packages/chimerax/graphics/drawing.py", line 1108, in
    28716 _first_intercept_excluding_children 
    28717 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    28718 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28719 File
    28720 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28721 packages/chimerax/geometry/place.py", line 201, in inverse 
    28722 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    28723 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28724 File
    28725 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28726 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    28727 rinv[:, :] = matrix_inverse(r) 
    28728 ^^^^^^^^^^^^^^^^^ 
    28729 File
    28730 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28731 packages/numpy/linalg/linalg.py", line 561, in inv 
    28732 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    28733 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28734 File
    28735 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28736 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    28737 raise LinAlgError("Singular matrix") 
    28738 numpy.linalg.LinAlgError: Singular matrix 
    28739  
    28740 numpy.linalg.LinAlgError: Singular matrix 
    28741  
    28742 File
    28743 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28744 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    28745 raise LinAlgError("Singular matrix") 
    28746  
    28747 See log for complete Python traceback. 
    28748  
    28749 Traceback (most recent call last): 
    28750 File
    28751 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28752 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    28753 self.session.ui.mouse_modes.mouse_pause_tracking() 
    28754 File
    28755 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28756 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    28757 mouse_pause_tracking 
    28758 self._mouse_pause() 
    28759 File
    28760 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28761 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    28762 m.pause(self._mouse_pause_position) 
    28763 File
    28764 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28765 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    28766 p = self.view.picked_object(x, y) 
    28767 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28768 File
    28769 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28770 packages/chimerax/graphics/view.py", line 838, in picked_object 
    28771 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    28772 beyond, 
    28773 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28774 File
    28775 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28776 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    28777 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    28778 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28779 File
    28780 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28781 packages/chimerax/core/models.py", line 143, in first_intercept 
    28782 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    28783 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28784 File
    28785 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28786 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    28787 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    28788 exclude=exclude) 
    28789 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28790 File
    28791 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28792 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    28793 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    28794 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28795 File
    28796 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28797 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    28798 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    28799 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28800 File
    28801 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28802 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    28803 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    28804 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28805 File
    28806 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28807 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    28808 p = super().first_intercept(mxyz1, mxyz2) 
    28809 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28810 File
    28811 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28812 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    28813 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    28814 exclude=exclude) 
    28815 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28816 File
    28817 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28818 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    28819 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    28820 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28821 File
    28822 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28823 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    28824 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    28825 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28826 File
    28827 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28828 packages/chimerax/graphics/drawing.py", line 1108, in
    28829 _first_intercept_excluding_children 
    28830 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    28831 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28832 File
    28833 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28834 packages/chimerax/geometry/place.py", line 201, in inverse 
    28835 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    28836 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28837 File
    28838 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28839 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    28840 rinv[:, :] = matrix_inverse(r) 
    28841 ^^^^^^^^^^^^^^^^^ 
    28842 File
    28843 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28844 packages/numpy/linalg/linalg.py", line 561, in inv 
    28845 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    28846 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28847 File
    28848 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28849 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    28850 raise LinAlgError("Singular matrix") 
    28851 numpy.linalg.LinAlgError: Singular matrix 
    28852  
    28853 numpy.linalg.LinAlgError: Singular matrix 
    28854  
    28855 File
    28856 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28857 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    28858 raise LinAlgError("Singular matrix") 
    28859  
    28860 See log for complete Python traceback. 
    28861  
    28862 Traceback (most recent call last): 
    28863 File
    28864 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28865 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    28866 self.session.ui.mouse_modes.mouse_pause_tracking() 
    28867 File
    28868 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28869 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    28870 mouse_pause_tracking 
    28871 self._mouse_pause() 
    28872 File
    28873 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28874 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    28875 m.pause(self._mouse_pause_position) 
    28876 File
    28877 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28878 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    28879 p = self.view.picked_object(x, y) 
    28880 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28881 File
    28882 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28883 packages/chimerax/graphics/view.py", line 838, in picked_object 
    28884 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    28885 beyond, 
    28886 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28887 File
    28888 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28889 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    28890 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    28891 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28892 File
    28893 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28894 packages/chimerax/core/models.py", line 143, in first_intercept 
    28895 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    28896 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28897 File
    28898 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28899 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    28900 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    28901 exclude=exclude) 
    28902 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28903 File
    28904 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28905 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    28906 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    28907 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28908 File
    28909 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28910 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    28911 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    28912 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28913 File
    28914 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28915 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    28916 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    28917 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28918 File
    28919 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28920 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    28921 p = super().first_intercept(mxyz1, mxyz2) 
    28922 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28923 File
    28924 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28925 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    28926 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    28927 exclude=exclude) 
    28928 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28929 File
    28930 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28931 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    28932 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    28933 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28934 File
    28935 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28936 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    28937 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    28938 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28939 File
    28940 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28941 packages/chimerax/graphics/drawing.py", line 1108, in
    28942 _first_intercept_excluding_children 
    28943 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    28944 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28945 File
    28946 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28947 packages/chimerax/geometry/place.py", line 201, in inverse 
    28948 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    28949 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28950 File
    28951 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28952 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    28953 rinv[:, :] = matrix_inverse(r) 
    28954 ^^^^^^^^^^^^^^^^^ 
    28955 File
    28956 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28957 packages/numpy/linalg/linalg.py", line 561, in inv 
    28958 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    28959 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28960 File
    28961 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28962 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    28963 raise LinAlgError("Singular matrix") 
    28964 numpy.linalg.LinAlgError: Singular matrix 
    28965  
    28966 numpy.linalg.LinAlgError: Singular matrix 
    28967  
    28968 File
    28969 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28970 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    28971 raise LinAlgError("Singular matrix") 
    28972  
    28973 See log for complete Python traceback. 
    28974  
    28975 Traceback (most recent call last): 
    28976 File
    28977 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28978 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    28979 self.session.ui.mouse_modes.mouse_pause_tracking() 
    28980 File
    28981 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28982 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    28983 mouse_pause_tracking 
    28984 self._mouse_pause() 
    28985 File
    28986 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28987 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    28988 m.pause(self._mouse_pause_position) 
    28989 File
    28990 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28991 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    28992 p = self.view.picked_object(x, y) 
    28993 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    28994 File
    28995 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    28996 packages/chimerax/graphics/view.py", line 838, in picked_object 
    28997 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    28998 beyond, 
    28999 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29000 File
    29001 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29002 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    29003 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    29004 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29005 File
    29006 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29007 packages/chimerax/core/models.py", line 143, in first_intercept 
    29008 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    29009 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29010 File
    29011 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29012 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    29013 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    29014 exclude=exclude) 
    29015 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29016 File
    29017 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29018 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    29019 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    29020 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29021 File
    29022 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29023 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    29024 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    29025 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29026 File
    29027 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29028 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    29029 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    29030 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29031 File
    29032 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29033 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    29034 p = super().first_intercept(mxyz1, mxyz2) 
    29035 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29036 File
    29037 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29038 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    29039 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    29040 exclude=exclude) 
    29041 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29042 File
    29043 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29044 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    29045 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    29046 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29047 File
    29048 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29049 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    29050 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    29051 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29052 File
    29053 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29054 packages/chimerax/graphics/drawing.py", line 1108, in
    29055 _first_intercept_excluding_children 
    29056 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    29057 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29058 File
    29059 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29060 packages/chimerax/geometry/place.py", line 201, in inverse 
    29061 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    29062 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29063 File
    29064 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29065 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    29066 rinv[:, :] = matrix_inverse(r) 
    29067 ^^^^^^^^^^^^^^^^^ 
    29068 File
    29069 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29070 packages/numpy/linalg/linalg.py", line 561, in inv 
    29071 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    29072 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29073 File
    29074 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29075 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    29076 raise LinAlgError("Singular matrix") 
    29077 numpy.linalg.LinAlgError: Singular matrix 
    29078  
    29079 numpy.linalg.LinAlgError: Singular matrix 
    29080  
    29081 File
    29082 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29083 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    29084 raise LinAlgError("Singular matrix") 
    29085  
    29086 See log for complete Python traceback. 
    29087  
    29088 Traceback (most recent call last): 
    29089 File
    29090 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29091 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    29092 self.session.ui.mouse_modes.mouse_pause_tracking() 
    29093 File
    29094 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29095 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    29096 mouse_pause_tracking 
    29097 self._mouse_pause() 
    29098 File
    29099 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29100 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    29101 m.pause(self._mouse_pause_position) 
    29102 File
    29103 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29104 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    29105 p = self.view.picked_object(x, y) 
    29106 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29107 File
    29108 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29109 packages/chimerax/graphics/view.py", line 838, in picked_object 
    29110 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    29111 beyond, 
    29112 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29113 File
    29114 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29115 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    29116 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    29117 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29118 File
    29119 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29120 packages/chimerax/core/models.py", line 143, in first_intercept 
    29121 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    29122 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29123 File
    29124 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29125 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    29126 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    29127 exclude=exclude) 
    29128 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29129 File
    29130 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29131 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    29132 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    29133 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29134 File
    29135 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29136 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    29137 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    29138 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29139 File
    29140 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29141 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    29142 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    29143 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29144 File
    29145 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29146 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    29147 p = super().first_intercept(mxyz1, mxyz2) 
    29148 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29149 File
    29150 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29151 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    29152 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    29153 exclude=exclude) 
    29154 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29155 File
    29156 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29157 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    29158 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    29159 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29160 File
    29161 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29162 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    29163 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    29164 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29165 File
    29166 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29167 packages/chimerax/graphics/drawing.py", line 1108, in
    29168 _first_intercept_excluding_children 
    29169 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    29170 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29171 File
    29172 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29173 packages/chimerax/geometry/place.py", line 201, in inverse 
    29174 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    29175 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29176 File
    29177 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29178 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    29179 rinv[:, :] = matrix_inverse(r) 
    29180 ^^^^^^^^^^^^^^^^^ 
    29181 File
    29182 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29183 packages/numpy/linalg/linalg.py", line 561, in inv 
    29184 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    29185 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29186 File
    29187 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29188 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    29189 raise LinAlgError("Singular matrix") 
    29190 numpy.linalg.LinAlgError: Singular matrix 
    29191  
    29192 numpy.linalg.LinAlgError: Singular matrix 
    29193  
    29194 File
    29195 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29196 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    29197 raise LinAlgError("Singular matrix") 
    29198  
    29199 See log for complete Python traceback. 
    29200  
    29201 Traceback (most recent call last): 
    29202 File
    29203 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29204 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    29205 self.session.ui.mouse_modes.mouse_pause_tracking() 
    29206 File
    29207 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29208 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    29209 mouse_pause_tracking 
    29210 self._mouse_pause() 
    29211 File
    29212 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29213 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    29214 m.pause(self._mouse_pause_position) 
    29215 File
    29216 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29217 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    29218 p = self.view.picked_object(x, y) 
    29219 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29220 File
    29221 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29222 packages/chimerax/graphics/view.py", line 838, in picked_object 
    29223 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    29224 beyond, 
    29225 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29226 File
    29227 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29228 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    29229 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    29230 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29231 File
    29232 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29233 packages/chimerax/core/models.py", line 143, in first_intercept 
    29234 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    29235 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29236 File
    29237 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29238 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    29239 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    29240 exclude=exclude) 
    29241 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29242 File
    29243 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29244 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    29245 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    29246 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29247 File
    29248 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29249 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    29250 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    29251 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29252 File
    29253 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29254 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    29255 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    29256 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29257 File
    29258 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29259 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    29260 p = super().first_intercept(mxyz1, mxyz2) 
    29261 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29262 File
    29263 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29264 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    29265 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    29266 exclude=exclude) 
    29267 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29268 File
    29269 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29270 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    29271 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    29272 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29273 File
    29274 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29275 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    29276 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    29277 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29278 File
    29279 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29280 packages/chimerax/graphics/drawing.py", line 1108, in
    29281 _first_intercept_excluding_children 
    29282 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    29283 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29284 File
    29285 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29286 packages/chimerax/geometry/place.py", line 201, in inverse 
    29287 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    29288 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29289 File
    29290 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29291 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    29292 rinv[:, :] = matrix_inverse(r) 
    29293 ^^^^^^^^^^^^^^^^^ 
    29294 File
    29295 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29296 packages/numpy/linalg/linalg.py", line 561, in inv 
    29297 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    29298 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29299 File
    29300 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29301 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    29302 raise LinAlgError("Singular matrix") 
    29303 numpy.linalg.LinAlgError: Singular matrix 
    29304  
    29305 numpy.linalg.LinAlgError: Singular matrix 
    29306  
    29307 File
    29308 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29309 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    29310 raise LinAlgError("Singular matrix") 
    29311  
    29312 See log for complete Python traceback. 
    29313  
    29314 Traceback (most recent call last): 
    29315 File
    29316 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29317 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    29318 self.session.ui.mouse_modes.mouse_pause_tracking() 
    29319 File
    29320 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29321 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    29322 mouse_pause_tracking 
    29323 self._mouse_pause() 
    29324 File
    29325 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29326 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    29327 m.pause(self._mouse_pause_position) 
    29328 File
    29329 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29330 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    29331 p = self.view.picked_object(x, y) 
    29332 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29333 File
    29334 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29335 packages/chimerax/graphics/view.py", line 838, in picked_object 
    29336 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    29337 beyond, 
    29338 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29339 File
    29340 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29341 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    29342 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    29343 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29344 File
    29345 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29346 packages/chimerax/core/models.py", line 143, in first_intercept 
    29347 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    29348 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29349 File
    29350 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29351 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    29352 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    29353 exclude=exclude) 
    29354 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29355 File
    29356 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29357 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    29358 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    29359 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29360 File
    29361 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29362 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    29363 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    29364 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29365 File
    29366 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29367 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    29368 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    29369 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29370 File
    29371 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29372 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    29373 p = super().first_intercept(mxyz1, mxyz2) 
    29374 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29375 File
    29376 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29377 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    29378 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    29379 exclude=exclude) 
    29380 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29381 File
    29382 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29383 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    29384 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    29385 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29386 File
    29387 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29388 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    29389 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    29390 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29391 File
    29392 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29393 packages/chimerax/graphics/drawing.py", line 1108, in
    29394 _first_intercept_excluding_children 
    29395 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    29396 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29397 File
    29398 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29399 packages/chimerax/geometry/place.py", line 201, in inverse 
    29400 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    29401 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29402 File
    29403 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29404 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    29405 rinv[:, :] = matrix_inverse(r) 
    29406 ^^^^^^^^^^^^^^^^^ 
    29407 File
    29408 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29409 packages/numpy/linalg/linalg.py", line 561, in inv 
    29410 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    29411 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29412 File
    29413 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29414 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    29415 raise LinAlgError("Singular matrix") 
    29416 numpy.linalg.LinAlgError: Singular matrix 
    29417  
    29418 numpy.linalg.LinAlgError: Singular matrix 
    29419  
    29420 File
    29421 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29422 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    29423 raise LinAlgError("Singular matrix") 
    29424  
    29425 See log for complete Python traceback. 
    29426  
    29427 Traceback (most recent call last): 
    29428 File
    29429 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29430 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    29431 self.session.ui.mouse_modes.mouse_pause_tracking() 
    29432 File
    29433 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29434 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    29435 mouse_pause_tracking 
    29436 self._mouse_pause() 
    29437 File
    29438 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29439 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    29440 m.pause(self._mouse_pause_position) 
    29441 File
    29442 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29443 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    29444 p = self.view.picked_object(x, y) 
    29445 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29446 File
    29447 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29448 packages/chimerax/graphics/view.py", line 838, in picked_object 
    29449 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    29450 beyond, 
    29451 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29452 File
    29453 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29454 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    29455 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    29456 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29457 File
    29458 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29459 packages/chimerax/core/models.py", line 143, in first_intercept 
    29460 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    29461 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29462 File
    29463 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29464 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    29465 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    29466 exclude=exclude) 
    29467 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29468 File
    29469 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29470 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    29471 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    29472 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29473 File
    29474 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29475 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    29476 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    29477 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29478 File
    29479 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29480 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    29481 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    29482 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29483 File
    29484 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29485 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    29486 p = super().first_intercept(mxyz1, mxyz2) 
    29487 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29488 File
    29489 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29490 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    29491 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    29492 exclude=exclude) 
    29493 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29494 File
    29495 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29496 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    29497 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    29498 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29499 File
    29500 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29501 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    29502 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    29503 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29504 File
    29505 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29506 packages/chimerax/graphics/drawing.py", line 1108, in
    29507 _first_intercept_excluding_children 
    29508 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    29509 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29510 File
    29511 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29512 packages/chimerax/geometry/place.py", line 201, in inverse 
    29513 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    29514 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29515 File
    29516 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29517 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    29518 rinv[:, :] = matrix_inverse(r) 
    29519 ^^^^^^^^^^^^^^^^^ 
    29520 File
    29521 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29522 packages/numpy/linalg/linalg.py", line 561, in inv 
    29523 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    29524 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29525 File
    29526 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29527 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    29528 raise LinAlgError("Singular matrix") 
    29529 numpy.linalg.LinAlgError: Singular matrix 
    29530  
    29531 numpy.linalg.LinAlgError: Singular matrix 
    29532  
    29533 File
    29534 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29535 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    29536 raise LinAlgError("Singular matrix") 
    29537  
    29538 See log for complete Python traceback. 
    29539  
    29540 Traceback (most recent call last): 
    29541 File
    29542 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29543 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    29544 self.session.ui.mouse_modes.mouse_pause_tracking() 
    29545 File
    29546 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29547 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    29548 mouse_pause_tracking 
    29549 self._mouse_pause() 
    29550 File
    29551 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29552 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    29553 m.pause(self._mouse_pause_position) 
    29554 File
    29555 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29556 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    29557 p = self.view.picked_object(x, y) 
    29558 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29559 File
    29560 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29561 packages/chimerax/graphics/view.py", line 838, in picked_object 
    29562 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    29563 beyond, 
    29564 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29565 File
    29566 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29567 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    29568 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    29569 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29570 File
    29571 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29572 packages/chimerax/core/models.py", line 143, in first_intercept 
    29573 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    29574 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29575 File
    29576 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29577 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    29578 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    29579 exclude=exclude) 
    29580 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29581 File
    29582 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29583 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    29584 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    29585 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29586 File
    29587 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29588 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    29589 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    29590 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29591 File
    29592 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29593 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    29594 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    29595 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29596 File
    29597 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29598 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    29599 p = super().first_intercept(mxyz1, mxyz2) 
    29600 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29601 File
    29602 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29603 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    29604 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    29605 exclude=exclude) 
    29606 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29607 File
    29608 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29609 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    29610 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    29611 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29612 File
    29613 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29614 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    29615 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    29616 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29617 File
    29618 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29619 packages/chimerax/graphics/drawing.py", line 1108, in
    29620 _first_intercept_excluding_children 
    29621 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    29622 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29623 File
    29624 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29625 packages/chimerax/geometry/place.py", line 201, in inverse 
    29626 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    29627 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29628 File
    29629 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29630 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    29631 rinv[:, :] = matrix_inverse(r) 
    29632 ^^^^^^^^^^^^^^^^^ 
    29633 File
    29634 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29635 packages/numpy/linalg/linalg.py", line 561, in inv 
    29636 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    29637 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29638 File
    29639 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29640 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    29641 raise LinAlgError("Singular matrix") 
    29642 numpy.linalg.LinAlgError: Singular matrix 
    29643  
    29644 numpy.linalg.LinAlgError: Singular matrix 
    29645  
    29646 File
    29647 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29648 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    29649 raise LinAlgError("Singular matrix") 
    29650  
    29651 See log for complete Python traceback. 
    29652  
    29653 Traceback (most recent call last): 
    29654 File
    29655 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29656 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    29657 self.session.ui.mouse_modes.mouse_pause_tracking() 
    29658 File
    29659 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29660 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    29661 mouse_pause_tracking 
    29662 self._mouse_pause() 
    29663 File
    29664 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29665 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    29666 m.pause(self._mouse_pause_position) 
    29667 File
    29668 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29669 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    29670 p = self.view.picked_object(x, y) 
    29671 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29672 File
    29673 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29674 packages/chimerax/graphics/view.py", line 838, in picked_object 
    29675 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    29676 beyond, 
    29677 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29678 File
    29679 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29680 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    29681 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    29682 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29683 File
    29684 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29685 packages/chimerax/core/models.py", line 143, in first_intercept 
    29686 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    29687 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29688 File
    29689 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29690 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    29691 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    29692 exclude=exclude) 
    29693 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29694 File
    29695 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29696 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    29697 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    29698 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29699 File
    29700 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29701 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    29702 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    29703 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29704 File
    29705 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29706 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    29707 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    29708 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29709 File
    29710 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29711 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    29712 p = super().first_intercept(mxyz1, mxyz2) 
    29713 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29714 File
    29715 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29716 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    29717 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    29718 exclude=exclude) 
    29719 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29720 File
    29721 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29722 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    29723 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    29724 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29725 File
    29726 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29727 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    29728 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    29729 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29730 File
    29731 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29732 packages/chimerax/graphics/drawing.py", line 1108, in
    29733 _first_intercept_excluding_children 
    29734 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    29735 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29736 File
    29737 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29738 packages/chimerax/geometry/place.py", line 201, in inverse 
    29739 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    29740 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29741 File
    29742 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29743 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    29744 rinv[:, :] = matrix_inverse(r) 
    29745 ^^^^^^^^^^^^^^^^^ 
    29746 File
    29747 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29748 packages/numpy/linalg/linalg.py", line 561, in inv 
    29749 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    29750 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29751 File
    29752 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29753 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    29754 raise LinAlgError("Singular matrix") 
    29755 numpy.linalg.LinAlgError: Singular matrix 
    29756  
    29757 numpy.linalg.LinAlgError: Singular matrix 
    29758  
    29759 File
    29760 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29761 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    29762 raise LinAlgError("Singular matrix") 
    29763  
    29764 See log for complete Python traceback. 
    29765  
    29766 Traceback (most recent call last): 
    29767 File
    29768 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29769 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    29770 self.session.ui.mouse_modes.mouse_pause_tracking() 
    29771 File
    29772 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29773 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    29774 mouse_pause_tracking 
    29775 self._mouse_pause() 
    29776 File
    29777 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29778 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    29779 m.pause(self._mouse_pause_position) 
    29780 File
    29781 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29782 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    29783 p = self.view.picked_object(x, y) 
    29784 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29785 File
    29786 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29787 packages/chimerax/graphics/view.py", line 838, in picked_object 
    29788 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    29789 beyond, 
    29790 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29791 File
    29792 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29793 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    29794 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    29795 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29796 File
    29797 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29798 packages/chimerax/core/models.py", line 143, in first_intercept 
    29799 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    29800 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29801 File
    29802 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29803 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    29804 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    29805 exclude=exclude) 
    29806 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29807 File
    29808 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29809 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    29810 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    29811 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29812 File
    29813 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29814 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    29815 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    29816 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29817 File
    29818 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29819 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    29820 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    29821 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29822 File
    29823 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29824 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    29825 p = super().first_intercept(mxyz1, mxyz2) 
    29826 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29827 File
    29828 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29829 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    29830 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    29831 exclude=exclude) 
    29832 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29833 File
    29834 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29835 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    29836 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    29837 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29838 File
    29839 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29840 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    29841 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    29842 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29843 File
    29844 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29845 packages/chimerax/graphics/drawing.py", line 1108, in
    29846 _first_intercept_excluding_children 
    29847 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    29848 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29849 File
    29850 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29851 packages/chimerax/geometry/place.py", line 201, in inverse 
    29852 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    29853 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29854 File
    29855 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29856 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    29857 rinv[:, :] = matrix_inverse(r) 
    29858 ^^^^^^^^^^^^^^^^^ 
    29859 File
    29860 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29861 packages/numpy/linalg/linalg.py", line 561, in inv 
    29862 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    29863 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29864 File
    29865 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29866 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    29867 raise LinAlgError("Singular matrix") 
    29868 numpy.linalg.LinAlgError: Singular matrix 
    29869  
    29870 numpy.linalg.LinAlgError: Singular matrix 
    29871  
    29872 File
    29873 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29874 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    29875 raise LinAlgError("Singular matrix") 
    29876  
    29877 See log for complete Python traceback. 
    29878  
    29879 Traceback (most recent call last): 
    29880 File
    29881 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29882 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    29883 self.session.ui.mouse_modes.mouse_pause_tracking() 
    29884 File
    29885 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29886 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    29887 mouse_pause_tracking 
    29888 self._mouse_pause() 
    29889 File
    29890 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29891 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    29892 m.pause(self._mouse_pause_position) 
    29893 File
    29894 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29895 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    29896 p = self.view.picked_object(x, y) 
    29897 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29898 File
    29899 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29900 packages/chimerax/graphics/view.py", line 838, in picked_object 
    29901 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    29902 beyond, 
    29903 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29904 File
    29905 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29906 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    29907 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    29908 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29909 File
    29910 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29911 packages/chimerax/core/models.py", line 143, in first_intercept 
    29912 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    29913 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29914 File
    29915 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29916 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    29917 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    29918 exclude=exclude) 
    29919 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29920 File
    29921 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29922 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    29923 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    29924 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29925 File
    29926 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29927 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    29928 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    29929 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29930 File
    29931 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29932 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    29933 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    29934 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29935 File
    29936 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29937 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    29938 p = super().first_intercept(mxyz1, mxyz2) 
    29939 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29940 File
    29941 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29942 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    29943 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    29944 exclude=exclude) 
    29945 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29946 File
    29947 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29948 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    29949 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    29950 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29951 File
    29952 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29953 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    29954 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    29955 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29956 File
    29957 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29958 packages/chimerax/graphics/drawing.py", line 1108, in
    29959 _first_intercept_excluding_children 
    29960 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    29961 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29962 File
    29963 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29964 packages/chimerax/geometry/place.py", line 201, in inverse 
    29965 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    29966 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29967 File
    29968 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29969 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    29970 rinv[:, :] = matrix_inverse(r) 
    29971 ^^^^^^^^^^^^^^^^^ 
    29972 File
    29973 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29974 packages/numpy/linalg/linalg.py", line 561, in inv 
    29975 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    29976 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    29977 File
    29978 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29979 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    29980 raise LinAlgError("Singular matrix") 
    29981 numpy.linalg.LinAlgError: Singular matrix 
    29982  
    29983 numpy.linalg.LinAlgError: Singular matrix 
    29984  
    29985 File
    29986 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29987 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    29988 raise LinAlgError("Singular matrix") 
    29989  
    29990 See log for complete Python traceback. 
    29991  
    29992 Traceback (most recent call last): 
    29993 File
    29994 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29995 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    29996 self.session.ui.mouse_modes.mouse_pause_tracking() 
    29997 File
    29998 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    29999 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    30000 mouse_pause_tracking 
    30001 self._mouse_pause() 
    30002 File
    30003 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30004 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    30005 m.pause(self._mouse_pause_position) 
    30006 File
    30007 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30008 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    30009 p = self.view.picked_object(x, y) 
    30010 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30011 File
    30012 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30013 packages/chimerax/graphics/view.py", line 838, in picked_object 
    30014 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    30015 beyond, 
    30016 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30017 File
    30018 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30019 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    30020 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    30021 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30022 File
    30023 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30024 packages/chimerax/core/models.py", line 143, in first_intercept 
    30025 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    30026 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30027 File
    30028 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30029 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    30030 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    30031 exclude=exclude) 
    30032 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30033 File
    30034 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30035 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    30036 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    30037 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30038 File
    30039 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30040 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    30041 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    30042 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30043 File
    30044 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30045 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    30046 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    30047 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30048 File
    30049 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30050 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    30051 p = super().first_intercept(mxyz1, mxyz2) 
    30052 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30053 File
    30054 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30055 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    30056 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    30057 exclude=exclude) 
    30058 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30059 File
    30060 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30061 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    30062 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    30063 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30064 File
    30065 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30066 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    30067 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    30068 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30069 File
    30070 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30071 packages/chimerax/graphics/drawing.py", line 1108, in
    30072 _first_intercept_excluding_children 
    30073 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    30074 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30075 File
    30076 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30077 packages/chimerax/geometry/place.py", line 201, in inverse 
    30078 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    30079 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30080 File
    30081 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30082 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    30083 rinv[:, :] = matrix_inverse(r) 
    30084 ^^^^^^^^^^^^^^^^^ 
    30085 File
    30086 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30087 packages/numpy/linalg/linalg.py", line 561, in inv 
    30088 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    30089 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30090 File
    30091 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30092 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    30093 raise LinAlgError("Singular matrix") 
    30094 numpy.linalg.LinAlgError: Singular matrix 
    30095  
    30096 numpy.linalg.LinAlgError: Singular matrix 
    30097  
    30098 File
    30099 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30100 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    30101 raise LinAlgError("Singular matrix") 
    30102  
    30103 See log for complete Python traceback. 
    30104  
    30105 Traceback (most recent call last): 
    30106 File
    30107 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30108 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    30109 self.session.ui.mouse_modes.mouse_pause_tracking() 
    30110 File
    30111 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30112 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    30113 mouse_pause_tracking 
    30114 self._mouse_pause() 
    30115 File
    30116 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30117 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    30118 m.pause(self._mouse_pause_position) 
    30119 File
    30120 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30121 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    30122 p = self.view.picked_object(x, y) 
    30123 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30124 File
    30125 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30126 packages/chimerax/graphics/view.py", line 838, in picked_object 
    30127 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    30128 beyond, 
    30129 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30130 File
    30131 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30132 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    30133 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    30134 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30135 File
    30136 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30137 packages/chimerax/core/models.py", line 143, in first_intercept 
    30138 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    30139 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30140 File
    30141 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30142 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    30143 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    30144 exclude=exclude) 
    30145 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30146 File
    30147 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30148 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    30149 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    30150 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30151 File
    30152 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30153 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    30154 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    30155 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30156 File
    30157 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30158 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    30159 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    30160 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30161 File
    30162 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30163 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    30164 p = super().first_intercept(mxyz1, mxyz2) 
    30165 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30166 File
    30167 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30168 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    30169 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    30170 exclude=exclude) 
    30171 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30172 File
    30173 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30174 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    30175 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    30176 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30177 File
    30178 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30179 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    30180 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    30181 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30182 File
    30183 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30184 packages/chimerax/graphics/drawing.py", line 1108, in
    30185 _first_intercept_excluding_children 
    30186 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    30187 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30188 File
    30189 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30190 packages/chimerax/geometry/place.py", line 201, in inverse 
    30191 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    30192 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30193 File
    30194 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30195 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    30196 rinv[:, :] = matrix_inverse(r) 
    30197 ^^^^^^^^^^^^^^^^^ 
    30198 File
    30199 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30200 packages/numpy/linalg/linalg.py", line 561, in inv 
    30201 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    30202 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30203 File
    30204 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30205 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    30206 raise LinAlgError("Singular matrix") 
    30207 numpy.linalg.LinAlgError: Singular matrix 
    30208  
    30209 numpy.linalg.LinAlgError: Singular matrix 
    30210  
    30211 File
    30212 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30213 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    30214 raise LinAlgError("Singular matrix") 
    30215  
    30216 See log for complete Python traceback. 
    30217  
    30218 Traceback (most recent call last): 
    30219 File
    30220 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30221 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    30222 self.session.ui.mouse_modes.mouse_pause_tracking() 
    30223 File
    30224 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30225 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    30226 mouse_pause_tracking 
    30227 self._mouse_pause() 
    30228 File
    30229 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30230 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    30231 m.pause(self._mouse_pause_position) 
    30232 File
    30233 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30234 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    30235 p = self.view.picked_object(x, y) 
    30236 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30237 File
    30238 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30239 packages/chimerax/graphics/view.py", line 838, in picked_object 
    30240 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    30241 beyond, 
    30242 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30243 File
    30244 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30245 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    30246 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    30247 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30248 File
    30249 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30250 packages/chimerax/core/models.py", line 143, in first_intercept 
    30251 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    30252 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30253 File
    30254 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30255 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    30256 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    30257 exclude=exclude) 
    30258 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30259 File
    30260 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30261 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    30262 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    30263 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30264 File
    30265 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30266 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    30267 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    30268 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30269 File
    30270 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30271 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    30272 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    30273 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30274 File
    30275 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30276 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    30277 p = super().first_intercept(mxyz1, mxyz2) 
    30278 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30279 File
    30280 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30281 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    30282 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    30283 exclude=exclude) 
    30284 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30285 File
    30286 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30287 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    30288 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    30289 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30290 File
    30291 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30292 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    30293 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    30294 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30295 File
    30296 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30297 packages/chimerax/graphics/drawing.py", line 1108, in
    30298 _first_intercept_excluding_children 
    30299 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    30300 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30301 File
    30302 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30303 packages/chimerax/geometry/place.py", line 201, in inverse 
    30304 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    30305 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30306 File
    30307 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30308 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    30309 rinv[:, :] = matrix_inverse(r) 
    30310 ^^^^^^^^^^^^^^^^^ 
    30311 File
    30312 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30313 packages/numpy/linalg/linalg.py", line 561, in inv 
    30314 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    30315 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30316 File
    30317 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30318 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    30319 raise LinAlgError("Singular matrix") 
    30320 numpy.linalg.LinAlgError: Singular matrix 
    30321  
    30322 numpy.linalg.LinAlgError: Singular matrix 
    30323  
    30324 File
    30325 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30326 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    30327 raise LinAlgError("Singular matrix") 
    30328  
    30329 See log for complete Python traceback. 
    30330  
    30331 Traceback (most recent call last): 
    30332 File
    30333 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30334 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    30335 self.session.ui.mouse_modes.mouse_pause_tracking() 
    30336 File
    30337 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30338 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    30339 mouse_pause_tracking 
    30340 self._mouse_pause() 
    30341 File
    30342 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30343 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    30344 m.pause(self._mouse_pause_position) 
    30345 File
    30346 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30347 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    30348 p = self.view.picked_object(x, y) 
    30349 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30350 File
    30351 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30352 packages/chimerax/graphics/view.py", line 838, in picked_object 
    30353 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    30354 beyond, 
    30355 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30356 File
    30357 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30358 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    30359 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    30360 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30361 File
    30362 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30363 packages/chimerax/core/models.py", line 143, in first_intercept 
    30364 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    30365 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30366 File
    30367 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30368 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    30369 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    30370 exclude=exclude) 
    30371 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30372 File
    30373 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30374 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    30375 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    30376 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30377 File
    30378 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30379 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    30380 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    30381 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30382 File
    30383 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30384 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    30385 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    30386 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30387 File
    30388 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30389 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    30390 p = super().first_intercept(mxyz1, mxyz2) 
    30391 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30392 File
    30393 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30394 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    30395 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    30396 exclude=exclude) 
    30397 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30398 File
    30399 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30400 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    30401 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    30402 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30403 File
    30404 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30405 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    30406 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    30407 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30408 File
    30409 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30410 packages/chimerax/graphics/drawing.py", line 1108, in
    30411 _first_intercept_excluding_children 
    30412 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    30413 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30414 File
    30415 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30416 packages/chimerax/geometry/place.py", line 201, in inverse 
    30417 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    30418 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30419 File
    30420 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30421 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    30422 rinv[:, :] = matrix_inverse(r) 
    30423 ^^^^^^^^^^^^^^^^^ 
    30424 File
    30425 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30426 packages/numpy/linalg/linalg.py", line 561, in inv 
    30427 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    30428 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30429 File
    30430 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30431 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    30432 raise LinAlgError("Singular matrix") 
    30433 numpy.linalg.LinAlgError: Singular matrix 
    30434  
    30435 numpy.linalg.LinAlgError: Singular matrix 
    30436  
    30437 File
    30438 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30439 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    30440 raise LinAlgError("Singular matrix") 
    30441  
    30442 See log for complete Python traceback. 
    30443  
    30444 Traceback (most recent call last): 
    30445 File
    30446 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30447 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    30448 self.session.ui.mouse_modes.mouse_pause_tracking() 
    30449 File
    30450 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30451 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    30452 mouse_pause_tracking 
    30453 self._mouse_pause() 
    30454 File
    30455 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30456 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    30457 m.pause(self._mouse_pause_position) 
    30458 File
    30459 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30460 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    30461 p = self.view.picked_object(x, y) 
    30462 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30463 File
    30464 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30465 packages/chimerax/graphics/view.py", line 838, in picked_object 
    30466 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    30467 beyond, 
    30468 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30469 File
    30470 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30471 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    30472 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    30473 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30474 File
    30475 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30476 packages/chimerax/core/models.py", line 143, in first_intercept 
    30477 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    30478 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30479 File
    30480 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30481 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    30482 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    30483 exclude=exclude) 
    30484 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30485 File
    30486 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30487 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    30488 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    30489 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30490 File
    30491 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30492 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    30493 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    30494 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30495 File
    30496 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30497 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    30498 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    30499 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30500 File
    30501 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30502 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    30503 p = super().first_intercept(mxyz1, mxyz2) 
    30504 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30505 File
    30506 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30507 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    30508 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    30509 exclude=exclude) 
    30510 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30511 File
    30512 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30513 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    30514 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    30515 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30516 File
    30517 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30518 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    30519 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    30520 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30521 File
    30522 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30523 packages/chimerax/graphics/drawing.py", line 1108, in
    30524 _first_intercept_excluding_children 
    30525 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    30526 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30527 File
    30528 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30529 packages/chimerax/geometry/place.py", line 201, in inverse 
    30530 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    30531 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30532 File
    30533 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30534 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    30535 rinv[:, :] = matrix_inverse(r) 
    30536 ^^^^^^^^^^^^^^^^^ 
    30537 File
    30538 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30539 packages/numpy/linalg/linalg.py", line 561, in inv 
    30540 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    30541 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30542 File
    30543 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30544 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    30545 raise LinAlgError("Singular matrix") 
    30546 numpy.linalg.LinAlgError: Singular matrix 
    30547  
    30548 numpy.linalg.LinAlgError: Singular matrix 
    30549  
    30550 File
    30551 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30552 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    30553 raise LinAlgError("Singular matrix") 
    30554  
    30555 See log for complete Python traceback. 
    30556  
    30557 Traceback (most recent call last): 
    30558 File
    30559 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30560 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    30561 self.session.ui.mouse_modes.mouse_pause_tracking() 
    30562 File
    30563 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30564 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    30565 mouse_pause_tracking 
    30566 self._mouse_pause() 
    30567 File
    30568 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30569 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    30570 m.pause(self._mouse_pause_position) 
    30571 File
    30572 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30573 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    30574 p = self.view.picked_object(x, y) 
    30575 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30576 File
    30577 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30578 packages/chimerax/graphics/view.py", line 838, in picked_object 
    30579 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    30580 beyond, 
    30581 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30582 File
    30583 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30584 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    30585 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    30586 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30587 File
    30588 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30589 packages/chimerax/core/models.py", line 143, in first_intercept 
    30590 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    30591 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30592 File
    30593 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30594 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    30595 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    30596 exclude=exclude) 
    30597 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30598 File
    30599 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30600 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    30601 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    30602 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30603 File
    30604 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30605 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    30606 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    30607 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30608 File
    30609 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30610 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    30611 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    30612 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30613 File
    30614 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30615 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    30616 p = super().first_intercept(mxyz1, mxyz2) 
    30617 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30618 File
    30619 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30620 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    30621 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    30622 exclude=exclude) 
    30623 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30624 File
    30625 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30626 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    30627 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    30628 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30629 File
    30630 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30631 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    30632 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    30633 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30634 File
    30635 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30636 packages/chimerax/graphics/drawing.py", line 1108, in
    30637 _first_intercept_excluding_children 
    30638 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    30639 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30640 File
    30641 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30642 packages/chimerax/geometry/place.py", line 201, in inverse 
    30643 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    30644 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30645 File
    30646 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30647 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    30648 rinv[:, :] = matrix_inverse(r) 
    30649 ^^^^^^^^^^^^^^^^^ 
    30650 File
    30651 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30652 packages/numpy/linalg/linalg.py", line 561, in inv 
    30653 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    30654 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30655 File
    30656 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30657 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    30658 raise LinAlgError("Singular matrix") 
    30659 numpy.linalg.LinAlgError: Singular matrix 
    30660  
    30661 numpy.linalg.LinAlgError: Singular matrix 
    30662  
    30663 File
    30664 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30665 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    30666 raise LinAlgError("Singular matrix") 
    30667  
    30668 See log for complete Python traceback. 
    30669  
    30670 Traceback (most recent call last): 
    30671 File
    30672 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30673 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    30674 self.session.ui.mouse_modes.mouse_pause_tracking() 
    30675 File
    30676 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30677 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    30678 mouse_pause_tracking 
    30679 self._mouse_pause() 
    30680 File
    30681 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30682 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    30683 m.pause(self._mouse_pause_position) 
    30684 File
    30685 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30686 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    30687 p = self.view.picked_object(x, y) 
    30688 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30689 File
    30690 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30691 packages/chimerax/graphics/view.py", line 838, in picked_object 
    30692 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    30693 beyond, 
    30694 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30695 File
    30696 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30697 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    30698 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    30699 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30700 File
    30701 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30702 packages/chimerax/core/models.py", line 143, in first_intercept 
    30703 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    30704 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30705 File
    30706 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30707 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    30708 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    30709 exclude=exclude) 
    30710 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30711 File
    30712 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30713 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    30714 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    30715 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30716 File
    30717 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30718 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    30719 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    30720 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30721 File
    30722 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30723 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    30724 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    30725 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30726 File
    30727 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30728 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    30729 p = super().first_intercept(mxyz1, mxyz2) 
    30730 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30731 File
    30732 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30733 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    30734 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    30735 exclude=exclude) 
    30736 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30737 File
    30738 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30739 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    30740 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    30741 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30742 File
    30743 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30744 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    30745 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    30746 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30747 File
    30748 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30749 packages/chimerax/graphics/drawing.py", line 1108, in
    30750 _first_intercept_excluding_children 
    30751 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    30752 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30753 File
    30754 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30755 packages/chimerax/geometry/place.py", line 201, in inverse 
    30756 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    30757 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30758 File
    30759 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30760 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    30761 rinv[:, :] = matrix_inverse(r) 
    30762 ^^^^^^^^^^^^^^^^^ 
    30763 File
    30764 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30765 packages/numpy/linalg/linalg.py", line 561, in inv 
    30766 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    30767 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30768 File
    30769 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30770 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    30771 raise LinAlgError("Singular matrix") 
    30772 numpy.linalg.LinAlgError: Singular matrix 
    30773  
    30774 numpy.linalg.LinAlgError: Singular matrix 
    30775  
    30776 File
    30777 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30778 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    30779 raise LinAlgError("Singular matrix") 
    30780  
    30781 See log for complete Python traceback. 
    30782  
    30783 Traceback (most recent call last): 
    30784 File
    30785 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30786 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    30787 self.session.ui.mouse_modes.mouse_pause_tracking() 
    30788 File
    30789 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30790 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    30791 mouse_pause_tracking 
    30792 self._mouse_pause() 
    30793 File
    30794 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30795 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    30796 m.pause(self._mouse_pause_position) 
    30797 File
    30798 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30799 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    30800 p = self.view.picked_object(x, y) 
    30801 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30802 File
    30803 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30804 packages/chimerax/graphics/view.py", line 838, in picked_object 
    30805 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    30806 beyond, 
    30807 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30808 File
    30809 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30810 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    30811 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    30812 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30813 File
    30814 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30815 packages/chimerax/core/models.py", line 143, in first_intercept 
    30816 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    30817 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30818 File
    30819 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30820 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    30821 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    30822 exclude=exclude) 
    30823 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30824 File
    30825 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30826 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    30827 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    30828 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30829 File
    30830 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30831 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    30832 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    30833 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30834 File
    30835 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30836 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    30837 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    30838 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30839 File
    30840 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30841 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    30842 p = super().first_intercept(mxyz1, mxyz2) 
    30843 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30844 File
    30845 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30846 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    30847 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    30848 exclude=exclude) 
    30849 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30850 File
    30851 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30852 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    30853 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    30854 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30855 File
    30856 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30857 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    30858 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    30859 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30860 File
    30861 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30862 packages/chimerax/graphics/drawing.py", line 1108, in
    30863 _first_intercept_excluding_children 
    30864 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    30865 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30866 File
    30867 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30868 packages/chimerax/geometry/place.py", line 201, in inverse 
    30869 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    30870 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30871 File
    30872 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30873 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    30874 rinv[:, :] = matrix_inverse(r) 
    30875 ^^^^^^^^^^^^^^^^^ 
    30876 File
    30877 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30878 packages/numpy/linalg/linalg.py", line 561, in inv 
    30879 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    30880 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30881 File
    30882 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30883 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    30884 raise LinAlgError("Singular matrix") 
    30885 numpy.linalg.LinAlgError: Singular matrix 
    30886  
    30887 numpy.linalg.LinAlgError: Singular matrix 
    30888  
    30889 File
    30890 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30891 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    30892 raise LinAlgError("Singular matrix") 
    30893  
    30894 See log for complete Python traceback. 
    30895  
    30896 Traceback (most recent call last): 
    30897 File
    30898 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30899 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    30900 self.session.ui.mouse_modes.mouse_pause_tracking() 
    30901 File
    30902 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30903 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    30904 mouse_pause_tracking 
    30905 self._mouse_pause() 
    30906 File
    30907 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30908 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    30909 m.pause(self._mouse_pause_position) 
    30910 File
    30911 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30912 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    30913 p = self.view.picked_object(x, y) 
    30914 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30915 File
    30916 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30917 packages/chimerax/graphics/view.py", line 838, in picked_object 
    30918 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    30919 beyond, 
    30920 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30921 File
    30922 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30923 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    30924 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    30925 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30926 File
    30927 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30928 packages/chimerax/core/models.py", line 143, in first_intercept 
    30929 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    30930 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30931 File
    30932 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30933 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    30934 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    30935 exclude=exclude) 
    30936 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30937 File
    30938 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30939 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    30940 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    30941 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30942 File
    30943 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30944 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    30945 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    30946 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30947 File
    30948 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30949 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    30950 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    30951 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30952 File
    30953 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30954 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    30955 p = super().first_intercept(mxyz1, mxyz2) 
    30956 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30957 File
    30958 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30959 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    30960 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    30961 exclude=exclude) 
    30962 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30963 File
    30964 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30965 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    30966 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    30967 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30968 File
    30969 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30970 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    30971 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    30972 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30973 File
    30974 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30975 packages/chimerax/graphics/drawing.py", line 1108, in
    30976 _first_intercept_excluding_children 
    30977 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    30978 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30979 File
    30980 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30981 packages/chimerax/geometry/place.py", line 201, in inverse 
    30982 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    30983 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30984 File
    30985 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30986 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    30987 rinv[:, :] = matrix_inverse(r) 
    30988 ^^^^^^^^^^^^^^^^^ 
    30989 File
    30990 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30991 packages/numpy/linalg/linalg.py", line 561, in inv 
    30992 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    30993 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    30994 File
    30995 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    30996 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    30997 raise LinAlgError("Singular matrix") 
    30998 numpy.linalg.LinAlgError: Singular matrix 
    30999  
    31000 numpy.linalg.LinAlgError: Singular matrix 
    31001  
    31002 File
    31003 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31004 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    31005 raise LinAlgError("Singular matrix") 
    31006  
    31007 See log for complete Python traceback. 
    31008  
    31009 Traceback (most recent call last): 
    31010 File
    31011 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31012 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    31013 self.session.ui.mouse_modes.mouse_pause_tracking() 
    31014 File
    31015 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31016 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    31017 mouse_pause_tracking 
    31018 self._mouse_pause() 
    31019 File
    31020 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31021 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    31022 m.pause(self._mouse_pause_position) 
    31023 File
    31024 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31025 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    31026 p = self.view.picked_object(x, y) 
    31027 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31028 File
    31029 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31030 packages/chimerax/graphics/view.py", line 838, in picked_object 
    31031 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    31032 beyond, 
    31033 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31034 File
    31035 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31036 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    31037 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    31038 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31039 File
    31040 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31041 packages/chimerax/core/models.py", line 143, in first_intercept 
    31042 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    31043 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31044 File
    31045 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31046 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    31047 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    31048 exclude=exclude) 
    31049 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31050 File
    31051 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31052 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    31053 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    31054 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31055 File
    31056 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31057 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    31058 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    31059 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31060 File
    31061 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31062 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    31063 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    31064 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31065 File
    31066 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31067 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    31068 p = super().first_intercept(mxyz1, mxyz2) 
    31069 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31070 File
    31071 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31072 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    31073 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    31074 exclude=exclude) 
    31075 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31076 File
    31077 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31078 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    31079 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    31080 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31081 File
    31082 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31083 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    31084 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    31085 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31086 File
    31087 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31088 packages/chimerax/graphics/drawing.py", line 1108, in
    31089 _first_intercept_excluding_children 
    31090 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    31091 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31092 File
    31093 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31094 packages/chimerax/geometry/place.py", line 201, in inverse 
    31095 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    31096 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31097 File
    31098 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31099 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    31100 rinv[:, :] = matrix_inverse(r) 
    31101 ^^^^^^^^^^^^^^^^^ 
    31102 File
    31103 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31104 packages/numpy/linalg/linalg.py", line 561, in inv 
    31105 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    31106 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31107 File
    31108 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31109 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    31110 raise LinAlgError("Singular matrix") 
    31111 numpy.linalg.LinAlgError: Singular matrix 
    31112  
    31113 numpy.linalg.LinAlgError: Singular matrix 
    31114  
    31115 File
    31116 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31117 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    31118 raise LinAlgError("Singular matrix") 
    31119  
    31120 See log for complete Python traceback. 
    31121  
    31122 Traceback (most recent call last): 
    31123 File
    31124 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31125 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    31126 self.session.ui.mouse_modes.mouse_pause_tracking() 
    31127 File
    31128 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31129 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    31130 mouse_pause_tracking 
    31131 self._mouse_pause() 
    31132 File
    31133 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31134 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    31135 m.pause(self._mouse_pause_position) 
    31136 File
    31137 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31138 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    31139 p = self.view.picked_object(x, y) 
    31140 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31141 File
    31142 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31143 packages/chimerax/graphics/view.py", line 838, in picked_object 
    31144 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    31145 beyond, 
    31146 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31147 File
    31148 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31149 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    31150 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    31151 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31152 File
    31153 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31154 packages/chimerax/core/models.py", line 143, in first_intercept 
    31155 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    31156 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31157 File
    31158 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31159 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    31160 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    31161 exclude=exclude) 
    31162 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31163 File
    31164 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31165 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    31166 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    31167 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31168 File
    31169 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31170 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    31171 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    31172 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31173 File
    31174 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31175 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    31176 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    31177 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31178 File
    31179 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31180 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    31181 p = super().first_intercept(mxyz1, mxyz2) 
    31182 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31183 File
    31184 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31185 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    31186 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    31187 exclude=exclude) 
    31188 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31189 File
    31190 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31191 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    31192 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    31193 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31194 File
    31195 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31196 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    31197 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    31198 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31199 File
    31200 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31201 packages/chimerax/graphics/drawing.py", line 1108, in
    31202 _first_intercept_excluding_children 
    31203 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    31204 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31205 File
    31206 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31207 packages/chimerax/geometry/place.py", line 201, in inverse 
    31208 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    31209 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31210 File
    31211 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31212 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    31213 rinv[:, :] = matrix_inverse(r) 
    31214 ^^^^^^^^^^^^^^^^^ 
    31215 File
    31216 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31217 packages/numpy/linalg/linalg.py", line 561, in inv 
    31218 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    31219 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31220 File
    31221 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31222 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    31223 raise LinAlgError("Singular matrix") 
    31224 numpy.linalg.LinAlgError: Singular matrix 
    31225  
    31226 numpy.linalg.LinAlgError: Singular matrix 
    31227  
    31228 File
    31229 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31230 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    31231 raise LinAlgError("Singular matrix") 
    31232  
    31233 See log for complete Python traceback. 
    31234  
    31235 Traceback (most recent call last): 
    31236 File
    31237 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31238 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    31239 self.session.ui.mouse_modes.mouse_pause_tracking() 
    31240 File
    31241 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31242 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    31243 mouse_pause_tracking 
    31244 self._mouse_pause() 
    31245 File
    31246 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31247 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    31248 m.pause(self._mouse_pause_position) 
    31249 File
    31250 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31251 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    31252 p = self.view.picked_object(x, y) 
    31253 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31254 File
    31255 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31256 packages/chimerax/graphics/view.py", line 838, in picked_object 
    31257 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    31258 beyond, 
    31259 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31260 File
    31261 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31262 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    31263 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    31264 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31265 File
    31266 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31267 packages/chimerax/core/models.py", line 143, in first_intercept 
    31268 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    31269 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31270 File
    31271 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31272 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    31273 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    31274 exclude=exclude) 
    31275 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31276 File
    31277 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31278 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    31279 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    31280 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31281 File
    31282 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31283 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    31284 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    31285 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31286 File
    31287 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31288 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    31289 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    31290 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31291 File
    31292 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31293 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    31294 p = super().first_intercept(mxyz1, mxyz2) 
    31295 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31296 File
    31297 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31298 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    31299 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    31300 exclude=exclude) 
    31301 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31302 File
    31303 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31304 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    31305 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    31306 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31307 File
    31308 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31309 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    31310 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    31311 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31312 File
    31313 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31314 packages/chimerax/graphics/drawing.py", line 1108, in
    31315 _first_intercept_excluding_children 
    31316 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    31317 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31318 File
    31319 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31320 packages/chimerax/geometry/place.py", line 201, in inverse 
    31321 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    31322 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31323 File
    31324 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31325 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    31326 rinv[:, :] = matrix_inverse(r) 
    31327 ^^^^^^^^^^^^^^^^^ 
    31328 File
    31329 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31330 packages/numpy/linalg/linalg.py", line 561, in inv 
    31331 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    31332 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31333 File
    31334 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31335 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    31336 raise LinAlgError("Singular matrix") 
    31337 numpy.linalg.LinAlgError: Singular matrix 
    31338  
    31339 numpy.linalg.LinAlgError: Singular matrix 
    31340  
    31341 File
    31342 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31343 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    31344 raise LinAlgError("Singular matrix") 
    31345  
    31346 See log for complete Python traceback. 
    31347  
    31348 Traceback (most recent call last): 
    31349 File
    31350 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31351 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    31352 self.session.ui.mouse_modes.mouse_pause_tracking() 
    31353 File
    31354 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31355 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    31356 mouse_pause_tracking 
    31357 self._mouse_pause() 
    31358 File
    31359 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31360 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    31361 m.pause(self._mouse_pause_position) 
    31362 File
    31363 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31364 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    31365 p = self.view.picked_object(x, y) 
    31366 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31367 File
    31368 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31369 packages/chimerax/graphics/view.py", line 838, in picked_object 
    31370 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    31371 beyond, 
    31372 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31373 File
    31374 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31375 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    31376 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    31377 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31378 File
    31379 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31380 packages/chimerax/core/models.py", line 143, in first_intercept 
    31381 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    31382 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31383 File
    31384 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31385 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    31386 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    31387 exclude=exclude) 
    31388 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31389 File
    31390 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31391 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    31392 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    31393 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31394 File
    31395 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31396 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    31397 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    31398 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31399 File
    31400 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31401 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    31402 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    31403 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31404 File
    31405 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31406 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    31407 p = super().first_intercept(mxyz1, mxyz2) 
    31408 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31409 File
    31410 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31411 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    31412 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    31413 exclude=exclude) 
    31414 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31415 File
    31416 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31417 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    31418 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    31419 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31420 File
    31421 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31422 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    31423 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    31424 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31425 File
    31426 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31427 packages/chimerax/graphics/drawing.py", line 1108, in
    31428 _first_intercept_excluding_children 
    31429 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    31430 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31431 File
    31432 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31433 packages/chimerax/geometry/place.py", line 201, in inverse 
    31434 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    31435 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31436 File
    31437 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31438 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    31439 rinv[:, :] = matrix_inverse(r) 
    31440 ^^^^^^^^^^^^^^^^^ 
    31441 File
    31442 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31443 packages/numpy/linalg/linalg.py", line 561, in inv 
    31444 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    31445 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31446 File
    31447 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31448 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    31449 raise LinAlgError("Singular matrix") 
    31450 numpy.linalg.LinAlgError: Singular matrix 
    31451  
    31452 numpy.linalg.LinAlgError: Singular matrix 
    31453  
    31454 File
    31455 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31456 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    31457 raise LinAlgError("Singular matrix") 
    31458  
    31459 See log for complete Python traceback. 
    31460  
    31461 Traceback (most recent call last): 
    31462 File
    31463 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31464 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    31465 self.session.ui.mouse_modes.mouse_pause_tracking() 
    31466 File
    31467 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31468 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    31469 mouse_pause_tracking 
    31470 self._mouse_pause() 
    31471 File
    31472 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31473 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    31474 m.pause(self._mouse_pause_position) 
    31475 File
    31476 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31477 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    31478 p = self.view.picked_object(x, y) 
    31479 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31480 File
    31481 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31482 packages/chimerax/graphics/view.py", line 838, in picked_object 
    31483 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    31484 beyond, 
    31485 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31486 File
    31487 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31488 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    31489 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    31490 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31491 File
    31492 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31493 packages/chimerax/core/models.py", line 143, in first_intercept 
    31494 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    31495 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31496 File
    31497 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31498 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    31499 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    31500 exclude=exclude) 
    31501 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31502 File
    31503 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31504 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    31505 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    31506 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31507 File
    31508 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31509 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    31510 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    31511 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31512 File
    31513 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31514 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    31515 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    31516 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31517 File
    31518 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31519 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    31520 p = super().first_intercept(mxyz1, mxyz2) 
    31521 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31522 File
    31523 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31524 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    31525 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    31526 exclude=exclude) 
    31527 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31528 File
    31529 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31530 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    31531 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    31532 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31533 File
    31534 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31535 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    31536 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    31537 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31538 File
    31539 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31540 packages/chimerax/graphics/drawing.py", line 1108, in
    31541 _first_intercept_excluding_children 
    31542 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    31543 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31544 File
    31545 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31546 packages/chimerax/geometry/place.py", line 201, in inverse 
    31547 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    31548 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31549 File
    31550 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31551 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    31552 rinv[:, :] = matrix_inverse(r) 
    31553 ^^^^^^^^^^^^^^^^^ 
    31554 File
    31555 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31556 packages/numpy/linalg/linalg.py", line 561, in inv 
    31557 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    31558 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31559 File
    31560 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31561 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    31562 raise LinAlgError("Singular matrix") 
    31563 numpy.linalg.LinAlgError: Singular matrix 
    31564  
    31565 numpy.linalg.LinAlgError: Singular matrix 
    31566  
    31567 File
    31568 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31569 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    31570 raise LinAlgError("Singular matrix") 
    31571  
    31572 See log for complete Python traceback. 
    31573  
    31574 Traceback (most recent call last): 
    31575 File
    31576 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31577 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    31578 self.session.ui.mouse_modes.mouse_pause_tracking() 
    31579 File
    31580 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31581 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    31582 mouse_pause_tracking 
    31583 self._mouse_pause() 
    31584 File
    31585 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31586 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    31587 m.pause(self._mouse_pause_position) 
    31588 File
    31589 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31590 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    31591 p = self.view.picked_object(x, y) 
    31592 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31593 File
    31594 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31595 packages/chimerax/graphics/view.py", line 838, in picked_object 
    31596 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    31597 beyond, 
    31598 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31599 File
    31600 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31601 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    31602 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    31603 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31604 File
    31605 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31606 packages/chimerax/core/models.py", line 143, in first_intercept 
    31607 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    31608 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31609 File
    31610 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31611 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    31612 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    31613 exclude=exclude) 
    31614 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31615 File
    31616 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31617 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    31618 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    31619 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31620 File
    31621 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31622 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    31623 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    31624 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31625 File
    31626 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31627 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    31628 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    31629 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31630 File
    31631 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31632 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    31633 p = super().first_intercept(mxyz1, mxyz2) 
    31634 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31635 File
    31636 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31637 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    31638 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    31639 exclude=exclude) 
    31640 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31641 File
    31642 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31643 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    31644 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    31645 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31646 File
    31647 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31648 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    31649 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    31650 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31651 File
    31652 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31653 packages/chimerax/graphics/drawing.py", line 1108, in
    31654 _first_intercept_excluding_children 
    31655 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    31656 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31657 File
    31658 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31659 packages/chimerax/geometry/place.py", line 201, in inverse 
    31660 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    31661 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31662 File
    31663 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31664 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    31665 rinv[:, :] = matrix_inverse(r) 
    31666 ^^^^^^^^^^^^^^^^^ 
    31667 File
    31668 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31669 packages/numpy/linalg/linalg.py", line 561, in inv 
    31670 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    31671 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31672 File
    31673 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31674 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    31675 raise LinAlgError("Singular matrix") 
    31676 numpy.linalg.LinAlgError: Singular matrix 
    31677  
    31678 numpy.linalg.LinAlgError: Singular matrix 
    31679  
    31680 File
    31681 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31682 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    31683 raise LinAlgError("Singular matrix") 
    31684  
    31685 See log for complete Python traceback. 
    31686  
    31687 Traceback (most recent call last): 
    31688 File
    31689 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31690 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    31691 self.session.ui.mouse_modes.mouse_pause_tracking() 
    31692 File
    31693 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31694 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    31695 mouse_pause_tracking 
    31696 self._mouse_pause() 
    31697 File
    31698 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31699 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    31700 m.pause(self._mouse_pause_position) 
    31701 File
    31702 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31703 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    31704 p = self.view.picked_object(x, y) 
    31705 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31706 File
    31707 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31708 packages/chimerax/graphics/view.py", line 838, in picked_object 
    31709 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    31710 beyond, 
    31711 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31712 File
    31713 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31714 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    31715 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    31716 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31717 File
    31718 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31719 packages/chimerax/core/models.py", line 143, in first_intercept 
    31720 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    31721 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31722 File
    31723 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31724 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    31725 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    31726 exclude=exclude) 
    31727 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31728 File
    31729 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31730 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    31731 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    31732 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31733 File
    31734 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31735 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    31736 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    31737 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31738 File
    31739 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31740 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    31741 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    31742 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31743 File
    31744 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31745 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    31746 p = super().first_intercept(mxyz1, mxyz2) 
    31747 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31748 File
    31749 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31750 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    31751 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    31752 exclude=exclude) 
    31753 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31754 File
    31755 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31756 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    31757 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    31758 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31759 File
    31760 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31761 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    31762 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    31763 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31764 File
    31765 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31766 packages/chimerax/graphics/drawing.py", line 1108, in
    31767 _first_intercept_excluding_children 
    31768 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    31769 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31770 File
    31771 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31772 packages/chimerax/geometry/place.py", line 201, in inverse 
    31773 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    31774 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31775 File
    31776 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31777 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    31778 rinv[:, :] = matrix_inverse(r) 
    31779 ^^^^^^^^^^^^^^^^^ 
    31780 File
    31781 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31782 packages/numpy/linalg/linalg.py", line 561, in inv 
    31783 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    31784 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31785 File
    31786 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31787 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    31788 raise LinAlgError("Singular matrix") 
    31789 numpy.linalg.LinAlgError: Singular matrix 
    31790  
    31791 numpy.linalg.LinAlgError: Singular matrix 
    31792  
    31793 File
    31794 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31795 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    31796 raise LinAlgError("Singular matrix") 
    31797  
    31798 See log for complete Python traceback. 
    31799  
    31800 Traceback (most recent call last): 
    31801 File
    31802 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31803 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    31804 self.session.ui.mouse_modes.mouse_pause_tracking() 
    31805 File
    31806 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31807 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    31808 mouse_pause_tracking 
    31809 self._mouse_pause() 
    31810 File
    31811 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31812 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    31813 m.pause(self._mouse_pause_position) 
    31814 File
    31815 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31816 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    31817 p = self.view.picked_object(x, y) 
    31818 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31819 File
    31820 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31821 packages/chimerax/graphics/view.py", line 838, in picked_object 
    31822 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    31823 beyond, 
    31824 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31825 File
    31826 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31827 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    31828 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    31829 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31830 File
    31831 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31832 packages/chimerax/core/models.py", line 143, in first_intercept 
    31833 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    31834 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31835 File
    31836 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31837 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    31838 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    31839 exclude=exclude) 
    31840 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31841 File
    31842 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31843 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    31844 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    31845 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31846 File
    31847 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31848 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    31849 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    31850 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31851 File
    31852 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31853 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    31854 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    31855 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31856 File
    31857 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31858 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    31859 p = super().first_intercept(mxyz1, mxyz2) 
    31860 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31861 File
    31862 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31863 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    31864 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    31865 exclude=exclude) 
    31866 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31867 File
    31868 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31869 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    31870 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    31871 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31872 File
    31873 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31874 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    31875 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    31876 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31877 File
    31878 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31879 packages/chimerax/graphics/drawing.py", line 1108, in
    31880 _first_intercept_excluding_children 
    31881 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    31882 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31883 File
    31884 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31885 packages/chimerax/geometry/place.py", line 201, in inverse 
    31886 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    31887 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31888 File
    31889 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31890 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    31891 rinv[:, :] = matrix_inverse(r) 
    31892 ^^^^^^^^^^^^^^^^^ 
    31893 File
    31894 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31895 packages/numpy/linalg/linalg.py", line 561, in inv 
    31896 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    31897 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31898 File
    31899 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31900 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    31901 raise LinAlgError("Singular matrix") 
    31902 numpy.linalg.LinAlgError: Singular matrix 
    31903  
    31904 numpy.linalg.LinAlgError: Singular matrix 
    31905  
    31906 File
    31907 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31908 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    31909 raise LinAlgError("Singular matrix") 
    31910  
    31911 See log for complete Python traceback. 
    31912  
    31913 Traceback (most recent call last): 
    31914 File
    31915 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31916 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    31917 self.session.ui.mouse_modes.mouse_pause_tracking() 
    31918 File
    31919 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31920 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    31921 mouse_pause_tracking 
    31922 self._mouse_pause() 
    31923 File
    31924 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31925 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    31926 m.pause(self._mouse_pause_position) 
    31927 File
    31928 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31929 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    31930 p = self.view.picked_object(x, y) 
    31931 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31932 File
    31933 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31934 packages/chimerax/graphics/view.py", line 838, in picked_object 
    31935 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    31936 beyond, 
    31937 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31938 File
    31939 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31940 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    31941 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    31942 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31943 File
    31944 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31945 packages/chimerax/core/models.py", line 143, in first_intercept 
    31946 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    31947 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31948 File
    31949 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31950 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    31951 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    31952 exclude=exclude) 
    31953 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31954 File
    31955 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31956 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    31957 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    31958 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31959 File
    31960 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31961 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    31962 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    31963 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31964 File
    31965 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31966 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    31967 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    31968 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31969 File
    31970 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31971 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    31972 p = super().first_intercept(mxyz1, mxyz2) 
    31973 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31974 File
    31975 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31976 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    31977 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    31978 exclude=exclude) 
    31979 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31980 File
    31981 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31982 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    31983 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    31984 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31985 File
    31986 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31987 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    31988 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    31989 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31990 File
    31991 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31992 packages/chimerax/graphics/drawing.py", line 1108, in
    31993 _first_intercept_excluding_children 
    31994 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    31995 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    31996 File
    31997 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    31998 packages/chimerax/geometry/place.py", line 201, in inverse 
    31999 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    32000 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32001 File
    32002 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32003 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    32004 rinv[:, :] = matrix_inverse(r) 
    32005 ^^^^^^^^^^^^^^^^^ 
    32006 File
    32007 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32008 packages/numpy/linalg/linalg.py", line 561, in inv 
    32009 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    32010 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32011 File
    32012 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32013 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    32014 raise LinAlgError("Singular matrix") 
    32015 numpy.linalg.LinAlgError: Singular matrix 
    32016  
    32017 numpy.linalg.LinAlgError: Singular matrix 
    32018  
    32019 File
    32020 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32021 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    32022 raise LinAlgError("Singular matrix") 
    32023  
    32024 See log for complete Python traceback. 
    32025  
    32026 Traceback (most recent call last): 
    32027 File
    32028 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32029 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    32030 self.session.ui.mouse_modes.mouse_pause_tracking() 
    32031 File
    32032 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32033 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    32034 mouse_pause_tracking 
    32035 self._mouse_pause() 
    32036 File
    32037 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32038 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    32039 m.pause(self._mouse_pause_position) 
    32040 File
    32041 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32042 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    32043 p = self.view.picked_object(x, y) 
    32044 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32045 File
    32046 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32047 packages/chimerax/graphics/view.py", line 838, in picked_object 
    32048 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    32049 beyond, 
    32050 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32051 File
    32052 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32053 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    32054 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    32055 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32056 File
    32057 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32058 packages/chimerax/core/models.py", line 143, in first_intercept 
    32059 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    32060 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32061 File
    32062 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32063 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    32064 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    32065 exclude=exclude) 
    32066 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32067 File
    32068 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32069 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    32070 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    32071 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32072 File
    32073 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32074 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    32075 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    32076 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32077 File
    32078 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32079 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    32080 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    32081 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32082 File
    32083 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32084 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    32085 p = super().first_intercept(mxyz1, mxyz2) 
    32086 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32087 File
    32088 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32089 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    32090 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    32091 exclude=exclude) 
    32092 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32093 File
    32094 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32095 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    32096 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    32097 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32098 File
    32099 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32100 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    32101 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    32102 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32103 File
    32104 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32105 packages/chimerax/graphics/drawing.py", line 1108, in
    32106 _first_intercept_excluding_children 
    32107 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    32108 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32109 File
    32110 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32111 packages/chimerax/geometry/place.py", line 201, in inverse 
    32112 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    32113 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32114 File
    32115 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32116 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    32117 rinv[:, :] = matrix_inverse(r) 
    32118 ^^^^^^^^^^^^^^^^^ 
    32119 File
    32120 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32121 packages/numpy/linalg/linalg.py", line 561, in inv 
    32122 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    32123 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32124 File
    32125 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32126 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    32127 raise LinAlgError("Singular matrix") 
    32128 numpy.linalg.LinAlgError: Singular matrix 
    32129  
    32130 numpy.linalg.LinAlgError: Singular matrix 
    32131  
    32132 File
    32133 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32134 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    32135 raise LinAlgError("Singular matrix") 
    32136  
    32137 See log for complete Python traceback. 
    32138  
    32139 Traceback (most recent call last): 
    32140 File
    32141 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32142 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    32143 self.session.ui.mouse_modes.mouse_pause_tracking() 
    32144 File
    32145 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32146 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    32147 mouse_pause_tracking 
    32148 self._mouse_pause() 
    32149 File
    32150 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32151 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    32152 m.pause(self._mouse_pause_position) 
    32153 File
    32154 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32155 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    32156 p = self.view.picked_object(x, y) 
    32157 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32158 File
    32159 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32160 packages/chimerax/graphics/view.py", line 838, in picked_object 
    32161 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    32162 beyond, 
    32163 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32164 File
    32165 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32166 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    32167 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    32168 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32169 File
    32170 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32171 packages/chimerax/core/models.py", line 143, in first_intercept 
    32172 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    32173 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32174 File
    32175 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32176 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    32177 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    32178 exclude=exclude) 
    32179 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32180 File
    32181 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32182 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    32183 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    32184 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32185 File
    32186 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32187 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    32188 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    32189 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32190 File
    32191 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32192 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    32193 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    32194 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32195 File
    32196 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32197 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    32198 p = super().first_intercept(mxyz1, mxyz2) 
    32199 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32200 File
    32201 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32202 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    32203 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    32204 exclude=exclude) 
    32205 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32206 File
    32207 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32208 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    32209 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    32210 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32211 File
    32212 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32213 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    32214 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    32215 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32216 File
    32217 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32218 packages/chimerax/graphics/drawing.py", line 1108, in
    32219 _first_intercept_excluding_children 
    32220 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    32221 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32222 File
    32223 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32224 packages/chimerax/geometry/place.py", line 201, in inverse 
    32225 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    32226 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32227 File
    32228 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32229 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    32230 rinv[:, :] = matrix_inverse(r) 
    32231 ^^^^^^^^^^^^^^^^^ 
    32232 File
    32233 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32234 packages/numpy/linalg/linalg.py", line 561, in inv 
    32235 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    32236 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32237 File
    32238 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32239 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    32240 raise LinAlgError("Singular matrix") 
    32241 numpy.linalg.LinAlgError: Singular matrix 
    32242  
    32243 numpy.linalg.LinAlgError: Singular matrix 
    32244  
    32245 File
    32246 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32247 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    32248 raise LinAlgError("Singular matrix") 
    32249  
    32250 See log for complete Python traceback. 
    32251  
    32252 Traceback (most recent call last): 
    32253 File
    32254 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32255 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    32256 self.session.ui.mouse_modes.mouse_pause_tracking() 
    32257 File
    32258 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32259 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    32260 mouse_pause_tracking 
    32261 self._mouse_pause() 
    32262 File
    32263 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32264 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    32265 m.pause(self._mouse_pause_position) 
    32266 File
    32267 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32268 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    32269 p = self.view.picked_object(x, y) 
    32270 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32271 File
    32272 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32273 packages/chimerax/graphics/view.py", line 838, in picked_object 
    32274 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    32275 beyond, 
    32276 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32277 File
    32278 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32279 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    32280 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    32281 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32282 File
    32283 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32284 packages/chimerax/core/models.py", line 143, in first_intercept 
    32285 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    32286 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32287 File
    32288 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32289 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    32290 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    32291 exclude=exclude) 
    32292 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32293 File
    32294 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32295 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    32296 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    32297 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32298 File
    32299 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32300 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    32301 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    32302 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32303 File
    32304 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32305 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    32306 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    32307 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32308 File
    32309 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32310 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    32311 p = super().first_intercept(mxyz1, mxyz2) 
    32312 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32313 File
    32314 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32315 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    32316 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    32317 exclude=exclude) 
    32318 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32319 File
    32320 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32321 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    32322 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    32323 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32324 File
    32325 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32326 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    32327 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    32328 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32329 File
    32330 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32331 packages/chimerax/graphics/drawing.py", line 1108, in
    32332 _first_intercept_excluding_children 
    32333 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    32334 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32335 File
    32336 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32337 packages/chimerax/geometry/place.py", line 201, in inverse 
    32338 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    32339 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32340 File
    32341 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32342 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    32343 rinv[:, :] = matrix_inverse(r) 
    32344 ^^^^^^^^^^^^^^^^^ 
    32345 File
    32346 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32347 packages/numpy/linalg/linalg.py", line 561, in inv 
    32348 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    32349 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32350 File
    32351 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32352 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    32353 raise LinAlgError("Singular matrix") 
    32354 numpy.linalg.LinAlgError: Singular matrix 
    32355  
    32356 numpy.linalg.LinAlgError: Singular matrix 
    32357  
    32358 File
    32359 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32360 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    32361 raise LinAlgError("Singular matrix") 
    32362  
    32363 See log for complete Python traceback. 
    32364  
    32365 
    32366 > select add #5/B:463
    32367 
    32368 66 atoms, 57 bonds, 9 residues, 2 models selected 
    32369 
    32370 > select add #5/B:462
    32371 
    32372 74 atoms, 64 bonds, 10 residues, 2 models selected 
    32373 Traceback (most recent call last): 
    32374 File
    32375 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32376 packages/chimerax/mouse_modes/mousemodes.py", line 656, in <lambda> 
    32377 gw.mouseReleaseEvent = lambda e, s=self: s._dispatch_mouse_event(e,
    32378 "mouse_up") 
    32379 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32380 File
    32381 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32382 packages/chimerax/mouse_modes/mousemodes.py", line 556, in
    32383 _dispatch_mouse_event 
    32384 f(MouseEvent(event, modifiers=modifiers)) 
    32385 File
    32386 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32387 packages/chimerax/mouse_modes/std_modes.py", line 70, in mouse_up 
    32388 mouse_select(event, mode, self.session, self.view) 
    32389 File
    32390 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32391 packages/chimerax/mouse_modes/std_modes.py", line 209, in mouse_select 
    32392 pick = view.picked_object(x, y) 
    32393 ^^^^^^^^^^^^^^^^^^^^^^^^ 
    32394 File
    32395 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32396 packages/chimerax/graphics/view.py", line 838, in picked_object 
    32397 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    32398 beyond, 
    32399 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32400 File
    32401 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32402 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    32403 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    32404 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32405 File
    32406 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32407 packages/chimerax/core/models.py", line 143, in first_intercept 
    32408 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    32409 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32410 File
    32411 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32412 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    32413 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    32414 exclude=exclude) 
    32415 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32416 File
    32417 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32418 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    32419 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    32420 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32421 File
    32422 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32423 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    32424 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    32425 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32426 File
    32427 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32428 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    32429 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    32430 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32431 File
    32432 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32433 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    32434 p = super().first_intercept(mxyz1, mxyz2) 
    32435 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32436 File
    32437 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32438 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    32439 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    32440 exclude=exclude) 
    32441 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32442 File
    32443 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32444 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    32445 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    32446 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32447 File
    32448 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32449 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    32450 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    32451 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32452 File
    32453 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32454 packages/chimerax/graphics/drawing.py", line 1108, in
    32455 _first_intercept_excluding_children 
    32456 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    32457 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32458 File
    32459 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32460 packages/chimerax/geometry/place.py", line 201, in inverse 
    32461 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    32462 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32463 File
    32464 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32465 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    32466 rinv[:, :] = matrix_inverse(r) 
    32467 ^^^^^^^^^^^^^^^^^ 
    32468 File
    32469 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32470 packages/numpy/linalg/linalg.py", line 561, in inv 
    32471 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    32472 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32473 File
    32474 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32475 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    32476 raise LinAlgError("Singular matrix") 
    32477 numpy.linalg.LinAlgError: Singular matrix 
    32478  
    32479 numpy.linalg.LinAlgError: Singular matrix 
    32480  
    32481 File
    32482 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32483 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    32484 raise LinAlgError("Singular matrix") 
    32485  
    32486 See log for complete Python traceback. 
    32487  
    32488 Traceback (most recent call last): 
    32489 File
    32490 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32491 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    32492 self.session.ui.mouse_modes.mouse_pause_tracking() 
    32493 File
    32494 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32495 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    32496 mouse_pause_tracking 
    32497 self._mouse_pause() 
    32498 File
    32499 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32500 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    32501 m.pause(self._mouse_pause_position) 
    32502 File
    32503 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32504 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    32505 p = self.view.picked_object(x, y) 
    32506 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32507 File
    32508 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32509 packages/chimerax/graphics/view.py", line 838, in picked_object 
    32510 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    32511 beyond, 
    32512 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32513 File
    32514 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32515 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    32516 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    32517 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32518 File
    32519 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32520 packages/chimerax/core/models.py", line 143, in first_intercept 
    32521 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    32522 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32523 File
    32524 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32525 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    32526 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    32527 exclude=exclude) 
    32528 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32529 File
    32530 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32531 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    32532 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    32533 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32534 File
    32535 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32536 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    32537 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    32538 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32539 File
    32540 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32541 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    32542 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    32543 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32544 File
    32545 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32546 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    32547 p = super().first_intercept(mxyz1, mxyz2) 
    32548 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32549 File
    32550 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32551 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    32552 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    32553 exclude=exclude) 
    32554 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32555 File
    32556 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32557 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    32558 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    32559 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32560 File
    32561 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32562 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    32563 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    32564 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32565 File
    32566 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32567 packages/chimerax/graphics/drawing.py", line 1108, in
    32568 _first_intercept_excluding_children 
    32569 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    32570 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32571 File
    32572 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32573 packages/chimerax/geometry/place.py", line 201, in inverse 
    32574 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    32575 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32576 File
    32577 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32578 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    32579 rinv[:, :] = matrix_inverse(r) 
    32580 ^^^^^^^^^^^^^^^^^ 
    32581 File
    32582 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32583 packages/numpy/linalg/linalg.py", line 561, in inv 
    32584 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    32585 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32586 File
    32587 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32588 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    32589 raise LinAlgError("Singular matrix") 
    32590 numpy.linalg.LinAlgError: Singular matrix 
    32591  
    32592 numpy.linalg.LinAlgError: Singular matrix 
    32593  
    32594 File
    32595 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32596 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    32597 raise LinAlgError("Singular matrix") 
    32598  
    32599 See log for complete Python traceback. 
    32600  
    32601 Traceback (most recent call last): 
    32602 File
    32603 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32604 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    32605 self.session.ui.mouse_modes.mouse_pause_tracking() 
    32606 File
    32607 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32608 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    32609 mouse_pause_tracking 
    32610 self._mouse_pause() 
    32611 File
    32612 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32613 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    32614 m.pause(self._mouse_pause_position) 
    32615 File
    32616 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32617 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    32618 p = self.view.picked_object(x, y) 
    32619 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32620 File
    32621 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32622 packages/chimerax/graphics/view.py", line 838, in picked_object 
    32623 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    32624 beyond, 
    32625 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32626 File
    32627 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32628 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    32629 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    32630 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32631 File
    32632 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32633 packages/chimerax/core/models.py", line 143, in first_intercept 
    32634 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    32635 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32636 File
    32637 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32638 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    32639 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    32640 exclude=exclude) 
    32641 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32642 File
    32643 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32644 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    32645 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    32646 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32647 File
    32648 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32649 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    32650 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    32651 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32652 File
    32653 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32654 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    32655 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    32656 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32657 File
    32658 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32659 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    32660 p = super().first_intercept(mxyz1, mxyz2) 
    32661 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32662 File
    32663 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32664 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    32665 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    32666 exclude=exclude) 
    32667 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32668 File
    32669 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32670 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    32671 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    32672 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32673 File
    32674 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32675 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    32676 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    32677 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32678 File
    32679 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32680 packages/chimerax/graphics/drawing.py", line 1108, in
    32681 _first_intercept_excluding_children 
    32682 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    32683 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32684 File
    32685 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32686 packages/chimerax/geometry/place.py", line 201, in inverse 
    32687 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    32688 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32689 File
    32690 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32691 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    32692 rinv[:, :] = matrix_inverse(r) 
    32693 ^^^^^^^^^^^^^^^^^ 
    32694 File
    32695 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32696 packages/numpy/linalg/linalg.py", line 561, in inv 
    32697 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    32698 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32699 File
    32700 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32701 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    32702 raise LinAlgError("Singular matrix") 
    32703 numpy.linalg.LinAlgError: Singular matrix 
    32704  
    32705 numpy.linalg.LinAlgError: Singular matrix 
    32706  
    32707 File
    32708 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32709 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    32710 raise LinAlgError("Singular matrix") 
    32711  
    32712 See log for complete Python traceback. 
    32713  
    32714 Traceback (most recent call last): 
    32715 File
    32716 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32717 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    32718 self.session.ui.mouse_modes.mouse_pause_tracking() 
    32719 File
    32720 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32721 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    32722 mouse_pause_tracking 
    32723 self._mouse_pause() 
    32724 File
    32725 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32726 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    32727 m.pause(self._mouse_pause_position) 
    32728 File
    32729 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32730 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    32731 p = self.view.picked_object(x, y) 
    32732 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32733 File
    32734 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32735 packages/chimerax/graphics/view.py", line 838, in picked_object 
    32736 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    32737 beyond, 
    32738 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32739 File
    32740 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32741 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    32742 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    32743 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32744 File
    32745 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32746 packages/chimerax/core/models.py", line 143, in first_intercept 
    32747 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    32748 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32749 File
    32750 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32751 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    32752 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    32753 exclude=exclude) 
    32754 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32755 File
    32756 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32757 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    32758 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    32759 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32760 File
    32761 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32762 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    32763 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    32764 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32765 File
    32766 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32767 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    32768 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    32769 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32770 File
    32771 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32772 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    32773 p = super().first_intercept(mxyz1, mxyz2) 
    32774 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32775 File
    32776 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32777 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    32778 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    32779 exclude=exclude) 
    32780 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32781 File
    32782 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32783 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    32784 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    32785 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32786 File
    32787 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32788 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    32789 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    32790 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32791 File
    32792 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32793 packages/chimerax/graphics/drawing.py", line 1108, in
    32794 _first_intercept_excluding_children 
    32795 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    32796 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32797 File
    32798 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32799 packages/chimerax/geometry/place.py", line 201, in inverse 
    32800 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    32801 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32802 File
    32803 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32804 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    32805 rinv[:, :] = matrix_inverse(r) 
    32806 ^^^^^^^^^^^^^^^^^ 
    32807 File
    32808 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32809 packages/numpy/linalg/linalg.py", line 561, in inv 
    32810 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    32811 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32812 File
    32813 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32814 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    32815 raise LinAlgError("Singular matrix") 
    32816 numpy.linalg.LinAlgError: Singular matrix 
    32817  
    32818 numpy.linalg.LinAlgError: Singular matrix 
    32819  
    32820 File
    32821 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32822 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    32823 raise LinAlgError("Singular matrix") 
    32824  
    32825 See log for complete Python traceback. 
    32826  
    32827 Traceback (most recent call last): 
    32828 File
    32829 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32830 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    32831 self.session.ui.mouse_modes.mouse_pause_tracking() 
    32832 File
    32833 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32834 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    32835 mouse_pause_tracking 
    32836 self._mouse_pause() 
    32837 File
    32838 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32839 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    32840 m.pause(self._mouse_pause_position) 
    32841 File
    32842 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32843 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    32844 p = self.view.picked_object(x, y) 
    32845 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32846 File
    32847 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32848 packages/chimerax/graphics/view.py", line 838, in picked_object 
    32849 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    32850 beyond, 
    32851 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32852 File
    32853 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32854 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    32855 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    32856 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32857 File
    32858 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32859 packages/chimerax/core/models.py", line 143, in first_intercept 
    32860 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    32861 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32862 File
    32863 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32864 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    32865 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    32866 exclude=exclude) 
    32867 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32868 File
    32869 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32870 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    32871 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    32872 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32873 File
    32874 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32875 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    32876 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    32877 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32878 File
    32879 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32880 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    32881 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    32882 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32883 File
    32884 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32885 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    32886 p = super().first_intercept(mxyz1, mxyz2) 
    32887 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32888 File
    32889 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32890 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    32891 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    32892 exclude=exclude) 
    32893 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32894 File
    32895 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32896 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    32897 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    32898 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32899 File
    32900 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32901 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    32902 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    32903 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32904 File
    32905 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32906 packages/chimerax/graphics/drawing.py", line 1108, in
    32907 _first_intercept_excluding_children 
    32908 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    32909 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32910 File
    32911 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32912 packages/chimerax/geometry/place.py", line 201, in inverse 
    32913 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    32914 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32915 File
    32916 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32917 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    32918 rinv[:, :] = matrix_inverse(r) 
    32919 ^^^^^^^^^^^^^^^^^ 
    32920 File
    32921 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32922 packages/numpy/linalg/linalg.py", line 561, in inv 
    32923 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    32924 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32925 File
    32926 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32927 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    32928 raise LinAlgError("Singular matrix") 
    32929 numpy.linalg.LinAlgError: Singular matrix 
    32930  
    32931 numpy.linalg.LinAlgError: Singular matrix 
    32932  
    32933 File
    32934 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32935 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    32936 raise LinAlgError("Singular matrix") 
    32937  
    32938 See log for complete Python traceback. 
    32939  
    32940 Traceback (most recent call last): 
    32941 File
    32942 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32943 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    32944 self.session.ui.mouse_modes.mouse_pause_tracking() 
    32945 File
    32946 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32947 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    32948 mouse_pause_tracking 
    32949 self._mouse_pause() 
    32950 File
    32951 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32952 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    32953 m.pause(self._mouse_pause_position) 
    32954 File
    32955 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32956 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    32957 p = self.view.picked_object(x, y) 
    32958 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32959 File
    32960 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32961 packages/chimerax/graphics/view.py", line 838, in picked_object 
    32962 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    32963 beyond, 
    32964 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32965 File
    32966 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32967 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    32968 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    32969 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32970 File
    32971 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32972 packages/chimerax/core/models.py", line 143, in first_intercept 
    32973 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    32974 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32975 File
    32976 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32977 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    32978 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    32979 exclude=exclude) 
    32980 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32981 File
    32982 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32983 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    32984 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    32985 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32986 File
    32987 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32988 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    32989 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    32990 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32991 File
    32992 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32993 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    32994 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    32995 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    32996 File
    32997 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    32998 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    32999 p = super().first_intercept(mxyz1, mxyz2) 
    33000 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33001 File
    33002 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33003 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    33004 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    33005 exclude=exclude) 
    33006 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33007 File
    33008 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33009 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    33010 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    33011 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33012 File
    33013 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33014 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    33015 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    33016 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33017 File
    33018 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33019 packages/chimerax/graphics/drawing.py", line 1108, in
    33020 _first_intercept_excluding_children 
    33021 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    33022 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33023 File
    33024 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33025 packages/chimerax/geometry/place.py", line 201, in inverse 
    33026 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    33027 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33028 File
    33029 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33030 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    33031 rinv[:, :] = matrix_inverse(r) 
    33032 ^^^^^^^^^^^^^^^^^ 
    33033 File
    33034 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33035 packages/numpy/linalg/linalg.py", line 561, in inv 
    33036 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    33037 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33038 File
    33039 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33040 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    33041 raise LinAlgError("Singular matrix") 
    33042 numpy.linalg.LinAlgError: Singular matrix 
    33043  
    33044 numpy.linalg.LinAlgError: Singular matrix 
    33045  
    33046 File
    33047 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33048 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    33049 raise LinAlgError("Singular matrix") 
    33050  
    33051 See log for complete Python traceback. 
    33052  
    33053 Traceback (most recent call last): 
    33054 File
    33055 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33056 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    33057 self.session.ui.mouse_modes.mouse_pause_tracking() 
    33058 File
    33059 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33060 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    33061 mouse_pause_tracking 
    33062 self._mouse_pause() 
    33063 File
    33064 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33065 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    33066 m.pause(self._mouse_pause_position) 
    33067 File
    33068 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33069 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    33070 p = self.view.picked_object(x, y) 
    33071 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33072 File
    33073 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33074 packages/chimerax/graphics/view.py", line 838, in picked_object 
    33075 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    33076 beyond, 
    33077 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33078 File
    33079 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33080 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    33081 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    33082 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33083 File
    33084 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33085 packages/chimerax/core/models.py", line 143, in first_intercept 
    33086 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    33087 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33088 File
    33089 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33090 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    33091 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    33092 exclude=exclude) 
    33093 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33094 File
    33095 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33096 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    33097 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    33098 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33099 File
    33100 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33101 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    33102 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    33103 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33104 File
    33105 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33106 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    33107 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    33108 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33109 File
    33110 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33111 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    33112 p = super().first_intercept(mxyz1, mxyz2) 
    33113 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33114 File
    33115 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33116 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    33117 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    33118 exclude=exclude) 
    33119 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33120 File
    33121 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33122 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    33123 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    33124 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33125 File
    33126 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33127 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    33128 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    33129 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33130 File
    33131 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33132 packages/chimerax/graphics/drawing.py", line 1108, in
    33133 _first_intercept_excluding_children 
    33134 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    33135 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33136 File
    33137 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33138 packages/chimerax/geometry/place.py", line 201, in inverse 
    33139 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    33140 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33141 File
    33142 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33143 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    33144 rinv[:, :] = matrix_inverse(r) 
    33145 ^^^^^^^^^^^^^^^^^ 
    33146 File
    33147 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33148 packages/numpy/linalg/linalg.py", line 561, in inv 
    33149 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    33150 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33151 File
    33152 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33153 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    33154 raise LinAlgError("Singular matrix") 
    33155 numpy.linalg.LinAlgError: Singular matrix 
    33156  
    33157 numpy.linalg.LinAlgError: Singular matrix 
    33158  
    33159 File
    33160 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33161 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    33162 raise LinAlgError("Singular matrix") 
    33163  
    33164 See log for complete Python traceback. 
    33165  
    33166 Traceback (most recent call last): 
    33167 File
    33168 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33169 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    33170 self.session.ui.mouse_modes.mouse_pause_tracking() 
    33171 File
    33172 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33173 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    33174 mouse_pause_tracking 
    33175 self._mouse_pause() 
    33176 File
    33177 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33178 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    33179 m.pause(self._mouse_pause_position) 
    33180 File
    33181 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33182 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    33183 p = self.view.picked_object(x, y) 
    33184 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33185 File
    33186 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33187 packages/chimerax/graphics/view.py", line 838, in picked_object 
    33188 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    33189 beyond, 
    33190 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33191 File
    33192 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33193 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    33194 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    33195 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33196 File
    33197 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33198 packages/chimerax/core/models.py", line 143, in first_intercept 
    33199 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    33200 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33201 File
    33202 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33203 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    33204 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    33205 exclude=exclude) 
    33206 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33207 File
    33208 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33209 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    33210 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    33211 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33212 File
    33213 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33214 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    33215 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    33216 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33217 File
    33218 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33219 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    33220 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    33221 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33222 File
    33223 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33224 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    33225 p = super().first_intercept(mxyz1, mxyz2) 
    33226 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33227 File
    33228 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33229 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    33230 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    33231 exclude=exclude) 
    33232 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33233 File
    33234 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33235 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    33236 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    33237 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33238 File
    33239 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33240 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    33241 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    33242 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33243 File
    33244 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33245 packages/chimerax/graphics/drawing.py", line 1108, in
    33246 _first_intercept_excluding_children 
    33247 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    33248 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33249 File
    33250 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33251 packages/chimerax/geometry/place.py", line 201, in inverse 
    33252 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    33253 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33254 File
    33255 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33256 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    33257 rinv[:, :] = matrix_inverse(r) 
    33258 ^^^^^^^^^^^^^^^^^ 
    33259 File
    33260 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33261 packages/numpy/linalg/linalg.py", line 561, in inv 
    33262 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    33263 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33264 File
    33265 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33266 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    33267 raise LinAlgError("Singular matrix") 
    33268 numpy.linalg.LinAlgError: Singular matrix 
    33269  
    33270 numpy.linalg.LinAlgError: Singular matrix 
    33271  
    33272 File
    33273 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33274 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    33275 raise LinAlgError("Singular matrix") 
    33276  
    33277 See log for complete Python traceback. 
    33278  
    33279 Traceback (most recent call last): 
    33280 File
    33281 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33282 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    33283 self.session.ui.mouse_modes.mouse_pause_tracking() 
    33284 File
    33285 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33286 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    33287 mouse_pause_tracking 
    33288 self._mouse_pause() 
    33289 File
    33290 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33291 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    33292 m.pause(self._mouse_pause_position) 
    33293 File
    33294 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33295 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    33296 p = self.view.picked_object(x, y) 
    33297 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33298 File
    33299 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33300 packages/chimerax/graphics/view.py", line 838, in picked_object 
    33301 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    33302 beyond, 
    33303 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33304 File
    33305 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33306 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    33307 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    33308 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33309 File
    33310 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33311 packages/chimerax/core/models.py", line 143, in first_intercept 
    33312 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    33313 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33314 File
    33315 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33316 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    33317 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    33318 exclude=exclude) 
    33319 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33320 File
    33321 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33322 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    33323 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    33324 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33325 File
    33326 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33327 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    33328 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    33329 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33330 File
    33331 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33332 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    33333 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    33334 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33335 File
    33336 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33337 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    33338 p = super().first_intercept(mxyz1, mxyz2) 
    33339 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33340 File
    33341 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33342 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    33343 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    33344 exclude=exclude) 
    33345 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33346 File
    33347 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33348 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    33349 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    33350 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33351 File
    33352 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33353 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    33354 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    33355 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33356 File
    33357 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33358 packages/chimerax/graphics/drawing.py", line 1108, in
    33359 _first_intercept_excluding_children 
    33360 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    33361 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33362 File
    33363 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33364 packages/chimerax/geometry/place.py", line 201, in inverse 
    33365 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    33366 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33367 File
    33368 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33369 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    33370 rinv[:, :] = matrix_inverse(r) 
    33371 ^^^^^^^^^^^^^^^^^ 
    33372 File
    33373 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33374 packages/numpy/linalg/linalg.py", line 561, in inv 
    33375 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    33376 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33377 File
    33378 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33379 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    33380 raise LinAlgError("Singular matrix") 
    33381 numpy.linalg.LinAlgError: Singular matrix 
    33382  
    33383 numpy.linalg.LinAlgError: Singular matrix 
    33384  
    33385 File
    33386 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33387 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    33388 raise LinAlgError("Singular matrix") 
    33389  
    33390 See log for complete Python traceback. 
    33391  
    33392 Traceback (most recent call last): 
    33393 File
    33394 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33395 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    33396 self.session.ui.mouse_modes.mouse_pause_tracking() 
    33397 File
    33398 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33399 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    33400 mouse_pause_tracking 
    33401 self._mouse_pause() 
    33402 File
    33403 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33404 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    33405 m.pause(self._mouse_pause_position) 
    33406 File
    33407 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33408 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    33409 p = self.view.picked_object(x, y) 
    33410 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33411 File
    33412 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33413 packages/chimerax/graphics/view.py", line 838, in picked_object 
    33414 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    33415 beyond, 
    33416 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33417 File
    33418 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33419 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    33420 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    33421 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33422 File
    33423 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33424 packages/chimerax/core/models.py", line 143, in first_intercept 
    33425 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    33426 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33427 File
    33428 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33429 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    33430 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    33431 exclude=exclude) 
    33432 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33433 File
    33434 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33435 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    33436 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    33437 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33438 File
    33439 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33440 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    33441 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    33442 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33443 File
    33444 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33445 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    33446 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    33447 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33448 File
    33449 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33450 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    33451 p = super().first_intercept(mxyz1, mxyz2) 
    33452 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33453 File
    33454 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33455 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    33456 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    33457 exclude=exclude) 
    33458 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33459 File
    33460 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33461 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    33462 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    33463 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33464 File
    33465 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33466 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    33467 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    33468 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33469 File
    33470 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33471 packages/chimerax/graphics/drawing.py", line 1108, in
    33472 _first_intercept_excluding_children 
    33473 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    33474 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33475 File
    33476 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33477 packages/chimerax/geometry/place.py", line 201, in inverse 
    33478 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    33479 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33480 File
    33481 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33482 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    33483 rinv[:, :] = matrix_inverse(r) 
    33484 ^^^^^^^^^^^^^^^^^ 
    33485 File
    33486 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33487 packages/numpy/linalg/linalg.py", line 561, in inv 
    33488 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    33489 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33490 File
    33491 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33492 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    33493 raise LinAlgError("Singular matrix") 
    33494 numpy.linalg.LinAlgError: Singular matrix 
    33495  
    33496 numpy.linalg.LinAlgError: Singular matrix 
    33497  
    33498 File
    33499 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33500 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    33501 raise LinAlgError("Singular matrix") 
    33502  
    33503 See log for complete Python traceback. 
    33504  
    33505 Traceback (most recent call last): 
    33506 File
    33507 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33508 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    33509 self.session.ui.mouse_modes.mouse_pause_tracking() 
    33510 File
    33511 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33512 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    33513 mouse_pause_tracking 
    33514 self._mouse_pause() 
    33515 File
    33516 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33517 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    33518 m.pause(self._mouse_pause_position) 
    33519 File
    33520 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33521 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    33522 p = self.view.picked_object(x, y) 
    33523 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33524 File
    33525 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33526 packages/chimerax/graphics/view.py", line 838, in picked_object 
    33527 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    33528 beyond, 
    33529 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33530 File
    33531 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33532 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    33533 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    33534 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33535 File
    33536 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33537 packages/chimerax/core/models.py", line 143, in first_intercept 
    33538 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    33539 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33540 File
    33541 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33542 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    33543 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    33544 exclude=exclude) 
    33545 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33546 File
    33547 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33548 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    33549 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    33550 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33551 File
    33552 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33553 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    33554 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    33555 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33556 File
    33557 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33558 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    33559 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    33560 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33561 File
    33562 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33563 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    33564 p = super().first_intercept(mxyz1, mxyz2) 
    33565 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33566 File
    33567 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33568 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    33569 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    33570 exclude=exclude) 
    33571 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33572 File
    33573 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33574 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    33575 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    33576 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33577 File
    33578 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33579 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    33580 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    33581 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33582 File
    33583 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33584 packages/chimerax/graphics/drawing.py", line 1108, in
    33585 _first_intercept_excluding_children 
    33586 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    33587 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33588 File
    33589 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33590 packages/chimerax/geometry/place.py", line 201, in inverse 
    33591 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    33592 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33593 File
    33594 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33595 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    33596 rinv[:, :] = matrix_inverse(r) 
    33597 ^^^^^^^^^^^^^^^^^ 
    33598 File
    33599 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33600 packages/numpy/linalg/linalg.py", line 561, in inv 
    33601 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    33602 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33603 File
    33604 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33605 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    33606 raise LinAlgError("Singular matrix") 
    33607 numpy.linalg.LinAlgError: Singular matrix 
    33608  
    33609 numpy.linalg.LinAlgError: Singular matrix 
    33610  
    33611 File
    33612 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33613 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    33614 raise LinAlgError("Singular matrix") 
    33615  
    33616 See log for complete Python traceback. 
    33617  
    33618 Traceback (most recent call last): 
    33619 File
    33620 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33621 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    33622 self.session.ui.mouse_modes.mouse_pause_tracking() 
    33623 File
    33624 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33625 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    33626 mouse_pause_tracking 
    33627 self._mouse_pause() 
    33628 File
    33629 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33630 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    33631 m.pause(self._mouse_pause_position) 
    33632 File
    33633 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33634 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    33635 p = self.view.picked_object(x, y) 
    33636 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33637 File
    33638 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33639 packages/chimerax/graphics/view.py", line 838, in picked_object 
    33640 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    33641 beyond, 
    33642 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33643 File
    33644 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33645 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    33646 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    33647 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33648 File
    33649 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33650 packages/chimerax/core/models.py", line 143, in first_intercept 
    33651 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    33652 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33653 File
    33654 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33655 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    33656 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    33657 exclude=exclude) 
    33658 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33659 File
    33660 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33661 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    33662 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    33663 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33664 File
    33665 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33666 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    33667 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    33668 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33669 File
    33670 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33671 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    33672 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    33673 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33674 File
    33675 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33676 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    33677 p = super().first_intercept(mxyz1, mxyz2) 
    33678 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33679 File
    33680 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33681 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    33682 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    33683 exclude=exclude) 
    33684 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33685 File
    33686 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33687 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    33688 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    33689 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33690 File
    33691 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33692 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    33693 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    33694 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33695 File
    33696 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33697 packages/chimerax/graphics/drawing.py", line 1108, in
    33698 _first_intercept_excluding_children 
    33699 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    33700 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33701 File
    33702 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33703 packages/chimerax/geometry/place.py", line 201, in inverse 
    33704 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    33705 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33706 File
    33707 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33708 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    33709 rinv[:, :] = matrix_inverse(r) 
    33710 ^^^^^^^^^^^^^^^^^ 
    33711 File
    33712 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33713 packages/numpy/linalg/linalg.py", line 561, in inv 
    33714 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    33715 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33716 File
    33717 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33718 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    33719 raise LinAlgError("Singular matrix") 
    33720 numpy.linalg.LinAlgError: Singular matrix 
    33721  
    33722 numpy.linalg.LinAlgError: Singular matrix 
    33723  
    33724 File
    33725 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33726 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    33727 raise LinAlgError("Singular matrix") 
    33728  
    33729 See log for complete Python traceback. 
    33730  
    33731 Traceback (most recent call last): 
    33732 File
    33733 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33734 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    33735 self.session.ui.mouse_modes.mouse_pause_tracking() 
    33736 File
    33737 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33738 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    33739 mouse_pause_tracking 
    33740 self._mouse_pause() 
    33741 File
    33742 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33743 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    33744 m.pause(self._mouse_pause_position) 
    33745 File
    33746 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33747 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    33748 p = self.view.picked_object(x, y) 
    33749 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33750 File
    33751 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33752 packages/chimerax/graphics/view.py", line 838, in picked_object 
    33753 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    33754 beyond, 
    33755 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33756 File
    33757 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33758 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    33759 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    33760 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33761 File
    33762 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33763 packages/chimerax/core/models.py", line 143, in first_intercept 
    33764 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    33765 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33766 File
    33767 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33768 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    33769 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    33770 exclude=exclude) 
    33771 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33772 File
    33773 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33774 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    33775 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    33776 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33777 File
    33778 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33779 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    33780 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    33781 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33782 File
    33783 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33784 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    33785 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    33786 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33787 File
    33788 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33789 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    33790 p = super().first_intercept(mxyz1, mxyz2) 
    33791 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33792 File
    33793 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33794 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    33795 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    33796 exclude=exclude) 
    33797 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33798 File
    33799 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33800 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    33801 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    33802 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33803 File
    33804 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33805 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    33806 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    33807 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33808 File
    33809 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33810 packages/chimerax/graphics/drawing.py", line 1108, in
    33811 _first_intercept_excluding_children 
    33812 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    33813 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33814 File
    33815 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33816 packages/chimerax/geometry/place.py", line 201, in inverse 
    33817 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    33818 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33819 File
    33820 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33821 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    33822 rinv[:, :] = matrix_inverse(r) 
    33823 ^^^^^^^^^^^^^^^^^ 
    33824 File
    33825 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33826 packages/numpy/linalg/linalg.py", line 561, in inv 
    33827 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    33828 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33829 File
    33830 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33831 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    33832 raise LinAlgError("Singular matrix") 
    33833 numpy.linalg.LinAlgError: Singular matrix 
    33834  
    33835 numpy.linalg.LinAlgError: Singular matrix 
    33836  
    33837 File
    33838 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33839 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    33840 raise LinAlgError("Singular matrix") 
    33841  
    33842 See log for complete Python traceback. 
    33843  
    33844 Traceback (most recent call last): 
    33845 File
    33846 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33847 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    33848 self.session.ui.mouse_modes.mouse_pause_tracking() 
    33849 File
    33850 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33851 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    33852 mouse_pause_tracking 
    33853 self._mouse_pause() 
    33854 File
    33855 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33856 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    33857 m.pause(self._mouse_pause_position) 
    33858 File
    33859 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33860 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    33861 p = self.view.picked_object(x, y) 
    33862 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33863 File
    33864 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33865 packages/chimerax/graphics/view.py", line 838, in picked_object 
    33866 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    33867 beyond, 
    33868 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33869 File
    33870 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33871 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    33872 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    33873 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33874 File
    33875 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33876 packages/chimerax/core/models.py", line 143, in first_intercept 
    33877 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    33878 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33879 File
    33880 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33881 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    33882 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    33883 exclude=exclude) 
    33884 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33885 File
    33886 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33887 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    33888 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    33889 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33890 File
    33891 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33892 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    33893 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    33894 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33895 File
    33896 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33897 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    33898 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    33899 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33900 File
    33901 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33902 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    33903 p = super().first_intercept(mxyz1, mxyz2) 
    33904 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33905 File
    33906 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33907 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    33908 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    33909 exclude=exclude) 
    33910 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33911 File
    33912 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33913 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    33914 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    33915 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33916 File
    33917 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33918 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    33919 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    33920 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33921 File
    33922 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33923 packages/chimerax/graphics/drawing.py", line 1108, in
    33924 _first_intercept_excluding_children 
    33925 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    33926 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33927 File
    33928 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33929 packages/chimerax/geometry/place.py", line 201, in inverse 
    33930 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    33931 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33932 File
    33933 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33934 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    33935 rinv[:, :] = matrix_inverse(r) 
    33936 ^^^^^^^^^^^^^^^^^ 
    33937 File
    33938 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33939 packages/numpy/linalg/linalg.py", line 561, in inv 
    33940 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    33941 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33942 File
    33943 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33944 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    33945 raise LinAlgError("Singular matrix") 
    33946 numpy.linalg.LinAlgError: Singular matrix 
    33947  
    33948 numpy.linalg.LinAlgError: Singular matrix 
    33949  
    33950 File
    33951 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33952 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    33953 raise LinAlgError("Singular matrix") 
    33954  
    33955 See log for complete Python traceback. 
    33956  
    33957 Traceback (most recent call last): 
    33958 File
    33959 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33960 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    33961 self.session.ui.mouse_modes.mouse_pause_tracking() 
    33962 File
    33963 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33964 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    33965 mouse_pause_tracking 
    33966 self._mouse_pause() 
    33967 File
    33968 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33969 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    33970 m.pause(self._mouse_pause_position) 
    33971 File
    33972 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33973 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    33974 p = self.view.picked_object(x, y) 
    33975 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33976 File
    33977 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33978 packages/chimerax/graphics/view.py", line 838, in picked_object 
    33979 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    33980 beyond, 
    33981 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33982 File
    33983 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33984 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    33985 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    33986 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33987 File
    33988 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33989 packages/chimerax/core/models.py", line 143, in first_intercept 
    33990 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    33991 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33992 File
    33993 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    33994 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    33995 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    33996 exclude=exclude) 
    33997 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    33998 File
    33999 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34000 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    34001 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    34002 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34003 File
    34004 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34005 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    34006 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    34007 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34008 File
    34009 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34010 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    34011 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    34012 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34013 File
    34014 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34015 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    34016 p = super().first_intercept(mxyz1, mxyz2) 
    34017 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34018 File
    34019 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34020 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    34021 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    34022 exclude=exclude) 
    34023 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34024 File
    34025 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34026 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    34027 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    34028 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34029 File
    34030 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34031 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    34032 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    34033 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34034 File
    34035 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34036 packages/chimerax/graphics/drawing.py", line 1108, in
    34037 _first_intercept_excluding_children 
    34038 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    34039 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34040 File
    34041 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34042 packages/chimerax/geometry/place.py", line 201, in inverse 
    34043 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    34044 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34045 File
    34046 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34047 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    34048 rinv[:, :] = matrix_inverse(r) 
    34049 ^^^^^^^^^^^^^^^^^ 
    34050 File
    34051 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34052 packages/numpy/linalg/linalg.py", line 561, in inv 
    34053 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    34054 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34055 File
    34056 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34057 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    34058 raise LinAlgError("Singular matrix") 
    34059 numpy.linalg.LinAlgError: Singular matrix 
    34060  
    34061 numpy.linalg.LinAlgError: Singular matrix 
    34062  
    34063 File
    34064 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34065 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    34066 raise LinAlgError("Singular matrix") 
    34067  
    34068 See log for complete Python traceback. 
    34069  
    34070 Traceback (most recent call last): 
    34071 File
    34072 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34073 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    34074 self.session.ui.mouse_modes.mouse_pause_tracking() 
    34075 File
    34076 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34077 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    34078 mouse_pause_tracking 
    34079 self._mouse_pause() 
    34080 File
    34081 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34082 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    34083 m.pause(self._mouse_pause_position) 
    34084 File
    34085 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34086 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    34087 p = self.view.picked_object(x, y) 
    34088 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34089 File
    34090 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34091 packages/chimerax/graphics/view.py", line 838, in picked_object 
    34092 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    34093 beyond, 
    34094 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34095 File
    34096 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34097 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    34098 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    34099 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34100 File
    34101 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34102 packages/chimerax/core/models.py", line 143, in first_intercept 
    34103 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    34104 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34105 File
    34106 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34107 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    34108 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    34109 exclude=exclude) 
    34110 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34111 File
    34112 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34113 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    34114 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    34115 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34116 File
    34117 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34118 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    34119 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    34120 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34121 File
    34122 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34123 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    34124 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    34125 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34126 File
    34127 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34128 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    34129 p = super().first_intercept(mxyz1, mxyz2) 
    34130 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34131 File
    34132 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34133 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    34134 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    34135 exclude=exclude) 
    34136 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34137 File
    34138 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34139 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    34140 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    34141 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34142 File
    34143 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34144 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    34145 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    34146 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34147 File
    34148 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34149 packages/chimerax/graphics/drawing.py", line 1108, in
    34150 _first_intercept_excluding_children 
    34151 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    34152 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34153 File
    34154 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34155 packages/chimerax/geometry/place.py", line 201, in inverse 
    34156 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    34157 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34158 File
    34159 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34160 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    34161 rinv[:, :] = matrix_inverse(r) 
    34162 ^^^^^^^^^^^^^^^^^ 
    34163 File
    34164 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34165 packages/numpy/linalg/linalg.py", line 561, in inv 
    34166 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    34167 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34168 File
    34169 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34170 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    34171 raise LinAlgError("Singular matrix") 
    34172 numpy.linalg.LinAlgError: Singular matrix 
    34173  
    34174 numpy.linalg.LinAlgError: Singular matrix 
    34175  
    34176 File
    34177 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34178 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    34179 raise LinAlgError("Singular matrix") 
    34180  
    34181 See log for complete Python traceback. 
    34182  
    34183 Traceback (most recent call last): 
    34184 File
    34185 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34186 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    34187 self.session.ui.mouse_modes.mouse_pause_tracking() 
    34188 File
    34189 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34190 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    34191 mouse_pause_tracking 
    34192 self._mouse_pause() 
    34193 File
    34194 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34195 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    34196 m.pause(self._mouse_pause_position) 
    34197 File
    34198 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34199 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    34200 p = self.view.picked_object(x, y) 
    34201 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34202 File
    34203 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34204 packages/chimerax/graphics/view.py", line 838, in picked_object 
    34205 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    34206 beyond, 
    34207 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34208 File
    34209 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34210 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    34211 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    34212 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34213 File
    34214 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34215 packages/chimerax/core/models.py", line 143, in first_intercept 
    34216 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    34217 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34218 File
    34219 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34220 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    34221 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    34222 exclude=exclude) 
    34223 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34224 File
    34225 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34226 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    34227 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    34228 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34229 File
    34230 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34231 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    34232 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    34233 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34234 File
    34235 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34236 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    34237 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    34238 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34239 File
    34240 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34241 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    34242 p = super().first_intercept(mxyz1, mxyz2) 
    34243 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34244 File
    34245 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34246 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    34247 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    34248 exclude=exclude) 
    34249 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34250 File
    34251 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34252 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    34253 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    34254 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34255 File
    34256 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34257 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    34258 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    34259 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34260 File
    34261 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34262 packages/chimerax/graphics/drawing.py", line 1108, in
    34263 _first_intercept_excluding_children 
    34264 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    34265 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34266 File
    34267 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34268 packages/chimerax/geometry/place.py", line 201, in inverse 
    34269 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    34270 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34271 File
    34272 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34273 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    34274 rinv[:, :] = matrix_inverse(r) 
    34275 ^^^^^^^^^^^^^^^^^ 
    34276 File
    34277 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34278 packages/numpy/linalg/linalg.py", line 561, in inv 
    34279 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    34280 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34281 File
    34282 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34283 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    34284 raise LinAlgError("Singular matrix") 
    34285 numpy.linalg.LinAlgError: Singular matrix 
    34286  
    34287 numpy.linalg.LinAlgError: Singular matrix 
    34288  
    34289 File
    34290 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34291 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    34292 raise LinAlgError("Singular matrix") 
    34293  
    34294 See log for complete Python traceback. 
    34295  
    34296 Traceback (most recent call last): 
    34297 File
    34298 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34299 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    34300 self.session.ui.mouse_modes.mouse_pause_tracking() 
    34301 File
    34302 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34303 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    34304 mouse_pause_tracking 
    34305 self._mouse_pause() 
    34306 File
    34307 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34308 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    34309 m.pause(self._mouse_pause_position) 
    34310 File
    34311 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34312 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    34313 p = self.view.picked_object(x, y) 
    34314 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34315 File
    34316 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34317 packages/chimerax/graphics/view.py", line 838, in picked_object 
    34318 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    34319 beyond, 
    34320 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34321 File
    34322 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34323 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    34324 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    34325 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34326 File
    34327 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34328 packages/chimerax/core/models.py", line 143, in first_intercept 
    34329 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    34330 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34331 File
    34332 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34333 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    34334 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    34335 exclude=exclude) 
    34336 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34337 File
    34338 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34339 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    34340 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    34341 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34342 File
    34343 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34344 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    34345 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    34346 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34347 File
    34348 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34349 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    34350 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    34351 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34352 File
    34353 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34354 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    34355 p = super().first_intercept(mxyz1, mxyz2) 
    34356 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34357 File
    34358 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34359 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    34360 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    34361 exclude=exclude) 
    34362 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34363 File
    34364 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34365 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    34366 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    34367 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34368 File
    34369 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34370 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    34371 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    34372 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34373 File
    34374 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34375 packages/chimerax/graphics/drawing.py", line 1108, in
    34376 _first_intercept_excluding_children 
    34377 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    34378 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34379 File
    34380 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34381 packages/chimerax/geometry/place.py", line 201, in inverse 
    34382 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    34383 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34384 File
    34385 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34386 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    34387 rinv[:, :] = matrix_inverse(r) 
    34388 ^^^^^^^^^^^^^^^^^ 
    34389 File
    34390 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34391 packages/numpy/linalg/linalg.py", line 561, in inv 
    34392 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    34393 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34394 File
    34395 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34396 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    34397 raise LinAlgError("Singular matrix") 
    34398 numpy.linalg.LinAlgError: Singular matrix 
    34399  
    34400 numpy.linalg.LinAlgError: Singular matrix 
    34401  
    34402 File
    34403 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34404 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    34405 raise LinAlgError("Singular matrix") 
    34406  
    34407 See log for complete Python traceback. 
    34408  
    34409 Traceback (most recent call last): 
    34410 File
    34411 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34412 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    34413 self.session.ui.mouse_modes.mouse_pause_tracking() 
    34414 File
    34415 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34416 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    34417 mouse_pause_tracking 
    34418 self._mouse_pause() 
    34419 File
    34420 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34421 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    34422 m.pause(self._mouse_pause_position) 
    34423 File
    34424 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34425 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    34426 p = self.view.picked_object(x, y) 
    34427 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34428 File
    34429 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34430 packages/chimerax/graphics/view.py", line 838, in picked_object 
    34431 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    34432 beyond, 
    34433 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34434 File
    34435 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34436 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    34437 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    34438 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34439 File
    34440 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34441 packages/chimerax/core/models.py", line 143, in first_intercept 
    34442 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    34443 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34444 File
    34445 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34446 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    34447 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    34448 exclude=exclude) 
    34449 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34450 File
    34451 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34452 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    34453 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    34454 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34455 File
    34456 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34457 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    34458 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    34459 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34460 File
    34461 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34462 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    34463 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    34464 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34465 File
    34466 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34467 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    34468 p = super().first_intercept(mxyz1, mxyz2) 
    34469 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34470 File
    34471 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34472 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    34473 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    34474 exclude=exclude) 
    34475 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34476 File
    34477 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34478 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    34479 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    34480 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34481 File
    34482 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34483 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    34484 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    34485 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34486 File
    34487 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34488 packages/chimerax/graphics/drawing.py", line 1108, in
    34489 _first_intercept_excluding_children 
    34490 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    34491 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34492 File
    34493 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34494 packages/chimerax/geometry/place.py", line 201, in inverse 
    34495 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    34496 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34497 File
    34498 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34499 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    34500 rinv[:, :] = matrix_inverse(r) 
    34501 ^^^^^^^^^^^^^^^^^ 
    34502 File
    34503 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34504 packages/numpy/linalg/linalg.py", line 561, in inv 
    34505 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    34506 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34507 File
    34508 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34509 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    34510 raise LinAlgError("Singular matrix") 
    34511 numpy.linalg.LinAlgError: Singular matrix 
    34512  
    34513 numpy.linalg.LinAlgError: Singular matrix 
    34514  
    34515 File
    34516 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34517 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    34518 raise LinAlgError("Singular matrix") 
    34519  
    34520 See log for complete Python traceback. 
    34521  
    34522 Traceback (most recent call last): 
    34523 File
    34524 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34525 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    34526 self.session.ui.mouse_modes.mouse_pause_tracking() 
    34527 File
    34528 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34529 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    34530 mouse_pause_tracking 
    34531 self._mouse_pause() 
    34532 File
    34533 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34534 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    34535 m.pause(self._mouse_pause_position) 
    34536 File
    34537 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34538 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    34539 p = self.view.picked_object(x, y) 
    34540 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34541 File
    34542 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34543 packages/chimerax/graphics/view.py", line 838, in picked_object 
    34544 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    34545 beyond, 
    34546 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34547 File
    34548 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34549 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    34550 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    34551 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34552 File
    34553 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34554 packages/chimerax/core/models.py", line 143, in first_intercept 
    34555 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    34556 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34557 File
    34558 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34559 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    34560 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    34561 exclude=exclude) 
    34562 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34563 File
    34564 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34565 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    34566 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    34567 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34568 File
    34569 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34570 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    34571 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    34572 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34573 File
    34574 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34575 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    34576 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    34577 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34578 File
    34579 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34580 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    34581 p = super().first_intercept(mxyz1, mxyz2) 
    34582 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34583 File
    34584 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34585 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    34586 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    34587 exclude=exclude) 
    34588 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34589 File
    34590 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34591 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    34592 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    34593 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34594 File
    34595 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34596 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    34597 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    34598 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34599 File
    34600 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34601 packages/chimerax/graphics/drawing.py", line 1108, in
    34602 _first_intercept_excluding_children 
    34603 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    34604 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34605 File
    34606 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34607 packages/chimerax/geometry/place.py", line 201, in inverse 
    34608 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    34609 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34610 File
    34611 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34612 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    34613 rinv[:, :] = matrix_inverse(r) 
    34614 ^^^^^^^^^^^^^^^^^ 
    34615 File
    34616 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34617 packages/numpy/linalg/linalg.py", line 561, in inv 
    34618 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    34619 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34620 File
    34621 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34622 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    34623 raise LinAlgError("Singular matrix") 
    34624 numpy.linalg.LinAlgError: Singular matrix 
    34625  
    34626 numpy.linalg.LinAlgError: Singular matrix 
    34627  
    34628 File
    34629 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34630 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    34631 raise LinAlgError("Singular matrix") 
    34632  
    34633 See log for complete Python traceback. 
    34634  
    34635 Traceback (most recent call last): 
    34636 File
    34637 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34638 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    34639 self.session.ui.mouse_modes.mouse_pause_tracking() 
    34640 File
    34641 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34642 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    34643 mouse_pause_tracking 
    34644 self._mouse_pause() 
    34645 File
    34646 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34647 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    34648 m.pause(self._mouse_pause_position) 
    34649 File
    34650 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34651 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    34652 p = self.view.picked_object(x, y) 
    34653 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34654 File
    34655 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34656 packages/chimerax/graphics/view.py", line 838, in picked_object 
    34657 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    34658 beyond, 
    34659 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34660 File
    34661 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34662 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    34663 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    34664 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34665 File
    34666 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34667 packages/chimerax/core/models.py", line 143, in first_intercept 
    34668 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    34669 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34670 File
    34671 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34672 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    34673 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    34674 exclude=exclude) 
    34675 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34676 File
    34677 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34678 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    34679 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    34680 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34681 File
    34682 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34683 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    34684 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    34685 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34686 File
    34687 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34688 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    34689 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    34690 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34691 File
    34692 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34693 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    34694 p = super().first_intercept(mxyz1, mxyz2) 
    34695 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34696 File
    34697 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34698 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    34699 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    34700 exclude=exclude) 
    34701 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34702 File
    34703 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34704 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    34705 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    34706 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34707 File
    34708 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34709 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    34710 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    34711 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34712 File
    34713 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34714 packages/chimerax/graphics/drawing.py", line 1108, in
    34715 _first_intercept_excluding_children 
    34716 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    34717 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34718 File
    34719 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34720 packages/chimerax/geometry/place.py", line 201, in inverse 
    34721 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    34722 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34723 File
    34724 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34725 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    34726 rinv[:, :] = matrix_inverse(r) 
    34727 ^^^^^^^^^^^^^^^^^ 
    34728 File
    34729 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34730 packages/numpy/linalg/linalg.py", line 561, in inv 
    34731 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    34732 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34733 File
    34734 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34735 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    34736 raise LinAlgError("Singular matrix") 
    34737 numpy.linalg.LinAlgError: Singular matrix 
    34738  
    34739 numpy.linalg.LinAlgError: Singular matrix 
    34740  
    34741 File
    34742 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34743 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    34744 raise LinAlgError("Singular matrix") 
    34745  
    34746 See log for complete Python traceback. 
    34747  
    34748 Traceback (most recent call last): 
    34749 File
    34750 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34751 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    34752 self.session.ui.mouse_modes.mouse_pause_tracking() 
    34753 File
    34754 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34755 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    34756 mouse_pause_tracking 
    34757 self._mouse_pause() 
    34758 File
    34759 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34760 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    34761 m.pause(self._mouse_pause_position) 
    34762 File
    34763 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34764 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    34765 p = self.view.picked_object(x, y) 
    34766 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34767 File
    34768 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34769 packages/chimerax/graphics/view.py", line 838, in picked_object 
    34770 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    34771 beyond, 
    34772 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34773 File
    34774 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34775 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    34776 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    34777 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34778 File
    34779 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34780 packages/chimerax/core/models.py", line 143, in first_intercept 
    34781 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    34782 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34783 File
    34784 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34785 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    34786 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    34787 exclude=exclude) 
    34788 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34789 File
    34790 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34791 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    34792 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    34793 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34794 File
    34795 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34796 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    34797 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    34798 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34799 File
    34800 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34801 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    34802 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    34803 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34804 File
    34805 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34806 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    34807 p = super().first_intercept(mxyz1, mxyz2) 
    34808 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34809 File
    34810 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34811 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    34812 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    34813 exclude=exclude) 
    34814 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34815 File
    34816 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34817 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    34818 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    34819 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34820 File
    34821 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34822 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    34823 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    34824 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34825 File
    34826 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34827 packages/chimerax/graphics/drawing.py", line 1108, in
    34828 _first_intercept_excluding_children 
    34829 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    34830 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34831 File
    34832 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34833 packages/chimerax/geometry/place.py", line 201, in inverse 
    34834 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    34835 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34836 File
    34837 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34838 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    34839 rinv[:, :] = matrix_inverse(r) 
    34840 ^^^^^^^^^^^^^^^^^ 
    34841 File
    34842 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34843 packages/numpy/linalg/linalg.py", line 561, in inv 
    34844 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    34845 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34846 File
    34847 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34848 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    34849 raise LinAlgError("Singular matrix") 
    34850 numpy.linalg.LinAlgError: Singular matrix 
    34851  
    34852 numpy.linalg.LinAlgError: Singular matrix 
    34853  
    34854 File
    34855 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34856 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    34857 raise LinAlgError("Singular matrix") 
    34858  
    34859 See log for complete Python traceback. 
    34860  
    34861 Traceback (most recent call last): 
    34862 File
    34863 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34864 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    34865 self.session.ui.mouse_modes.mouse_pause_tracking() 
    34866 File
    34867 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34868 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    34869 mouse_pause_tracking 
    34870 self._mouse_pause() 
    34871 File
    34872 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34873 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    34874 m.pause(self._mouse_pause_position) 
    34875 File
    34876 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34877 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    34878 p = self.view.picked_object(x, y) 
    34879 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34880 File
    34881 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34882 packages/chimerax/graphics/view.py", line 838, in picked_object 
    34883 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    34884 beyond, 
    34885 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34886 File
    34887 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34888 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    34889 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    34890 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34891 File
    34892 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34893 packages/chimerax/core/models.py", line 143, in first_intercept 
    34894 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    34895 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34896 File
    34897 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34898 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    34899 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    34900 exclude=exclude) 
    34901 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34902 File
    34903 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34904 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    34905 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    34906 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34907 File
    34908 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34909 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    34910 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    34911 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34912 File
    34913 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34914 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    34915 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    34916 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34917 File
    34918 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34919 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    34920 p = super().first_intercept(mxyz1, mxyz2) 
    34921 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34922 File
    34923 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34924 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    34925 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    34926 exclude=exclude) 
    34927 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34928 File
    34929 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34930 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    34931 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    34932 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34933 File
    34934 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34935 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    34936 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    34937 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34938 File
    34939 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34940 packages/chimerax/graphics/drawing.py", line 1108, in
    34941 _first_intercept_excluding_children 
    34942 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    34943 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34944 File
    34945 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34946 packages/chimerax/geometry/place.py", line 201, in inverse 
    34947 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    34948 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34949 File
    34950 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34951 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    34952 rinv[:, :] = matrix_inverse(r) 
    34953 ^^^^^^^^^^^^^^^^^ 
    34954 File
    34955 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34956 packages/numpy/linalg/linalg.py", line 561, in inv 
    34957 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    34958 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34959 File
    34960 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34961 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    34962 raise LinAlgError("Singular matrix") 
    34963 numpy.linalg.LinAlgError: Singular matrix 
    34964  
    34965 numpy.linalg.LinAlgError: Singular matrix 
    34966  
    34967 File
    34968 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34969 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    34970 raise LinAlgError("Singular matrix") 
    34971  
    34972 See log for complete Python traceback. 
    34973  
    34974 Traceback (most recent call last): 
    34975 File
    34976 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34977 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    34978 self.session.ui.mouse_modes.mouse_pause_tracking() 
    34979 File
    34980 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34981 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    34982 mouse_pause_tracking 
    34983 self._mouse_pause() 
    34984 File
    34985 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34986 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    34987 m.pause(self._mouse_pause_position) 
    34988 File
    34989 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34990 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    34991 p = self.view.picked_object(x, y) 
    34992 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34993 File
    34994 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    34995 packages/chimerax/graphics/view.py", line 838, in picked_object 
    34996 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    34997 beyond, 
    34998 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    34999 File
    35000 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35001 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    35002 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    35003 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35004 File
    35005 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35006 packages/chimerax/core/models.py", line 143, in first_intercept 
    35007 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    35008 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35009 File
    35010 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35011 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    35012 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    35013 exclude=exclude) 
    35014 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35015 File
    35016 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35017 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    35018 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    35019 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35020 File
    35021 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35022 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    35023 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    35024 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35025 File
    35026 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35027 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    35028 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    35029 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35030 File
    35031 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35032 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    35033 p = super().first_intercept(mxyz1, mxyz2) 
    35034 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35035 File
    35036 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35037 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    35038 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    35039 exclude=exclude) 
    35040 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35041 File
    35042 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35043 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    35044 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    35045 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35046 File
    35047 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35048 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    35049 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    35050 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35051 File
    35052 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35053 packages/chimerax/graphics/drawing.py", line 1108, in
    35054 _first_intercept_excluding_children 
    35055 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    35056 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35057 File
    35058 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35059 packages/chimerax/geometry/place.py", line 201, in inverse 
    35060 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    35061 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35062 File
    35063 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35064 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    35065 rinv[:, :] = matrix_inverse(r) 
    35066 ^^^^^^^^^^^^^^^^^ 
    35067 File
    35068 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35069 packages/numpy/linalg/linalg.py", line 561, in inv 
    35070 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    35071 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35072 File
    35073 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35074 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    35075 raise LinAlgError("Singular matrix") 
    35076 numpy.linalg.LinAlgError: Singular matrix 
    35077  
    35078 numpy.linalg.LinAlgError: Singular matrix 
    35079  
    35080 File
    35081 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35082 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    35083 raise LinAlgError("Singular matrix") 
    35084  
    35085 See log for complete Python traceback. 
    35086  
    35087 Traceback (most recent call last): 
    35088 File
    35089 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35090 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    35091 self.session.ui.mouse_modes.mouse_pause_tracking() 
    35092 File
    35093 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35094 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    35095 mouse_pause_tracking 
    35096 self._mouse_pause() 
    35097 File
    35098 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35099 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    35100 m.pause(self._mouse_pause_position) 
    35101 File
    35102 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35103 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    35104 p = self.view.picked_object(x, y) 
    35105 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35106 File
    35107 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35108 packages/chimerax/graphics/view.py", line 838, in picked_object 
    35109 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    35110 beyond, 
    35111 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35112 File
    35113 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35114 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    35115 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    35116 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35117 File
    35118 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35119 packages/chimerax/core/models.py", line 143, in first_intercept 
    35120 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    35121 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35122 File
    35123 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35124 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    35125 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    35126 exclude=exclude) 
    35127 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35128 File
    35129 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35130 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    35131 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    35132 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35133 File
    35134 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35135 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    35136 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    35137 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35138 File
    35139 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35140 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    35141 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    35142 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35143 File
    35144 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35145 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    35146 p = super().first_intercept(mxyz1, mxyz2) 
    35147 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35148 File
    35149 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35150 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    35151 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    35152 exclude=exclude) 
    35153 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35154 File
    35155 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35156 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    35157 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    35158 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35159 File
    35160 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35161 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    35162 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    35163 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35164 File
    35165 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35166 packages/chimerax/graphics/drawing.py", line 1108, in
    35167 _first_intercept_excluding_children 
    35168 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    35169 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35170 File
    35171 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35172 packages/chimerax/geometry/place.py", line 201, in inverse 
    35173 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    35174 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35175 File
    35176 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35177 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    35178 rinv[:, :] = matrix_inverse(r) 
    35179 ^^^^^^^^^^^^^^^^^ 
    35180 File
    35181 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35182 packages/numpy/linalg/linalg.py", line 561, in inv 
    35183 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    35184 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35185 File
    35186 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35187 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    35188 raise LinAlgError("Singular matrix") 
    35189 numpy.linalg.LinAlgError: Singular matrix 
    35190  
    35191 numpy.linalg.LinAlgError: Singular matrix 
    35192  
    35193 File
    35194 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35195 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    35196 raise LinAlgError("Singular matrix") 
    35197  
    35198 See log for complete Python traceback. 
    35199  
    35200 Traceback (most recent call last): 
    35201 File
    35202 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35203 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    35204 self.session.ui.mouse_modes.mouse_pause_tracking() 
    35205 File
    35206 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35207 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    35208 mouse_pause_tracking 
    35209 self._mouse_pause() 
    35210 File
    35211 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35212 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    35213 m.pause(self._mouse_pause_position) 
    35214 File
    35215 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35216 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    35217 p = self.view.picked_object(x, y) 
    35218 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35219 File
    35220 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35221 packages/chimerax/graphics/view.py", line 838, in picked_object 
    35222 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    35223 beyond, 
    35224 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35225 File
    35226 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35227 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    35228 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    35229 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35230 File
    35231 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35232 packages/chimerax/core/models.py", line 143, in first_intercept 
    35233 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    35234 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35235 File
    35236 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35237 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    35238 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    35239 exclude=exclude) 
    35240 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35241 File
    35242 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35243 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    35244 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    35245 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35246 File
    35247 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35248 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    35249 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    35250 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35251 File
    35252 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35253 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    35254 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    35255 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35256 File
    35257 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35258 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    35259 p = super().first_intercept(mxyz1, mxyz2) 
    35260 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35261 File
    35262 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35263 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    35264 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    35265 exclude=exclude) 
    35266 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35267 File
    35268 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35269 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    35270 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    35271 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35272 File
    35273 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35274 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    35275 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    35276 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35277 File
    35278 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35279 packages/chimerax/graphics/drawing.py", line 1108, in
    35280 _first_intercept_excluding_children 
    35281 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    35282 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35283 File
    35284 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35285 packages/chimerax/geometry/place.py", line 201, in inverse 
    35286 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    35287 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35288 File
    35289 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35290 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    35291 rinv[:, :] = matrix_inverse(r) 
    35292 ^^^^^^^^^^^^^^^^^ 
    35293 File
    35294 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35295 packages/numpy/linalg/linalg.py", line 561, in inv 
    35296 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    35297 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35298 File
    35299 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35300 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    35301 raise LinAlgError("Singular matrix") 
    35302 numpy.linalg.LinAlgError: Singular matrix 
    35303  
    35304 numpy.linalg.LinAlgError: Singular matrix 
    35305  
    35306 File
    35307 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35308 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    35309 raise LinAlgError("Singular matrix") 
    35310  
    35311 See log for complete Python traceback. 
    35312  
    35313 Traceback (most recent call last): 
    35314 File
    35315 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35316 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    35317 self.session.ui.mouse_modes.mouse_pause_tracking() 
    35318 File
    35319 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35320 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    35321 mouse_pause_tracking 
    35322 self._mouse_pause() 
    35323 File
    35324 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35325 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    35326 m.pause(self._mouse_pause_position) 
    35327 File
    35328 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35329 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    35330 p = self.view.picked_object(x, y) 
    35331 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35332 File
    35333 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35334 packages/chimerax/graphics/view.py", line 838, in picked_object 
    35335 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    35336 beyond, 
    35337 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35338 File
    35339 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35340 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    35341 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    35342 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35343 File
    35344 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35345 packages/chimerax/core/models.py", line 143, in first_intercept 
    35346 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    35347 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35348 File
    35349 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35350 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    35351 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    35352 exclude=exclude) 
    35353 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35354 File
    35355 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35356 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    35357 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    35358 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35359 File
    35360 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35361 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    35362 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    35363 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35364 File
    35365 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35366 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    35367 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    35368 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35369 File
    35370 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35371 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    35372 p = super().first_intercept(mxyz1, mxyz2) 
    35373 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35374 File
    35375 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35376 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    35377 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    35378 exclude=exclude) 
    35379 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35380 File
    35381 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35382 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    35383 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    35384 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35385 File
    35386 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35387 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    35388 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    35389 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35390 File
    35391 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35392 packages/chimerax/graphics/drawing.py", line 1108, in
    35393 _first_intercept_excluding_children 
    35394 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    35395 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35396 File
    35397 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35398 packages/chimerax/geometry/place.py", line 201, in inverse 
    35399 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    35400 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35401 File
    35402 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35403 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    35404 rinv[:, :] = matrix_inverse(r) 
    35405 ^^^^^^^^^^^^^^^^^ 
    35406 File
    35407 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35408 packages/numpy/linalg/linalg.py", line 561, in inv 
    35409 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    35410 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35411 File
    35412 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35413 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    35414 raise LinAlgError("Singular matrix") 
    35415 numpy.linalg.LinAlgError: Singular matrix 
    35416  
    35417 numpy.linalg.LinAlgError: Singular matrix 
    35418  
    35419 File
    35420 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35421 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    35422 raise LinAlgError("Singular matrix") 
    35423  
    35424 See log for complete Python traceback. 
    35425  
    35426 Traceback (most recent call last): 
    35427 File
    35428 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35429 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    35430 self.session.ui.mouse_modes.mouse_pause_tracking() 
    35431 File
    35432 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35433 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    35434 mouse_pause_tracking 
    35435 self._mouse_pause() 
    35436 File
    35437 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35438 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    35439 m.pause(self._mouse_pause_position) 
    35440 File
    35441 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35442 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    35443 p = self.view.picked_object(x, y) 
    35444 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35445 File
    35446 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35447 packages/chimerax/graphics/view.py", line 838, in picked_object 
    35448 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    35449 beyond, 
    35450 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35451 File
    35452 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35453 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    35454 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    35455 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35456 File
    35457 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35458 packages/chimerax/core/models.py", line 143, in first_intercept 
    35459 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    35460 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35461 File
    35462 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35463 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    35464 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    35465 exclude=exclude) 
    35466 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35467 File
    35468 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35469 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    35470 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    35471 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35472 File
    35473 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35474 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    35475 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    35476 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35477 File
    35478 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35479 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    35480 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    35481 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35482 File
    35483 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35484 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    35485 p = super().first_intercept(mxyz1, mxyz2) 
    35486 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35487 File
    35488 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35489 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    35490 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    35491 exclude=exclude) 
    35492 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35493 File
    35494 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35495 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    35496 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    35497 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35498 File
    35499 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35500 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    35501 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    35502 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35503 File
    35504 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35505 packages/chimerax/graphics/drawing.py", line 1108, in
    35506 _first_intercept_excluding_children 
    35507 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    35508 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35509 File
    35510 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35511 packages/chimerax/geometry/place.py", line 201, in inverse 
    35512 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    35513 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35514 File
    35515 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35516 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    35517 rinv[:, :] = matrix_inverse(r) 
    35518 ^^^^^^^^^^^^^^^^^ 
    35519 File
    35520 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35521 packages/numpy/linalg/linalg.py", line 561, in inv 
    35522 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    35523 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35524 File
    35525 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35526 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    35527 raise LinAlgError("Singular matrix") 
    35528 numpy.linalg.LinAlgError: Singular matrix 
    35529  
    35530 numpy.linalg.LinAlgError: Singular matrix 
    35531  
    35532 File
    35533 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35534 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    35535 raise LinAlgError("Singular matrix") 
    35536  
    35537 See log for complete Python traceback. 
    35538  
    35539 Traceback (most recent call last): 
    35540 File
    35541 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35542 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    35543 self.session.ui.mouse_modes.mouse_pause_tracking() 
    35544 File
    35545 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35546 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    35547 mouse_pause_tracking 
    35548 self._mouse_pause() 
    35549 File
    35550 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35551 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    35552 m.pause(self._mouse_pause_position) 
    35553 File
    35554 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35555 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    35556 p = self.view.picked_object(x, y) 
    35557 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35558 File
    35559 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35560 packages/chimerax/graphics/view.py", line 838, in picked_object 
    35561 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    35562 beyond, 
    35563 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35564 File
    35565 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35566 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    35567 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    35568 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35569 File
    35570 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35571 packages/chimerax/core/models.py", line 143, in first_intercept 
    35572 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    35573 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35574 File
    35575 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35576 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    35577 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    35578 exclude=exclude) 
    35579 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35580 File
    35581 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35582 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    35583 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    35584 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35585 File
    35586 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35587 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    35588 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    35589 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35590 File
    35591 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35592 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    35593 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    35594 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35595 File
    35596 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35597 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    35598 p = super().first_intercept(mxyz1, mxyz2) 
    35599 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35600 File
    35601 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35602 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    35603 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    35604 exclude=exclude) 
    35605 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35606 File
    35607 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35608 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    35609 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    35610 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35611 File
    35612 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35613 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    35614 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    35615 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35616 File
    35617 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35618 packages/chimerax/graphics/drawing.py", line 1108, in
    35619 _first_intercept_excluding_children 
    35620 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    35621 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35622 File
    35623 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35624 packages/chimerax/geometry/place.py", line 201, in inverse 
    35625 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    35626 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35627 File
    35628 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35629 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    35630 rinv[:, :] = matrix_inverse(r) 
    35631 ^^^^^^^^^^^^^^^^^ 
    35632 File
    35633 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35634 packages/numpy/linalg/linalg.py", line 561, in inv 
    35635 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    35636 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35637 File
    35638 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35639 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    35640 raise LinAlgError("Singular matrix") 
    35641 numpy.linalg.LinAlgError: Singular matrix 
    35642  
    35643 numpy.linalg.LinAlgError: Singular matrix 
    35644  
    35645 File
    35646 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35647 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    35648 raise LinAlgError("Singular matrix") 
    35649  
    35650 See log for complete Python traceback. 
    35651  
    35652 Traceback (most recent call last): 
    35653 File
    35654 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35655 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    35656 self.session.ui.mouse_modes.mouse_pause_tracking() 
    35657 File
    35658 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35659 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    35660 mouse_pause_tracking 
    35661 self._mouse_pause() 
    35662 File
    35663 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35664 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    35665 m.pause(self._mouse_pause_position) 
    35666 File
    35667 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35668 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    35669 p = self.view.picked_object(x, y) 
    35670 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35671 File
    35672 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35673 packages/chimerax/graphics/view.py", line 838, in picked_object 
    35674 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    35675 beyond, 
    35676 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35677 File
    35678 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35679 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    35680 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    35681 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35682 File
    35683 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35684 packages/chimerax/core/models.py", line 143, in first_intercept 
    35685 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    35686 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35687 File
    35688 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35689 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    35690 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    35691 exclude=exclude) 
    35692 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35693 File
    35694 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35695 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    35696 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    35697 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35698 File
    35699 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35700 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    35701 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    35702 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35703 File
    35704 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35705 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    35706 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    35707 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35708 File
    35709 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35710 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    35711 p = super().first_intercept(mxyz1, mxyz2) 
    35712 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35713 File
    35714 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35715 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    35716 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    35717 exclude=exclude) 
    35718 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35719 File
    35720 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35721 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    35722 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    35723 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35724 File
    35725 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35726 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    35727 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    35728 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35729 File
    35730 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35731 packages/chimerax/graphics/drawing.py", line 1108, in
    35732 _first_intercept_excluding_children 
    35733 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    35734 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35735 File
    35736 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35737 packages/chimerax/geometry/place.py", line 201, in inverse 
    35738 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    35739 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35740 File
    35741 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35742 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    35743 rinv[:, :] = matrix_inverse(r) 
    35744 ^^^^^^^^^^^^^^^^^ 
    35745 File
    35746 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35747 packages/numpy/linalg/linalg.py", line 561, in inv 
    35748 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    35749 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35750 File
    35751 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35752 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    35753 raise LinAlgError("Singular matrix") 
    35754 numpy.linalg.LinAlgError: Singular matrix 
    35755  
    35756 numpy.linalg.LinAlgError: Singular matrix 
    35757  
    35758 File
    35759 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35760 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    35761 raise LinAlgError("Singular matrix") 
    35762  
    35763 See log for complete Python traceback. 
    35764  
    35765 Traceback (most recent call last): 
    35766 File
    35767 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35768 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    35769 self.session.ui.mouse_modes.mouse_pause_tracking() 
    35770 File
    35771 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35772 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    35773 mouse_pause_tracking 
    35774 self._mouse_pause() 
    35775 File
    35776 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35777 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    35778 m.pause(self._mouse_pause_position) 
    35779 File
    35780 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35781 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    35782 p = self.view.picked_object(x, y) 
    35783 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35784 File
    35785 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35786 packages/chimerax/graphics/view.py", line 838, in picked_object 
    35787 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    35788 beyond, 
    35789 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35790 File
    35791 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35792 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    35793 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    35794 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35795 File
    35796 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35797 packages/chimerax/core/models.py", line 143, in first_intercept 
    35798 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    35799 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35800 File
    35801 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35802 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    35803 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    35804 exclude=exclude) 
    35805 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35806 File
    35807 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35808 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    35809 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    35810 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35811 File
    35812 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35813 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    35814 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    35815 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35816 File
    35817 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35818 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    35819 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    35820 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35821 File
    35822 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35823 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    35824 p = super().first_intercept(mxyz1, mxyz2) 
    35825 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35826 File
    35827 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35828 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    35829 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    35830 exclude=exclude) 
    35831 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35832 File
    35833 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35834 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    35835 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    35836 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35837 File
    35838 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35839 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    35840 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    35841 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35842 File
    35843 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35844 packages/chimerax/graphics/drawing.py", line 1108, in
    35845 _first_intercept_excluding_children 
    35846 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    35847 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35848 File
    35849 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35850 packages/chimerax/geometry/place.py", line 201, in inverse 
    35851 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    35852 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35853 File
    35854 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35855 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    35856 rinv[:, :] = matrix_inverse(r) 
    35857 ^^^^^^^^^^^^^^^^^ 
    35858 File
    35859 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35860 packages/numpy/linalg/linalg.py", line 561, in inv 
    35861 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    35862 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35863 File
    35864 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35865 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    35866 raise LinAlgError("Singular matrix") 
    35867 numpy.linalg.LinAlgError: Singular matrix 
    35868  
    35869 numpy.linalg.LinAlgError: Singular matrix 
    35870  
    35871 File
    35872 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35873 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    35874 raise LinAlgError("Singular matrix") 
    35875  
    35876 See log for complete Python traceback. 
    35877  
    35878 Traceback (most recent call last): 
    35879 File
    35880 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35881 packages/chimerax/mouse_modes/mousemodes.py", line 656, in <lambda> 
    35882 gw.mouseReleaseEvent = lambda e, s=self: s._dispatch_mouse_event(e,
    35883 "mouse_up") 
    35884 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35885 File
    35886 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35887 packages/chimerax/mouse_modes/mousemodes.py", line 556, in
    35888 _dispatch_mouse_event 
    35889 f(MouseEvent(event, modifiers=modifiers)) 
    35890 File
    35891 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35892 packages/chimerax/mouse_modes/std_modes.py", line 70, in mouse_up 
    35893 mouse_select(event, mode, self.session, self.view) 
    35894 File
    35895 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35896 packages/chimerax/mouse_modes/std_modes.py", line 209, in mouse_select 
    35897 pick = view.picked_object(x, y) 
    35898 ^^^^^^^^^^^^^^^^^^^^^^^^ 
    35899 File
    35900 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35901 packages/chimerax/graphics/view.py", line 838, in picked_object 
    35902 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    35903 beyond, 
    35904 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35905 File
    35906 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35907 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    35908 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    35909 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35910 File
    35911 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35912 packages/chimerax/core/models.py", line 143, in first_intercept 
    35913 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    35914 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35915 File
    35916 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35917 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    35918 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    35919 exclude=exclude) 
    35920 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35921 File
    35922 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35923 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    35924 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    35925 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35926 File
    35927 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35928 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    35929 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    35930 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35931 File
    35932 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35933 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    35934 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    35935 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35936 File
    35937 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35938 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    35939 p = super().first_intercept(mxyz1, mxyz2) 
    35940 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35941 File
    35942 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35943 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    35944 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    35945 exclude=exclude) 
    35946 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35947 File
    35948 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35949 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    35950 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    35951 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35952 File
    35953 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35954 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    35955 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    35956 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35957 File
    35958 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35959 packages/chimerax/graphics/drawing.py", line 1108, in
    35960 _first_intercept_excluding_children 
    35961 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    35962 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35963 File
    35964 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35965 packages/chimerax/geometry/place.py", line 201, in inverse 
    35966 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    35967 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35968 File
    35969 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35970 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    35971 rinv[:, :] = matrix_inverse(r) 
    35972 ^^^^^^^^^^^^^^^^^ 
    35973 File
    35974 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35975 packages/numpy/linalg/linalg.py", line 561, in inv 
    35976 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    35977 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    35978 File
    35979 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35980 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    35981 raise LinAlgError("Singular matrix") 
    35982 numpy.linalg.LinAlgError: Singular matrix 
    35983  
    35984 numpy.linalg.LinAlgError: Singular matrix 
    35985  
    35986 File
    35987 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    35988 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    35989 raise LinAlgError("Singular matrix") 
    35990  
    35991 See log for complete Python traceback. 
    35992  
    35993 
    35994 > select add #5/B:461
    35995 
    35996 82 atoms, 71 bonds, 11 residues, 2 models selected 
    35997 
    35998 > hide sel cartoons
    35999 
    36000 > select ::name="MFX"
    36001 
    36002 174 atoms, 198 bonds, 6 residues, 1 model selected 
    36003 
    36004 > color sel cadet blue
    36005 
    36006 > color sel byhetero
    36007 
    36008 > select clear
    36009 
    36010 Traceback (most recent call last): 
    36011 File
    36012 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36013 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    36014 self.session.ui.mouse_modes.mouse_pause_tracking() 
    36015 File
    36016 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36017 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    36018 mouse_pause_tracking 
    36019 self._mouse_pause() 
    36020 File
    36021 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36022 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    36023 m.pause(self._mouse_pause_position) 
    36024 File
    36025 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36026 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    36027 p = self.view.picked_object(x, y) 
    36028 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36029 File
    36030 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36031 packages/chimerax/graphics/view.py", line 838, in picked_object 
    36032 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    36033 beyond, 
    36034 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36035 File
    36036 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36037 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    36038 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    36039 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36040 File
    36041 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36042 packages/chimerax/core/models.py", line 143, in first_intercept 
    36043 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    36044 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36045 File
    36046 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36047 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    36048 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    36049 exclude=exclude) 
    36050 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36051 File
    36052 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36053 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    36054 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    36055 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36056 File
    36057 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36058 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    36059 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    36060 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36061 File
    36062 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36063 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    36064 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    36065 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36066 File
    36067 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36068 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    36069 p = super().first_intercept(mxyz1, mxyz2) 
    36070 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36071 File
    36072 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36073 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    36074 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    36075 exclude=exclude) 
    36076 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36077 File
    36078 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36079 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    36080 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    36081 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36082 File
    36083 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36084 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    36085 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    36086 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36087 File
    36088 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36089 packages/chimerax/graphics/drawing.py", line 1108, in
    36090 _first_intercept_excluding_children 
    36091 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    36092 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36093 File
    36094 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36095 packages/chimerax/geometry/place.py", line 201, in inverse 
    36096 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    36097 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36098 File
    36099 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36100 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    36101 rinv[:, :] = matrix_inverse(r) 
    36102 ^^^^^^^^^^^^^^^^^ 
    36103 File
    36104 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36105 packages/numpy/linalg/linalg.py", line 561, in inv 
    36106 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    36107 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36108 File
    36109 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36110 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    36111 raise LinAlgError("Singular matrix") 
    36112 numpy.linalg.LinAlgError: Singular matrix 
    36113  
    36114 numpy.linalg.LinAlgError: Singular matrix 
    36115  
    36116 File
    36117 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36118 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    36119 raise LinAlgError("Singular matrix") 
    36120  
    36121 See log for complete Python traceback. 
    36122  
    36123 Traceback (most recent call last): 
    36124 File
    36125 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36126 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    36127 self.session.ui.mouse_modes.mouse_pause_tracking() 
    36128 File
    36129 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36130 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    36131 mouse_pause_tracking 
    36132 self._mouse_pause() 
    36133 File
    36134 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36135 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    36136 m.pause(self._mouse_pause_position) 
    36137 File
    36138 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36139 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    36140 p = self.view.picked_object(x, y) 
    36141 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36142 File
    36143 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36144 packages/chimerax/graphics/view.py", line 838, in picked_object 
    36145 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    36146 beyond, 
    36147 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36148 File
    36149 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36150 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    36151 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    36152 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36153 File
    36154 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36155 packages/chimerax/core/models.py", line 143, in first_intercept 
    36156 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    36157 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36158 File
    36159 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36160 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    36161 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    36162 exclude=exclude) 
    36163 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36164 File
    36165 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36166 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    36167 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    36168 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36169 File
    36170 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36171 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    36172 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    36173 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36174 File
    36175 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36176 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    36177 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    36178 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36179 File
    36180 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36181 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    36182 p = super().first_intercept(mxyz1, mxyz2) 
    36183 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36184 File
    36185 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36186 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    36187 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    36188 exclude=exclude) 
    36189 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36190 File
    36191 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36192 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    36193 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    36194 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36195 File
    36196 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36197 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    36198 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    36199 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36200 File
    36201 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36202 packages/chimerax/graphics/drawing.py", line 1108, in
    36203 _first_intercept_excluding_children 
    36204 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    36205 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36206 File
    36207 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36208 packages/chimerax/geometry/place.py", line 201, in inverse 
    36209 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    36210 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36211 File
    36212 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36213 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    36214 rinv[:, :] = matrix_inverse(r) 
    36215 ^^^^^^^^^^^^^^^^^ 
    36216 File
    36217 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36218 packages/numpy/linalg/linalg.py", line 561, in inv 
    36219 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    36220 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36221 File
    36222 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36223 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    36224 raise LinAlgError("Singular matrix") 
    36225 numpy.linalg.LinAlgError: Singular matrix 
    36226  
    36227 numpy.linalg.LinAlgError: Singular matrix 
    36228  
    36229 File
    36230 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36231 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    36232 raise LinAlgError("Singular matrix") 
    36233  
    36234 See log for complete Python traceback. 
    36235  
    36236 Traceback (most recent call last): 
    36237 File
    36238 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36239 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    36240 self.session.ui.mouse_modes.mouse_pause_tracking() 
    36241 File
    36242 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36243 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    36244 mouse_pause_tracking 
    36245 self._mouse_pause() 
    36246 File
    36247 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36248 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    36249 m.pause(self._mouse_pause_position) 
    36250 File
    36251 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36252 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    36253 p = self.view.picked_object(x, y) 
    36254 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36255 File
    36256 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36257 packages/chimerax/graphics/view.py", line 838, in picked_object 
    36258 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    36259 beyond, 
    36260 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36261 File
    36262 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36263 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    36264 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    36265 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36266 File
    36267 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36268 packages/chimerax/core/models.py", line 143, in first_intercept 
    36269 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    36270 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36271 File
    36272 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36273 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    36274 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    36275 exclude=exclude) 
    36276 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36277 File
    36278 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36279 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    36280 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    36281 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36282 File
    36283 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36284 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    36285 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    36286 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36287 File
    36288 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36289 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    36290 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    36291 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36292 File
    36293 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36294 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    36295 p = super().first_intercept(mxyz1, mxyz2) 
    36296 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36297 File
    36298 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36299 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    36300 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    36301 exclude=exclude) 
    36302 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36303 File
    36304 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36305 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    36306 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    36307 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36308 File
    36309 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36310 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    36311 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    36312 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36313 File
    36314 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36315 packages/chimerax/graphics/drawing.py", line 1108, in
    36316 _first_intercept_excluding_children 
    36317 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    36318 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36319 File
    36320 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36321 packages/chimerax/geometry/place.py", line 201, in inverse 
    36322 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    36323 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36324 File
    36325 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36326 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    36327 rinv[:, :] = matrix_inverse(r) 
    36328 ^^^^^^^^^^^^^^^^^ 
    36329 File
    36330 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36331 packages/numpy/linalg/linalg.py", line 561, in inv 
    36332 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    36333 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36334 File
    36335 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36336 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    36337 raise LinAlgError("Singular matrix") 
    36338 numpy.linalg.LinAlgError: Singular matrix 
    36339  
    36340 numpy.linalg.LinAlgError: Singular matrix 
    36341  
    36342 File
    36343 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36344 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    36345 raise LinAlgError("Singular matrix") 
    36346  
    36347 See log for complete Python traceback. 
    36348  
    36349 Traceback (most recent call last): 
    36350 File
    36351 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36352 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    36353 self.session.ui.mouse_modes.mouse_pause_tracking() 
    36354 File
    36355 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36356 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    36357 mouse_pause_tracking 
    36358 self._mouse_pause() 
    36359 File
    36360 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36361 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    36362 m.pause(self._mouse_pause_position) 
    36363 File
    36364 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36365 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    36366 p = self.view.picked_object(x, y) 
    36367 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36368 File
    36369 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36370 packages/chimerax/graphics/view.py", line 838, in picked_object 
    36371 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    36372 beyond, 
    36373 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36374 File
    36375 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36376 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    36377 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    36378 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36379 File
    36380 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36381 packages/chimerax/core/models.py", line 143, in first_intercept 
    36382 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    36383 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36384 File
    36385 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36386 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    36387 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    36388 exclude=exclude) 
    36389 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36390 File
    36391 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36392 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    36393 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    36394 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36395 File
    36396 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36397 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    36398 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    36399 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36400 File
    36401 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36402 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    36403 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    36404 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36405 File
    36406 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36407 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    36408 p = super().first_intercept(mxyz1, mxyz2) 
    36409 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36410 File
    36411 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36412 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    36413 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    36414 exclude=exclude) 
    36415 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36416 File
    36417 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36418 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    36419 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    36420 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36421 File
    36422 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36423 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    36424 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    36425 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36426 File
    36427 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36428 packages/chimerax/graphics/drawing.py", line 1108, in
    36429 _first_intercept_excluding_children 
    36430 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    36431 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36432 File
    36433 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36434 packages/chimerax/geometry/place.py", line 201, in inverse 
    36435 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    36436 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36437 File
    36438 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36439 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    36440 rinv[:, :] = matrix_inverse(r) 
    36441 ^^^^^^^^^^^^^^^^^ 
    36442 File
    36443 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36444 packages/numpy/linalg/linalg.py", line 561, in inv 
    36445 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    36446 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36447 File
    36448 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36449 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    36450 raise LinAlgError("Singular matrix") 
    36451 numpy.linalg.LinAlgError: Singular matrix 
    36452  
    36453 numpy.linalg.LinAlgError: Singular matrix 
    36454  
    36455 File
    36456 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36457 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    36458 raise LinAlgError("Singular matrix") 
    36459  
    36460 See log for complete Python traceback. 
    36461  
    36462 Traceback (most recent call last): 
    36463 File
    36464 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36465 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    36466 self.session.ui.mouse_modes.mouse_pause_tracking() 
    36467 File
    36468 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36469 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    36470 mouse_pause_tracking 
    36471 self._mouse_pause() 
    36472 File
    36473 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36474 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    36475 m.pause(self._mouse_pause_position) 
    36476 File
    36477 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36478 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    36479 p = self.view.picked_object(x, y) 
    36480 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36481 File
    36482 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36483 packages/chimerax/graphics/view.py", line 838, in picked_object 
    36484 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    36485 beyond, 
    36486 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36487 File
    36488 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36489 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    36490 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    36491 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36492 File
    36493 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36494 packages/chimerax/core/models.py", line 143, in first_intercept 
    36495 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    36496 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36497 File
    36498 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36499 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    36500 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    36501 exclude=exclude) 
    36502 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36503 File
    36504 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36505 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    36506 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    36507 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36508 File
    36509 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36510 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    36511 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    36512 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36513 File
    36514 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36515 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    36516 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    36517 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36518 File
    36519 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36520 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    36521 p = super().first_intercept(mxyz1, mxyz2) 
    36522 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36523 File
    36524 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36525 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    36526 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    36527 exclude=exclude) 
    36528 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36529 File
    36530 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36531 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    36532 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    36533 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36534 File
    36535 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36536 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    36537 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    36538 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36539 File
    36540 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36541 packages/chimerax/graphics/drawing.py", line 1108, in
    36542 _first_intercept_excluding_children 
    36543 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    36544 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36545 File
    36546 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36547 packages/chimerax/geometry/place.py", line 201, in inverse 
    36548 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    36549 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36550 File
    36551 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36552 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    36553 rinv[:, :] = matrix_inverse(r) 
    36554 ^^^^^^^^^^^^^^^^^ 
    36555 File
    36556 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36557 packages/numpy/linalg/linalg.py", line 561, in inv 
    36558 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    36559 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36560 File
    36561 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36562 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    36563 raise LinAlgError("Singular matrix") 
    36564 numpy.linalg.LinAlgError: Singular matrix 
    36565  
    36566 numpy.linalg.LinAlgError: Singular matrix 
    36567  
    36568 File
    36569 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36570 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    36571 raise LinAlgError("Singular matrix") 
    36572  
    36573 See log for complete Python traceback. 
    36574  
    36575 Traceback (most recent call last): 
    36576 File
    36577 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36578 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    36579 self.session.ui.mouse_modes.mouse_pause_tracking() 
    36580 File
    36581 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36582 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    36583 mouse_pause_tracking 
    36584 self._mouse_pause() 
    36585 File
    36586 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36587 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    36588 m.pause(self._mouse_pause_position) 
    36589 File
    36590 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36591 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    36592 p = self.view.picked_object(x, y) 
    36593 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36594 File
    36595 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36596 packages/chimerax/graphics/view.py", line 838, in picked_object 
    36597 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    36598 beyond, 
    36599 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36600 File
    36601 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36602 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    36603 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    36604 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36605 File
    36606 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36607 packages/chimerax/core/models.py", line 143, in first_intercept 
    36608 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    36609 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36610 File
    36611 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36612 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    36613 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    36614 exclude=exclude) 
    36615 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36616 File
    36617 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36618 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    36619 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    36620 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36621 File
    36622 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36623 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    36624 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    36625 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36626 File
    36627 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36628 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    36629 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    36630 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36631 File
    36632 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36633 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    36634 p = super().first_intercept(mxyz1, mxyz2) 
    36635 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36636 File
    36637 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36638 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    36639 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    36640 exclude=exclude) 
    36641 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36642 File
    36643 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36644 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    36645 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    36646 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36647 File
    36648 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36649 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    36650 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    36651 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36652 File
    36653 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36654 packages/chimerax/graphics/drawing.py", line 1108, in
    36655 _first_intercept_excluding_children 
    36656 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    36657 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36658 File
    36659 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36660 packages/chimerax/geometry/place.py", line 201, in inverse 
    36661 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    36662 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36663 File
    36664 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36665 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    36666 rinv[:, :] = matrix_inverse(r) 
    36667 ^^^^^^^^^^^^^^^^^ 
    36668 File
    36669 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36670 packages/numpy/linalg/linalg.py", line 561, in inv 
    36671 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    36672 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36673 File
    36674 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36675 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    36676 raise LinAlgError("Singular matrix") 
    36677 numpy.linalg.LinAlgError: Singular matrix 
    36678  
    36679 numpy.linalg.LinAlgError: Singular matrix 
    36680  
    36681 File
    36682 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36683 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    36684 raise LinAlgError("Singular matrix") 
    36685  
    36686 See log for complete Python traceback. 
    36687  
    36688 Traceback (most recent call last): 
    36689 File
    36690 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36691 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    36692 self.session.ui.mouse_modes.mouse_pause_tracking() 
    36693 File
    36694 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36695 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    36696 mouse_pause_tracking 
    36697 self._mouse_pause() 
    36698 File
    36699 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36700 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    36701 m.pause(self._mouse_pause_position) 
    36702 File
    36703 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36704 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    36705 p = self.view.picked_object(x, y) 
    36706 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36707 File
    36708 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36709 packages/chimerax/graphics/view.py", line 838, in picked_object 
    36710 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    36711 beyond, 
    36712 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36713 File
    36714 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36715 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    36716 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    36717 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36718 File
    36719 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36720 packages/chimerax/core/models.py", line 143, in first_intercept 
    36721 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    36722 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36723 File
    36724 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36725 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    36726 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    36727 exclude=exclude) 
    36728 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36729 File
    36730 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36731 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    36732 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    36733 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36734 File
    36735 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36736 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    36737 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    36738 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36739 File
    36740 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36741 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    36742 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    36743 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36744 File
    36745 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36746 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    36747 p = super().first_intercept(mxyz1, mxyz2) 
    36748 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36749 File
    36750 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36751 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    36752 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    36753 exclude=exclude) 
    36754 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36755 File
    36756 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36757 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    36758 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    36759 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36760 File
    36761 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36762 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    36763 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    36764 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36765 File
    36766 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36767 packages/chimerax/graphics/drawing.py", line 1108, in
    36768 _first_intercept_excluding_children 
    36769 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    36770 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36771 File
    36772 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36773 packages/chimerax/geometry/place.py", line 201, in inverse 
    36774 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    36775 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36776 File
    36777 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36778 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    36779 rinv[:, :] = matrix_inverse(r) 
    36780 ^^^^^^^^^^^^^^^^^ 
    36781 File
    36782 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36783 packages/numpy/linalg/linalg.py", line 561, in inv 
    36784 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    36785 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36786 File
    36787 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36788 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    36789 raise LinAlgError("Singular matrix") 
    36790 numpy.linalg.LinAlgError: Singular matrix 
    36791  
    36792 numpy.linalg.LinAlgError: Singular matrix 
    36793  
    36794 File
    36795 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36796 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    36797 raise LinAlgError("Singular matrix") 
    36798  
    36799 See log for complete Python traceback. 
    36800  
    36801 Traceback (most recent call last): 
    36802 File
    36803 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36804 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    36805 self.session.ui.mouse_modes.mouse_pause_tracking() 
    36806 File
    36807 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36808 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    36809 mouse_pause_tracking 
    36810 self._mouse_pause() 
    36811 File
    36812 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36813 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    36814 m.pause(self._mouse_pause_position) 
    36815 File
    36816 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36817 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    36818 p = self.view.picked_object(x, y) 
    36819 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36820 File
    36821 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36822 packages/chimerax/graphics/view.py", line 838, in picked_object 
    36823 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    36824 beyond, 
    36825 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36826 File
    36827 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36828 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    36829 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    36830 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36831 File
    36832 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36833 packages/chimerax/core/models.py", line 143, in first_intercept 
    36834 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    36835 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36836 File
    36837 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36838 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    36839 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    36840 exclude=exclude) 
    36841 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36842 File
    36843 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36844 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    36845 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    36846 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36847 File
    36848 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36849 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    36850 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    36851 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36852 File
    36853 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36854 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    36855 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    36856 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36857 File
    36858 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36859 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    36860 p = super().first_intercept(mxyz1, mxyz2) 
    36861 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36862 File
    36863 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36864 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    36865 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    36866 exclude=exclude) 
    36867 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36868 File
    36869 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36870 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    36871 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    36872 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36873 File
    36874 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36875 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    36876 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    36877 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36878 File
    36879 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36880 packages/chimerax/graphics/drawing.py", line 1108, in
    36881 _first_intercept_excluding_children 
    36882 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    36883 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36884 File
    36885 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36886 packages/chimerax/geometry/place.py", line 201, in inverse 
    36887 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    36888 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36889 File
    36890 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36891 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    36892 rinv[:, :] = matrix_inverse(r) 
    36893 ^^^^^^^^^^^^^^^^^ 
    36894 File
    36895 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36896 packages/numpy/linalg/linalg.py", line 561, in inv 
    36897 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    36898 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36899 File
    36900 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36901 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    36902 raise LinAlgError("Singular matrix") 
    36903 numpy.linalg.LinAlgError: Singular matrix 
    36904  
    36905 numpy.linalg.LinAlgError: Singular matrix 
    36906  
    36907 File
    36908 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36909 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    36910 raise LinAlgError("Singular matrix") 
    36911  
    36912 See log for complete Python traceback. 
    36913  
    36914 Traceback (most recent call last): 
    36915 File
    36916 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36917 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    36918 self.session.ui.mouse_modes.mouse_pause_tracking() 
    36919 File
    36920 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36921 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    36922 mouse_pause_tracking 
    36923 self._mouse_pause() 
    36924 File
    36925 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36926 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    36927 m.pause(self._mouse_pause_position) 
    36928 File
    36929 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36930 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    36931 p = self.view.picked_object(x, y) 
    36932 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36933 File
    36934 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36935 packages/chimerax/graphics/view.py", line 838, in picked_object 
    36936 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    36937 beyond, 
    36938 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36939 File
    36940 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36941 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    36942 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    36943 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36944 File
    36945 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36946 packages/chimerax/core/models.py", line 143, in first_intercept 
    36947 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    36948 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36949 File
    36950 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36951 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    36952 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    36953 exclude=exclude) 
    36954 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36955 File
    36956 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36957 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    36958 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    36959 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36960 File
    36961 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36962 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    36963 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    36964 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36965 File
    36966 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36967 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    36968 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    36969 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36970 File
    36971 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36972 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    36973 p = super().first_intercept(mxyz1, mxyz2) 
    36974 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36975 File
    36976 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36977 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    36978 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    36979 exclude=exclude) 
    36980 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36981 File
    36982 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36983 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    36984 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    36985 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36986 File
    36987 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36988 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    36989 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    36990 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36991 File
    36992 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36993 packages/chimerax/graphics/drawing.py", line 1108, in
    36994 _first_intercept_excluding_children 
    36995 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    36996 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    36997 File
    36998 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    36999 packages/chimerax/geometry/place.py", line 201, in inverse 
    37000 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    37001 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37002 File
    37003 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37004 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    37005 rinv[:, :] = matrix_inverse(r) 
    37006 ^^^^^^^^^^^^^^^^^ 
    37007 File
    37008 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37009 packages/numpy/linalg/linalg.py", line 561, in inv 
    37010 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    37011 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37012 File
    37013 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37014 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    37015 raise LinAlgError("Singular matrix") 
    37016 numpy.linalg.LinAlgError: Singular matrix 
    37017  
    37018 numpy.linalg.LinAlgError: Singular matrix 
    37019  
    37020 File
    37021 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37022 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    37023 raise LinAlgError("Singular matrix") 
    37024  
    37025 See log for complete Python traceback. 
    37026  
    37027 Traceback (most recent call last): 
    37028 File
    37029 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37030 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    37031 self.session.ui.mouse_modes.mouse_pause_tracking() 
    37032 File
    37033 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37034 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    37035 mouse_pause_tracking 
    37036 self._mouse_pause() 
    37037 File
    37038 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37039 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    37040 m.pause(self._mouse_pause_position) 
    37041 File
    37042 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37043 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    37044 p = self.view.picked_object(x, y) 
    37045 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37046 File
    37047 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37048 packages/chimerax/graphics/view.py", line 838, in picked_object 
    37049 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    37050 beyond, 
    37051 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37052 File
    37053 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37054 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    37055 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    37056 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37057 File
    37058 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37059 packages/chimerax/core/models.py", line 143, in first_intercept 
    37060 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    37061 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37062 File
    37063 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37064 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    37065 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    37066 exclude=exclude) 
    37067 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37068 File
    37069 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37070 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    37071 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    37072 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37073 File
    37074 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37075 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    37076 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    37077 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37078 File
    37079 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37080 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    37081 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    37082 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37083 File
    37084 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37085 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    37086 p = super().first_intercept(mxyz1, mxyz2) 
    37087 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37088 File
    37089 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37090 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    37091 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    37092 exclude=exclude) 
    37093 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37094 File
    37095 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37096 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    37097 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    37098 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37099 File
    37100 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37101 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    37102 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    37103 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37104 File
    37105 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37106 packages/chimerax/graphics/drawing.py", line 1108, in
    37107 _first_intercept_excluding_children 
    37108 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    37109 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37110 File
    37111 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37112 packages/chimerax/geometry/place.py", line 201, in inverse 
    37113 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    37114 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37115 File
    37116 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37117 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    37118 rinv[:, :] = matrix_inverse(r) 
    37119 ^^^^^^^^^^^^^^^^^ 
    37120 File
    37121 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37122 packages/numpy/linalg/linalg.py", line 561, in inv 
    37123 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    37124 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37125 File
    37126 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37127 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    37128 raise LinAlgError("Singular matrix") 
    37129 numpy.linalg.LinAlgError: Singular matrix 
    37130  
    37131 numpy.linalg.LinAlgError: Singular matrix 
    37132  
    37133 File
    37134 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37135 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    37136 raise LinAlgError("Singular matrix") 
    37137  
    37138 See log for complete Python traceback. 
    37139  
    37140 Traceback (most recent call last): 
    37141 File
    37142 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37143 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    37144 self.session.ui.mouse_modes.mouse_pause_tracking() 
    37145 File
    37146 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37147 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    37148 mouse_pause_tracking 
    37149 self._mouse_pause() 
    37150 File
    37151 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37152 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    37153 m.pause(self._mouse_pause_position) 
    37154 File
    37155 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37156 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    37157 p = self.view.picked_object(x, y) 
    37158 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37159 File
    37160 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37161 packages/chimerax/graphics/view.py", line 838, in picked_object 
    37162 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    37163 beyond, 
    37164 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37165 File
    37166 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37167 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    37168 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    37169 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37170 File
    37171 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37172 packages/chimerax/core/models.py", line 143, in first_intercept 
    37173 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    37174 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37175 File
    37176 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37177 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    37178 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    37179 exclude=exclude) 
    37180 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37181 File
    37182 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37183 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    37184 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    37185 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37186 File
    37187 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37188 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    37189 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    37190 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37191 File
    37192 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37193 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    37194 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    37195 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37196 File
    37197 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37198 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    37199 p = super().first_intercept(mxyz1, mxyz2) 
    37200 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37201 File
    37202 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37203 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    37204 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    37205 exclude=exclude) 
    37206 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37207 File
    37208 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37209 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    37210 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    37211 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37212 File
    37213 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37214 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    37215 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    37216 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37217 File
    37218 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37219 packages/chimerax/graphics/drawing.py", line 1108, in
    37220 _first_intercept_excluding_children 
    37221 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    37222 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37223 File
    37224 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37225 packages/chimerax/geometry/place.py", line 201, in inverse 
    37226 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    37227 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37228 File
    37229 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37230 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    37231 rinv[:, :] = matrix_inverse(r) 
    37232 ^^^^^^^^^^^^^^^^^ 
    37233 File
    37234 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37235 packages/numpy/linalg/linalg.py", line 561, in inv 
    37236 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    37237 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37238 File
    37239 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37240 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    37241 raise LinAlgError("Singular matrix") 
    37242 numpy.linalg.LinAlgError: Singular matrix 
    37243  
    37244 numpy.linalg.LinAlgError: Singular matrix 
    37245  
    37246 File
    37247 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37248 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    37249 raise LinAlgError("Singular matrix") 
    37250  
    37251 See log for complete Python traceback. 
    37252  
    37253 Traceback (most recent call last): 
    37254 File
    37255 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37256 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    37257 self.session.ui.mouse_modes.mouse_pause_tracking() 
    37258 File
    37259 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37260 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    37261 mouse_pause_tracking 
    37262 self._mouse_pause() 
    37263 File
    37264 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37265 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    37266 m.pause(self._mouse_pause_position) 
    37267 File
    37268 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37269 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    37270 p = self.view.picked_object(x, y) 
    37271 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37272 File
    37273 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37274 packages/chimerax/graphics/view.py", line 838, in picked_object 
    37275 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    37276 beyond, 
    37277 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37278 File
    37279 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37280 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    37281 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    37282 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37283 File
    37284 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37285 packages/chimerax/core/models.py", line 143, in first_intercept 
    37286 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    37287 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37288 File
    37289 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37290 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    37291 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    37292 exclude=exclude) 
    37293 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37294 File
    37295 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37296 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    37297 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    37298 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37299 File
    37300 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37301 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    37302 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    37303 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37304 File
    37305 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37306 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    37307 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    37308 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37309 File
    37310 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37311 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    37312 p = super().first_intercept(mxyz1, mxyz2) 
    37313 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37314 File
    37315 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37316 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    37317 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    37318 exclude=exclude) 
    37319 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37320 File
    37321 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37322 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    37323 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    37324 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37325 File
    37326 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37327 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    37328 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    37329 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37330 File
    37331 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37332 packages/chimerax/graphics/drawing.py", line 1108, in
    37333 _first_intercept_excluding_children 
    37334 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    37335 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37336 File
    37337 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37338 packages/chimerax/geometry/place.py", line 201, in inverse 
    37339 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    37340 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37341 File
    37342 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37343 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    37344 rinv[:, :] = matrix_inverse(r) 
    37345 ^^^^^^^^^^^^^^^^^ 
    37346 File
    37347 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37348 packages/numpy/linalg/linalg.py", line 561, in inv 
    37349 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    37350 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37351 File
    37352 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37353 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    37354 raise LinAlgError("Singular matrix") 
    37355 numpy.linalg.LinAlgError: Singular matrix 
    37356  
    37357 numpy.linalg.LinAlgError: Singular matrix 
    37358  
    37359 File
    37360 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37361 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    37362 raise LinAlgError("Singular matrix") 
    37363  
    37364 See log for complete Python traceback. 
    37365  
    37366 Traceback (most recent call last): 
    37367 File
    37368 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37369 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    37370 self.session.ui.mouse_modes.mouse_pause_tracking() 
    37371 File
    37372 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37373 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    37374 mouse_pause_tracking 
    37375 self._mouse_pause() 
    37376 File
    37377 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37378 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    37379 m.pause(self._mouse_pause_position) 
    37380 File
    37381 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37382 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    37383 p = self.view.picked_object(x, y) 
    37384 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37385 File
    37386 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37387 packages/chimerax/graphics/view.py", line 838, in picked_object 
    37388 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    37389 beyond, 
    37390 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37391 File
    37392 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37393 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    37394 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    37395 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37396 File
    37397 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37398 packages/chimerax/core/models.py", line 143, in first_intercept 
    37399 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    37400 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37401 File
    37402 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37403 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    37404 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    37405 exclude=exclude) 
    37406 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37407 File
    37408 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37409 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    37410 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    37411 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37412 File
    37413 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37414 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    37415 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    37416 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37417 File
    37418 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37419 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    37420 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    37421 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37422 File
    37423 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37424 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    37425 p = super().first_intercept(mxyz1, mxyz2) 
    37426 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37427 File
    37428 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37429 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    37430 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    37431 exclude=exclude) 
    37432 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37433 File
    37434 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37435 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    37436 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    37437 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37438 File
    37439 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37440 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    37441 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    37442 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37443 File
    37444 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37445 packages/chimerax/graphics/drawing.py", line 1108, in
    37446 _first_intercept_excluding_children 
    37447 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    37448 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37449 File
    37450 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37451 packages/chimerax/geometry/place.py", line 201, in inverse 
    37452 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    37453 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37454 File
    37455 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37456 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    37457 rinv[:, :] = matrix_inverse(r) 
    37458 ^^^^^^^^^^^^^^^^^ 
    37459 File
    37460 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37461 packages/numpy/linalg/linalg.py", line 561, in inv 
    37462 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    37463 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37464 File
    37465 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37466 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    37467 raise LinAlgError("Singular matrix") 
    37468 numpy.linalg.LinAlgError: Singular matrix 
    37469  
    37470 numpy.linalg.LinAlgError: Singular matrix 
    37471  
    37472 File
    37473 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37474 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    37475 raise LinAlgError("Singular matrix") 
    37476  
    37477 See log for complete Python traceback. 
    37478  
    37479 Traceback (most recent call last): 
    37480 File
    37481 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37482 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    37483 self.session.ui.mouse_modes.mouse_pause_tracking() 
    37484 File
    37485 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37486 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    37487 mouse_pause_tracking 
    37488 self._mouse_pause() 
    37489 File
    37490 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37491 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    37492 m.pause(self._mouse_pause_position) 
    37493 File
    37494 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37495 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    37496 p = self.view.picked_object(x, y) 
    37497 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37498 File
    37499 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37500 packages/chimerax/graphics/view.py", line 838, in picked_object 
    37501 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    37502 beyond, 
    37503 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37504 File
    37505 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37506 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    37507 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    37508 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37509 File
    37510 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37511 packages/chimerax/core/models.py", line 143, in first_intercept 
    37512 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    37513 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37514 File
    37515 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37516 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    37517 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    37518 exclude=exclude) 
    37519 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37520 File
    37521 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37522 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    37523 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    37524 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37525 File
    37526 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37527 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    37528 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    37529 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37530 File
    37531 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37532 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    37533 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    37534 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37535 File
    37536 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37537 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    37538 p = super().first_intercept(mxyz1, mxyz2) 
    37539 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37540 File
    37541 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37542 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    37543 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    37544 exclude=exclude) 
    37545 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37546 File
    37547 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37548 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    37549 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    37550 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37551 File
    37552 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37553 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    37554 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    37555 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37556 File
    37557 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37558 packages/chimerax/graphics/drawing.py", line 1108, in
    37559 _first_intercept_excluding_children 
    37560 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    37561 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37562 File
    37563 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37564 packages/chimerax/geometry/place.py", line 201, in inverse 
    37565 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    37566 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37567 File
    37568 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37569 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    37570 rinv[:, :] = matrix_inverse(r) 
    37571 ^^^^^^^^^^^^^^^^^ 
    37572 File
    37573 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37574 packages/numpy/linalg/linalg.py", line 561, in inv 
    37575 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    37576 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37577 File
    37578 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37579 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    37580 raise LinAlgError("Singular matrix") 
    37581 numpy.linalg.LinAlgError: Singular matrix 
    37582  
    37583 numpy.linalg.LinAlgError: Singular matrix 
    37584  
    37585 File
    37586 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37587 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    37588 raise LinAlgError("Singular matrix") 
    37589  
    37590 See log for complete Python traceback. 
    37591  
    37592 Traceback (most recent call last): 
    37593 File
    37594 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37595 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    37596 self.session.ui.mouse_modes.mouse_pause_tracking() 
    37597 File
    37598 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37599 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    37600 mouse_pause_tracking 
    37601 self._mouse_pause() 
    37602 File
    37603 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37604 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    37605 m.pause(self._mouse_pause_position) 
    37606 File
    37607 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37608 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    37609 p = self.view.picked_object(x, y) 
    37610 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37611 File
    37612 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37613 packages/chimerax/graphics/view.py", line 838, in picked_object 
    37614 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    37615 beyond, 
    37616 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37617 File
    37618 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37619 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    37620 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    37621 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37622 File
    37623 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37624 packages/chimerax/core/models.py", line 143, in first_intercept 
    37625 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    37626 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37627 File
    37628 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37629 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    37630 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    37631 exclude=exclude) 
    37632 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37633 File
    37634 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37635 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    37636 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    37637 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37638 File
    37639 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37640 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    37641 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    37642 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37643 File
    37644 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37645 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    37646 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    37647 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37648 File
    37649 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37650 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    37651 p = super().first_intercept(mxyz1, mxyz2) 
    37652 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37653 File
    37654 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37655 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    37656 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    37657 exclude=exclude) 
    37658 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37659 File
    37660 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37661 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    37662 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    37663 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37664 File
    37665 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37666 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    37667 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    37668 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37669 File
    37670 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37671 packages/chimerax/graphics/drawing.py", line 1108, in
    37672 _first_intercept_excluding_children 
    37673 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    37674 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37675 File
    37676 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37677 packages/chimerax/geometry/place.py", line 201, in inverse 
    37678 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    37679 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37680 File
    37681 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37682 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    37683 rinv[:, :] = matrix_inverse(r) 
    37684 ^^^^^^^^^^^^^^^^^ 
    37685 File
    37686 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37687 packages/numpy/linalg/linalg.py", line 561, in inv 
    37688 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    37689 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37690 File
    37691 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37692 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    37693 raise LinAlgError("Singular matrix") 
    37694 numpy.linalg.LinAlgError: Singular matrix 
    37695  
    37696 numpy.linalg.LinAlgError: Singular matrix 
    37697  
    37698 File
    37699 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37700 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    37701 raise LinAlgError("Singular matrix") 
    37702  
    37703 See log for complete Python traceback. 
    37704  
    37705 Traceback (most recent call last): 
    37706 File
    37707 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37708 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    37709 self.session.ui.mouse_modes.mouse_pause_tracking() 
    37710 File
    37711 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37712 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    37713 mouse_pause_tracking 
    37714 self._mouse_pause() 
    37715 File
    37716 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37717 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    37718 m.pause(self._mouse_pause_position) 
    37719 File
    37720 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37721 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    37722 p = self.view.picked_object(x, y) 
    37723 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37724 File
    37725 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37726 packages/chimerax/graphics/view.py", line 838, in picked_object 
    37727 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    37728 beyond, 
    37729 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37730 File
    37731 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37732 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    37733 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    37734 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37735 File
    37736 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37737 packages/chimerax/core/models.py", line 143, in first_intercept 
    37738 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    37739 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37740 File
    37741 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37742 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    37743 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    37744 exclude=exclude) 
    37745 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37746 File
    37747 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37748 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    37749 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    37750 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37751 File
    37752 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37753 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    37754 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    37755 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37756 File
    37757 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37758 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    37759 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    37760 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37761 File
    37762 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37763 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    37764 p = super().first_intercept(mxyz1, mxyz2) 
    37765 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37766 File
    37767 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37768 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    37769 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    37770 exclude=exclude) 
    37771 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37772 File
    37773 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37774 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    37775 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    37776 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37777 File
    37778 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37779 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    37780 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    37781 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37782 File
    37783 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37784 packages/chimerax/graphics/drawing.py", line 1108, in
    37785 _first_intercept_excluding_children 
    37786 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    37787 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37788 File
    37789 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37790 packages/chimerax/geometry/place.py", line 201, in inverse 
    37791 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    37792 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37793 File
    37794 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37795 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    37796 rinv[:, :] = matrix_inverse(r) 
    37797 ^^^^^^^^^^^^^^^^^ 
    37798 File
    37799 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37800 packages/numpy/linalg/linalg.py", line 561, in inv 
    37801 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    37802 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37803 File
    37804 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37805 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    37806 raise LinAlgError("Singular matrix") 
    37807 numpy.linalg.LinAlgError: Singular matrix 
    37808  
    37809 numpy.linalg.LinAlgError: Singular matrix 
    37810  
    37811 File
    37812 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37813 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    37814 raise LinAlgError("Singular matrix") 
    37815  
    37816 See log for complete Python traceback. 
    37817  
    37818 Traceback (most recent call last): 
    37819 File
    37820 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37821 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    37822 self.session.ui.mouse_modes.mouse_pause_tracking() 
    37823 File
    37824 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37825 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    37826 mouse_pause_tracking 
    37827 self._mouse_pause() 
    37828 File
    37829 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37830 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    37831 m.pause(self._mouse_pause_position) 
    37832 File
    37833 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37834 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    37835 p = self.view.picked_object(x, y) 
    37836 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37837 File
    37838 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37839 packages/chimerax/graphics/view.py", line 838, in picked_object 
    37840 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    37841 beyond, 
    37842 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37843 File
    37844 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37845 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    37846 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    37847 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37848 File
    37849 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37850 packages/chimerax/core/models.py", line 143, in first_intercept 
    37851 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    37852 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37853 File
    37854 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37855 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    37856 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    37857 exclude=exclude) 
    37858 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37859 File
    37860 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37861 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    37862 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    37863 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37864 File
    37865 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37866 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    37867 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    37868 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37869 File
    37870 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37871 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    37872 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    37873 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37874 File
    37875 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37876 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    37877 p = super().first_intercept(mxyz1, mxyz2) 
    37878 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37879 File
    37880 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37881 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    37882 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    37883 exclude=exclude) 
    37884 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37885 File
    37886 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37887 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    37888 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    37889 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37890 File
    37891 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37892 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    37893 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    37894 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37895 File
    37896 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37897 packages/chimerax/graphics/drawing.py", line 1108, in
    37898 _first_intercept_excluding_children 
    37899 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    37900 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37901 File
    37902 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37903 packages/chimerax/geometry/place.py", line 201, in inverse 
    37904 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    37905 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37906 File
    37907 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37908 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    37909 rinv[:, :] = matrix_inverse(r) 
    37910 ^^^^^^^^^^^^^^^^^ 
    37911 File
    37912 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37913 packages/numpy/linalg/linalg.py", line 561, in inv 
    37914 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    37915 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37916 File
    37917 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37918 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    37919 raise LinAlgError("Singular matrix") 
    37920 numpy.linalg.LinAlgError: Singular matrix 
    37921  
    37922 numpy.linalg.LinAlgError: Singular matrix 
    37923  
    37924 File
    37925 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37926 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    37927 raise LinAlgError("Singular matrix") 
    37928  
    37929 See log for complete Python traceback. 
    37930  
    37931 Traceback (most recent call last): 
    37932 File
    37933 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37934 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    37935 self.session.ui.mouse_modes.mouse_pause_tracking() 
    37936 File
    37937 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37938 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    37939 mouse_pause_tracking 
    37940 self._mouse_pause() 
    37941 File
    37942 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37943 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    37944 m.pause(self._mouse_pause_position) 
    37945 File
    37946 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37947 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    37948 p = self.view.picked_object(x, y) 
    37949 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37950 File
    37951 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37952 packages/chimerax/graphics/view.py", line 838, in picked_object 
    37953 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    37954 beyond, 
    37955 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37956 File
    37957 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37958 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    37959 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    37960 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37961 File
    37962 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37963 packages/chimerax/core/models.py", line 143, in first_intercept 
    37964 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    37965 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37966 File
    37967 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37968 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    37969 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    37970 exclude=exclude) 
    37971 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37972 File
    37973 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37974 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    37975 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    37976 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37977 File
    37978 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37979 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    37980 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    37981 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37982 File
    37983 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37984 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    37985 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    37986 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37987 File
    37988 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37989 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    37990 p = super().first_intercept(mxyz1, mxyz2) 
    37991 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37992 File
    37993 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    37994 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    37995 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    37996 exclude=exclude) 
    37997 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    37998 File
    37999 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38000 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    38001 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    38002 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38003 File
    38004 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38005 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    38006 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    38007 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38008 File
    38009 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38010 packages/chimerax/graphics/drawing.py", line 1108, in
    38011 _first_intercept_excluding_children 
    38012 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    38013 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38014 File
    38015 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38016 packages/chimerax/geometry/place.py", line 201, in inverse 
    38017 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    38018 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38019 File
    38020 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38021 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    38022 rinv[:, :] = matrix_inverse(r) 
    38023 ^^^^^^^^^^^^^^^^^ 
    38024 File
    38025 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38026 packages/numpy/linalg/linalg.py", line 561, in inv 
    38027 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    38028 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38029 File
    38030 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38031 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    38032 raise LinAlgError("Singular matrix") 
    38033 numpy.linalg.LinAlgError: Singular matrix 
    38034  
    38035 numpy.linalg.LinAlgError: Singular matrix 
    38036  
    38037 File
    38038 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38039 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    38040 raise LinAlgError("Singular matrix") 
    38041  
    38042 See log for complete Python traceback. 
    38043  
    38044 Traceback (most recent call last): 
    38045 File
    38046 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38047 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    38048 self.session.ui.mouse_modes.mouse_pause_tracking() 
    38049 File
    38050 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38051 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    38052 mouse_pause_tracking 
    38053 self._mouse_pause() 
    38054 File
    38055 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38056 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    38057 m.pause(self._mouse_pause_position) 
    38058 File
    38059 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38060 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    38061 p = self.view.picked_object(x, y) 
    38062 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38063 File
    38064 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38065 packages/chimerax/graphics/view.py", line 838, in picked_object 
    38066 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    38067 beyond, 
    38068 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38069 File
    38070 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38071 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    38072 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    38073 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38074 File
    38075 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38076 packages/chimerax/core/models.py", line 143, in first_intercept 
    38077 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    38078 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38079 File
    38080 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38081 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    38082 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    38083 exclude=exclude) 
    38084 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38085 File
    38086 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38087 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    38088 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    38089 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38090 File
    38091 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38092 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    38093 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    38094 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38095 File
    38096 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38097 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    38098 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    38099 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38100 File
    38101 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38102 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    38103 p = super().first_intercept(mxyz1, mxyz2) 
    38104 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38105 File
    38106 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38107 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    38108 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    38109 exclude=exclude) 
    38110 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38111 File
    38112 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38113 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    38114 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    38115 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38116 File
    38117 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38118 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    38119 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    38120 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38121 File
    38122 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38123 packages/chimerax/graphics/drawing.py", line 1108, in
    38124 _first_intercept_excluding_children 
    38125 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    38126 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38127 File
    38128 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38129 packages/chimerax/geometry/place.py", line 201, in inverse 
    38130 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    38131 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38132 File
    38133 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38134 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    38135 rinv[:, :] = matrix_inverse(r) 
    38136 ^^^^^^^^^^^^^^^^^ 
    38137 File
    38138 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38139 packages/numpy/linalg/linalg.py", line 561, in inv 
    38140 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    38141 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38142 File
    38143 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38144 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    38145 raise LinAlgError("Singular matrix") 
    38146 numpy.linalg.LinAlgError: Singular matrix 
    38147  
    38148 numpy.linalg.LinAlgError: Singular matrix 
    38149  
    38150 File
    38151 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38152 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    38153 raise LinAlgError("Singular matrix") 
    38154  
    38155 See log for complete Python traceback. 
    38156  
    38157 Traceback (most recent call last): 
    38158 File
    38159 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38160 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    38161 self.session.ui.mouse_modes.mouse_pause_tracking() 
    38162 File
    38163 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38164 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    38165 mouse_pause_tracking 
    38166 self._mouse_pause() 
    38167 File
    38168 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38169 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    38170 m.pause(self._mouse_pause_position) 
    38171 File
    38172 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38173 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    38174 p = self.view.picked_object(x, y) 
    38175 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38176 File
    38177 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38178 packages/chimerax/graphics/view.py", line 838, in picked_object 
    38179 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    38180 beyond, 
    38181 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38182 File
    38183 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38184 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    38185 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    38186 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38187 File
    38188 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38189 packages/chimerax/core/models.py", line 143, in first_intercept 
    38190 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    38191 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38192 File
    38193 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38194 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    38195 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    38196 exclude=exclude) 
    38197 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38198 File
    38199 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38200 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    38201 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    38202 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38203 File
    38204 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38205 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    38206 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    38207 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38208 File
    38209 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38210 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    38211 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    38212 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38213 File
    38214 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38215 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    38216 p = super().first_intercept(mxyz1, mxyz2) 
    38217 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38218 File
    38219 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38220 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    38221 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    38222 exclude=exclude) 
    38223 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38224 File
    38225 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38226 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    38227 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    38228 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38229 File
    38230 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38231 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    38232 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    38233 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38234 File
    38235 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38236 packages/chimerax/graphics/drawing.py", line 1108, in
    38237 _first_intercept_excluding_children 
    38238 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    38239 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38240 File
    38241 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38242 packages/chimerax/geometry/place.py", line 201, in inverse 
    38243 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    38244 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38245 File
    38246 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38247 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    38248 rinv[:, :] = matrix_inverse(r) 
    38249 ^^^^^^^^^^^^^^^^^ 
    38250 File
    38251 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38252 packages/numpy/linalg/linalg.py", line 561, in inv 
    38253 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    38254 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38255 File
    38256 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38257 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    38258 raise LinAlgError("Singular matrix") 
    38259 numpy.linalg.LinAlgError: Singular matrix 
    38260  
    38261 numpy.linalg.LinAlgError: Singular matrix 
    38262  
    38263 File
    38264 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38265 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    38266 raise LinAlgError("Singular matrix") 
    38267  
    38268 See log for complete Python traceback. 
    38269  
    38270 Traceback (most recent call last): 
    38271 File
    38272 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38273 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    38274 self.session.ui.mouse_modes.mouse_pause_tracking() 
    38275 File
    38276 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38277 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    38278 mouse_pause_tracking 
    38279 self._mouse_pause() 
    38280 File
    38281 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38282 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    38283 m.pause(self._mouse_pause_position) 
    38284 File
    38285 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38286 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    38287 p = self.view.picked_object(x, y) 
    38288 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38289 File
    38290 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38291 packages/chimerax/graphics/view.py", line 838, in picked_object 
    38292 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    38293 beyond, 
    38294 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38295 File
    38296 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38297 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    38298 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    38299 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38300 File
    38301 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38302 packages/chimerax/core/models.py", line 143, in first_intercept 
    38303 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    38304 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38305 File
    38306 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38307 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    38308 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    38309 exclude=exclude) 
    38310 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38311 File
    38312 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38313 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    38314 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    38315 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38316 File
    38317 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38318 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    38319 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    38320 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38321 File
    38322 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38323 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    38324 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    38325 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38326 File
    38327 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38328 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    38329 p = super().first_intercept(mxyz1, mxyz2) 
    38330 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38331 File
    38332 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38333 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    38334 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    38335 exclude=exclude) 
    38336 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38337 File
    38338 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38339 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    38340 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    38341 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38342 File
    38343 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38344 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    38345 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    38346 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38347 File
    38348 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38349 packages/chimerax/graphics/drawing.py", line 1108, in
    38350 _first_intercept_excluding_children 
    38351 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    38352 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38353 File
    38354 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38355 packages/chimerax/geometry/place.py", line 201, in inverse 
    38356 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    38357 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38358 File
    38359 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38360 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    38361 rinv[:, :] = matrix_inverse(r) 
    38362 ^^^^^^^^^^^^^^^^^ 
    38363 File
    38364 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38365 packages/numpy/linalg/linalg.py", line 561, in inv 
    38366 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    38367 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38368 File
    38369 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38370 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    38371 raise LinAlgError("Singular matrix") 
    38372 numpy.linalg.LinAlgError: Singular matrix 
    38373  
    38374 numpy.linalg.LinAlgError: Singular matrix 
    38375  
    38376 File
    38377 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38378 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    38379 raise LinAlgError("Singular matrix") 
    38380  
    38381 See log for complete Python traceback. 
    38382  
    38383 Traceback (most recent call last): 
    38384 File
    38385 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38386 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    38387 self.session.ui.mouse_modes.mouse_pause_tracking() 
    38388 File
    38389 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38390 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    38391 mouse_pause_tracking 
    38392 self._mouse_pause() 
    38393 File
    38394 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38395 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    38396 m.pause(self._mouse_pause_position) 
    38397 File
    38398 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38399 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    38400 p = self.view.picked_object(x, y) 
    38401 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38402 File
    38403 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38404 packages/chimerax/graphics/view.py", line 838, in picked_object 
    38405 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    38406 beyond, 
    38407 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38408 File
    38409 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38410 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    38411 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    38412 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38413 File
    38414 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38415 packages/chimerax/core/models.py", line 143, in first_intercept 
    38416 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    38417 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38418 File
    38419 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38420 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    38421 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    38422 exclude=exclude) 
    38423 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38424 File
    38425 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38426 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    38427 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    38428 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38429 File
    38430 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38431 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    38432 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    38433 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38434 File
    38435 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38436 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    38437 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    38438 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38439 File
    38440 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38441 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    38442 p = super().first_intercept(mxyz1, mxyz2) 
    38443 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38444 File
    38445 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38446 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    38447 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    38448 exclude=exclude) 
    38449 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38450 File
    38451 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38452 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    38453 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    38454 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38455 File
    38456 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38457 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    38458 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    38459 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38460 File
    38461 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38462 packages/chimerax/graphics/drawing.py", line 1108, in
    38463 _first_intercept_excluding_children 
    38464 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    38465 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38466 File
    38467 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38468 packages/chimerax/geometry/place.py", line 201, in inverse 
    38469 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    38470 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38471 File
    38472 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38473 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    38474 rinv[:, :] = matrix_inverse(r) 
    38475 ^^^^^^^^^^^^^^^^^ 
    38476 File
    38477 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38478 packages/numpy/linalg/linalg.py", line 561, in inv 
    38479 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    38480 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38481 File
    38482 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38483 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    38484 raise LinAlgError("Singular matrix") 
    38485 numpy.linalg.LinAlgError: Singular matrix 
    38486  
    38487 numpy.linalg.LinAlgError: Singular matrix 
    38488  
    38489 File
    38490 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38491 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    38492 raise LinAlgError("Singular matrix") 
    38493  
    38494 See log for complete Python traceback. 
    38495  
    38496 Traceback (most recent call last): 
    38497 File
    38498 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38499 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    38500 self.session.ui.mouse_modes.mouse_pause_tracking() 
    38501 File
    38502 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38503 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    38504 mouse_pause_tracking 
    38505 self._mouse_pause() 
    38506 File
    38507 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38508 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    38509 m.pause(self._mouse_pause_position) 
    38510 File
    38511 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38512 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    38513 p = self.view.picked_object(x, y) 
    38514 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38515 File
    38516 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38517 packages/chimerax/graphics/view.py", line 838, in picked_object 
    38518 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    38519 beyond, 
    38520 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38521 File
    38522 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38523 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    38524 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    38525 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38526 File
    38527 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38528 packages/chimerax/core/models.py", line 143, in first_intercept 
    38529 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    38530 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38531 File
    38532 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38533 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    38534 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    38535 exclude=exclude) 
    38536 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38537 File
    38538 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38539 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    38540 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    38541 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38542 File
    38543 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38544 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    38545 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    38546 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38547 File
    38548 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38549 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    38550 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    38551 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38552 File
    38553 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38554 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    38555 p = super().first_intercept(mxyz1, mxyz2) 
    38556 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38557 File
    38558 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38559 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    38560 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    38561 exclude=exclude) 
    38562 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38563 File
    38564 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38565 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    38566 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    38567 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38568 File
    38569 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38570 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    38571 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    38572 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38573 File
    38574 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38575 packages/chimerax/graphics/drawing.py", line 1108, in
    38576 _first_intercept_excluding_children 
    38577 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    38578 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38579 File
    38580 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38581 packages/chimerax/geometry/place.py", line 201, in inverse 
    38582 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    38583 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38584 File
    38585 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38586 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    38587 rinv[:, :] = matrix_inverse(r) 
    38588 ^^^^^^^^^^^^^^^^^ 
    38589 File
    38590 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38591 packages/numpy/linalg/linalg.py", line 561, in inv 
    38592 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    38593 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38594 File
    38595 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38596 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    38597 raise LinAlgError("Singular matrix") 
    38598 numpy.linalg.LinAlgError: Singular matrix 
    38599  
    38600 numpy.linalg.LinAlgError: Singular matrix 
    38601  
    38602 File
    38603 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38604 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    38605 raise LinAlgError("Singular matrix") 
    38606  
    38607 See log for complete Python traceback. 
    38608  
    38609 Traceback (most recent call last): 
    38610 File
    38611 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38612 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    38613 self.session.ui.mouse_modes.mouse_pause_tracking() 
    38614 File
    38615 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38616 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    38617 mouse_pause_tracking 
    38618 self._mouse_pause() 
    38619 File
    38620 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38621 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    38622 m.pause(self._mouse_pause_position) 
    38623 File
    38624 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38625 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    38626 p = self.view.picked_object(x, y) 
    38627 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38628 File
    38629 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38630 packages/chimerax/graphics/view.py", line 838, in picked_object 
    38631 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    38632 beyond, 
    38633 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38634 File
    38635 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38636 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    38637 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    38638 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38639 File
    38640 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38641 packages/chimerax/core/models.py", line 143, in first_intercept 
    38642 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    38643 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38644 File
    38645 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38646 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    38647 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    38648 exclude=exclude) 
    38649 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38650 File
    38651 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38652 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    38653 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    38654 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38655 File
    38656 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38657 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    38658 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    38659 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38660 File
    38661 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38662 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    38663 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    38664 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38665 File
    38666 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38667 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    38668 p = super().first_intercept(mxyz1, mxyz2) 
    38669 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38670 File
    38671 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38672 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    38673 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    38674 exclude=exclude) 
    38675 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38676 File
    38677 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38678 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    38679 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    38680 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38681 File
    38682 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38683 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    38684 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    38685 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38686 File
    38687 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38688 packages/chimerax/graphics/drawing.py", line 1108, in
    38689 _first_intercept_excluding_children 
    38690 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    38691 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38692 File
    38693 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38694 packages/chimerax/geometry/place.py", line 201, in inverse 
    38695 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    38696 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38697 File
    38698 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38699 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    38700 rinv[:, :] = matrix_inverse(r) 
    38701 ^^^^^^^^^^^^^^^^^ 
    38702 File
    38703 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38704 packages/numpy/linalg/linalg.py", line 561, in inv 
    38705 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    38706 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38707 File
    38708 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38709 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    38710 raise LinAlgError("Singular matrix") 
    38711 numpy.linalg.LinAlgError: Singular matrix 
    38712  
    38713 numpy.linalg.LinAlgError: Singular matrix 
    38714  
    38715 File
    38716 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38717 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    38718 raise LinAlgError("Singular matrix") 
    38719  
    38720 See log for complete Python traceback. 
    38721  
    38722 Traceback (most recent call last): 
    38723 File
    38724 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38725 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    38726 self.session.ui.mouse_modes.mouse_pause_tracking() 
    38727 File
    38728 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38729 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    38730 mouse_pause_tracking 
    38731 self._mouse_pause() 
    38732 File
    38733 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38734 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    38735 m.pause(self._mouse_pause_position) 
    38736 File
    38737 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38738 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    38739 p = self.view.picked_object(x, y) 
    38740 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38741 File
    38742 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38743 packages/chimerax/graphics/view.py", line 838, in picked_object 
    38744 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    38745 beyond, 
    38746 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38747 File
    38748 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38749 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    38750 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    38751 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38752 File
    38753 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38754 packages/chimerax/core/models.py", line 143, in first_intercept 
    38755 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    38756 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38757 File
    38758 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38759 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    38760 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    38761 exclude=exclude) 
    38762 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38763 File
    38764 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38765 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    38766 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    38767 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38768 File
    38769 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38770 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    38771 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    38772 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38773 File
    38774 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38775 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    38776 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    38777 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38778 File
    38779 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38780 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    38781 p = super().first_intercept(mxyz1, mxyz2) 
    38782 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38783 File
    38784 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38785 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    38786 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    38787 exclude=exclude) 
    38788 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38789 File
    38790 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38791 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    38792 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    38793 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38794 File
    38795 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38796 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    38797 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    38798 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38799 File
    38800 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38801 packages/chimerax/graphics/drawing.py", line 1108, in
    38802 _first_intercept_excluding_children 
    38803 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    38804 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38805 File
    38806 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38807 packages/chimerax/geometry/place.py", line 201, in inverse 
    38808 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    38809 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38810 File
    38811 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38812 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    38813 rinv[:, :] = matrix_inverse(r) 
    38814 ^^^^^^^^^^^^^^^^^ 
    38815 File
    38816 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38817 packages/numpy/linalg/linalg.py", line 561, in inv 
    38818 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    38819 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38820 File
    38821 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38822 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    38823 raise LinAlgError("Singular matrix") 
    38824 numpy.linalg.LinAlgError: Singular matrix 
    38825  
    38826 numpy.linalg.LinAlgError: Singular matrix 
    38827  
    38828 File
    38829 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38830 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    38831 raise LinAlgError("Singular matrix") 
    38832  
    38833 See log for complete Python traceback. 
    38834  
    38835 Traceback (most recent call last): 
    38836 File
    38837 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38838 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    38839 self.session.ui.mouse_modes.mouse_pause_tracking() 
    38840 File
    38841 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38842 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    38843 mouse_pause_tracking 
    38844 self._mouse_pause() 
    38845 File
    38846 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38847 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    38848 m.pause(self._mouse_pause_position) 
    38849 File
    38850 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38851 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    38852 p = self.view.picked_object(x, y) 
    38853 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38854 File
    38855 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38856 packages/chimerax/graphics/view.py", line 838, in picked_object 
    38857 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    38858 beyond, 
    38859 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38860 File
    38861 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38862 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    38863 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    38864 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38865 File
    38866 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38867 packages/chimerax/core/models.py", line 143, in first_intercept 
    38868 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    38869 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38870 File
    38871 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38872 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    38873 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    38874 exclude=exclude) 
    38875 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38876 File
    38877 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38878 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    38879 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    38880 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38881 File
    38882 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38883 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    38884 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    38885 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38886 File
    38887 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38888 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    38889 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    38890 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38891 File
    38892 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38893 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    38894 p = super().first_intercept(mxyz1, mxyz2) 
    38895 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38896 File
    38897 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38898 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    38899 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    38900 exclude=exclude) 
    38901 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38902 File
    38903 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38904 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    38905 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    38906 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38907 File
    38908 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38909 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    38910 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    38911 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38912 File
    38913 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38914 packages/chimerax/graphics/drawing.py", line 1108, in
    38915 _first_intercept_excluding_children 
    38916 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    38917 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38918 File
    38919 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38920 packages/chimerax/geometry/place.py", line 201, in inverse 
    38921 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    38922 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38923 File
    38924 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38925 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    38926 rinv[:, :] = matrix_inverse(r) 
    38927 ^^^^^^^^^^^^^^^^^ 
    38928 File
    38929 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38930 packages/numpy/linalg/linalg.py", line 561, in inv 
    38931 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    38932 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38933 File
    38934 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38935 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    38936 raise LinAlgError("Singular matrix") 
    38937 numpy.linalg.LinAlgError: Singular matrix 
    38938  
    38939 numpy.linalg.LinAlgError: Singular matrix 
    38940  
    38941 File
    38942 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38943 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    38944 raise LinAlgError("Singular matrix") 
    38945  
    38946 See log for complete Python traceback. 
    38947  
    38948 Traceback (most recent call last): 
    38949 File
    38950 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38951 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    38952 self.session.ui.mouse_modes.mouse_pause_tracking() 
    38953 File
    38954 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38955 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    38956 mouse_pause_tracking 
    38957 self._mouse_pause() 
    38958 File
    38959 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38960 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    38961 m.pause(self._mouse_pause_position) 
    38962 File
    38963 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38964 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    38965 p = self.view.picked_object(x, y) 
    38966 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38967 File
    38968 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38969 packages/chimerax/graphics/view.py", line 838, in picked_object 
    38970 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    38971 beyond, 
    38972 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38973 File
    38974 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38975 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    38976 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    38977 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38978 File
    38979 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38980 packages/chimerax/core/models.py", line 143, in first_intercept 
    38981 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    38982 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38983 File
    38984 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38985 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    38986 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    38987 exclude=exclude) 
    38988 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38989 File
    38990 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38991 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    38992 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    38993 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38994 File
    38995 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    38996 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    38997 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    38998 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    38999 File
    39000 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39001 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    39002 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    39003 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39004 File
    39005 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39006 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    39007 p = super().first_intercept(mxyz1, mxyz2) 
    39008 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39009 File
    39010 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39011 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    39012 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    39013 exclude=exclude) 
    39014 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39015 File
    39016 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39017 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    39018 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    39019 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39020 File
    39021 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39022 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    39023 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    39024 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39025 File
    39026 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39027 packages/chimerax/graphics/drawing.py", line 1108, in
    39028 _first_intercept_excluding_children 
    39029 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    39030 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39031 File
    39032 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39033 packages/chimerax/geometry/place.py", line 201, in inverse 
    39034 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    39035 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39036 File
    39037 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39038 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    39039 rinv[:, :] = matrix_inverse(r) 
    39040 ^^^^^^^^^^^^^^^^^ 
    39041 File
    39042 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39043 packages/numpy/linalg/linalg.py", line 561, in inv 
    39044 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    39045 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39046 File
    39047 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39048 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    39049 raise LinAlgError("Singular matrix") 
    39050 numpy.linalg.LinAlgError: Singular matrix 
    39051  
    39052 numpy.linalg.LinAlgError: Singular matrix 
    39053  
    39054 File
    39055 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39056 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    39057 raise LinAlgError("Singular matrix") 
    39058  
    39059 See log for complete Python traceback. 
    39060  
    39061 Traceback (most recent call last): 
    39062 File
    39063 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39064 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    39065 self.session.ui.mouse_modes.mouse_pause_tracking() 
    39066 File
    39067 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39068 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    39069 mouse_pause_tracking 
    39070 self._mouse_pause() 
    39071 File
    39072 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39073 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    39074 m.pause(self._mouse_pause_position) 
    39075 File
    39076 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39077 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    39078 p = self.view.picked_object(x, y) 
    39079 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39080 File
    39081 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39082 packages/chimerax/graphics/view.py", line 838, in picked_object 
    39083 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    39084 beyond, 
    39085 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39086 File
    39087 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39088 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    39089 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    39090 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39091 File
    39092 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39093 packages/chimerax/core/models.py", line 143, in first_intercept 
    39094 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    39095 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39096 File
    39097 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39098 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    39099 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    39100 exclude=exclude) 
    39101 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39102 File
    39103 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39104 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    39105 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    39106 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39107 File
    39108 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39109 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    39110 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    39111 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39112 File
    39113 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39114 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    39115 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    39116 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39117 File
    39118 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39119 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    39120 p = super().first_intercept(mxyz1, mxyz2) 
    39121 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39122 File
    39123 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39124 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    39125 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    39126 exclude=exclude) 
    39127 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39128 File
    39129 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39130 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    39131 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    39132 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39133 File
    39134 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39135 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    39136 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    39137 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39138 File
    39139 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39140 packages/chimerax/graphics/drawing.py", line 1108, in
    39141 _first_intercept_excluding_children 
    39142 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    39143 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39144 File
    39145 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39146 packages/chimerax/geometry/place.py", line 201, in inverse 
    39147 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    39148 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39149 File
    39150 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39151 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    39152 rinv[:, :] = matrix_inverse(r) 
    39153 ^^^^^^^^^^^^^^^^^ 
    39154 File
    39155 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39156 packages/numpy/linalg/linalg.py", line 561, in inv 
    39157 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    39158 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39159 File
    39160 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39161 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    39162 raise LinAlgError("Singular matrix") 
    39163 numpy.linalg.LinAlgError: Singular matrix 
    39164  
    39165 numpy.linalg.LinAlgError: Singular matrix 
    39166  
    39167 File
    39168 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39169 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    39170 raise LinAlgError("Singular matrix") 
    39171  
    39172 See log for complete Python traceback. 
    39173  
    39174 Traceback (most recent call last): 
    39175 File
    39176 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39177 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    39178 self.session.ui.mouse_modes.mouse_pause_tracking() 
    39179 File
    39180 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39181 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    39182 mouse_pause_tracking 
    39183 self._mouse_pause() 
    39184 File
    39185 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39186 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    39187 m.pause(self._mouse_pause_position) 
    39188 File
    39189 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39190 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    39191 p = self.view.picked_object(x, y) 
    39192 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39193 File
    39194 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39195 packages/chimerax/graphics/view.py", line 838, in picked_object 
    39196 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    39197 beyond, 
    39198 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39199 File
    39200 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39201 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    39202 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    39203 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39204 File
    39205 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39206 packages/chimerax/core/models.py", line 143, in first_intercept 
    39207 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    39208 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39209 File
    39210 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39211 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    39212 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    39213 exclude=exclude) 
    39214 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39215 File
    39216 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39217 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    39218 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    39219 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39220 File
    39221 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39222 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    39223 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    39224 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39225 File
    39226 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39227 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    39228 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    39229 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39230 File
    39231 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39232 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    39233 p = super().first_intercept(mxyz1, mxyz2) 
    39234 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39235 File
    39236 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39237 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    39238 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    39239 exclude=exclude) 
    39240 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39241 File
    39242 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39243 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    39244 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    39245 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39246 File
    39247 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39248 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    39249 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    39250 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39251 File
    39252 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39253 packages/chimerax/graphics/drawing.py", line 1108, in
    39254 _first_intercept_excluding_children 
    39255 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    39256 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39257 File
    39258 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39259 packages/chimerax/geometry/place.py", line 201, in inverse 
    39260 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    39261 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39262 File
    39263 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39264 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    39265 rinv[:, :] = matrix_inverse(r) 
    39266 ^^^^^^^^^^^^^^^^^ 
    39267 File
    39268 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39269 packages/numpy/linalg/linalg.py", line 561, in inv 
    39270 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    39271 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39272 File
    39273 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39274 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    39275 raise LinAlgError("Singular matrix") 
    39276 numpy.linalg.LinAlgError: Singular matrix 
    39277  
    39278 numpy.linalg.LinAlgError: Singular matrix 
    39279  
    39280 File
    39281 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39282 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    39283 raise LinAlgError("Singular matrix") 
    39284  
    39285 See log for complete Python traceback. 
    39286  
    39287 Traceback (most recent call last): 
    39288 File
    39289 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39290 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    39291 self.session.ui.mouse_modes.mouse_pause_tracking() 
    39292 File
    39293 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39294 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    39295 mouse_pause_tracking 
    39296 self._mouse_pause() 
    39297 File
    39298 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39299 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    39300 m.pause(self._mouse_pause_position) 
    39301 File
    39302 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39303 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    39304 p = self.view.picked_object(x, y) 
    39305 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39306 File
    39307 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39308 packages/chimerax/graphics/view.py", line 838, in picked_object 
    39309 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    39310 beyond, 
    39311 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39312 File
    39313 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39314 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    39315 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    39316 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39317 File
    39318 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39319 packages/chimerax/core/models.py", line 143, in first_intercept 
    39320 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    39321 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39322 File
    39323 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39324 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    39325 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    39326 exclude=exclude) 
    39327 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39328 File
    39329 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39330 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    39331 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    39332 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39333 File
    39334 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39335 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    39336 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    39337 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39338 File
    39339 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39340 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    39341 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    39342 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39343 File
    39344 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39345 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    39346 p = super().first_intercept(mxyz1, mxyz2) 
    39347 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39348 File
    39349 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39350 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    39351 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    39352 exclude=exclude) 
    39353 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39354 File
    39355 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39356 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    39357 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    39358 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39359 File
    39360 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39361 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    39362 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    39363 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39364 File
    39365 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39366 packages/chimerax/graphics/drawing.py", line 1108, in
    39367 _first_intercept_excluding_children 
    39368 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    39369 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39370 File
    39371 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39372 packages/chimerax/geometry/place.py", line 201, in inverse 
    39373 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    39374 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39375 File
    39376 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39377 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    39378 rinv[:, :] = matrix_inverse(r) 
    39379 ^^^^^^^^^^^^^^^^^ 
    39380 File
    39381 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39382 packages/numpy/linalg/linalg.py", line 561, in inv 
    39383 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    39384 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39385 File
    39386 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39387 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    39388 raise LinAlgError("Singular matrix") 
    39389 numpy.linalg.LinAlgError: Singular matrix 
    39390  
    39391 numpy.linalg.LinAlgError: Singular matrix 
    39392  
    39393 File
    39394 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39395 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    39396 raise LinAlgError("Singular matrix") 
    39397  
    39398 See log for complete Python traceback. 
    39399  
    39400 Traceback (most recent call last): 
    39401 File
    39402 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39403 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    39404 self.session.ui.mouse_modes.mouse_pause_tracking() 
    39405 File
    39406 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39407 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    39408 mouse_pause_tracking 
    39409 self._mouse_pause() 
    39410 File
    39411 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39412 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    39413 m.pause(self._mouse_pause_position) 
    39414 File
    39415 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39416 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    39417 p = self.view.picked_object(x, y) 
    39418 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39419 File
    39420 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39421 packages/chimerax/graphics/view.py", line 838, in picked_object 
    39422 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    39423 beyond, 
    39424 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39425 File
    39426 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39427 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    39428 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    39429 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39430 File
    39431 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39432 packages/chimerax/core/models.py", line 143, in first_intercept 
    39433 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    39434 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39435 File
    39436 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39437 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    39438 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    39439 exclude=exclude) 
    39440 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39441 File
    39442 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39443 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    39444 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    39445 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39446 File
    39447 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39448 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    39449 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    39450 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39451 File
    39452 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39453 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    39454 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    39455 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39456 File
    39457 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39458 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    39459 p = super().first_intercept(mxyz1, mxyz2) 
    39460 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39461 File
    39462 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39463 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    39464 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    39465 exclude=exclude) 
    39466 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39467 File
    39468 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39469 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    39470 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    39471 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39472 File
    39473 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39474 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    39475 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    39476 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39477 File
    39478 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39479 packages/chimerax/graphics/drawing.py", line 1108, in
    39480 _first_intercept_excluding_children 
    39481 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    39482 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39483 File
    39484 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39485 packages/chimerax/geometry/place.py", line 201, in inverse 
    39486 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    39487 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39488 File
    39489 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39490 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    39491 rinv[:, :] = matrix_inverse(r) 
    39492 ^^^^^^^^^^^^^^^^^ 
    39493 File
    39494 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39495 packages/numpy/linalg/linalg.py", line 561, in inv 
    39496 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    39497 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39498 File
    39499 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39500 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    39501 raise LinAlgError("Singular matrix") 
    39502 numpy.linalg.LinAlgError: Singular matrix 
    39503  
    39504 numpy.linalg.LinAlgError: Singular matrix 
    39505  
    39506 File
    39507 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39508 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    39509 raise LinAlgError("Singular matrix") 
    39510  
    39511 See log for complete Python traceback. 
    39512  
    39513 Traceback (most recent call last): 
    39514 File
    39515 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39516 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    39517 self.session.ui.mouse_modes.mouse_pause_tracking() 
    39518 File
    39519 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39520 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    39521 mouse_pause_tracking 
    39522 self._mouse_pause() 
    39523 File
    39524 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39525 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    39526 m.pause(self._mouse_pause_position) 
    39527 File
    39528 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39529 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    39530 p = self.view.picked_object(x, y) 
    39531 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39532 File
    39533 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39534 packages/chimerax/graphics/view.py", line 838, in picked_object 
    39535 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    39536 beyond, 
    39537 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39538 File
    39539 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39540 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    39541 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    39542 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39543 File
    39544 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39545 packages/chimerax/core/models.py", line 143, in first_intercept 
    39546 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    39547 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39548 File
    39549 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39550 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    39551 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    39552 exclude=exclude) 
    39553 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39554 File
    39555 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39556 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    39557 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    39558 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39559 File
    39560 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39561 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    39562 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    39563 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39564 File
    39565 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39566 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    39567 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    39568 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39569 File
    39570 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39571 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    39572 p = super().first_intercept(mxyz1, mxyz2) 
    39573 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39574 File
    39575 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39576 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    39577 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    39578 exclude=exclude) 
    39579 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39580 File
    39581 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39582 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    39583 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    39584 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39585 File
    39586 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39587 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    39588 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    39589 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39590 File
    39591 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39592 packages/chimerax/graphics/drawing.py", line 1108, in
    39593 _first_intercept_excluding_children 
    39594 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    39595 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39596 File
    39597 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39598 packages/chimerax/geometry/place.py", line 201, in inverse 
    39599 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    39600 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39601 File
    39602 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39603 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    39604 rinv[:, :] = matrix_inverse(r) 
    39605 ^^^^^^^^^^^^^^^^^ 
    39606 File
    39607 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39608 packages/numpy/linalg/linalg.py", line 561, in inv 
    39609 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    39610 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39611 File
    39612 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39613 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    39614 raise LinAlgError("Singular matrix") 
    39615 numpy.linalg.LinAlgError: Singular matrix 
    39616  
    39617 numpy.linalg.LinAlgError: Singular matrix 
    39618  
    39619 File
    39620 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39621 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    39622 raise LinAlgError("Singular matrix") 
    39623  
    39624 See log for complete Python traceback. 
    39625  
    39626 Traceback (most recent call last): 
    39627 File
    39628 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39629 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    39630 self.session.ui.mouse_modes.mouse_pause_tracking() 
    39631 File
    39632 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39633 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    39634 mouse_pause_tracking 
    39635 self._mouse_pause() 
    39636 File
    39637 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39638 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    39639 m.pause(self._mouse_pause_position) 
    39640 File
    39641 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39642 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    39643 p = self.view.picked_object(x, y) 
    39644 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39645 File
    39646 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39647 packages/chimerax/graphics/view.py", line 838, in picked_object 
    39648 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    39649 beyond, 
    39650 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39651 File
    39652 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39653 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    39654 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    39655 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39656 File
    39657 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39658 packages/chimerax/core/models.py", line 143, in first_intercept 
    39659 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    39660 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39661 File
    39662 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39663 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    39664 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    39665 exclude=exclude) 
    39666 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39667 File
    39668 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39669 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    39670 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    39671 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39672 File
    39673 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39674 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    39675 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    39676 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39677 File
    39678 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39679 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    39680 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    39681 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39682 File
    39683 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39684 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    39685 p = super().first_intercept(mxyz1, mxyz2) 
    39686 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39687 File
    39688 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39689 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    39690 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    39691 exclude=exclude) 
    39692 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39693 File
    39694 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39695 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    39696 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    39697 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39698 File
    39699 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39700 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    39701 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    39702 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39703 File
    39704 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39705 packages/chimerax/graphics/drawing.py", line 1108, in
    39706 _first_intercept_excluding_children 
    39707 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    39708 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39709 File
    39710 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39711 packages/chimerax/geometry/place.py", line 201, in inverse 
    39712 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    39713 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39714 File
    39715 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39716 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    39717 rinv[:, :] = matrix_inverse(r) 
    39718 ^^^^^^^^^^^^^^^^^ 
    39719 File
    39720 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39721 packages/numpy/linalg/linalg.py", line 561, in inv 
    39722 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    39723 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39724 File
    39725 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39726 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    39727 raise LinAlgError("Singular matrix") 
    39728 numpy.linalg.LinAlgError: Singular matrix 
    39729  
    39730 numpy.linalg.LinAlgError: Singular matrix 
    39731  
    39732 File
    39733 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39734 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    39735 raise LinAlgError("Singular matrix") 
    39736  
    39737 See log for complete Python traceback. 
    39738  
    39739 Traceback (most recent call last): 
    39740 File
    39741 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39742 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    39743 self.session.ui.mouse_modes.mouse_pause_tracking() 
    39744 File
    39745 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39746 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    39747 mouse_pause_tracking 
    39748 self._mouse_pause() 
    39749 File
    39750 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39751 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    39752 m.pause(self._mouse_pause_position) 
    39753 File
    39754 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39755 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    39756 p = self.view.picked_object(x, y) 
    39757 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39758 File
    39759 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39760 packages/chimerax/graphics/view.py", line 838, in picked_object 
    39761 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    39762 beyond, 
    39763 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39764 File
    39765 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39766 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    39767 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    39768 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39769 File
    39770 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39771 packages/chimerax/core/models.py", line 143, in first_intercept 
    39772 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    39773 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39774 File
    39775 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39776 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    39777 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    39778 exclude=exclude) 
    39779 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39780 File
    39781 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39782 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    39783 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    39784 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39785 File
    39786 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39787 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    39788 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    39789 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39790 File
    39791 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39792 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    39793 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    39794 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39795 File
    39796 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39797 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    39798 p = super().first_intercept(mxyz1, mxyz2) 
    39799 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39800 File
    39801 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39802 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    39803 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    39804 exclude=exclude) 
    39805 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39806 File
    39807 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39808 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    39809 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    39810 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39811 File
    39812 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39813 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    39814 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    39815 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39816 File
    39817 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39818 packages/chimerax/graphics/drawing.py", line 1108, in
    39819 _first_intercept_excluding_children 
    39820 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    39821 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39822 File
    39823 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39824 packages/chimerax/geometry/place.py", line 201, in inverse 
    39825 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    39826 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39827 File
    39828 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39829 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    39830 rinv[:, :] = matrix_inverse(r) 
    39831 ^^^^^^^^^^^^^^^^^ 
    39832 File
    39833 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39834 packages/numpy/linalg/linalg.py", line 561, in inv 
    39835 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    39836 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39837 File
    39838 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39839 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    39840 raise LinAlgError("Singular matrix") 
    39841 numpy.linalg.LinAlgError: Singular matrix 
    39842  
    39843 numpy.linalg.LinAlgError: Singular matrix 
    39844  
    39845 File
    39846 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39847 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    39848 raise LinAlgError("Singular matrix") 
    39849  
    39850 See log for complete Python traceback. 
    39851  
    39852 Traceback (most recent call last): 
    39853 File
    39854 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39855 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    39856 self.session.ui.mouse_modes.mouse_pause_tracking() 
    39857 File
    39858 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39859 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    39860 mouse_pause_tracking 
    39861 self._mouse_pause() 
    39862 File
    39863 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39864 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    39865 m.pause(self._mouse_pause_position) 
    39866 File
    39867 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39868 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    39869 p = self.view.picked_object(x, y) 
    39870 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39871 File
    39872 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39873 packages/chimerax/graphics/view.py", line 838, in picked_object 
    39874 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    39875 beyond, 
    39876 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39877 File
    39878 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39879 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    39880 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    39881 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39882 File
    39883 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39884 packages/chimerax/core/models.py", line 143, in first_intercept 
    39885 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    39886 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39887 File
    39888 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39889 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    39890 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    39891 exclude=exclude) 
    39892 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39893 File
    39894 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39895 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    39896 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    39897 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39898 File
    39899 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39900 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    39901 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    39902 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39903 File
    39904 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39905 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    39906 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    39907 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39908 File
    39909 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39910 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    39911 p = super().first_intercept(mxyz1, mxyz2) 
    39912 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39913 File
    39914 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39915 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    39916 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    39917 exclude=exclude) 
    39918 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39919 File
    39920 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39921 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    39922 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    39923 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39924 File
    39925 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39926 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    39927 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    39928 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39929 File
    39930 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39931 packages/chimerax/graphics/drawing.py", line 1108, in
    39932 _first_intercept_excluding_children 
    39933 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    39934 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39935 File
    39936 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39937 packages/chimerax/geometry/place.py", line 201, in inverse 
    39938 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    39939 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39940 File
    39941 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39942 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    39943 rinv[:, :] = matrix_inverse(r) 
    39944 ^^^^^^^^^^^^^^^^^ 
    39945 File
    39946 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39947 packages/numpy/linalg/linalg.py", line 561, in inv 
    39948 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    39949 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39950 File
    39951 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39952 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    39953 raise LinAlgError("Singular matrix") 
    39954 numpy.linalg.LinAlgError: Singular matrix 
    39955  
    39956 numpy.linalg.LinAlgError: Singular matrix 
    39957  
    39958 File
    39959 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39960 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    39961 raise LinAlgError("Singular matrix") 
    39962  
    39963 See log for complete Python traceback. 
    39964  
    39965 Traceback (most recent call last): 
    39966 File
    39967 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39968 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    39969 self.session.ui.mouse_modes.mouse_pause_tracking() 
    39970 File
    39971 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39972 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    39973 mouse_pause_tracking 
    39974 self._mouse_pause() 
    39975 File
    39976 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39977 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    39978 m.pause(self._mouse_pause_position) 
    39979 File
    39980 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39981 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    39982 p = self.view.picked_object(x, y) 
    39983 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39984 File
    39985 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39986 packages/chimerax/graphics/view.py", line 838, in picked_object 
    39987 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    39988 beyond, 
    39989 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39990 File
    39991 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39992 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    39993 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    39994 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    39995 File
    39996 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    39997 packages/chimerax/core/models.py", line 143, in first_intercept 
    39998 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    39999 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40000 File
    40001 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40002 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    40003 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    40004 exclude=exclude) 
    40005 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40006 File
    40007 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40008 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    40009 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    40010 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40011 File
    40012 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40013 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    40014 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    40015 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40016 File
    40017 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40018 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    40019 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    40020 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40021 File
    40022 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40023 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    40024 p = super().first_intercept(mxyz1, mxyz2) 
    40025 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40026 File
    40027 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40028 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    40029 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    40030 exclude=exclude) 
    40031 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40032 File
    40033 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40034 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    40035 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    40036 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40037 File
    40038 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40039 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    40040 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    40041 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40042 File
    40043 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40044 packages/chimerax/graphics/drawing.py", line 1108, in
    40045 _first_intercept_excluding_children 
    40046 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    40047 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40048 File
    40049 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40050 packages/chimerax/geometry/place.py", line 201, in inverse 
    40051 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    40052 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40053 File
    40054 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40055 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    40056 rinv[:, :] = matrix_inverse(r) 
    40057 ^^^^^^^^^^^^^^^^^ 
    40058 File
    40059 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40060 packages/numpy/linalg/linalg.py", line 561, in inv 
    40061 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    40062 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40063 File
    40064 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40065 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    40066 raise LinAlgError("Singular matrix") 
    40067 numpy.linalg.LinAlgError: Singular matrix 
    40068  
    40069 numpy.linalg.LinAlgError: Singular matrix 
    40070  
    40071 File
    40072 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40073 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    40074 raise LinAlgError("Singular matrix") 
    40075  
    40076 See log for complete Python traceback. 
    40077  
    40078 Traceback (most recent call last): 
    40079 File
    40080 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40081 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    40082 self.session.ui.mouse_modes.mouse_pause_tracking() 
    40083 File
    40084 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40085 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    40086 mouse_pause_tracking 
    40087 self._mouse_pause() 
    40088 File
    40089 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40090 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    40091 m.pause(self._mouse_pause_position) 
    40092 File
    40093 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40094 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    40095 p = self.view.picked_object(x, y) 
    40096 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40097 File
    40098 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40099 packages/chimerax/graphics/view.py", line 838, in picked_object 
    40100 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    40101 beyond, 
    40102 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40103 File
    40104 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40105 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    40106 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    40107 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40108 File
    40109 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40110 packages/chimerax/core/models.py", line 143, in first_intercept 
    40111 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    40112 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40113 File
    40114 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40115 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    40116 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    40117 exclude=exclude) 
    40118 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40119 File
    40120 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40121 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    40122 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    40123 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40124 File
    40125 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40126 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    40127 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    40128 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40129 File
    40130 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40131 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    40132 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    40133 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40134 File
    40135 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40136 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    40137 p = super().first_intercept(mxyz1, mxyz2) 
    40138 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40139 File
    40140 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40141 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    40142 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    40143 exclude=exclude) 
    40144 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40145 File
    40146 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40147 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    40148 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    40149 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40150 File
    40151 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40152 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    40153 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    40154 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40155 File
    40156 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40157 packages/chimerax/graphics/drawing.py", line 1108, in
    40158 _first_intercept_excluding_children 
    40159 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    40160 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40161 File
    40162 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40163 packages/chimerax/geometry/place.py", line 201, in inverse 
    40164 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    40165 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40166 File
    40167 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40168 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    40169 rinv[:, :] = matrix_inverse(r) 
    40170 ^^^^^^^^^^^^^^^^^ 
    40171 File
    40172 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40173 packages/numpy/linalg/linalg.py", line 561, in inv 
    40174 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    40175 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40176 File
    40177 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40178 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    40179 raise LinAlgError("Singular matrix") 
    40180 numpy.linalg.LinAlgError: Singular matrix 
    40181  
    40182 numpy.linalg.LinAlgError: Singular matrix 
    40183  
    40184 File
    40185 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40186 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    40187 raise LinAlgError("Singular matrix") 
    40188  
    40189 See log for complete Python traceback. 
    40190  
    40191 Traceback (most recent call last): 
    40192 File
    40193 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40194 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    40195 self.session.ui.mouse_modes.mouse_pause_tracking() 
    40196 File
    40197 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40198 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    40199 mouse_pause_tracking 
    40200 self._mouse_pause() 
    40201 File
    40202 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40203 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    40204 m.pause(self._mouse_pause_position) 
    40205 File
    40206 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40207 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    40208 p = self.view.picked_object(x, y) 
    40209 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40210 File
    40211 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40212 packages/chimerax/graphics/view.py", line 838, in picked_object 
    40213 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    40214 beyond, 
    40215 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40216 File
    40217 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40218 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    40219 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    40220 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40221 File
    40222 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40223 packages/chimerax/core/models.py", line 143, in first_intercept 
    40224 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    40225 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40226 File
    40227 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40228 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    40229 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    40230 exclude=exclude) 
    40231 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40232 File
    40233 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40234 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    40235 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    40236 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40237 File
    40238 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40239 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    40240 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    40241 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40242 File
    40243 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40244 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    40245 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    40246 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40247 File
    40248 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40249 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    40250 p = super().first_intercept(mxyz1, mxyz2) 
    40251 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40252 File
    40253 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40254 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    40255 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    40256 exclude=exclude) 
    40257 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40258 File
    40259 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40260 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    40261 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    40262 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40263 File
    40264 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40265 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    40266 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    40267 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40268 File
    40269 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40270 packages/chimerax/graphics/drawing.py", line 1108, in
    40271 _first_intercept_excluding_children 
    40272 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    40273 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40274 File
    40275 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40276 packages/chimerax/geometry/place.py", line 201, in inverse 
    40277 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    40278 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40279 File
    40280 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40281 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    40282 rinv[:, :] = matrix_inverse(r) 
    40283 ^^^^^^^^^^^^^^^^^ 
    40284 File
    40285 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40286 packages/numpy/linalg/linalg.py", line 561, in inv 
    40287 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    40288 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40289 File
    40290 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40291 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    40292 raise LinAlgError("Singular matrix") 
    40293 numpy.linalg.LinAlgError: Singular matrix 
    40294  
    40295 numpy.linalg.LinAlgError: Singular matrix 
    40296  
    40297 File
    40298 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40299 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    40300 raise LinAlgError("Singular matrix") 
    40301  
    40302 See log for complete Python traceback. 
    40303  
    40304 Traceback (most recent call last): 
    40305 File
    40306 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40307 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    40308 self.session.ui.mouse_modes.mouse_pause_tracking() 
    40309 File
    40310 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40311 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    40312 mouse_pause_tracking 
    40313 self._mouse_pause() 
    40314 File
    40315 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40316 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    40317 m.pause(self._mouse_pause_position) 
    40318 File
    40319 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40320 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    40321 p = self.view.picked_object(x, y) 
    40322 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40323 File
    40324 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40325 packages/chimerax/graphics/view.py", line 838, in picked_object 
    40326 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    40327 beyond, 
    40328 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40329 File
    40330 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40331 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    40332 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    40333 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40334 File
    40335 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40336 packages/chimerax/core/models.py", line 143, in first_intercept 
    40337 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    40338 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40339 File
    40340 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40341 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    40342 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    40343 exclude=exclude) 
    40344 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40345 File
    40346 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40347 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    40348 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    40349 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40350 File
    40351 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40352 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    40353 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    40354 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40355 File
    40356 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40357 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    40358 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    40359 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40360 File
    40361 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40362 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    40363 p = super().first_intercept(mxyz1, mxyz2) 
    40364 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40365 File
    40366 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40367 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    40368 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    40369 exclude=exclude) 
    40370 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40371 File
    40372 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40373 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    40374 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    40375 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40376 File
    40377 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40378 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    40379 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    40380 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40381 File
    40382 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40383 packages/chimerax/graphics/drawing.py", line 1108, in
    40384 _first_intercept_excluding_children 
    40385 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    40386 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40387 File
    40388 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40389 packages/chimerax/geometry/place.py", line 201, in inverse 
    40390 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    40391 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40392 File
    40393 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40394 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    40395 rinv[:, :] = matrix_inverse(r) 
    40396 ^^^^^^^^^^^^^^^^^ 
    40397 File
    40398 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40399 packages/numpy/linalg/linalg.py", line 561, in inv 
    40400 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    40401 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40402 File
    40403 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40404 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    40405 raise LinAlgError("Singular matrix") 
    40406 numpy.linalg.LinAlgError: Singular matrix 
    40407  
    40408 numpy.linalg.LinAlgError: Singular matrix 
    40409  
    40410 File
    40411 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40412 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    40413 raise LinAlgError("Singular matrix") 
    40414  
    40415 See log for complete Python traceback. 
    40416  
    40417 Traceback (most recent call last): 
    40418 File
    40419 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40420 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    40421 self.session.ui.mouse_modes.mouse_pause_tracking() 
    40422 File
    40423 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40424 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    40425 mouse_pause_tracking 
    40426 self._mouse_pause() 
    40427 File
    40428 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40429 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    40430 m.pause(self._mouse_pause_position) 
    40431 File
    40432 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40433 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    40434 p = self.view.picked_object(x, y) 
    40435 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40436 File
    40437 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40438 packages/chimerax/graphics/view.py", line 838, in picked_object 
    40439 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    40440 beyond, 
    40441 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40442 File
    40443 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40444 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    40445 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    40446 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40447 File
    40448 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40449 packages/chimerax/core/models.py", line 143, in first_intercept 
    40450 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    40451 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40452 File
    40453 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40454 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    40455 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    40456 exclude=exclude) 
    40457 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40458 File
    40459 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40460 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    40461 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    40462 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40463 File
    40464 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40465 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    40466 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    40467 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40468 File
    40469 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40470 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    40471 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    40472 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40473 File
    40474 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40475 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    40476 p = super().first_intercept(mxyz1, mxyz2) 
    40477 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40478 File
    40479 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40480 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    40481 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    40482 exclude=exclude) 
    40483 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40484 File
    40485 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40486 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    40487 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    40488 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40489 File
    40490 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40491 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    40492 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    40493 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40494 File
    40495 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40496 packages/chimerax/graphics/drawing.py", line 1108, in
    40497 _first_intercept_excluding_children 
    40498 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    40499 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40500 File
    40501 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40502 packages/chimerax/geometry/place.py", line 201, in inverse 
    40503 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    40504 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40505 File
    40506 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40507 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    40508 rinv[:, :] = matrix_inverse(r) 
    40509 ^^^^^^^^^^^^^^^^^ 
    40510 File
    40511 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40512 packages/numpy/linalg/linalg.py", line 561, in inv 
    40513 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    40514 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40515 File
    40516 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40517 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    40518 raise LinAlgError("Singular matrix") 
    40519 numpy.linalg.LinAlgError: Singular matrix 
    40520  
    40521 numpy.linalg.LinAlgError: Singular matrix 
    40522  
    40523 File
    40524 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40525 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    40526 raise LinAlgError("Singular matrix") 
    40527  
    40528 See log for complete Python traceback. 
    40529  
    40530 Traceback (most recent call last): 
    40531 File
    40532 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40533 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    40534 self.session.ui.mouse_modes.mouse_pause_tracking() 
    40535 File
    40536 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40537 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    40538 mouse_pause_tracking 
    40539 self._mouse_pause() 
    40540 File
    40541 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40542 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    40543 m.pause(self._mouse_pause_position) 
    40544 File
    40545 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40546 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    40547 p = self.view.picked_object(x, y) 
    40548 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40549 File
    40550 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40551 packages/chimerax/graphics/view.py", line 838, in picked_object 
    40552 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    40553 beyond, 
    40554 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40555 File
    40556 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40557 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    40558 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    40559 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40560 File
    40561 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40562 packages/chimerax/core/models.py", line 143, in first_intercept 
    40563 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    40564 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40565 File
    40566 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40567 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    40568 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    40569 exclude=exclude) 
    40570 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40571 File
    40572 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40573 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    40574 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    40575 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40576 File
    40577 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40578 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    40579 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    40580 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40581 File
    40582 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40583 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    40584 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    40585 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40586 File
    40587 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40588 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    40589 p = super().first_intercept(mxyz1, mxyz2) 
    40590 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40591 File
    40592 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40593 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    40594 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    40595 exclude=exclude) 
    40596 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40597 File
    40598 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40599 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    40600 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    40601 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40602 File
    40603 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40604 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    40605 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    40606 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40607 File
    40608 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40609 packages/chimerax/graphics/drawing.py", line 1108, in
    40610 _first_intercept_excluding_children 
    40611 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    40612 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40613 File
    40614 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40615 packages/chimerax/geometry/place.py", line 201, in inverse 
    40616 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    40617 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40618 File
    40619 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40620 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    40621 rinv[:, :] = matrix_inverse(r) 
    40622 ^^^^^^^^^^^^^^^^^ 
    40623 File
    40624 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40625 packages/numpy/linalg/linalg.py", line 561, in inv 
    40626 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    40627 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40628 File
    40629 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40630 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    40631 raise LinAlgError("Singular matrix") 
    40632 numpy.linalg.LinAlgError: Singular matrix 
    40633  
    40634 numpy.linalg.LinAlgError: Singular matrix 
    40635  
    40636 File
    40637 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40638 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    40639 raise LinAlgError("Singular matrix") 
    40640  
    40641 See log for complete Python traceback. 
    40642  
    40643 Traceback (most recent call last): 
    40644 File
    40645 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40646 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    40647 self.session.ui.mouse_modes.mouse_pause_tracking() 
    40648 File
    40649 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40650 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    40651 mouse_pause_tracking 
    40652 self._mouse_pause() 
    40653 File
    40654 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40655 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    40656 m.pause(self._mouse_pause_position) 
    40657 File
    40658 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40659 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    40660 p = self.view.picked_object(x, y) 
    40661 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40662 File
    40663 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40664 packages/chimerax/graphics/view.py", line 838, in picked_object 
    40665 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    40666 beyond, 
    40667 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40668 File
    40669 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40670 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    40671 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    40672 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40673 File
    40674 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40675 packages/chimerax/core/models.py", line 143, in first_intercept 
    40676 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    40677 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40678 File
    40679 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40680 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    40681 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    40682 exclude=exclude) 
    40683 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40684 File
    40685 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40686 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    40687 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    40688 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40689 File
    40690 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40691 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    40692 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    40693 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40694 File
    40695 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40696 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    40697 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    40698 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40699 File
    40700 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40701 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    40702 p = super().first_intercept(mxyz1, mxyz2) 
    40703 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40704 File
    40705 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40706 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    40707 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    40708 exclude=exclude) 
    40709 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40710 File
    40711 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40712 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    40713 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    40714 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40715 File
    40716 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40717 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    40718 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    40719 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40720 File
    40721 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40722 packages/chimerax/graphics/drawing.py", line 1108, in
    40723 _first_intercept_excluding_children 
    40724 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    40725 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40726 File
    40727 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40728 packages/chimerax/geometry/place.py", line 201, in inverse 
    40729 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    40730 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40731 File
    40732 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40733 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    40734 rinv[:, :] = matrix_inverse(r) 
    40735 ^^^^^^^^^^^^^^^^^ 
    40736 File
    40737 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40738 packages/numpy/linalg/linalg.py", line 561, in inv 
    40739 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    40740 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40741 File
    40742 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40743 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    40744 raise LinAlgError("Singular matrix") 
    40745 numpy.linalg.LinAlgError: Singular matrix 
    40746  
    40747 numpy.linalg.LinAlgError: Singular matrix 
    40748  
    40749 File
    40750 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40751 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    40752 raise LinAlgError("Singular matrix") 
    40753  
    40754 See log for complete Python traceback. 
    40755  
    40756 Traceback (most recent call last): 
    40757 File
    40758 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40759 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    40760 self.session.ui.mouse_modes.mouse_pause_tracking() 
    40761 File
    40762 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40763 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    40764 mouse_pause_tracking 
    40765 self._mouse_pause() 
    40766 File
    40767 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40768 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    40769 m.pause(self._mouse_pause_position) 
    40770 File
    40771 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40772 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    40773 p = self.view.picked_object(x, y) 
    40774 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40775 File
    40776 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40777 packages/chimerax/graphics/view.py", line 838, in picked_object 
    40778 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    40779 beyond, 
    40780 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40781 File
    40782 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40783 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    40784 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    40785 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40786 File
    40787 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40788 packages/chimerax/core/models.py", line 143, in first_intercept 
    40789 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    40790 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40791 File
    40792 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40793 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    40794 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    40795 exclude=exclude) 
    40796 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40797 File
    40798 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40799 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    40800 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    40801 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40802 File
    40803 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40804 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    40805 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    40806 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40807 File
    40808 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40809 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    40810 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    40811 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40812 File
    40813 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40814 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    40815 p = super().first_intercept(mxyz1, mxyz2) 
    40816 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40817 File
    40818 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40819 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    40820 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    40821 exclude=exclude) 
    40822 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40823 File
    40824 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40825 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    40826 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    40827 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40828 File
    40829 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40830 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    40831 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    40832 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40833 File
    40834 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40835 packages/chimerax/graphics/drawing.py", line 1108, in
    40836 _first_intercept_excluding_children 
    40837 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    40838 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40839 File
    40840 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40841 packages/chimerax/geometry/place.py", line 201, in inverse 
    40842 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    40843 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40844 File
    40845 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40846 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    40847 rinv[:, :] = matrix_inverse(r) 
    40848 ^^^^^^^^^^^^^^^^^ 
    40849 File
    40850 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40851 packages/numpy/linalg/linalg.py", line 561, in inv 
    40852 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    40853 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40854 File
    40855 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40856 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    40857 raise LinAlgError("Singular matrix") 
    40858 numpy.linalg.LinAlgError: Singular matrix 
    40859  
    40860 numpy.linalg.LinAlgError: Singular matrix 
    40861  
    40862 File
    40863 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40864 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    40865 raise LinAlgError("Singular matrix") 
    40866  
    40867 See log for complete Python traceback. 
    40868  
    40869 Traceback (most recent call last): 
    40870 File
    40871 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40872 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    40873 self.session.ui.mouse_modes.mouse_pause_tracking() 
    40874 File
    40875 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40876 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    40877 mouse_pause_tracking 
    40878 self._mouse_pause() 
    40879 File
    40880 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40881 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    40882 m.pause(self._mouse_pause_position) 
    40883 File
    40884 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40885 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    40886 p = self.view.picked_object(x, y) 
    40887 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40888 File
    40889 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40890 packages/chimerax/graphics/view.py", line 838, in picked_object 
    40891 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    40892 beyond, 
    40893 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40894 File
    40895 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40896 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    40897 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    40898 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40899 File
    40900 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40901 packages/chimerax/core/models.py", line 143, in first_intercept 
    40902 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    40903 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40904 File
    40905 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40906 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    40907 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    40908 exclude=exclude) 
    40909 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40910 File
    40911 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40912 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    40913 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    40914 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40915 File
    40916 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40917 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    40918 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    40919 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40920 File
    40921 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40922 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    40923 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    40924 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40925 File
    40926 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40927 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    40928 p = super().first_intercept(mxyz1, mxyz2) 
    40929 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40930 File
    40931 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40932 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    40933 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    40934 exclude=exclude) 
    40935 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40936 File
    40937 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40938 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    40939 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    40940 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40941 File
    40942 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40943 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    40944 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    40945 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40946 File
    40947 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40948 packages/chimerax/graphics/drawing.py", line 1108, in
    40949 _first_intercept_excluding_children 
    40950 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    40951 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40952 File
    40953 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40954 packages/chimerax/geometry/place.py", line 201, in inverse 
    40955 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    40956 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40957 File
    40958 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40959 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    40960 rinv[:, :] = matrix_inverse(r) 
    40961 ^^^^^^^^^^^^^^^^^ 
    40962 File
    40963 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40964 packages/numpy/linalg/linalg.py", line 561, in inv 
    40965 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    40966 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    40967 File
    40968 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40969 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    40970 raise LinAlgError("Singular matrix") 
    40971 numpy.linalg.LinAlgError: Singular matrix 
    40972  
    40973 numpy.linalg.LinAlgError: Singular matrix 
    40974  
    40975 File
    40976 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40977 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    40978 raise LinAlgError("Singular matrix") 
    40979  
    40980 See log for complete Python traceback. 
    40981  
    40982 Traceback (most recent call last): 
    40983 File
    40984 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40985 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    40986 self.session.ui.mouse_modes.mouse_pause_tracking() 
    40987 File
    40988 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40989 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    40990 mouse_pause_tracking 
    40991 self._mouse_pause() 
    40992 File
    40993 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40994 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    40995 m.pause(self._mouse_pause_position) 
    40996 File
    40997 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    40998 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    40999 p = self.view.picked_object(x, y) 
    41000 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41001 File
    41002 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41003 packages/chimerax/graphics/view.py", line 838, in picked_object 
    41004 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    41005 beyond, 
    41006 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41007 File
    41008 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41009 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    41010 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    41011 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41012 File
    41013 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41014 packages/chimerax/core/models.py", line 143, in first_intercept 
    41015 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    41016 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41017 File
    41018 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41019 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    41020 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    41021 exclude=exclude) 
    41022 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41023 File
    41024 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41025 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    41026 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    41027 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41028 File
    41029 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41030 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    41031 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    41032 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41033 File
    41034 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41035 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    41036 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    41037 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41038 File
    41039 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41040 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    41041 p = super().first_intercept(mxyz1, mxyz2) 
    41042 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41043 File
    41044 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41045 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    41046 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    41047 exclude=exclude) 
    41048 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41049 File
    41050 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41051 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    41052 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    41053 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41054 File
    41055 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41056 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    41057 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    41058 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41059 File
    41060 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41061 packages/chimerax/graphics/drawing.py", line 1108, in
    41062 _first_intercept_excluding_children 
    41063 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    41064 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41065 File
    41066 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41067 packages/chimerax/geometry/place.py", line 201, in inverse 
    41068 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    41069 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41070 File
    41071 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41072 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    41073 rinv[:, :] = matrix_inverse(r) 
    41074 ^^^^^^^^^^^^^^^^^ 
    41075 File
    41076 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41077 packages/numpy/linalg/linalg.py", line 561, in inv 
    41078 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    41079 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41080 File
    41081 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41082 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    41083 raise LinAlgError("Singular matrix") 
    41084 numpy.linalg.LinAlgError: Singular matrix 
    41085  
    41086 numpy.linalg.LinAlgError: Singular matrix 
    41087  
    41088 File
    41089 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41090 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    41091 raise LinAlgError("Singular matrix") 
    41092  
    41093 See log for complete Python traceback. 
    41094  
    41095 Traceback (most recent call last): 
    41096 File
    41097 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41098 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    41099 self.session.ui.mouse_modes.mouse_pause_tracking() 
    41100 File
    41101 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41102 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    41103 mouse_pause_tracking 
    41104 self._mouse_pause() 
    41105 File
    41106 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41107 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    41108 m.pause(self._mouse_pause_position) 
    41109 File
    41110 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41111 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    41112 p = self.view.picked_object(x, y) 
    41113 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41114 File
    41115 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41116 packages/chimerax/graphics/view.py", line 838, in picked_object 
    41117 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    41118 beyond, 
    41119 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41120 File
    41121 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41122 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    41123 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    41124 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41125 File
    41126 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41127 packages/chimerax/core/models.py", line 143, in first_intercept 
    41128 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    41129 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41130 File
    41131 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41132 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    41133 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    41134 exclude=exclude) 
    41135 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41136 File
    41137 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41138 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    41139 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    41140 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41141 File
    41142 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41143 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    41144 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    41145 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41146 File
    41147 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41148 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    41149 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    41150 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41151 File
    41152 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41153 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    41154 p = super().first_intercept(mxyz1, mxyz2) 
    41155 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41156 File
    41157 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41158 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    41159 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    41160 exclude=exclude) 
    41161 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41162 File
    41163 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41164 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    41165 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    41166 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41167 File
    41168 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41169 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    41170 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    41171 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41172 File
    41173 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41174 packages/chimerax/graphics/drawing.py", line 1108, in
    41175 _first_intercept_excluding_children 
    41176 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    41177 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41178 File
    41179 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41180 packages/chimerax/geometry/place.py", line 201, in inverse 
    41181 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    41182 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41183 File
    41184 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41185 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    41186 rinv[:, :] = matrix_inverse(r) 
    41187 ^^^^^^^^^^^^^^^^^ 
    41188 File
    41189 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41190 packages/numpy/linalg/linalg.py", line 561, in inv 
    41191 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    41192 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41193 File
    41194 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41195 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    41196 raise LinAlgError("Singular matrix") 
    41197 numpy.linalg.LinAlgError: Singular matrix 
    41198  
    41199 numpy.linalg.LinAlgError: Singular matrix 
    41200  
    41201 File
    41202 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41203 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    41204 raise LinAlgError("Singular matrix") 
    41205  
    41206 See log for complete Python traceback. 
    41207  
    41208 Traceback (most recent call last): 
    41209 File
    41210 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41211 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    41212 self.session.ui.mouse_modes.mouse_pause_tracking() 
    41213 File
    41214 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41215 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    41216 mouse_pause_tracking 
    41217 self._mouse_pause() 
    41218 File
    41219 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41220 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    41221 m.pause(self._mouse_pause_position) 
    41222 File
    41223 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41224 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    41225 p = self.view.picked_object(x, y) 
    41226 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41227 File
    41228 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41229 packages/chimerax/graphics/view.py", line 838, in picked_object 
    41230 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    41231 beyond, 
    41232 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41233 File
    41234 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41235 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    41236 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    41237 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41238 File
    41239 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41240 packages/chimerax/core/models.py", line 143, in first_intercept 
    41241 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    41242 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41243 File
    41244 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41245 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    41246 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    41247 exclude=exclude) 
    41248 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41249 File
    41250 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41251 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    41252 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    41253 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41254 File
    41255 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41256 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    41257 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    41258 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41259 File
    41260 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41261 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    41262 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    41263 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41264 File
    41265 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41266 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    41267 p = super().first_intercept(mxyz1, mxyz2) 
    41268 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41269 File
    41270 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41271 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    41272 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    41273 exclude=exclude) 
    41274 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41275 File
    41276 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41277 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    41278 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    41279 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41280 File
    41281 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41282 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    41283 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    41284 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41285 File
    41286 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41287 packages/chimerax/graphics/drawing.py", line 1108, in
    41288 _first_intercept_excluding_children 
    41289 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    41290 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41291 File
    41292 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41293 packages/chimerax/geometry/place.py", line 201, in inverse 
    41294 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    41295 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41296 File
    41297 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41298 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    41299 rinv[:, :] = matrix_inverse(r) 
    41300 ^^^^^^^^^^^^^^^^^ 
    41301 File
    41302 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41303 packages/numpy/linalg/linalg.py", line 561, in inv 
    41304 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    41305 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41306 File
    41307 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41308 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    41309 raise LinAlgError("Singular matrix") 
    41310 numpy.linalg.LinAlgError: Singular matrix 
    41311  
    41312 numpy.linalg.LinAlgError: Singular matrix 
    41313  
    41314 File
    41315 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41316 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    41317 raise LinAlgError("Singular matrix") 
    41318  
    41319 See log for complete Python traceback. 
    41320  
    41321 Traceback (most recent call last): 
    41322 File
    41323 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41324 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    41325 self.session.ui.mouse_modes.mouse_pause_tracking() 
    41326 File
    41327 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41328 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    41329 mouse_pause_tracking 
    41330 self._mouse_pause() 
    41331 File
    41332 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41333 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    41334 m.pause(self._mouse_pause_position) 
    41335 File
    41336 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41337 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    41338 p = self.view.picked_object(x, y) 
    41339 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41340 File
    41341 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41342 packages/chimerax/graphics/view.py", line 838, in picked_object 
    41343 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    41344 beyond, 
    41345 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41346 File
    41347 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41348 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    41349 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    41350 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41351 File
    41352 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41353 packages/chimerax/core/models.py", line 143, in first_intercept 
    41354 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    41355 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41356 File
    41357 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41358 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    41359 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    41360 exclude=exclude) 
    41361 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41362 File
    41363 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41364 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    41365 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    41366 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41367 File
    41368 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41369 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    41370 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    41371 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41372 File
    41373 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41374 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    41375 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    41376 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41377 File
    41378 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41379 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    41380 p = super().first_intercept(mxyz1, mxyz2) 
    41381 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41382 File
    41383 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41384 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    41385 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    41386 exclude=exclude) 
    41387 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41388 File
    41389 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41390 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    41391 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    41392 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41393 File
    41394 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41395 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    41396 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    41397 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41398 File
    41399 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41400 packages/chimerax/graphics/drawing.py", line 1108, in
    41401 _first_intercept_excluding_children 
    41402 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    41403 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41404 File
    41405 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41406 packages/chimerax/geometry/place.py", line 201, in inverse 
    41407 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    41408 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41409 File
    41410 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41411 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    41412 rinv[:, :] = matrix_inverse(r) 
    41413 ^^^^^^^^^^^^^^^^^ 
    41414 File
    41415 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41416 packages/numpy/linalg/linalg.py", line 561, in inv 
    41417 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    41418 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41419 File
    41420 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41421 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    41422 raise LinAlgError("Singular matrix") 
    41423 numpy.linalg.LinAlgError: Singular matrix 
    41424  
    41425 numpy.linalg.LinAlgError: Singular matrix 
    41426  
    41427 File
    41428 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41429 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    41430 raise LinAlgError("Singular matrix") 
    41431  
    41432 See log for complete Python traceback. 
    41433  
    41434 Traceback (most recent call last): 
    41435 File
    41436 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41437 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    41438 self.session.ui.mouse_modes.mouse_pause_tracking() 
    41439 File
    41440 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41441 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    41442 mouse_pause_tracking 
    41443 self._mouse_pause() 
    41444 File
    41445 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41446 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    41447 m.pause(self._mouse_pause_position) 
    41448 File
    41449 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41450 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    41451 p = self.view.picked_object(x, y) 
    41452 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41453 File
    41454 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41455 packages/chimerax/graphics/view.py", line 838, in picked_object 
    41456 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    41457 beyond, 
    41458 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41459 File
    41460 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41461 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    41462 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    41463 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41464 File
    41465 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41466 packages/chimerax/core/models.py", line 143, in first_intercept 
    41467 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    41468 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41469 File
    41470 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41471 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    41472 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    41473 exclude=exclude) 
    41474 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41475 File
    41476 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41477 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    41478 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    41479 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41480 File
    41481 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41482 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    41483 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    41484 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41485 File
    41486 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41487 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    41488 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    41489 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41490 File
    41491 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41492 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    41493 p = super().first_intercept(mxyz1, mxyz2) 
    41494 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41495 File
    41496 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41497 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    41498 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    41499 exclude=exclude) 
    41500 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41501 File
    41502 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41503 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    41504 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    41505 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41506 File
    41507 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41508 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    41509 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    41510 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41511 File
    41512 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41513 packages/chimerax/graphics/drawing.py", line 1108, in
    41514 _first_intercept_excluding_children 
    41515 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    41516 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41517 File
    41518 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41519 packages/chimerax/geometry/place.py", line 201, in inverse 
    41520 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    41521 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41522 File
    41523 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41524 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    41525 rinv[:, :] = matrix_inverse(r) 
    41526 ^^^^^^^^^^^^^^^^^ 
    41527 File
    41528 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41529 packages/numpy/linalg/linalg.py", line 561, in inv 
    41530 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    41531 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41532 File
    41533 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41534 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    41535 raise LinAlgError("Singular matrix") 
    41536 numpy.linalg.LinAlgError: Singular matrix 
    41537  
    41538 numpy.linalg.LinAlgError: Singular matrix 
    41539  
    41540 File
    41541 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41542 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    41543 raise LinAlgError("Singular matrix") 
    41544  
    41545 See log for complete Python traceback. 
    41546  
    41547 Traceback (most recent call last): 
    41548 File
    41549 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41550 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    41551 self.session.ui.mouse_modes.mouse_pause_tracking() 
    41552 File
    41553 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41554 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    41555 mouse_pause_tracking 
    41556 self._mouse_pause() 
    41557 File
    41558 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41559 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    41560 m.pause(self._mouse_pause_position) 
    41561 File
    41562 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41563 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    41564 p = self.view.picked_object(x, y) 
    41565 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41566 File
    41567 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41568 packages/chimerax/graphics/view.py", line 838, in picked_object 
    41569 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    41570 beyond, 
    41571 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41572 File
    41573 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41574 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    41575 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    41576 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41577 File
    41578 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41579 packages/chimerax/core/models.py", line 143, in first_intercept 
    41580 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    41581 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41582 File
    41583 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41584 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    41585 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    41586 exclude=exclude) 
    41587 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41588 File
    41589 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41590 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    41591 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    41592 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41593 File
    41594 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41595 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    41596 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    41597 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41598 File
    41599 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41600 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    41601 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    41602 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41603 File
    41604 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41605 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    41606 p = super().first_intercept(mxyz1, mxyz2) 
    41607 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41608 File
    41609 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41610 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    41611 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    41612 exclude=exclude) 
    41613 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41614 File
    41615 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41616 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    41617 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    41618 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41619 File
    41620 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41621 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    41622 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    41623 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41624 File
    41625 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41626 packages/chimerax/graphics/drawing.py", line 1108, in
    41627 _first_intercept_excluding_children 
    41628 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    41629 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41630 File
    41631 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41632 packages/chimerax/geometry/place.py", line 201, in inverse 
    41633 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    41634 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41635 File
    41636 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41637 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    41638 rinv[:, :] = matrix_inverse(r) 
    41639 ^^^^^^^^^^^^^^^^^ 
    41640 File
    41641 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41642 packages/numpy/linalg/linalg.py", line 561, in inv 
    41643 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    41644 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41645 File
    41646 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41647 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    41648 raise LinAlgError("Singular matrix") 
    41649 numpy.linalg.LinAlgError: Singular matrix 
    41650  
    41651 numpy.linalg.LinAlgError: Singular matrix 
    41652  
    41653 File
    41654 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41655 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    41656 raise LinAlgError("Singular matrix") 
    41657  
    41658 See log for complete Python traceback. 
    41659  
    41660 Traceback (most recent call last): 
    41661 File
    41662 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41663 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    41664 self.session.ui.mouse_modes.mouse_pause_tracking() 
    41665 File
    41666 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41667 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    41668 mouse_pause_tracking 
    41669 self._mouse_pause() 
    41670 File
    41671 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41672 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    41673 m.pause(self._mouse_pause_position) 
    41674 File
    41675 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41676 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    41677 p = self.view.picked_object(x, y) 
    41678 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41679 File
    41680 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41681 packages/chimerax/graphics/view.py", line 838, in picked_object 
    41682 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    41683 beyond, 
    41684 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41685 File
    41686 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41687 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    41688 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    41689 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41690 File
    41691 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41692 packages/chimerax/core/models.py", line 143, in first_intercept 
    41693 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    41694 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41695 File
    41696 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41697 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    41698 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    41699 exclude=exclude) 
    41700 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41701 File
    41702 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41703 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    41704 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    41705 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41706 File
    41707 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41708 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    41709 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    41710 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41711 File
    41712 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41713 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    41714 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    41715 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41716 File
    41717 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41718 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    41719 p = super().first_intercept(mxyz1, mxyz2) 
    41720 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41721 File
    41722 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41723 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    41724 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    41725 exclude=exclude) 
    41726 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41727 File
    41728 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41729 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    41730 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    41731 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41732 File
    41733 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41734 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    41735 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    41736 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41737 File
    41738 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41739 packages/chimerax/graphics/drawing.py", line 1108, in
    41740 _first_intercept_excluding_children 
    41741 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    41742 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41743 File
    41744 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41745 packages/chimerax/geometry/place.py", line 201, in inverse 
    41746 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    41747 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41748 File
    41749 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41750 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    41751 rinv[:, :] = matrix_inverse(r) 
    41752 ^^^^^^^^^^^^^^^^^ 
    41753 File
    41754 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41755 packages/numpy/linalg/linalg.py", line 561, in inv 
    41756 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    41757 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41758 File
    41759 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41760 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    41761 raise LinAlgError("Singular matrix") 
    41762 numpy.linalg.LinAlgError: Singular matrix 
    41763  
    41764 numpy.linalg.LinAlgError: Singular matrix 
    41765  
    41766 File
    41767 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41768 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    41769 raise LinAlgError("Singular matrix") 
    41770  
    41771 See log for complete Python traceback. 
    41772  
    41773 Traceback (most recent call last): 
    41774 File
    41775 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41776 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    41777 self.session.ui.mouse_modes.mouse_pause_tracking() 
    41778 File
    41779 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41780 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    41781 mouse_pause_tracking 
    41782 self._mouse_pause() 
    41783 File
    41784 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41785 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    41786 m.pause(self._mouse_pause_position) 
    41787 File
    41788 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41789 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    41790 p = self.view.picked_object(x, y) 
    41791 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41792 File
    41793 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41794 packages/chimerax/graphics/view.py", line 838, in picked_object 
    41795 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    41796 beyond, 
    41797 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41798 File
    41799 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41800 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    41801 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    41802 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41803 File
    41804 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41805 packages/chimerax/core/models.py", line 143, in first_intercept 
    41806 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    41807 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41808 File
    41809 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41810 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    41811 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    41812 exclude=exclude) 
    41813 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41814 File
    41815 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41816 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    41817 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    41818 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41819 File
    41820 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41821 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    41822 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    41823 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41824 File
    41825 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41826 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    41827 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    41828 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41829 File
    41830 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41831 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    41832 p = super().first_intercept(mxyz1, mxyz2) 
    41833 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41834 File
    41835 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41836 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    41837 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    41838 exclude=exclude) 
    41839 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41840 File
    41841 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41842 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    41843 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    41844 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41845 File
    41846 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41847 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    41848 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    41849 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41850 File
    41851 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41852 packages/chimerax/graphics/drawing.py", line 1108, in
    41853 _first_intercept_excluding_children 
    41854 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    41855 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41856 File
    41857 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41858 packages/chimerax/geometry/place.py", line 201, in inverse 
    41859 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    41860 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41861 File
    41862 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41863 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    41864 rinv[:, :] = matrix_inverse(r) 
    41865 ^^^^^^^^^^^^^^^^^ 
    41866 File
    41867 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41868 packages/numpy/linalg/linalg.py", line 561, in inv 
    41869 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    41870 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41871 File
    41872 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41873 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    41874 raise LinAlgError("Singular matrix") 
    41875 numpy.linalg.LinAlgError: Singular matrix 
    41876  
    41877 numpy.linalg.LinAlgError: Singular matrix 
    41878  
    41879 File
    41880 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41881 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    41882 raise LinAlgError("Singular matrix") 
    41883  
    41884 See log for complete Python traceback. 
    41885  
    41886 Traceback (most recent call last): 
    41887 File
    41888 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41889 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    41890 self.session.ui.mouse_modes.mouse_pause_tracking() 
    41891 File
    41892 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41893 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    41894 mouse_pause_tracking 
    41895 self._mouse_pause() 
    41896 File
    41897 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41898 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    41899 m.pause(self._mouse_pause_position) 
    41900 File
    41901 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41902 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    41903 p = self.view.picked_object(x, y) 
    41904 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41905 File
    41906 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41907 packages/chimerax/graphics/view.py", line 838, in picked_object 
    41908 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    41909 beyond, 
    41910 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41911 File
    41912 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41913 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    41914 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    41915 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41916 File
    41917 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41918 packages/chimerax/core/models.py", line 143, in first_intercept 
    41919 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    41920 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41921 File
    41922 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41923 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    41924 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    41925 exclude=exclude) 
    41926 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41927 File
    41928 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41929 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    41930 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    41931 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41932 File
    41933 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41934 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    41935 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    41936 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41937 File
    41938 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41939 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    41940 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    41941 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41942 File
    41943 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41944 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    41945 p = super().first_intercept(mxyz1, mxyz2) 
    41946 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41947 File
    41948 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41949 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    41950 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    41951 exclude=exclude) 
    41952 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41953 File
    41954 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41955 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    41956 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    41957 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41958 File
    41959 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41960 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    41961 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    41962 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41963 File
    41964 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41965 packages/chimerax/graphics/drawing.py", line 1108, in
    41966 _first_intercept_excluding_children 
    41967 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    41968 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41969 File
    41970 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41971 packages/chimerax/geometry/place.py", line 201, in inverse 
    41972 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    41973 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41974 File
    41975 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41976 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    41977 rinv[:, :] = matrix_inverse(r) 
    41978 ^^^^^^^^^^^^^^^^^ 
    41979 File
    41980 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41981 packages/numpy/linalg/linalg.py", line 561, in inv 
    41982 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    41983 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    41984 File
    41985 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41986 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    41987 raise LinAlgError("Singular matrix") 
    41988 numpy.linalg.LinAlgError: Singular matrix 
    41989  
    41990 numpy.linalg.LinAlgError: Singular matrix 
    41991  
    41992 File
    41993 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    41994 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    41995 raise LinAlgError("Singular matrix") 
    41996  
    41997 See log for complete Python traceback. 
    41998  
    41999 
    42000 > select add #5/B:1117@O
    42001 
    42002 1 atom, 1 residue, 1 model selected 
    42003 
    42004 > select add #5/E:2208@O
    42005 
    42006 2 atoms, 2 residues, 1 model selected 
    42007 
    42008 > select add #5/F:2212@O
    42009 
    42010 3 atoms, 3 residues, 1 model selected 
    42011 
    42012 > select add #5/F:2102@MG
    42013 
    42014 4 atoms, 4 residues, 1 model selected 
    42015 
    42016 > select add #5/F:2103@O02
    42017 
    42018 5 atoms, 5 residues, 1 model selected 
    42019 
    42020 > select add #5/F:2103@O
    42021 
    42022 6 atoms, 5 residues, 1 model selected 
    42023 
    42024 > hide sel atoms
    42025 
    42026 > color #5 black
    42027 
    42028 > undo
    42029 
    42030 > hide #5.3 models
    42031 
    42032 > show #5.3 models
    42033 
    42034 > hide #5.2 models
    42035 
    42036 > show #5.2 models
    42037 
    42038 > color #5.2 black models
    42039 
    42040 > color #5.2 #fffb00ff models
    42041 
    42042 > color #5.2 #ff9a2aff models
    42043 
    42044 > color #5.2 #fdb22fff models
    42045 
    42046 > color #5.2 #f2cd34ff models
    42047 
    42048 > color #5.2 #ffca33ff models
    42049 
    42050 > color #5.2 #ffaf2eff models
    42051 
    42052 > select add #5/B:582
    42053 
    42054 10 atoms, 3 bonds, 6 residues, 1 model selected 
    42055 
    42056 > select add #5/B:583
    42057 
    42058 18 atoms, 10 bonds, 7 residues, 1 model selected 
    42059 
    42060 > hide sel cartoons
    42061 
    42062 > select clear
    42063 
    42064 Traceback (most recent call last): 
    42065 File
    42066 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42067 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    42068 self.session.ui.mouse_modes.mouse_pause_tracking() 
    42069 File
    42070 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42071 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    42072 mouse_pause_tracking 
    42073 self._mouse_pause() 
    42074 File
    42075 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42076 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    42077 m.pause(self._mouse_pause_position) 
    42078 File
    42079 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42080 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    42081 p = self.view.picked_object(x, y) 
    42082 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42083 File
    42084 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42085 packages/chimerax/graphics/view.py", line 838, in picked_object 
    42086 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    42087 beyond, 
    42088 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42089 File
    42090 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42091 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    42092 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    42093 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42094 File
    42095 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42096 packages/chimerax/core/models.py", line 143, in first_intercept 
    42097 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    42098 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42099 File
    42100 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42101 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    42102 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    42103 exclude=exclude) 
    42104 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42105 File
    42106 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42107 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    42108 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    42109 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42110 File
    42111 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42112 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    42113 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    42114 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42115 File
    42116 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42117 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    42118 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    42119 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42120 File
    42121 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42122 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    42123 p = super().first_intercept(mxyz1, mxyz2) 
    42124 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42125 File
    42126 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42127 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    42128 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    42129 exclude=exclude) 
    42130 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42131 File
    42132 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42133 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    42134 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    42135 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42136 File
    42137 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42138 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    42139 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    42140 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42141 File
    42142 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42143 packages/chimerax/graphics/drawing.py", line 1108, in
    42144 _first_intercept_excluding_children 
    42145 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    42146 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42147 File
    42148 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42149 packages/chimerax/geometry/place.py", line 201, in inverse 
    42150 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    42151 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42152 File
    42153 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42154 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    42155 rinv[:, :] = matrix_inverse(r) 
    42156 ^^^^^^^^^^^^^^^^^ 
    42157 File
    42158 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42159 packages/numpy/linalg/linalg.py", line 561, in inv 
    42160 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    42161 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42162 File
    42163 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42164 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    42165 raise LinAlgError("Singular matrix") 
    42166 numpy.linalg.LinAlgError: Singular matrix 
    42167  
    42168 numpy.linalg.LinAlgError: Singular matrix 
    42169  
    42170 File
    42171 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42172 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    42173 raise LinAlgError("Singular matrix") 
    42174  
    42175 See log for complete Python traceback. 
    42176  
    42177 Traceback (most recent call last): 
    42178 File
    42179 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42180 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    42181 self.session.ui.mouse_modes.mouse_pause_tracking() 
    42182 File
    42183 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42184 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    42185 mouse_pause_tracking 
    42186 self._mouse_pause() 
    42187 File
    42188 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42189 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    42190 m.pause(self._mouse_pause_position) 
    42191 File
    42192 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42193 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    42194 p = self.view.picked_object(x, y) 
    42195 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42196 File
    42197 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42198 packages/chimerax/graphics/view.py", line 838, in picked_object 
    42199 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    42200 beyond, 
    42201 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42202 File
    42203 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42204 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    42205 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    42206 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42207 File
    42208 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42209 packages/chimerax/core/models.py", line 143, in first_intercept 
    42210 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    42211 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42212 File
    42213 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42214 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    42215 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    42216 exclude=exclude) 
    42217 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42218 File
    42219 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42220 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    42221 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    42222 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42223 File
    42224 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42225 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    42226 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    42227 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42228 File
    42229 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42230 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    42231 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    42232 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42233 File
    42234 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42235 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    42236 p = super().first_intercept(mxyz1, mxyz2) 
    42237 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42238 File
    42239 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42240 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    42241 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    42242 exclude=exclude) 
    42243 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42244 File
    42245 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42246 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    42247 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    42248 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42249 File
    42250 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42251 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    42252 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    42253 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42254 File
    42255 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42256 packages/chimerax/graphics/drawing.py", line 1108, in
    42257 _first_intercept_excluding_children 
    42258 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    42259 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42260 File
    42261 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42262 packages/chimerax/geometry/place.py", line 201, in inverse 
    42263 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    42264 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42265 File
    42266 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42267 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    42268 rinv[:, :] = matrix_inverse(r) 
    42269 ^^^^^^^^^^^^^^^^^ 
    42270 File
    42271 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42272 packages/numpy/linalg/linalg.py", line 561, in inv 
    42273 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    42274 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42275 File
    42276 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42277 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    42278 raise LinAlgError("Singular matrix") 
    42279 numpy.linalg.LinAlgError: Singular matrix 
    42280  
    42281 numpy.linalg.LinAlgError: Singular matrix 
    42282  
    42283 File
    42284 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42285 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    42286 raise LinAlgError("Singular matrix") 
    42287  
    42288 See log for complete Python traceback. 
    42289  
    42290 Traceback (most recent call last): 
    42291 File
    42292 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42293 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    42294 self.session.ui.mouse_modes.mouse_pause_tracking() 
    42295 File
    42296 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42297 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    42298 mouse_pause_tracking 
    42299 self._mouse_pause() 
    42300 File
    42301 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42302 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    42303 m.pause(self._mouse_pause_position) 
    42304 File
    42305 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42306 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    42307 p = self.view.picked_object(x, y) 
    42308 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42309 File
    42310 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42311 packages/chimerax/graphics/view.py", line 838, in picked_object 
    42312 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    42313 beyond, 
    42314 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42315 File
    42316 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42317 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    42318 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    42319 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42320 File
    42321 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42322 packages/chimerax/core/models.py", line 143, in first_intercept 
    42323 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    42324 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42325 File
    42326 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42327 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    42328 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    42329 exclude=exclude) 
    42330 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42331 File
    42332 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42333 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    42334 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    42335 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42336 File
    42337 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42338 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    42339 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    42340 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42341 File
    42342 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42343 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    42344 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    42345 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42346 File
    42347 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42348 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    42349 p = super().first_intercept(mxyz1, mxyz2) 
    42350 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42351 File
    42352 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42353 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    42354 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    42355 exclude=exclude) 
    42356 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42357 File
    42358 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42359 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    42360 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    42361 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42362 File
    42363 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42364 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    42365 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    42366 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42367 File
    42368 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42369 packages/chimerax/graphics/drawing.py", line 1108, in
    42370 _first_intercept_excluding_children 
    42371 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    42372 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42373 File
    42374 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42375 packages/chimerax/geometry/place.py", line 201, in inverse 
    42376 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    42377 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42378 File
    42379 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42380 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    42381 rinv[:, :] = matrix_inverse(r) 
    42382 ^^^^^^^^^^^^^^^^^ 
    42383 File
    42384 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42385 packages/numpy/linalg/linalg.py", line 561, in inv 
    42386 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    42387 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42388 File
    42389 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42390 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    42391 raise LinAlgError("Singular matrix") 
    42392 numpy.linalg.LinAlgError: Singular matrix 
    42393  
    42394 numpy.linalg.LinAlgError: Singular matrix 
    42395  
    42396 File
    42397 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42398 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    42399 raise LinAlgError("Singular matrix") 
    42400  
    42401 See log for complete Python traceback. 
    42402  
    42403 Traceback (most recent call last): 
    42404 File
    42405 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42406 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    42407 self.session.ui.mouse_modes.mouse_pause_tracking() 
    42408 File
    42409 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42410 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    42411 mouse_pause_tracking 
    42412 self._mouse_pause() 
    42413 File
    42414 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42415 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    42416 m.pause(self._mouse_pause_position) 
    42417 File
    42418 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42419 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    42420 p = self.view.picked_object(x, y) 
    42421 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42422 File
    42423 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42424 packages/chimerax/graphics/view.py", line 838, in picked_object 
    42425 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    42426 beyond, 
    42427 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42428 File
    42429 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42430 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    42431 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    42432 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42433 File
    42434 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42435 packages/chimerax/core/models.py", line 143, in first_intercept 
    42436 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    42437 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42438 File
    42439 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42440 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    42441 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    42442 exclude=exclude) 
    42443 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42444 File
    42445 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42446 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    42447 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    42448 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42449 File
    42450 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42451 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    42452 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    42453 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42454 File
    42455 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42456 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    42457 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    42458 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42459 File
    42460 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42461 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    42462 p = super().first_intercept(mxyz1, mxyz2) 
    42463 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42464 File
    42465 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42466 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    42467 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    42468 exclude=exclude) 
    42469 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42470 File
    42471 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42472 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    42473 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    42474 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42475 File
    42476 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42477 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    42478 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    42479 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42480 File
    42481 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42482 packages/chimerax/graphics/drawing.py", line 1108, in
    42483 _first_intercept_excluding_children 
    42484 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    42485 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42486 File
    42487 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42488 packages/chimerax/geometry/place.py", line 201, in inverse 
    42489 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    42490 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42491 File
    42492 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42493 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    42494 rinv[:, :] = matrix_inverse(r) 
    42495 ^^^^^^^^^^^^^^^^^ 
    42496 File
    42497 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42498 packages/numpy/linalg/linalg.py", line 561, in inv 
    42499 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    42500 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42501 File
    42502 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42503 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    42504 raise LinAlgError("Singular matrix") 
    42505 numpy.linalg.LinAlgError: Singular matrix 
    42506  
    42507 numpy.linalg.LinAlgError: Singular matrix 
    42508  
    42509 File
    42510 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42511 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    42512 raise LinAlgError("Singular matrix") 
    42513  
    42514 See log for complete Python traceback. 
    42515  
    42516 Traceback (most recent call last): 
    42517 File
    42518 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42519 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    42520 self.session.ui.mouse_modes.mouse_pause_tracking() 
    42521 File
    42522 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42523 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    42524 mouse_pause_tracking 
    42525 self._mouse_pause() 
    42526 File
    42527 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42528 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    42529 m.pause(self._mouse_pause_position) 
    42530 File
    42531 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42532 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    42533 p = self.view.picked_object(x, y) 
    42534 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42535 File
    42536 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42537 packages/chimerax/graphics/view.py", line 838, in picked_object 
    42538 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    42539 beyond, 
    42540 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42541 File
    42542 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42543 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    42544 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    42545 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42546 File
    42547 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42548 packages/chimerax/core/models.py", line 143, in first_intercept 
    42549 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    42550 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42551 File
    42552 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42553 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    42554 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    42555 exclude=exclude) 
    42556 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42557 File
    42558 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42559 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    42560 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    42561 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42562 File
    42563 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42564 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    42565 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    42566 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42567 File
    42568 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42569 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    42570 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    42571 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42572 File
    42573 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42574 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    42575 p = super().first_intercept(mxyz1, mxyz2) 
    42576 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42577 File
    42578 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42579 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    42580 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    42581 exclude=exclude) 
    42582 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42583 File
    42584 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42585 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    42586 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    42587 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42588 File
    42589 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42590 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    42591 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    42592 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42593 File
    42594 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42595 packages/chimerax/graphics/drawing.py", line 1108, in
    42596 _first_intercept_excluding_children 
    42597 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    42598 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42599 File
    42600 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42601 packages/chimerax/geometry/place.py", line 201, in inverse 
    42602 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    42603 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42604 File
    42605 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42606 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    42607 rinv[:, :] = matrix_inverse(r) 
    42608 ^^^^^^^^^^^^^^^^^ 
    42609 File
    42610 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42611 packages/numpy/linalg/linalg.py", line 561, in inv 
    42612 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    42613 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42614 File
    42615 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42616 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    42617 raise LinAlgError("Singular matrix") 
    42618 numpy.linalg.LinAlgError: Singular matrix 
    42619  
    42620 numpy.linalg.LinAlgError: Singular matrix 
    42621  
    42622 File
    42623 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42624 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    42625 raise LinAlgError("Singular matrix") 
    42626  
    42627 See log for complete Python traceback. 
    42628  
    42629 Traceback (most recent call last): 
    42630 File
    42631 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42632 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    42633 self.session.ui.mouse_modes.mouse_pause_tracking() 
    42634 File
    42635 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42636 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    42637 mouse_pause_tracking 
    42638 self._mouse_pause() 
    42639 File
    42640 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42641 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    42642 m.pause(self._mouse_pause_position) 
    42643 File
    42644 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42645 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    42646 p = self.view.picked_object(x, y) 
    42647 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42648 File
    42649 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42650 packages/chimerax/graphics/view.py", line 838, in picked_object 
    42651 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    42652 beyond, 
    42653 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42654 File
    42655 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42656 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    42657 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    42658 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42659 File
    42660 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42661 packages/chimerax/core/models.py", line 143, in first_intercept 
    42662 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    42663 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42664 File
    42665 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42666 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    42667 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    42668 exclude=exclude) 
    42669 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42670 File
    42671 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42672 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    42673 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    42674 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42675 File
    42676 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42677 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    42678 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    42679 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42680 File
    42681 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42682 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    42683 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    42684 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42685 File
    42686 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42687 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    42688 p = super().first_intercept(mxyz1, mxyz2) 
    42689 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42690 File
    42691 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42692 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    42693 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    42694 exclude=exclude) 
    42695 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42696 File
    42697 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42698 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    42699 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    42700 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42701 File
    42702 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42703 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    42704 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    42705 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42706 File
    42707 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42708 packages/chimerax/graphics/drawing.py", line 1108, in
    42709 _first_intercept_excluding_children 
    42710 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    42711 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42712 File
    42713 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42714 packages/chimerax/geometry/place.py", line 201, in inverse 
    42715 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    42716 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42717 File
    42718 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42719 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    42720 rinv[:, :] = matrix_inverse(r) 
    42721 ^^^^^^^^^^^^^^^^^ 
    42722 File
    42723 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42724 packages/numpy/linalg/linalg.py", line 561, in inv 
    42725 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    42726 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42727 File
    42728 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42729 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    42730 raise LinAlgError("Singular matrix") 
    42731 numpy.linalg.LinAlgError: Singular matrix 
    42732  
    42733 numpy.linalg.LinAlgError: Singular matrix 
    42734  
    42735 File
    42736 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42737 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    42738 raise LinAlgError("Singular matrix") 
    42739  
    42740 See log for complete Python traceback. 
    42741  
    42742 Traceback (most recent call last): 
    42743 File
    42744 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42745 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    42746 self.session.ui.mouse_modes.mouse_pause_tracking() 
    42747 File
    42748 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42749 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    42750 mouse_pause_tracking 
    42751 self._mouse_pause() 
    42752 File
    42753 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42754 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    42755 m.pause(self._mouse_pause_position) 
    42756 File
    42757 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42758 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    42759 p = self.view.picked_object(x, y) 
    42760 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42761 File
    42762 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42763 packages/chimerax/graphics/view.py", line 838, in picked_object 
    42764 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    42765 beyond, 
    42766 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42767 File
    42768 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42769 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    42770 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    42771 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42772 File
    42773 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42774 packages/chimerax/core/models.py", line 143, in first_intercept 
    42775 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    42776 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42777 File
    42778 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42779 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    42780 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    42781 exclude=exclude) 
    42782 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42783 File
    42784 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42785 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    42786 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    42787 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42788 File
    42789 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42790 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    42791 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    42792 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42793 File
    42794 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42795 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    42796 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    42797 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42798 File
    42799 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42800 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    42801 p = super().first_intercept(mxyz1, mxyz2) 
    42802 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42803 File
    42804 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42805 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    42806 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    42807 exclude=exclude) 
    42808 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42809 File
    42810 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42811 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    42812 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    42813 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42814 File
    42815 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42816 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    42817 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    42818 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42819 File
    42820 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42821 packages/chimerax/graphics/drawing.py", line 1108, in
    42822 _first_intercept_excluding_children 
    42823 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    42824 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42825 File
    42826 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42827 packages/chimerax/geometry/place.py", line 201, in inverse 
    42828 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    42829 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42830 File
    42831 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42832 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    42833 rinv[:, :] = matrix_inverse(r) 
    42834 ^^^^^^^^^^^^^^^^^ 
    42835 File
    42836 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42837 packages/numpy/linalg/linalg.py", line 561, in inv 
    42838 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    42839 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42840 File
    42841 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42842 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    42843 raise LinAlgError("Singular matrix") 
    42844 numpy.linalg.LinAlgError: Singular matrix 
    42845  
    42846 numpy.linalg.LinAlgError: Singular matrix 
    42847  
    42848 File
    42849 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42850 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    42851 raise LinAlgError("Singular matrix") 
    42852  
    42853 See log for complete Python traceback. 
    42854  
    42855 Traceback (most recent call last): 
    42856 File
    42857 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42858 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    42859 self.session.ui.mouse_modes.mouse_pause_tracking() 
    42860 File
    42861 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42862 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    42863 mouse_pause_tracking 
    42864 self._mouse_pause() 
    42865 File
    42866 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42867 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    42868 m.pause(self._mouse_pause_position) 
    42869 File
    42870 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42871 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    42872 p = self.view.picked_object(x, y) 
    42873 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42874 File
    42875 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42876 packages/chimerax/graphics/view.py", line 838, in picked_object 
    42877 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    42878 beyond, 
    42879 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42880 File
    42881 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42882 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    42883 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    42884 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42885 File
    42886 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42887 packages/chimerax/core/models.py", line 143, in first_intercept 
    42888 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    42889 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42890 File
    42891 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42892 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    42893 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    42894 exclude=exclude) 
    42895 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42896 File
    42897 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42898 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    42899 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    42900 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42901 File
    42902 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42903 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    42904 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    42905 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42906 File
    42907 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42908 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    42909 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    42910 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42911 File
    42912 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42913 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    42914 p = super().first_intercept(mxyz1, mxyz2) 
    42915 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42916 File
    42917 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42918 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    42919 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    42920 exclude=exclude) 
    42921 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42922 File
    42923 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42924 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    42925 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    42926 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42927 File
    42928 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42929 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    42930 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    42931 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42932 File
    42933 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42934 packages/chimerax/graphics/drawing.py", line 1108, in
    42935 _first_intercept_excluding_children 
    42936 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    42937 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42938 File
    42939 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42940 packages/chimerax/geometry/place.py", line 201, in inverse 
    42941 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    42942 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42943 File
    42944 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42945 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    42946 rinv[:, :] = matrix_inverse(r) 
    42947 ^^^^^^^^^^^^^^^^^ 
    42948 File
    42949 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42950 packages/numpy/linalg/linalg.py", line 561, in inv 
    42951 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    42952 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42953 File
    42954 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42955 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    42956 raise LinAlgError("Singular matrix") 
    42957 numpy.linalg.LinAlgError: Singular matrix 
    42958  
    42959 numpy.linalg.LinAlgError: Singular matrix 
    42960  
    42961 File
    42962 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42963 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    42964 raise LinAlgError("Singular matrix") 
    42965  
    42966 See log for complete Python traceback. 
    42967  
    42968 Traceback (most recent call last): 
    42969 File
    42970 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42971 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    42972 self.session.ui.mouse_modes.mouse_pause_tracking() 
    42973 File
    42974 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42975 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    42976 mouse_pause_tracking 
    42977 self._mouse_pause() 
    42978 File
    42979 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42980 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    42981 m.pause(self._mouse_pause_position) 
    42982 File
    42983 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42984 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    42985 p = self.view.picked_object(x, y) 
    42986 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42987 File
    42988 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42989 packages/chimerax/graphics/view.py", line 838, in picked_object 
    42990 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    42991 beyond, 
    42992 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42993 File
    42994 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    42995 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    42996 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    42997 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    42998 File
    42999 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43000 packages/chimerax/core/models.py", line 143, in first_intercept 
    43001 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    43002 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43003 File
    43004 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43005 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    43006 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    43007 exclude=exclude) 
    43008 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43009 File
    43010 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43011 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    43012 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    43013 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43014 File
    43015 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43016 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    43017 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    43018 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43019 File
    43020 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43021 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    43022 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    43023 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43024 File
    43025 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43026 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    43027 p = super().first_intercept(mxyz1, mxyz2) 
    43028 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43029 File
    43030 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43031 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    43032 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    43033 exclude=exclude) 
    43034 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43035 File
    43036 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43037 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    43038 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    43039 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43040 File
    43041 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43042 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    43043 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    43044 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43045 File
    43046 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43047 packages/chimerax/graphics/drawing.py", line 1108, in
    43048 _first_intercept_excluding_children 
    43049 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    43050 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43051 File
    43052 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43053 packages/chimerax/geometry/place.py", line 201, in inverse 
    43054 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    43055 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43056 File
    43057 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43058 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    43059 rinv[:, :] = matrix_inverse(r) 
    43060 ^^^^^^^^^^^^^^^^^ 
    43061 File
    43062 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43063 packages/numpy/linalg/linalg.py", line 561, in inv 
    43064 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    43065 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43066 File
    43067 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43068 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    43069 raise LinAlgError("Singular matrix") 
    43070 numpy.linalg.LinAlgError: Singular matrix 
    43071  
    43072 numpy.linalg.LinAlgError: Singular matrix 
    43073  
    43074 File
    43075 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43076 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    43077 raise LinAlgError("Singular matrix") 
    43078  
    43079 See log for complete Python traceback. 
    43080  
    43081 Traceback (most recent call last): 
    43082 File
    43083 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43084 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    43085 self.session.ui.mouse_modes.mouse_pause_tracking() 
    43086 File
    43087 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43088 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    43089 mouse_pause_tracking 
    43090 self._mouse_pause() 
    43091 File
    43092 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43093 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    43094 m.pause(self._mouse_pause_position) 
    43095 File
    43096 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43097 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    43098 p = self.view.picked_object(x, y) 
    43099 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43100 File
    43101 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43102 packages/chimerax/graphics/view.py", line 838, in picked_object 
    43103 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    43104 beyond, 
    43105 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43106 File
    43107 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43108 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    43109 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    43110 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43111 File
    43112 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43113 packages/chimerax/core/models.py", line 143, in first_intercept 
    43114 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    43115 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43116 File
    43117 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43118 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    43119 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    43120 exclude=exclude) 
    43121 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43122 File
    43123 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43124 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    43125 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    43126 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43127 File
    43128 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43129 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    43130 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    43131 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43132 File
    43133 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43134 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    43135 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    43136 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43137 File
    43138 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43139 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    43140 p = super().first_intercept(mxyz1, mxyz2) 
    43141 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43142 File
    43143 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43144 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    43145 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    43146 exclude=exclude) 
    43147 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43148 File
    43149 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43150 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    43151 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    43152 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43153 File
    43154 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43155 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    43156 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    43157 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43158 File
    43159 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43160 packages/chimerax/graphics/drawing.py", line 1108, in
    43161 _first_intercept_excluding_children 
    43162 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    43163 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43164 File
    43165 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43166 packages/chimerax/geometry/place.py", line 201, in inverse 
    43167 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    43168 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43169 File
    43170 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43171 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    43172 rinv[:, :] = matrix_inverse(r) 
    43173 ^^^^^^^^^^^^^^^^^ 
    43174 File
    43175 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43176 packages/numpy/linalg/linalg.py", line 561, in inv 
    43177 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    43178 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43179 File
    43180 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43181 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    43182 raise LinAlgError("Singular matrix") 
    43183 numpy.linalg.LinAlgError: Singular matrix 
    43184  
    43185 numpy.linalg.LinAlgError: Singular matrix 
    43186  
    43187 File
    43188 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43189 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    43190 raise LinAlgError("Singular matrix") 
    43191  
    43192 See log for complete Python traceback. 
    43193  
    43194 Traceback (most recent call last): 
    43195 File
    43196 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43197 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    43198 self.session.ui.mouse_modes.mouse_pause_tracking() 
    43199 File
    43200 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43201 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    43202 mouse_pause_tracking 
    43203 self._mouse_pause() 
    43204 File
    43205 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43206 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    43207 m.pause(self._mouse_pause_position) 
    43208 File
    43209 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43210 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    43211 p = self.view.picked_object(x, y) 
    43212 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43213 File
    43214 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43215 packages/chimerax/graphics/view.py", line 838, in picked_object 
    43216 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    43217 beyond, 
    43218 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43219 File
    43220 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43221 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    43222 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    43223 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43224 File
    43225 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43226 packages/chimerax/core/models.py", line 143, in first_intercept 
    43227 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    43228 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43229 File
    43230 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43231 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    43232 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    43233 exclude=exclude) 
    43234 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43235 File
    43236 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43237 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    43238 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    43239 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43240 File
    43241 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43242 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    43243 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    43244 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43245 File
    43246 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43247 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    43248 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    43249 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43250 File
    43251 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43252 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    43253 p = super().first_intercept(mxyz1, mxyz2) 
    43254 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43255 File
    43256 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43257 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    43258 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    43259 exclude=exclude) 
    43260 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43261 File
    43262 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43263 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    43264 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    43265 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43266 File
    43267 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43268 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    43269 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    43270 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43271 File
    43272 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43273 packages/chimerax/graphics/drawing.py", line 1108, in
    43274 _first_intercept_excluding_children 
    43275 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    43276 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43277 File
    43278 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43279 packages/chimerax/geometry/place.py", line 201, in inverse 
    43280 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    43281 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43282 File
    43283 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43284 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    43285 rinv[:, :] = matrix_inverse(r) 
    43286 ^^^^^^^^^^^^^^^^^ 
    43287 File
    43288 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43289 packages/numpy/linalg/linalg.py", line 561, in inv 
    43290 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    43291 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43292 File
    43293 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43294 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    43295 raise LinAlgError("Singular matrix") 
    43296 numpy.linalg.LinAlgError: Singular matrix 
    43297  
    43298 numpy.linalg.LinAlgError: Singular matrix 
    43299  
    43300 File
    43301 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43302 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    43303 raise LinAlgError("Singular matrix") 
    43304  
    43305 See log for complete Python traceback. 
    43306  
    43307 Traceback (most recent call last): 
    43308 File
    43309 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43310 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    43311 self.session.ui.mouse_modes.mouse_pause_tracking() 
    43312 File
    43313 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43314 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    43315 mouse_pause_tracking 
    43316 self._mouse_pause() 
    43317 File
    43318 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43319 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    43320 m.pause(self._mouse_pause_position) 
    43321 File
    43322 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43323 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    43324 p = self.view.picked_object(x, y) 
    43325 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43326 File
    43327 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43328 packages/chimerax/graphics/view.py", line 838, in picked_object 
    43329 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    43330 beyond, 
    43331 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43332 File
    43333 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43334 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    43335 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    43336 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43337 File
    43338 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43339 packages/chimerax/core/models.py", line 143, in first_intercept 
    43340 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    43341 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43342 File
    43343 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43344 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    43345 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    43346 exclude=exclude) 
    43347 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43348 File
    43349 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43350 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    43351 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    43352 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43353 File
    43354 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43355 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    43356 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    43357 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43358 File
    43359 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43360 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    43361 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    43362 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43363 File
    43364 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43365 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    43366 p = super().first_intercept(mxyz1, mxyz2) 
    43367 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43368 File
    43369 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43370 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    43371 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    43372 exclude=exclude) 
    43373 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43374 File
    43375 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43376 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    43377 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    43378 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43379 File
    43380 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43381 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    43382 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    43383 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43384 File
    43385 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43386 packages/chimerax/graphics/drawing.py", line 1108, in
    43387 _first_intercept_excluding_children 
    43388 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    43389 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43390 File
    43391 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43392 packages/chimerax/geometry/place.py", line 201, in inverse 
    43393 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    43394 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43395 File
    43396 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43397 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    43398 rinv[:, :] = matrix_inverse(r) 
    43399 ^^^^^^^^^^^^^^^^^ 
    43400 File
    43401 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43402 packages/numpy/linalg/linalg.py", line 561, in inv 
    43403 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    43404 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43405 File
    43406 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43407 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    43408 raise LinAlgError("Singular matrix") 
    43409 numpy.linalg.LinAlgError: Singular matrix 
    43410  
    43411 numpy.linalg.LinAlgError: Singular matrix 
    43412  
    43413 File
    43414 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43415 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    43416 raise LinAlgError("Singular matrix") 
    43417  
    43418 See log for complete Python traceback. 
    43419  
    43420 Traceback (most recent call last): 
    43421 File
    43422 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43423 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    43424 self.session.ui.mouse_modes.mouse_pause_tracking() 
    43425 File
    43426 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43427 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    43428 mouse_pause_tracking 
    43429 self._mouse_pause() 
    43430 File
    43431 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43432 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    43433 m.pause(self._mouse_pause_position) 
    43434 File
    43435 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43436 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    43437 p = self.view.picked_object(x, y) 
    43438 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43439 File
    43440 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43441 packages/chimerax/graphics/view.py", line 838, in picked_object 
    43442 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    43443 beyond, 
    43444 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43445 File
    43446 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43447 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    43448 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    43449 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43450 File
    43451 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43452 packages/chimerax/core/models.py", line 143, in first_intercept 
    43453 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    43454 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43455 File
    43456 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43457 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    43458 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    43459 exclude=exclude) 
    43460 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43461 File
    43462 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43463 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    43464 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    43465 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43466 File
    43467 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43468 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    43469 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    43470 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43471 File
    43472 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43473 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    43474 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    43475 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43476 File
    43477 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43478 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    43479 p = super().first_intercept(mxyz1, mxyz2) 
    43480 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43481 File
    43482 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43483 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    43484 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    43485 exclude=exclude) 
    43486 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43487 File
    43488 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43489 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    43490 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    43491 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43492 File
    43493 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43494 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    43495 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    43496 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43497 File
    43498 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43499 packages/chimerax/graphics/drawing.py", line 1108, in
    43500 _first_intercept_excluding_children 
    43501 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    43502 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43503 File
    43504 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43505 packages/chimerax/geometry/place.py", line 201, in inverse 
    43506 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    43507 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43508 File
    43509 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43510 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    43511 rinv[:, :] = matrix_inverse(r) 
    43512 ^^^^^^^^^^^^^^^^^ 
    43513 File
    43514 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43515 packages/numpy/linalg/linalg.py", line 561, in inv 
    43516 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    43517 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43518 File
    43519 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43520 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    43521 raise LinAlgError("Singular matrix") 
    43522 numpy.linalg.LinAlgError: Singular matrix 
    43523  
    43524 numpy.linalg.LinAlgError: Singular matrix 
    43525  
    43526 File
    43527 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43528 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    43529 raise LinAlgError("Singular matrix") 
    43530  
    43531 See log for complete Python traceback. 
    43532  
    43533 Traceback (most recent call last): 
    43534 File
    43535 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43536 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    43537 self.session.ui.mouse_modes.mouse_pause_tracking() 
    43538 File
    43539 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43540 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    43541 mouse_pause_tracking 
    43542 self._mouse_pause() 
    43543 File
    43544 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43545 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    43546 m.pause(self._mouse_pause_position) 
    43547 File
    43548 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43549 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    43550 p = self.view.picked_object(x, y) 
    43551 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43552 File
    43553 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43554 packages/chimerax/graphics/view.py", line 838, in picked_object 
    43555 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    43556 beyond, 
    43557 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43558 File
    43559 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43560 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    43561 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    43562 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43563 File
    43564 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43565 packages/chimerax/core/models.py", line 143, in first_intercept 
    43566 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    43567 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43568 File
    43569 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43570 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    43571 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    43572 exclude=exclude) 
    43573 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43574 File
    43575 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43576 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    43577 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    43578 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43579 File
    43580 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43581 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    43582 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    43583 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43584 File
    43585 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43586 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    43587 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    43588 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43589 File
    43590 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43591 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    43592 p = super().first_intercept(mxyz1, mxyz2) 
    43593 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43594 File
    43595 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43596 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    43597 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    43598 exclude=exclude) 
    43599 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43600 File
    43601 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43602 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    43603 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    43604 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43605 File
    43606 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43607 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    43608 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    43609 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43610 File
    43611 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43612 packages/chimerax/graphics/drawing.py", line 1108, in
    43613 _first_intercept_excluding_children 
    43614 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    43615 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43616 File
    43617 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43618 packages/chimerax/geometry/place.py", line 201, in inverse 
    43619 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    43620 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43621 File
    43622 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43623 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    43624 rinv[:, :] = matrix_inverse(r) 
    43625 ^^^^^^^^^^^^^^^^^ 
    43626 File
    43627 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43628 packages/numpy/linalg/linalg.py", line 561, in inv 
    43629 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    43630 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43631 File
    43632 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43633 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    43634 raise LinAlgError("Singular matrix") 
    43635 numpy.linalg.LinAlgError: Singular matrix 
    43636  
    43637 numpy.linalg.LinAlgError: Singular matrix 
    43638  
    43639 File
    43640 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43641 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    43642 raise LinAlgError("Singular matrix") 
    43643  
    43644 See log for complete Python traceback. 
    43645  
    43646 Traceback (most recent call last): 
    43647 File
    43648 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43649 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    43650 self.session.ui.mouse_modes.mouse_pause_tracking() 
    43651 File
    43652 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43653 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    43654 mouse_pause_tracking 
    43655 self._mouse_pause() 
    43656 File
    43657 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43658 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    43659 m.pause(self._mouse_pause_position) 
    43660 File
    43661 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43662 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    43663 p = self.view.picked_object(x, y) 
    43664 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43665 File
    43666 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43667 packages/chimerax/graphics/view.py", line 838, in picked_object 
    43668 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    43669 beyond, 
    43670 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43671 File
    43672 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43673 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    43674 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    43675 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43676 File
    43677 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43678 packages/chimerax/core/models.py", line 143, in first_intercept 
    43679 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    43680 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43681 File
    43682 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43683 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    43684 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    43685 exclude=exclude) 
    43686 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43687 File
    43688 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43689 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    43690 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    43691 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43692 File
    43693 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43694 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    43695 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    43696 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43697 File
    43698 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43699 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    43700 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    43701 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43702 File
    43703 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43704 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    43705 p = super().first_intercept(mxyz1, mxyz2) 
    43706 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43707 File
    43708 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43709 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    43710 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    43711 exclude=exclude) 
    43712 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43713 File
    43714 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43715 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    43716 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    43717 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43718 File
    43719 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43720 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    43721 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    43722 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43723 File
    43724 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43725 packages/chimerax/graphics/drawing.py", line 1108, in
    43726 _first_intercept_excluding_children 
    43727 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    43728 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43729 File
    43730 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43731 packages/chimerax/geometry/place.py", line 201, in inverse 
    43732 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    43733 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43734 File
    43735 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43736 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    43737 rinv[:, :] = matrix_inverse(r) 
    43738 ^^^^^^^^^^^^^^^^^ 
    43739 File
    43740 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43741 packages/numpy/linalg/linalg.py", line 561, in inv 
    43742 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    43743 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43744 File
    43745 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43746 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    43747 raise LinAlgError("Singular matrix") 
    43748 numpy.linalg.LinAlgError: Singular matrix 
    43749  
    43750 numpy.linalg.LinAlgError: Singular matrix 
    43751  
    43752 File
    43753 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43754 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    43755 raise LinAlgError("Singular matrix") 
    43756  
    43757 See log for complete Python traceback. 
    43758  
    43759 Traceback (most recent call last): 
    43760 File
    43761 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43762 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    43763 self.session.ui.mouse_modes.mouse_pause_tracking() 
    43764 File
    43765 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43766 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    43767 mouse_pause_tracking 
    43768 self._mouse_pause() 
    43769 File
    43770 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43771 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    43772 m.pause(self._mouse_pause_position) 
    43773 File
    43774 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43775 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    43776 p = self.view.picked_object(x, y) 
    43777 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43778 File
    43779 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43780 packages/chimerax/graphics/view.py", line 838, in picked_object 
    43781 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    43782 beyond, 
    43783 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43784 File
    43785 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43786 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    43787 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    43788 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43789 File
    43790 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43791 packages/chimerax/core/models.py", line 143, in first_intercept 
    43792 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    43793 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43794 File
    43795 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43796 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    43797 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    43798 exclude=exclude) 
    43799 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43800 File
    43801 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43802 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    43803 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    43804 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43805 File
    43806 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43807 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    43808 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    43809 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43810 File
    43811 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43812 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    43813 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    43814 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43815 File
    43816 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43817 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    43818 p = super().first_intercept(mxyz1, mxyz2) 
    43819 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43820 File
    43821 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43822 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    43823 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    43824 exclude=exclude) 
    43825 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43826 File
    43827 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43828 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    43829 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    43830 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43831 File
    43832 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43833 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    43834 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    43835 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43836 File
    43837 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43838 packages/chimerax/graphics/drawing.py", line 1108, in
    43839 _first_intercept_excluding_children 
    43840 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    43841 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43842 File
    43843 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43844 packages/chimerax/geometry/place.py", line 201, in inverse 
    43845 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    43846 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43847 File
    43848 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43849 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    43850 rinv[:, :] = matrix_inverse(r) 
    43851 ^^^^^^^^^^^^^^^^^ 
    43852 File
    43853 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43854 packages/numpy/linalg/linalg.py", line 561, in inv 
    43855 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    43856 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43857 File
    43858 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43859 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    43860 raise LinAlgError("Singular matrix") 
    43861 numpy.linalg.LinAlgError: Singular matrix 
    43862  
    43863 numpy.linalg.LinAlgError: Singular matrix 
    43864  
    43865 File
    43866 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43867 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    43868 raise LinAlgError("Singular matrix") 
    43869  
    43870 See log for complete Python traceback. 
    43871  
    43872 Traceback (most recent call last): 
    43873 File
    43874 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43875 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    43876 self.session.ui.mouse_modes.mouse_pause_tracking() 
    43877 File
    43878 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43879 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    43880 mouse_pause_tracking 
    43881 self._mouse_pause() 
    43882 File
    43883 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43884 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    43885 m.pause(self._mouse_pause_position) 
    43886 File
    43887 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43888 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    43889 p = self.view.picked_object(x, y) 
    43890 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43891 File
    43892 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43893 packages/chimerax/graphics/view.py", line 838, in picked_object 
    43894 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    43895 beyond, 
    43896 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43897 File
    43898 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43899 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    43900 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    43901 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43902 File
    43903 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43904 packages/chimerax/core/models.py", line 143, in first_intercept 
    43905 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    43906 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43907 File
    43908 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43909 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    43910 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    43911 exclude=exclude) 
    43912 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43913 File
    43914 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43915 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    43916 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    43917 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43918 File
    43919 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43920 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    43921 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    43922 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43923 File
    43924 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43925 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    43926 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    43927 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43928 File
    43929 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43930 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    43931 p = super().first_intercept(mxyz1, mxyz2) 
    43932 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43933 File
    43934 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43935 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    43936 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    43937 exclude=exclude) 
    43938 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43939 File
    43940 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43941 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    43942 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    43943 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43944 File
    43945 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43946 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    43947 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    43948 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43949 File
    43950 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43951 packages/chimerax/graphics/drawing.py", line 1108, in
    43952 _first_intercept_excluding_children 
    43953 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    43954 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43955 File
    43956 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43957 packages/chimerax/geometry/place.py", line 201, in inverse 
    43958 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    43959 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43960 File
    43961 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43962 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    43963 rinv[:, :] = matrix_inverse(r) 
    43964 ^^^^^^^^^^^^^^^^^ 
    43965 File
    43966 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43967 packages/numpy/linalg/linalg.py", line 561, in inv 
    43968 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    43969 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    43970 File
    43971 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43972 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    43973 raise LinAlgError("Singular matrix") 
    43974 numpy.linalg.LinAlgError: Singular matrix 
    43975  
    43976 numpy.linalg.LinAlgError: Singular matrix 
    43977  
    43978 File
    43979 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43980 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    43981 raise LinAlgError("Singular matrix") 
    43982  
    43983 See log for complete Python traceback. 
    43984  
    43985 Traceback (most recent call last): 
    43986 File
    43987 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43988 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    43989 self.session.ui.mouse_modes.mouse_pause_tracking() 
    43990 File
    43991 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43992 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    43993 mouse_pause_tracking 
    43994 self._mouse_pause() 
    43995 File
    43996 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    43997 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    43998 m.pause(self._mouse_pause_position) 
    43999 File
    44000 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44001 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    44002 p = self.view.picked_object(x, y) 
    44003 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44004 File
    44005 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44006 packages/chimerax/graphics/view.py", line 838, in picked_object 
    44007 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    44008 beyond, 
    44009 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44010 File
    44011 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44012 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    44013 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    44014 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44015 File
    44016 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44017 packages/chimerax/core/models.py", line 143, in first_intercept 
    44018 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    44019 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44020 File
    44021 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44022 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    44023 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    44024 exclude=exclude) 
    44025 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44026 File
    44027 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44028 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    44029 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    44030 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44031 File
    44032 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44033 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    44034 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    44035 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44036 File
    44037 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44038 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    44039 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    44040 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44041 File
    44042 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44043 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    44044 p = super().first_intercept(mxyz1, mxyz2) 
    44045 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44046 File
    44047 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44048 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    44049 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    44050 exclude=exclude) 
    44051 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44052 File
    44053 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44054 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    44055 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    44056 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44057 File
    44058 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44059 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    44060 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    44061 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44062 File
    44063 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44064 packages/chimerax/graphics/drawing.py", line 1108, in
    44065 _first_intercept_excluding_children 
    44066 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    44067 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44068 File
    44069 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44070 packages/chimerax/geometry/place.py", line 201, in inverse 
    44071 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    44072 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44073 File
    44074 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44075 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    44076 rinv[:, :] = matrix_inverse(r) 
    44077 ^^^^^^^^^^^^^^^^^ 
    44078 File
    44079 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44080 packages/numpy/linalg/linalg.py", line 561, in inv 
    44081 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    44082 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44083 File
    44084 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44085 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    44086 raise LinAlgError("Singular matrix") 
    44087 numpy.linalg.LinAlgError: Singular matrix 
    44088  
    44089 numpy.linalg.LinAlgError: Singular matrix 
    44090  
    44091 File
    44092 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44093 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    44094 raise LinAlgError("Singular matrix") 
    44095  
    44096 See log for complete Python traceback. 
    44097  
    44098 Traceback (most recent call last): 
    44099 File
    44100 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44101 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    44102 self.session.ui.mouse_modes.mouse_pause_tracking() 
    44103 File
    44104 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44105 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    44106 mouse_pause_tracking 
    44107 self._mouse_pause() 
    44108 File
    44109 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44110 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    44111 m.pause(self._mouse_pause_position) 
    44112 File
    44113 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44114 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    44115 p = self.view.picked_object(x, y) 
    44116 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44117 File
    44118 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44119 packages/chimerax/graphics/view.py", line 838, in picked_object 
    44120 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    44121 beyond, 
    44122 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44123 File
    44124 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44125 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    44126 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    44127 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44128 File
    44129 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44130 packages/chimerax/core/models.py", line 143, in first_intercept 
    44131 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    44132 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44133 File
    44134 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44135 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    44136 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    44137 exclude=exclude) 
    44138 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44139 File
    44140 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44141 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    44142 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    44143 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44144 File
    44145 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44146 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    44147 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    44148 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44149 File
    44150 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44151 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    44152 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    44153 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44154 File
    44155 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44156 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    44157 p = super().first_intercept(mxyz1, mxyz2) 
    44158 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44159 File
    44160 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44161 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    44162 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    44163 exclude=exclude) 
    44164 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44165 File
    44166 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44167 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    44168 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    44169 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44170 File
    44171 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44172 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    44173 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    44174 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44175 File
    44176 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44177 packages/chimerax/graphics/drawing.py", line 1108, in
    44178 _first_intercept_excluding_children 
    44179 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    44180 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44181 File
    44182 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44183 packages/chimerax/geometry/place.py", line 201, in inverse 
    44184 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    44185 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44186 File
    44187 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44188 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    44189 rinv[:, :] = matrix_inverse(r) 
    44190 ^^^^^^^^^^^^^^^^^ 
    44191 File
    44192 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44193 packages/numpy/linalg/linalg.py", line 561, in inv 
    44194 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    44195 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44196 File
    44197 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44198 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    44199 raise LinAlgError("Singular matrix") 
    44200 numpy.linalg.LinAlgError: Singular matrix 
    44201  
    44202 numpy.linalg.LinAlgError: Singular matrix 
    44203  
    44204 File
    44205 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44206 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    44207 raise LinAlgError("Singular matrix") 
    44208  
    44209 See log for complete Python traceback. 
    44210  
    44211 Traceback (most recent call last): 
    44212 File
    44213 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44214 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    44215 self.session.ui.mouse_modes.mouse_pause_tracking() 
    44216 File
    44217 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44218 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    44219 mouse_pause_tracking 
    44220 self._mouse_pause() 
    44221 File
    44222 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44223 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    44224 m.pause(self._mouse_pause_position) 
    44225 File
    44226 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44227 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    44228 p = self.view.picked_object(x, y) 
    44229 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44230 File
    44231 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44232 packages/chimerax/graphics/view.py", line 838, in picked_object 
    44233 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    44234 beyond, 
    44235 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44236 File
    44237 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44238 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    44239 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    44240 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44241 File
    44242 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44243 packages/chimerax/core/models.py", line 143, in first_intercept 
    44244 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    44245 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44246 File
    44247 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44248 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    44249 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    44250 exclude=exclude) 
    44251 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44252 File
    44253 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44254 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    44255 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    44256 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44257 File
    44258 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44259 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    44260 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    44261 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44262 File
    44263 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44264 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    44265 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    44266 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44267 File
    44268 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44269 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    44270 p = super().first_intercept(mxyz1, mxyz2) 
    44271 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44272 File
    44273 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44274 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    44275 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    44276 exclude=exclude) 
    44277 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44278 File
    44279 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44280 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    44281 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    44282 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44283 File
    44284 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44285 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    44286 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    44287 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44288 File
    44289 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44290 packages/chimerax/graphics/drawing.py", line 1108, in
    44291 _first_intercept_excluding_children 
    44292 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    44293 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44294 File
    44295 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44296 packages/chimerax/geometry/place.py", line 201, in inverse 
    44297 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    44298 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44299 File
    44300 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44301 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    44302 rinv[:, :] = matrix_inverse(r) 
    44303 ^^^^^^^^^^^^^^^^^ 
    44304 File
    44305 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44306 packages/numpy/linalg/linalg.py", line 561, in inv 
    44307 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    44308 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44309 File
    44310 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44311 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    44312 raise LinAlgError("Singular matrix") 
    44313 numpy.linalg.LinAlgError: Singular matrix 
    44314  
    44315 numpy.linalg.LinAlgError: Singular matrix 
    44316  
    44317 File
    44318 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44319 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    44320 raise LinAlgError("Singular matrix") 
    44321  
    44322 See log for complete Python traceback. 
    44323  
    44324 Traceback (most recent call last): 
    44325 File
    44326 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44327 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    44328 self.session.ui.mouse_modes.mouse_pause_tracking() 
    44329 File
    44330 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44331 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    44332 mouse_pause_tracking 
    44333 self._mouse_pause() 
    44334 File
    44335 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44336 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    44337 m.pause(self._mouse_pause_position) 
    44338 File
    44339 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44340 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    44341 p = self.view.picked_object(x, y) 
    44342 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44343 File
    44344 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44345 packages/chimerax/graphics/view.py", line 838, in picked_object 
    44346 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    44347 beyond, 
    44348 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44349 File
    44350 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44351 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    44352 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    44353 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44354 File
    44355 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44356 packages/chimerax/core/models.py", line 143, in first_intercept 
    44357 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    44358 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44359 File
    44360 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44361 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    44362 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    44363 exclude=exclude) 
    44364 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44365 File
    44366 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44367 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    44368 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    44369 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44370 File
    44371 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44372 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    44373 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    44374 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44375 File
    44376 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44377 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    44378 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    44379 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44380 File
    44381 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44382 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    44383 p = super().first_intercept(mxyz1, mxyz2) 
    44384 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44385 File
    44386 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44387 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    44388 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    44389 exclude=exclude) 
    44390 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44391 File
    44392 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44393 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    44394 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    44395 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44396 File
    44397 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44398 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    44399 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    44400 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44401 File
    44402 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44403 packages/chimerax/graphics/drawing.py", line 1108, in
    44404 _first_intercept_excluding_children 
    44405 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    44406 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44407 File
    44408 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44409 packages/chimerax/geometry/place.py", line 201, in inverse 
    44410 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    44411 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44412 File
    44413 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44414 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    44415 rinv[:, :] = matrix_inverse(r) 
    44416 ^^^^^^^^^^^^^^^^^ 
    44417 File
    44418 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44419 packages/numpy/linalg/linalg.py", line 561, in inv 
    44420 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    44421 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44422 File
    44423 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44424 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    44425 raise LinAlgError("Singular matrix") 
    44426 numpy.linalg.LinAlgError: Singular matrix 
    44427  
    44428 numpy.linalg.LinAlgError: Singular matrix 
    44429  
    44430 File
    44431 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44432 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    44433 raise LinAlgError("Singular matrix") 
    44434  
    44435 See log for complete Python traceback. 
    44436  
    44437 
    44438 > select add #5/E:2204@O
    44439 
    44440 1 atom, 1 residue, 1 model selected 
    44441 
    44442 > hide sel atoms
    44443 
    44444 > select clear
    44445 
    44446 Traceback (most recent call last): 
    44447 File
    44448 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44449 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    44450 self.session.ui.mouse_modes.mouse_pause_tracking() 
    44451 File
    44452 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44453 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    44454 mouse_pause_tracking 
    44455 self._mouse_pause() 
    44456 File
    44457 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44458 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    44459 m.pause(self._mouse_pause_position) 
    44460 File
    44461 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44462 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    44463 p = self.view.picked_object(x, y) 
    44464 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44465 File
    44466 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44467 packages/chimerax/graphics/view.py", line 838, in picked_object 
    44468 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    44469 beyond, 
    44470 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44471 File
    44472 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44473 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    44474 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    44475 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44476 File
    44477 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44478 packages/chimerax/core/models.py", line 143, in first_intercept 
    44479 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    44480 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44481 File
    44482 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44483 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    44484 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    44485 exclude=exclude) 
    44486 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44487 File
    44488 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44489 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    44490 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    44491 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44492 File
    44493 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44494 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    44495 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    44496 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44497 File
    44498 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44499 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    44500 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    44501 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44502 File
    44503 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44504 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    44505 p = super().first_intercept(mxyz1, mxyz2) 
    44506 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44507 File
    44508 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44509 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    44510 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    44511 exclude=exclude) 
    44512 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44513 File
    44514 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44515 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    44516 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    44517 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44518 File
    44519 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44520 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    44521 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    44522 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44523 File
    44524 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44525 packages/chimerax/graphics/drawing.py", line 1108, in
    44526 _first_intercept_excluding_children 
    44527 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    44528 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44529 File
    44530 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44531 packages/chimerax/geometry/place.py", line 201, in inverse 
    44532 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    44533 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44534 File
    44535 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44536 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    44537 rinv[:, :] = matrix_inverse(r) 
    44538 ^^^^^^^^^^^^^^^^^ 
    44539 File
    44540 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44541 packages/numpy/linalg/linalg.py", line 561, in inv 
    44542 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    44543 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44544 File
    44545 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44546 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    44547 raise LinAlgError("Singular matrix") 
    44548 numpy.linalg.LinAlgError: Singular matrix 
    44549  
    44550 numpy.linalg.LinAlgError: Singular matrix 
    44551  
    44552 File
    44553 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44554 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    44555 raise LinAlgError("Singular matrix") 
    44556  
    44557 See log for complete Python traceback. 
    44558  
    44559 Traceback (most recent call last): 
    44560 File
    44561 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44562 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    44563 self.session.ui.mouse_modes.mouse_pause_tracking() 
    44564 File
    44565 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44566 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    44567 mouse_pause_tracking 
    44568 self._mouse_pause() 
    44569 File
    44570 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44571 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    44572 m.pause(self._mouse_pause_position) 
    44573 File
    44574 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44575 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    44576 p = self.view.picked_object(x, y) 
    44577 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44578 File
    44579 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44580 packages/chimerax/graphics/view.py", line 838, in picked_object 
    44581 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    44582 beyond, 
    44583 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44584 File
    44585 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44586 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    44587 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    44588 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44589 File
    44590 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44591 packages/chimerax/core/models.py", line 143, in first_intercept 
    44592 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    44593 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44594 File
    44595 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44596 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    44597 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    44598 exclude=exclude) 
    44599 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44600 File
    44601 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44602 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    44603 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    44604 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44605 File
    44606 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44607 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    44608 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    44609 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44610 File
    44611 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44612 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    44613 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    44614 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44615 File
    44616 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44617 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    44618 p = super().first_intercept(mxyz1, mxyz2) 
    44619 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44620 File
    44621 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44622 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    44623 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    44624 exclude=exclude) 
    44625 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44626 File
    44627 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44628 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    44629 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    44630 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44631 File
    44632 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44633 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    44634 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    44635 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44636 File
    44637 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44638 packages/chimerax/graphics/drawing.py", line 1108, in
    44639 _first_intercept_excluding_children 
    44640 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    44641 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44642 File
    44643 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44644 packages/chimerax/geometry/place.py", line 201, in inverse 
    44645 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    44646 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44647 File
    44648 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44649 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    44650 rinv[:, :] = matrix_inverse(r) 
    44651 ^^^^^^^^^^^^^^^^^ 
    44652 File
    44653 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44654 packages/numpy/linalg/linalg.py", line 561, in inv 
    44655 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    44656 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44657 File
    44658 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44659 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    44660 raise LinAlgError("Singular matrix") 
    44661 numpy.linalg.LinAlgError: Singular matrix 
    44662  
    44663 numpy.linalg.LinAlgError: Singular matrix 
    44664  
    44665 File
    44666 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44667 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    44668 raise LinAlgError("Singular matrix") 
    44669  
    44670 See log for complete Python traceback. 
    44671  
    44672 Traceback (most recent call last): 
    44673 File
    44674 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44675 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    44676 self.session.ui.mouse_modes.mouse_pause_tracking() 
    44677 File
    44678 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44679 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    44680 mouse_pause_tracking 
    44681 self._mouse_pause() 
    44682 File
    44683 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44684 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    44685 m.pause(self._mouse_pause_position) 
    44686 File
    44687 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44688 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    44689 p = self.view.picked_object(x, y) 
    44690 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44691 File
    44692 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44693 packages/chimerax/graphics/view.py", line 838, in picked_object 
    44694 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    44695 beyond, 
    44696 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44697 File
    44698 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44699 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    44700 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    44701 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44702 File
    44703 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44704 packages/chimerax/core/models.py", line 143, in first_intercept 
    44705 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    44706 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44707 File
    44708 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44709 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    44710 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    44711 exclude=exclude) 
    44712 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44713 File
    44714 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44715 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    44716 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    44717 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44718 File
    44719 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44720 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    44721 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    44722 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44723 File
    44724 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44725 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    44726 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    44727 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44728 File
    44729 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44730 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    44731 p = super().first_intercept(mxyz1, mxyz2) 
    44732 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44733 File
    44734 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44735 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    44736 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    44737 exclude=exclude) 
    44738 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44739 File
    44740 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44741 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    44742 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    44743 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44744 File
    44745 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44746 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    44747 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    44748 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44749 File
    44750 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44751 packages/chimerax/graphics/drawing.py", line 1108, in
    44752 _first_intercept_excluding_children 
    44753 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    44754 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44755 File
    44756 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44757 packages/chimerax/geometry/place.py", line 201, in inverse 
    44758 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    44759 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44760 File
    44761 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44762 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    44763 rinv[:, :] = matrix_inverse(r) 
    44764 ^^^^^^^^^^^^^^^^^ 
    44765 File
    44766 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44767 packages/numpy/linalg/linalg.py", line 561, in inv 
    44768 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    44769 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44770 File
    44771 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44772 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    44773 raise LinAlgError("Singular matrix") 
    44774 numpy.linalg.LinAlgError: Singular matrix 
    44775  
    44776 numpy.linalg.LinAlgError: Singular matrix 
    44777  
    44778 File
    44779 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44780 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    44781 raise LinAlgError("Singular matrix") 
    44782  
    44783 See log for complete Python traceback. 
    44784  
    44785 Traceback (most recent call last): 
    44786 File
    44787 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44788 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    44789 self.session.ui.mouse_modes.mouse_pause_tracking() 
    44790 File
    44791 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44792 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    44793 mouse_pause_tracking 
    44794 self._mouse_pause() 
    44795 File
    44796 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44797 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    44798 m.pause(self._mouse_pause_position) 
    44799 File
    44800 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44801 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    44802 p = self.view.picked_object(x, y) 
    44803 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44804 File
    44805 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44806 packages/chimerax/graphics/view.py", line 838, in picked_object 
    44807 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    44808 beyond, 
    44809 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44810 File
    44811 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44812 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    44813 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    44814 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44815 File
    44816 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44817 packages/chimerax/core/models.py", line 143, in first_intercept 
    44818 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    44819 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44820 File
    44821 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44822 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    44823 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    44824 exclude=exclude) 
    44825 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44826 File
    44827 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44828 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    44829 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    44830 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44831 File
    44832 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44833 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    44834 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    44835 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44836 File
    44837 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44838 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    44839 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    44840 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44841 File
    44842 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44843 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    44844 p = super().first_intercept(mxyz1, mxyz2) 
    44845 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44846 File
    44847 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44848 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    44849 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    44850 exclude=exclude) 
    44851 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44852 File
    44853 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44854 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    44855 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    44856 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44857 File
    44858 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44859 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    44860 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    44861 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44862 File
    44863 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44864 packages/chimerax/graphics/drawing.py", line 1108, in
    44865 _first_intercept_excluding_children 
    44866 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    44867 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44868 File
    44869 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44870 packages/chimerax/geometry/place.py", line 201, in inverse 
    44871 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    44872 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44873 File
    44874 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44875 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    44876 rinv[:, :] = matrix_inverse(r) 
    44877 ^^^^^^^^^^^^^^^^^ 
    44878 File
    44879 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44880 packages/numpy/linalg/linalg.py", line 561, in inv 
    44881 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    44882 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44883 File
    44884 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44885 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    44886 raise LinAlgError("Singular matrix") 
    44887 numpy.linalg.LinAlgError: Singular matrix 
    44888  
    44889 numpy.linalg.LinAlgError: Singular matrix 
    44890  
    44891 File
    44892 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44893 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    44894 raise LinAlgError("Singular matrix") 
    44895  
    44896 See log for complete Python traceback. 
    44897  
    44898 Traceback (most recent call last): 
    44899 File
    44900 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44901 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    44902 self.session.ui.mouse_modes.mouse_pause_tracking() 
    44903 File
    44904 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44905 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    44906 mouse_pause_tracking 
    44907 self._mouse_pause() 
    44908 File
    44909 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44910 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    44911 m.pause(self._mouse_pause_position) 
    44912 File
    44913 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44914 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    44915 p = self.view.picked_object(x, y) 
    44916 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44917 File
    44918 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44919 packages/chimerax/graphics/view.py", line 838, in picked_object 
    44920 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    44921 beyond, 
    44922 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44923 File
    44924 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44925 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    44926 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    44927 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44928 File
    44929 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44930 packages/chimerax/core/models.py", line 143, in first_intercept 
    44931 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    44932 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44933 File
    44934 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44935 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    44936 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    44937 exclude=exclude) 
    44938 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44939 File
    44940 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44941 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    44942 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    44943 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44944 File
    44945 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44946 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    44947 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    44948 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44949 File
    44950 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44951 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    44952 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    44953 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44954 File
    44955 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44956 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    44957 p = super().first_intercept(mxyz1, mxyz2) 
    44958 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44959 File
    44960 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44961 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    44962 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    44963 exclude=exclude) 
    44964 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44965 File
    44966 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44967 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    44968 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    44969 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44970 File
    44971 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44972 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    44973 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    44974 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44975 File
    44976 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44977 packages/chimerax/graphics/drawing.py", line 1108, in
    44978 _first_intercept_excluding_children 
    44979 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    44980 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44981 File
    44982 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44983 packages/chimerax/geometry/place.py", line 201, in inverse 
    44984 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    44985 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44986 File
    44987 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44988 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    44989 rinv[:, :] = matrix_inverse(r) 
    44990 ^^^^^^^^^^^^^^^^^ 
    44991 File
    44992 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44993 packages/numpy/linalg/linalg.py", line 561, in inv 
    44994 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    44995 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    44996 File
    44997 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    44998 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    44999 raise LinAlgError("Singular matrix") 
    45000 numpy.linalg.LinAlgError: Singular matrix 
    45001  
    45002 numpy.linalg.LinAlgError: Singular matrix 
    45003  
    45004 File
    45005 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45006 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    45007 raise LinAlgError("Singular matrix") 
    45008  
    45009 See log for complete Python traceback. 
    45010  
    45011 Traceback (most recent call last): 
    45012 File
    45013 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45014 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    45015 self.session.ui.mouse_modes.mouse_pause_tracking() 
    45016 File
    45017 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45018 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    45019 mouse_pause_tracking 
    45020 self._mouse_pause() 
    45021 File
    45022 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45023 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    45024 m.pause(self._mouse_pause_position) 
    45025 File
    45026 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45027 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    45028 p = self.view.picked_object(x, y) 
    45029 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45030 File
    45031 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45032 packages/chimerax/graphics/view.py", line 838, in picked_object 
    45033 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    45034 beyond, 
    45035 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45036 File
    45037 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45038 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    45039 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    45040 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45041 File
    45042 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45043 packages/chimerax/core/models.py", line 143, in first_intercept 
    45044 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    45045 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45046 File
    45047 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45048 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    45049 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    45050 exclude=exclude) 
    45051 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45052 File
    45053 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45054 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    45055 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    45056 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45057 File
    45058 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45059 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    45060 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    45061 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45062 File
    45063 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45064 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    45065 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    45066 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45067 File
    45068 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45069 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    45070 p = super().first_intercept(mxyz1, mxyz2) 
    45071 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45072 File
    45073 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45074 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    45075 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    45076 exclude=exclude) 
    45077 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45078 File
    45079 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45080 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    45081 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    45082 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45083 File
    45084 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45085 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    45086 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    45087 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45088 File
    45089 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45090 packages/chimerax/graphics/drawing.py", line 1108, in
    45091 _first_intercept_excluding_children 
    45092 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    45093 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45094 File
    45095 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45096 packages/chimerax/geometry/place.py", line 201, in inverse 
    45097 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    45098 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45099 File
    45100 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45101 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    45102 rinv[:, :] = matrix_inverse(r) 
    45103 ^^^^^^^^^^^^^^^^^ 
    45104 File
    45105 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45106 packages/numpy/linalg/linalg.py", line 561, in inv 
    45107 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    45108 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45109 File
    45110 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45111 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    45112 raise LinAlgError("Singular matrix") 
    45113 numpy.linalg.LinAlgError: Singular matrix 
    45114  
    45115 numpy.linalg.LinAlgError: Singular matrix 
    45116  
    45117 File
    45118 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45119 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    45120 raise LinAlgError("Singular matrix") 
    45121  
    45122 See log for complete Python traceback. 
    45123  
    45124 
    45125 > select nucleic-acid
    45126 
    45127 3689 atoms, 4125 bonds, 93 pseudobonds, 184 residues, 5 models selected 
    45128 
    45129 > select clear
    45130 
    45131 > select #5/E/F
    45132 
    45133 907 atoms, 972 bonds, 51 pseudobonds, 82 residues, 4 models selected 
    45134 
    45135 > color sel gainsboro
    45136 
    45137 > color #5.2 #fed635ff models
    45138 
    45139 > color #5.2 #f56522ff models
    45140 
    45141 > color #5.2 #ff962aff models
    45142 
    45143 > color #5.2 #ff8126ff models
    45144 
    45145 > color #5.2 #fd7023ff models
    45146 
    45147 > color #5.2 #0f0914ff models
    45148 
    45149 > color #5.2 #cf8227ff models
    45150 
    45151 > nucleotides sel stubs
    45152 
    45153 > nucleotides sel tube/slab shape box
    45154 
    45155 > nucleotides sel ladder
    45156 
    45157 > select #1/E/F/G/H
    45158 
    45159 821 atoms, 917 bonds, 40 residues, 1 model selected 
    45160 
    45161 > nucleotides sel ladder
    45162 
    45163 > nucleotides sel tube/slab shape box
    45164 
    45165 [Repeated 1 time(s)]
    45166 
    45167 > nucleotides sel ladder
    45168 
    45169 > select clear
    45170 
    45171 > select ::name="MFX"
    45172 
    45173 174 atoms, 198 bonds, 6 residues, 1 model selected 
    45174 
    45175 > color sel cadet blue
    45176 
    45177 > color sel byhetero
    45178 
    45179 > select #1/E/F/G/H
    45180 
    45181 821 atoms, 917 bonds, 40 residues, 1 model selected 
    45182 
    45183 > color sel goldenrod
    45184 
    45185 [Repeated 1 time(s)]
    45186 
    45187 > lighting full
    45188 
    45189 > select clear
    45190 
    45191 > lighting simple
    45192 
    45193 > select add #5/F:2214@O
    45194 
    45195 1 atom, 1 residue, 1 model selected 
    45196 
    45197 > select add #5/E:2206@O
    45198 
    45199 2 atoms, 2 residues, 1 model selected 
    45200 
    45201 > select add #5/E:2210@O
    45202 
    45203 3 atoms, 3 residues, 1 model selected 
    45204 
    45205 > select add #5/E:2211@O
    45206 
    45207 4 atoms, 4 residues, 1 model selected 
    45208 
    45209 > color sel red
    45210 
    45211 > select clear
    45212 
    45213 > select add #5/F:2103@C17
    45214 
    45215 1 atom, 1 residue, 1 model selected 
    45216 
    45217 > select subtract #5/F:2103@C17
    45218 
    45219 Nothing selected 
    45220 
    45221 > select add #5/E:2206@O
    45222 
    45223 1 atom, 1 residue, 1 model selected 
    45224 
    45225 > select add #5/E:2210@O
    45226 
    45227 2 atoms, 2 residues, 1 model selected 
    45228 
    45229 > select add #5/B:1104@O
    45230 
    45231 3 atoms, 3 residues, 1 model selected 
    45232 
    45233 > hide sel cartoons
    45234 
    45235 > hide sel atoms
    45236 
    45237 > select clear
    45238 
    45239 > select add #5/B:584
    45240 
    45241 4 atoms, 3 bonds, 1 residue, 1 model selected 
    45242 
    45243 > select add #5/B:585
    45244 
    45245 13 atoms, 11 bonds, 2 residues, 1 model selected 
    45246 
    45247 > select add #5/B:586
    45248 
    45249 21 atoms, 18 bonds, 3 residues, 1 model selected 
    45250 
    45251 > select add #5/B:587
    45252 
    45253 29 atoms, 25 bonds, 4 residues, 1 model selected 
    45254 
    45255 > select add #5/B:435
    45256 
    45257 38 atoms, 33 bonds, 5 residues, 1 model selected 
    45258 
    45259 > select add #5/B:436
    45260 
    45261 42 atoms, 36 bonds, 6 residues, 1 model selected 
    45262 
    45263 > hide sel cartoons
    45264 
    45265 > select add #5/B:437
    45266 
    45267 50 atoms, 43 bonds, 7 residues, 1 model selected 
    45268 
    45269 > select add #5/B:457
    45270 
    45271 58 atoms, 50 bonds, 8 residues, 1 model selected 
    45272 
    45273 > hide sel cartoons
    45274 
    45275 > select add #1/D:765
    45276 
    45277 66 atoms, 57 bonds, 9 residues, 2 models selected 
    45278 
    45279 > hide sel cartoons
    45280 
    45281 Traceback (most recent call last): 
    45282 File
    45283 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45284 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    45285 self.session.ui.mouse_modes.mouse_pause_tracking() 
    45286 File
    45287 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45288 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    45289 mouse_pause_tracking 
    45290 self._mouse_pause() 
    45291 File
    45292 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45293 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    45294 m.pause(self._mouse_pause_position) 
    45295 File
    45296 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45297 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    45298 p = self.view.picked_object(x, y) 
    45299 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45300 File
    45301 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45302 packages/chimerax/graphics/view.py", line 838, in picked_object 
    45303 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    45304 beyond, 
    45305 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45306 File
    45307 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45308 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    45309 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    45310 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45311 File
    45312 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45313 packages/chimerax/core/models.py", line 143, in first_intercept 
    45314 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    45315 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45316 File
    45317 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45318 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    45319 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    45320 exclude=exclude) 
    45321 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45322 File
    45323 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45324 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    45325 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    45326 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45327 File
    45328 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45329 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    45330 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    45331 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45332 File
    45333 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45334 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    45335 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    45336 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45337 File
    45338 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45339 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    45340 p = super().first_intercept(mxyz1, mxyz2) 
    45341 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45342 File
    45343 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45344 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    45345 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    45346 exclude=exclude) 
    45347 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45348 File
    45349 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45350 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    45351 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    45352 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45353 File
    45354 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45355 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    45356 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    45357 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45358 File
    45359 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45360 packages/chimerax/graphics/drawing.py", line 1108, in
    45361 _first_intercept_excluding_children 
    45362 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    45363 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45364 File
    45365 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45366 packages/chimerax/geometry/place.py", line 201, in inverse 
    45367 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    45368 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45369 File
    45370 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45371 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    45372 rinv[:, :] = matrix_inverse(r) 
    45373 ^^^^^^^^^^^^^^^^^ 
    45374 File
    45375 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45376 packages/numpy/linalg/linalg.py", line 561, in inv 
    45377 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    45378 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45379 File
    45380 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45381 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    45382 raise LinAlgError("Singular matrix") 
    45383 numpy.linalg.LinAlgError: Singular matrix 
    45384  
    45385 numpy.linalg.LinAlgError: Singular matrix 
    45386  
    45387 File
    45388 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45389 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    45390 raise LinAlgError("Singular matrix") 
    45391  
    45392 See log for complete Python traceback. 
    45393  
    45394 Traceback (most recent call last): 
    45395 File
    45396 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45397 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    45398 self.session.ui.mouse_modes.mouse_pause_tracking() 
    45399 File
    45400 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45401 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    45402 mouse_pause_tracking 
    45403 self._mouse_pause() 
    45404 File
    45405 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45406 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    45407 m.pause(self._mouse_pause_position) 
    45408 File
    45409 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45410 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    45411 p = self.view.picked_object(x, y) 
    45412 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45413 File
    45414 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45415 packages/chimerax/graphics/view.py", line 838, in picked_object 
    45416 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    45417 beyond, 
    45418 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45419 File
    45420 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45421 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    45422 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    45423 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45424 File
    45425 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45426 packages/chimerax/core/models.py", line 143, in first_intercept 
    45427 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    45428 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45429 File
    45430 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45431 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    45432 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    45433 exclude=exclude) 
    45434 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45435 File
    45436 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45437 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    45438 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    45439 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45440 File
    45441 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45442 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    45443 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    45444 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45445 File
    45446 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45447 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    45448 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    45449 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45450 File
    45451 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45452 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    45453 p = super().first_intercept(mxyz1, mxyz2) 
    45454 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45455 File
    45456 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45457 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    45458 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    45459 exclude=exclude) 
    45460 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45461 File
    45462 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45463 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    45464 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    45465 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45466 File
    45467 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45468 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    45469 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    45470 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45471 File
    45472 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45473 packages/chimerax/graphics/drawing.py", line 1108, in
    45474 _first_intercept_excluding_children 
    45475 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    45476 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45477 File
    45478 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45479 packages/chimerax/geometry/place.py", line 201, in inverse 
    45480 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    45481 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45482 File
    45483 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45484 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    45485 rinv[:, :] = matrix_inverse(r) 
    45486 ^^^^^^^^^^^^^^^^^ 
    45487 File
    45488 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45489 packages/numpy/linalg/linalg.py", line 561, in inv 
    45490 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    45491 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45492 File
    45493 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45494 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    45495 raise LinAlgError("Singular matrix") 
    45496 numpy.linalg.LinAlgError: Singular matrix 
    45497  
    45498 numpy.linalg.LinAlgError: Singular matrix 
    45499  
    45500 File
    45501 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45502 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    45503 raise LinAlgError("Singular matrix") 
    45504  
    45505 See log for complete Python traceback. 
    45506  
    45507 Traceback (most recent call last): 
    45508 File
    45509 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45510 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    45511 self.session.ui.mouse_modes.mouse_pause_tracking() 
    45512 File
    45513 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45514 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    45515 mouse_pause_tracking 
    45516 self._mouse_pause() 
    45517 File
    45518 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45519 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    45520 m.pause(self._mouse_pause_position) 
    45521 File
    45522 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45523 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    45524 p = self.view.picked_object(x, y) 
    45525 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45526 File
    45527 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45528 packages/chimerax/graphics/view.py", line 838, in picked_object 
    45529 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    45530 beyond, 
    45531 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45532 File
    45533 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45534 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    45535 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    45536 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45537 File
    45538 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45539 packages/chimerax/core/models.py", line 143, in first_intercept 
    45540 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    45541 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45542 File
    45543 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45544 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    45545 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    45546 exclude=exclude) 
    45547 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45548 File
    45549 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45550 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    45551 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    45552 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45553 File
    45554 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45555 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    45556 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    45557 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45558 File
    45559 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45560 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    45561 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    45562 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45563 File
    45564 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45565 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    45566 p = super().first_intercept(mxyz1, mxyz2) 
    45567 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45568 File
    45569 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45570 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    45571 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    45572 exclude=exclude) 
    45573 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45574 File
    45575 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45576 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    45577 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    45578 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45579 File
    45580 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45581 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    45582 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    45583 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45584 File
    45585 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45586 packages/chimerax/graphics/drawing.py", line 1108, in
    45587 _first_intercept_excluding_children 
    45588 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    45589 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45590 File
    45591 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45592 packages/chimerax/geometry/place.py", line 201, in inverse 
    45593 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    45594 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45595 File
    45596 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45597 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    45598 rinv[:, :] = matrix_inverse(r) 
    45599 ^^^^^^^^^^^^^^^^^ 
    45600 File
    45601 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45602 packages/numpy/linalg/linalg.py", line 561, in inv 
    45603 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    45604 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45605 File
    45606 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45607 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    45608 raise LinAlgError("Singular matrix") 
    45609 numpy.linalg.LinAlgError: Singular matrix 
    45610  
    45611 numpy.linalg.LinAlgError: Singular matrix 
    45612  
    45613 File
    45614 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45615 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    45616 raise LinAlgError("Singular matrix") 
    45617  
    45618 See log for complete Python traceback. 
    45619  
    45620 Traceback (most recent call last): 
    45621 File
    45622 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45623 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    45624 self.session.ui.mouse_modes.mouse_pause_tracking() 
    45625 File
    45626 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45627 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    45628 mouse_pause_tracking 
    45629 self._mouse_pause() 
    45630 File
    45631 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45632 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    45633 m.pause(self._mouse_pause_position) 
    45634 File
    45635 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45636 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    45637 p = self.view.picked_object(x, y) 
    45638 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45639 File
    45640 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45641 packages/chimerax/graphics/view.py", line 838, in picked_object 
    45642 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    45643 beyond, 
    45644 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45645 File
    45646 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45647 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    45648 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    45649 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45650 File
    45651 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45652 packages/chimerax/core/models.py", line 143, in first_intercept 
    45653 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    45654 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45655 File
    45656 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45657 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    45658 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    45659 exclude=exclude) 
    45660 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45661 File
    45662 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45663 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    45664 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    45665 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45666 File
    45667 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45668 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    45669 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    45670 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45671 File
    45672 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45673 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    45674 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    45675 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45676 File
    45677 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45678 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    45679 p = super().first_intercept(mxyz1, mxyz2) 
    45680 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45681 File
    45682 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45683 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    45684 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    45685 exclude=exclude) 
    45686 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45687 File
    45688 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45689 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    45690 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    45691 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45692 File
    45693 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45694 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    45695 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    45696 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45697 File
    45698 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45699 packages/chimerax/graphics/drawing.py", line 1108, in
    45700 _first_intercept_excluding_children 
    45701 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    45702 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45703 File
    45704 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45705 packages/chimerax/geometry/place.py", line 201, in inverse 
    45706 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    45707 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45708 File
    45709 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45710 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    45711 rinv[:, :] = matrix_inverse(r) 
    45712 ^^^^^^^^^^^^^^^^^ 
    45713 File
    45714 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45715 packages/numpy/linalg/linalg.py", line 561, in inv 
    45716 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    45717 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45718 File
    45719 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45720 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    45721 raise LinAlgError("Singular matrix") 
    45722 numpy.linalg.LinAlgError: Singular matrix 
    45723  
    45724 numpy.linalg.LinAlgError: Singular matrix 
    45725  
    45726 File
    45727 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45728 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    45729 raise LinAlgError("Singular matrix") 
    45730  
    45731 See log for complete Python traceback. 
    45732  
    45733 Traceback (most recent call last): 
    45734 File
    45735 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45736 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    45737 self.session.ui.mouse_modes.mouse_pause_tracking() 
    45738 File
    45739 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45740 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    45741 mouse_pause_tracking 
    45742 self._mouse_pause() 
    45743 File
    45744 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45745 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    45746 m.pause(self._mouse_pause_position) 
    45747 File
    45748 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45749 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    45750 p = self.view.picked_object(x, y) 
    45751 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45752 File
    45753 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45754 packages/chimerax/graphics/view.py", line 838, in picked_object 
    45755 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    45756 beyond, 
    45757 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45758 File
    45759 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45760 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    45761 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    45762 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45763 File
    45764 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45765 packages/chimerax/core/models.py", line 143, in first_intercept 
    45766 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    45767 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45768 File
    45769 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45770 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    45771 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    45772 exclude=exclude) 
    45773 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45774 File
    45775 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45776 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    45777 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    45778 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45779 File
    45780 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45781 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    45782 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    45783 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45784 File
    45785 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45786 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    45787 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    45788 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45789 File
    45790 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45791 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    45792 p = super().first_intercept(mxyz1, mxyz2) 
    45793 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45794 File
    45795 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45796 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    45797 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    45798 exclude=exclude) 
    45799 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45800 File
    45801 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45802 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    45803 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    45804 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45805 File
    45806 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45807 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    45808 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    45809 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45810 File
    45811 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45812 packages/chimerax/graphics/drawing.py", line 1108, in
    45813 _first_intercept_excluding_children 
    45814 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    45815 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45816 File
    45817 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45818 packages/chimerax/geometry/place.py", line 201, in inverse 
    45819 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    45820 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45821 File
    45822 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45823 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    45824 rinv[:, :] = matrix_inverse(r) 
    45825 ^^^^^^^^^^^^^^^^^ 
    45826 File
    45827 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45828 packages/numpy/linalg/linalg.py", line 561, in inv 
    45829 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    45830 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45831 File
    45832 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45833 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    45834 raise LinAlgError("Singular matrix") 
    45835 numpy.linalg.LinAlgError: Singular matrix 
    45836  
    45837 numpy.linalg.LinAlgError: Singular matrix 
    45838  
    45839 File
    45840 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45841 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    45842 raise LinAlgError("Singular matrix") 
    45843  
    45844 See log for complete Python traceback. 
    45845  
    45846 Traceback (most recent call last): 
    45847 File
    45848 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45849 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    45850 self.session.ui.mouse_modes.mouse_pause_tracking() 
    45851 File
    45852 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45853 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    45854 mouse_pause_tracking 
    45855 self._mouse_pause() 
    45856 File
    45857 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45858 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    45859 m.pause(self._mouse_pause_position) 
    45860 File
    45861 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45862 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    45863 p = self.view.picked_object(x, y) 
    45864 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45865 File
    45866 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45867 packages/chimerax/graphics/view.py", line 838, in picked_object 
    45868 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    45869 beyond, 
    45870 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45871 File
    45872 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45873 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    45874 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    45875 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45876 File
    45877 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45878 packages/chimerax/core/models.py", line 143, in first_intercept 
    45879 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    45880 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45881 File
    45882 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45883 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    45884 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    45885 exclude=exclude) 
    45886 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45887 File
    45888 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45889 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    45890 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    45891 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45892 File
    45893 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45894 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    45895 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    45896 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45897 File
    45898 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45899 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    45900 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    45901 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45902 File
    45903 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45904 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    45905 p = super().first_intercept(mxyz1, mxyz2) 
    45906 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45907 File
    45908 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45909 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    45910 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    45911 exclude=exclude) 
    45912 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45913 File
    45914 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45915 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    45916 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    45917 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45918 File
    45919 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45920 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    45921 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    45922 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45923 File
    45924 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45925 packages/chimerax/graphics/drawing.py", line 1108, in
    45926 _first_intercept_excluding_children 
    45927 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    45928 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45929 File
    45930 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45931 packages/chimerax/geometry/place.py", line 201, in inverse 
    45932 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    45933 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45934 File
    45935 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45936 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    45937 rinv[:, :] = matrix_inverse(r) 
    45938 ^^^^^^^^^^^^^^^^^ 
    45939 File
    45940 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45941 packages/numpy/linalg/linalg.py", line 561, in inv 
    45942 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    45943 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45944 File
    45945 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45946 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    45947 raise LinAlgError("Singular matrix") 
    45948 numpy.linalg.LinAlgError: Singular matrix 
    45949  
    45950 numpy.linalg.LinAlgError: Singular matrix 
    45951  
    45952 File
    45953 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45954 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    45955 raise LinAlgError("Singular matrix") 
    45956  
    45957 See log for complete Python traceback. 
    45958  
    45959 Traceback (most recent call last): 
    45960 File
    45961 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45962 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    45963 self.session.ui.mouse_modes.mouse_pause_tracking() 
    45964 File
    45965 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45966 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    45967 mouse_pause_tracking 
    45968 self._mouse_pause() 
    45969 File
    45970 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45971 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    45972 m.pause(self._mouse_pause_position) 
    45973 File
    45974 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45975 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    45976 p = self.view.picked_object(x, y) 
    45977 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45978 File
    45979 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45980 packages/chimerax/graphics/view.py", line 838, in picked_object 
    45981 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    45982 beyond, 
    45983 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45984 File
    45985 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45986 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    45987 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    45988 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45989 File
    45990 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45991 packages/chimerax/core/models.py", line 143, in first_intercept 
    45992 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    45993 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    45994 File
    45995 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    45996 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    45997 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    45998 exclude=exclude) 
    45999 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46000 File
    46001 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46002 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    46003 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    46004 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46005 File
    46006 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46007 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    46008 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    46009 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46010 File
    46011 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46012 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    46013 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    46014 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46015 File
    46016 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46017 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    46018 p = super().first_intercept(mxyz1, mxyz2) 
    46019 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46020 File
    46021 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46022 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    46023 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    46024 exclude=exclude) 
    46025 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46026 File
    46027 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46028 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    46029 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    46030 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46031 File
    46032 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46033 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    46034 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    46035 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46036 File
    46037 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46038 packages/chimerax/graphics/drawing.py", line 1108, in
    46039 _first_intercept_excluding_children 
    46040 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    46041 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46042 File
    46043 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46044 packages/chimerax/geometry/place.py", line 201, in inverse 
    46045 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    46046 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46047 File
    46048 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46049 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    46050 rinv[:, :] = matrix_inverse(r) 
    46051 ^^^^^^^^^^^^^^^^^ 
    46052 File
    46053 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46054 packages/numpy/linalg/linalg.py", line 561, in inv 
    46055 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    46056 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46057 File
    46058 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46059 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    46060 raise LinAlgError("Singular matrix") 
    46061 numpy.linalg.LinAlgError: Singular matrix 
    46062  
    46063 numpy.linalg.LinAlgError: Singular matrix 
    46064  
    46065 File
    46066 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46067 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    46068 raise LinAlgError("Singular matrix") 
    46069  
    46070 See log for complete Python traceback. 
    46071  
    46072 Traceback (most recent call last): 
    46073 File
    46074 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46075 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    46076 self.session.ui.mouse_modes.mouse_pause_tracking() 
    46077 File
    46078 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46079 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    46080 mouse_pause_tracking 
    46081 self._mouse_pause() 
    46082 File
    46083 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46084 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    46085 m.pause(self._mouse_pause_position) 
    46086 File
    46087 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46088 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    46089 p = self.view.picked_object(x, y) 
    46090 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46091 File
    46092 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46093 packages/chimerax/graphics/view.py", line 838, in picked_object 
    46094 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    46095 beyond, 
    46096 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46097 File
    46098 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46099 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    46100 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    46101 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46102 File
    46103 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46104 packages/chimerax/core/models.py", line 143, in first_intercept 
    46105 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    46106 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46107 File
    46108 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46109 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    46110 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    46111 exclude=exclude) 
    46112 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46113 File
    46114 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46115 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    46116 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    46117 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46118 File
    46119 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46120 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    46121 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    46122 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46123 File
    46124 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46125 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    46126 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    46127 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46128 File
    46129 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46130 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    46131 p = super().first_intercept(mxyz1, mxyz2) 
    46132 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46133 File
    46134 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46135 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    46136 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    46137 exclude=exclude) 
    46138 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46139 File
    46140 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46141 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    46142 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    46143 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46144 File
    46145 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46146 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    46147 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    46148 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46149 File
    46150 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46151 packages/chimerax/graphics/drawing.py", line 1108, in
    46152 _first_intercept_excluding_children 
    46153 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    46154 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46155 File
    46156 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46157 packages/chimerax/geometry/place.py", line 201, in inverse 
    46158 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    46159 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46160 File
    46161 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46162 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    46163 rinv[:, :] = matrix_inverse(r) 
    46164 ^^^^^^^^^^^^^^^^^ 
    46165 File
    46166 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46167 packages/numpy/linalg/linalg.py", line 561, in inv 
    46168 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    46169 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46170 File
    46171 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46172 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    46173 raise LinAlgError("Singular matrix") 
    46174 numpy.linalg.LinAlgError: Singular matrix 
    46175  
    46176 numpy.linalg.LinAlgError: Singular matrix 
    46177  
    46178 File
    46179 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46180 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    46181 raise LinAlgError("Singular matrix") 
    46182  
    46183 See log for complete Python traceback. 
    46184  
    46185 Traceback (most recent call last): 
    46186 File
    46187 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46188 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    46189 self.session.ui.mouse_modes.mouse_pause_tracking() 
    46190 File
    46191 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46192 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    46193 mouse_pause_tracking 
    46194 self._mouse_pause() 
    46195 File
    46196 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46197 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    46198 m.pause(self._mouse_pause_position) 
    46199 File
    46200 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46201 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    46202 p = self.view.picked_object(x, y) 
    46203 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46204 File
    46205 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46206 packages/chimerax/graphics/view.py", line 838, in picked_object 
    46207 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    46208 beyond, 
    46209 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46210 File
    46211 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46212 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    46213 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    46214 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46215 File
    46216 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46217 packages/chimerax/core/models.py", line 143, in first_intercept 
    46218 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    46219 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46220 File
    46221 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46222 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    46223 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    46224 exclude=exclude) 
    46225 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46226 File
    46227 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46228 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    46229 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    46230 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46231 File
    46232 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46233 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    46234 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    46235 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46236 File
    46237 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46238 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    46239 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    46240 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46241 File
    46242 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46243 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    46244 p = super().first_intercept(mxyz1, mxyz2) 
    46245 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46246 File
    46247 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46248 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    46249 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    46250 exclude=exclude) 
    46251 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46252 File
    46253 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46254 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    46255 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    46256 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46257 File
    46258 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46259 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    46260 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    46261 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46262 File
    46263 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46264 packages/chimerax/graphics/drawing.py", line 1108, in
    46265 _first_intercept_excluding_children 
    46266 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    46267 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46268 File
    46269 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46270 packages/chimerax/geometry/place.py", line 201, in inverse 
    46271 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    46272 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46273 File
    46274 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46275 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    46276 rinv[:, :] = matrix_inverse(r) 
    46277 ^^^^^^^^^^^^^^^^^ 
    46278 File
    46279 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46280 packages/numpy/linalg/linalg.py", line 561, in inv 
    46281 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    46282 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46283 File
    46284 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46285 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    46286 raise LinAlgError("Singular matrix") 
    46287 numpy.linalg.LinAlgError: Singular matrix 
    46288  
    46289 numpy.linalg.LinAlgError: Singular matrix 
    46290  
    46291 File
    46292 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46293 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    46294 raise LinAlgError("Singular matrix") 
    46295  
    46296 See log for complete Python traceback. 
    46297  
    46298 Traceback (most recent call last): 
    46299 File
    46300 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46301 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    46302 self.session.ui.mouse_modes.mouse_pause_tracking() 
    46303 File
    46304 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46305 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    46306 mouse_pause_tracking 
    46307 self._mouse_pause() 
    46308 File
    46309 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46310 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    46311 m.pause(self._mouse_pause_position) 
    46312 File
    46313 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46314 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    46315 p = self.view.picked_object(x, y) 
    46316 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46317 File
    46318 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46319 packages/chimerax/graphics/view.py", line 838, in picked_object 
    46320 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    46321 beyond, 
    46322 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46323 File
    46324 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46325 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    46326 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    46327 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46328 File
    46329 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46330 packages/chimerax/core/models.py", line 143, in first_intercept 
    46331 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    46332 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46333 File
    46334 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46335 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    46336 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    46337 exclude=exclude) 
    46338 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46339 File
    46340 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46341 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    46342 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    46343 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46344 File
    46345 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46346 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    46347 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    46348 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46349 File
    46350 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46351 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    46352 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    46353 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46354 File
    46355 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46356 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    46357 p = super().first_intercept(mxyz1, mxyz2) 
    46358 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46359 File
    46360 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46361 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    46362 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    46363 exclude=exclude) 
    46364 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46365 File
    46366 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46367 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    46368 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    46369 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46370 File
    46371 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46372 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    46373 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    46374 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46375 File
    46376 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46377 packages/chimerax/graphics/drawing.py", line 1108, in
    46378 _first_intercept_excluding_children 
    46379 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    46380 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46381 File
    46382 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46383 packages/chimerax/geometry/place.py", line 201, in inverse 
    46384 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    46385 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46386 File
    46387 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46388 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    46389 rinv[:, :] = matrix_inverse(r) 
    46390 ^^^^^^^^^^^^^^^^^ 
    46391 File
    46392 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46393 packages/numpy/linalg/linalg.py", line 561, in inv 
    46394 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    46395 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46396 File
    46397 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46398 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    46399 raise LinAlgError("Singular matrix") 
    46400 numpy.linalg.LinAlgError: Singular matrix 
    46401  
    46402 numpy.linalg.LinAlgError: Singular matrix 
    46403  
    46404 File
    46405 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46406 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    46407 raise LinAlgError("Singular matrix") 
    46408  
    46409 See log for complete Python traceback. 
    46410  
    46411 Traceback (most recent call last): 
    46412 File
    46413 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46414 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    46415 self.session.ui.mouse_modes.mouse_pause_tracking() 
    46416 File
    46417 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46418 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    46419 mouse_pause_tracking 
    46420 self._mouse_pause() 
    46421 File
    46422 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46423 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    46424 m.pause(self._mouse_pause_position) 
    46425 File
    46426 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46427 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    46428 p = self.view.picked_object(x, y) 
    46429 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46430 File
    46431 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46432 packages/chimerax/graphics/view.py", line 838, in picked_object 
    46433 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    46434 beyond, 
    46435 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46436 File
    46437 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46438 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    46439 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    46440 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46441 File
    46442 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46443 packages/chimerax/core/models.py", line 143, in first_intercept 
    46444 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    46445 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46446 File
    46447 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46448 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    46449 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    46450 exclude=exclude) 
    46451 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46452 File
    46453 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46454 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    46455 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    46456 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46457 File
    46458 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46459 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    46460 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    46461 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46462 File
    46463 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46464 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    46465 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    46466 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46467 File
    46468 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46469 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    46470 p = super().first_intercept(mxyz1, mxyz2) 
    46471 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46472 File
    46473 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46474 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    46475 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    46476 exclude=exclude) 
    46477 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46478 File
    46479 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46480 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    46481 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    46482 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46483 File
    46484 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46485 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    46486 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    46487 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46488 File
    46489 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46490 packages/chimerax/graphics/drawing.py", line 1108, in
    46491 _first_intercept_excluding_children 
    46492 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    46493 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46494 File
    46495 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46496 packages/chimerax/geometry/place.py", line 201, in inverse 
    46497 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    46498 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46499 File
    46500 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46501 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    46502 rinv[:, :] = matrix_inverse(r) 
    46503 ^^^^^^^^^^^^^^^^^ 
    46504 File
    46505 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46506 packages/numpy/linalg/linalg.py", line 561, in inv 
    46507 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    46508 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46509 File
    46510 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46511 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    46512 raise LinAlgError("Singular matrix") 
    46513 numpy.linalg.LinAlgError: Singular matrix 
    46514  
    46515 numpy.linalg.LinAlgError: Singular matrix 
    46516  
    46517 File
    46518 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46519 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    46520 raise LinAlgError("Singular matrix") 
    46521  
    46522 See log for complete Python traceback. 
    46523  
    46524 Traceback (most recent call last): 
    46525 File
    46526 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46527 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    46528 self.session.ui.mouse_modes.mouse_pause_tracking() 
    46529 File
    46530 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46531 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    46532 mouse_pause_tracking 
    46533 self._mouse_pause() 
    46534 File
    46535 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46536 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    46537 m.pause(self._mouse_pause_position) 
    46538 File
    46539 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46540 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    46541 p = self.view.picked_object(x, y) 
    46542 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46543 File
    46544 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46545 packages/chimerax/graphics/view.py", line 838, in picked_object 
    46546 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    46547 beyond, 
    46548 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46549 File
    46550 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46551 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    46552 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    46553 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46554 File
    46555 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46556 packages/chimerax/core/models.py", line 143, in first_intercept 
    46557 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    46558 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46559 File
    46560 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46561 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    46562 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    46563 exclude=exclude) 
    46564 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46565 File
    46566 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46567 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    46568 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    46569 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46570 File
    46571 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46572 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    46573 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    46574 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46575 File
    46576 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46577 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    46578 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    46579 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46580 File
    46581 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46582 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    46583 p = super().first_intercept(mxyz1, mxyz2) 
    46584 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46585 File
    46586 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46587 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    46588 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    46589 exclude=exclude) 
    46590 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46591 File
    46592 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46593 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    46594 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    46595 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46596 File
    46597 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46598 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    46599 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    46600 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46601 File
    46602 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46603 packages/chimerax/graphics/drawing.py", line 1108, in
    46604 _first_intercept_excluding_children 
    46605 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    46606 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46607 File
    46608 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46609 packages/chimerax/geometry/place.py", line 201, in inverse 
    46610 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    46611 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46612 File
    46613 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46614 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    46615 rinv[:, :] = matrix_inverse(r) 
    46616 ^^^^^^^^^^^^^^^^^ 
    46617 File
    46618 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46619 packages/numpy/linalg/linalg.py", line 561, in inv 
    46620 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    46621 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46622 File
    46623 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46624 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    46625 raise LinAlgError("Singular matrix") 
    46626 numpy.linalg.LinAlgError: Singular matrix 
    46627  
    46628 numpy.linalg.LinAlgError: Singular matrix 
    46629  
    46630 File
    46631 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46632 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    46633 raise LinAlgError("Singular matrix") 
    46634  
    46635 See log for complete Python traceback. 
    46636  
    46637 Traceback (most recent call last): 
    46638 File
    46639 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46640 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    46641 self.session.ui.mouse_modes.mouse_pause_tracking() 
    46642 File
    46643 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46644 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    46645 mouse_pause_tracking 
    46646 self._mouse_pause() 
    46647 File
    46648 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46649 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    46650 m.pause(self._mouse_pause_position) 
    46651 File
    46652 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46653 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    46654 p = self.view.picked_object(x, y) 
    46655 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46656 File
    46657 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46658 packages/chimerax/graphics/view.py", line 838, in picked_object 
    46659 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    46660 beyond, 
    46661 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46662 File
    46663 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46664 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    46665 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    46666 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46667 File
    46668 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46669 packages/chimerax/core/models.py", line 143, in first_intercept 
    46670 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    46671 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46672 File
    46673 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46674 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    46675 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    46676 exclude=exclude) 
    46677 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46678 File
    46679 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46680 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    46681 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    46682 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46683 File
    46684 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46685 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    46686 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    46687 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46688 File
    46689 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46690 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    46691 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    46692 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46693 File
    46694 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46695 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    46696 p = super().first_intercept(mxyz1, mxyz2) 
    46697 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46698 File
    46699 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46700 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    46701 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    46702 exclude=exclude) 
    46703 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46704 File
    46705 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46706 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    46707 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    46708 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46709 File
    46710 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46711 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    46712 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    46713 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46714 File
    46715 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46716 packages/chimerax/graphics/drawing.py", line 1108, in
    46717 _first_intercept_excluding_children 
    46718 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    46719 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46720 File
    46721 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46722 packages/chimerax/geometry/place.py", line 201, in inverse 
    46723 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    46724 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46725 File
    46726 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46727 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    46728 rinv[:, :] = matrix_inverse(r) 
    46729 ^^^^^^^^^^^^^^^^^ 
    46730 File
    46731 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46732 packages/numpy/linalg/linalg.py", line 561, in inv 
    46733 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    46734 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46735 File
    46736 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46737 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    46738 raise LinAlgError("Singular matrix") 
    46739 numpy.linalg.LinAlgError: Singular matrix 
    46740  
    46741 numpy.linalg.LinAlgError: Singular matrix 
    46742  
    46743 File
    46744 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46745 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    46746 raise LinAlgError("Singular matrix") 
    46747  
    46748 See log for complete Python traceback. 
    46749  
    46750 Traceback (most recent call last): 
    46751 File
    46752 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46753 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    46754 self.session.ui.mouse_modes.mouse_pause_tracking() 
    46755 File
    46756 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46757 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    46758 mouse_pause_tracking 
    46759 self._mouse_pause() 
    46760 File
    46761 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46762 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    46763 m.pause(self._mouse_pause_position) 
    46764 File
    46765 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46766 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    46767 p = self.view.picked_object(x, y) 
    46768 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46769 File
    46770 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46771 packages/chimerax/graphics/view.py", line 838, in picked_object 
    46772 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    46773 beyond, 
    46774 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46775 File
    46776 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46777 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    46778 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    46779 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46780 File
    46781 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46782 packages/chimerax/core/models.py", line 143, in first_intercept 
    46783 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    46784 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46785 File
    46786 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46787 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    46788 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    46789 exclude=exclude) 
    46790 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46791 File
    46792 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46793 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    46794 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    46795 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46796 File
    46797 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46798 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    46799 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    46800 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46801 File
    46802 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46803 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    46804 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    46805 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46806 File
    46807 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46808 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    46809 p = super().first_intercept(mxyz1, mxyz2) 
    46810 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46811 File
    46812 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46813 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    46814 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    46815 exclude=exclude) 
    46816 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46817 File
    46818 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46819 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    46820 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    46821 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46822 File
    46823 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46824 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    46825 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    46826 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46827 File
    46828 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46829 packages/chimerax/graphics/drawing.py", line 1108, in
    46830 _first_intercept_excluding_children 
    46831 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    46832 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46833 File
    46834 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46835 packages/chimerax/geometry/place.py", line 201, in inverse 
    46836 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    46837 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46838 File
    46839 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46840 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    46841 rinv[:, :] = matrix_inverse(r) 
    46842 ^^^^^^^^^^^^^^^^^ 
    46843 File
    46844 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46845 packages/numpy/linalg/linalg.py", line 561, in inv 
    46846 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    46847 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46848 File
    46849 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46850 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    46851 raise LinAlgError("Singular matrix") 
    46852 numpy.linalg.LinAlgError: Singular matrix 
    46853  
    46854 numpy.linalg.LinAlgError: Singular matrix 
    46855  
    46856 File
    46857 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46858 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    46859 raise LinAlgError("Singular matrix") 
    46860  
    46861 See log for complete Python traceback. 
    46862  
    46863 Traceback (most recent call last): 
    46864 File
    46865 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46866 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    46867 self.session.ui.mouse_modes.mouse_pause_tracking() 
    46868 File
    46869 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46870 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    46871 mouse_pause_tracking 
    46872 self._mouse_pause() 
    46873 File
    46874 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46875 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    46876 m.pause(self._mouse_pause_position) 
    46877 File
    46878 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46879 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    46880 p = self.view.picked_object(x, y) 
    46881 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46882 File
    46883 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46884 packages/chimerax/graphics/view.py", line 838, in picked_object 
    46885 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    46886 beyond, 
    46887 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46888 File
    46889 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46890 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    46891 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    46892 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46893 File
    46894 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46895 packages/chimerax/core/models.py", line 143, in first_intercept 
    46896 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    46897 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46898 File
    46899 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46900 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    46901 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    46902 exclude=exclude) 
    46903 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46904 File
    46905 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46906 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    46907 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    46908 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46909 File
    46910 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46911 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    46912 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    46913 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46914 File
    46915 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46916 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    46917 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    46918 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46919 File
    46920 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46921 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    46922 p = super().first_intercept(mxyz1, mxyz2) 
    46923 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46924 File
    46925 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46926 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    46927 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    46928 exclude=exclude) 
    46929 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46930 File
    46931 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46932 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    46933 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    46934 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46935 File
    46936 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46937 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    46938 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    46939 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46940 File
    46941 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46942 packages/chimerax/graphics/drawing.py", line 1108, in
    46943 _first_intercept_excluding_children 
    46944 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    46945 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46946 File
    46947 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46948 packages/chimerax/geometry/place.py", line 201, in inverse 
    46949 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    46950 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46951 File
    46952 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46953 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    46954 rinv[:, :] = matrix_inverse(r) 
    46955 ^^^^^^^^^^^^^^^^^ 
    46956 File
    46957 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46958 packages/numpy/linalg/linalg.py", line 561, in inv 
    46959 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    46960 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46961 File
    46962 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46963 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    46964 raise LinAlgError("Singular matrix") 
    46965 numpy.linalg.LinAlgError: Singular matrix 
    46966  
    46967 numpy.linalg.LinAlgError: Singular matrix 
    46968  
    46969 File
    46970 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46971 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    46972 raise LinAlgError("Singular matrix") 
    46973  
    46974 See log for complete Python traceback. 
    46975  
    46976 Traceback (most recent call last): 
    46977 File
    46978 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46979 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    46980 self.session.ui.mouse_modes.mouse_pause_tracking() 
    46981 File
    46982 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46983 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    46984 mouse_pause_tracking 
    46985 self._mouse_pause() 
    46986 File
    46987 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46988 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    46989 m.pause(self._mouse_pause_position) 
    46990 File
    46991 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46992 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    46993 p = self.view.picked_object(x, y) 
    46994 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    46995 File
    46996 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    46997 packages/chimerax/graphics/view.py", line 838, in picked_object 
    46998 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    46999 beyond, 
    47000 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47001 File
    47002 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47003 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    47004 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    47005 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47006 File
    47007 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47008 packages/chimerax/core/models.py", line 143, in first_intercept 
    47009 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    47010 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47011 File
    47012 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47013 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    47014 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    47015 exclude=exclude) 
    47016 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47017 File
    47018 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47019 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    47020 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    47021 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47022 File
    47023 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47024 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    47025 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    47026 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47027 File
    47028 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47029 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    47030 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    47031 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47032 File
    47033 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47034 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    47035 p = super().first_intercept(mxyz1, mxyz2) 
    47036 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47037 File
    47038 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47039 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    47040 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    47041 exclude=exclude) 
    47042 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47043 File
    47044 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47045 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    47046 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    47047 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47048 File
    47049 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47050 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    47051 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    47052 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47053 File
    47054 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47055 packages/chimerax/graphics/drawing.py", line 1108, in
    47056 _first_intercept_excluding_children 
    47057 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    47058 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47059 File
    47060 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47061 packages/chimerax/geometry/place.py", line 201, in inverse 
    47062 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    47063 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47064 File
    47065 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47066 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    47067 rinv[:, :] = matrix_inverse(r) 
    47068 ^^^^^^^^^^^^^^^^^ 
    47069 File
    47070 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47071 packages/numpy/linalg/linalg.py", line 561, in inv 
    47072 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    47073 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47074 File
    47075 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47076 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    47077 raise LinAlgError("Singular matrix") 
    47078 numpy.linalg.LinAlgError: Singular matrix 
    47079  
    47080 numpy.linalg.LinAlgError: Singular matrix 
    47081  
    47082 File
    47083 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47084 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    47085 raise LinAlgError("Singular matrix") 
    47086  
    47087 See log for complete Python traceback. 
    47088  
    47089 Traceback (most recent call last): 
    47090 File
    47091 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47092 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    47093 self.session.ui.mouse_modes.mouse_pause_tracking() 
    47094 File
    47095 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47096 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    47097 mouse_pause_tracking 
    47098 self._mouse_pause() 
    47099 File
    47100 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47101 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    47102 m.pause(self._mouse_pause_position) 
    47103 File
    47104 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47105 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    47106 p = self.view.picked_object(x, y) 
    47107 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47108 File
    47109 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47110 packages/chimerax/graphics/view.py", line 838, in picked_object 
    47111 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    47112 beyond, 
    47113 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47114 File
    47115 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47116 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    47117 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    47118 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47119 File
    47120 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47121 packages/chimerax/core/models.py", line 143, in first_intercept 
    47122 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    47123 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47124 File
    47125 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47126 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    47127 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    47128 exclude=exclude) 
    47129 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47130 File
    47131 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47132 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    47133 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    47134 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47135 File
    47136 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47137 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    47138 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    47139 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47140 File
    47141 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47142 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    47143 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    47144 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47145 File
    47146 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47147 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    47148 p = super().first_intercept(mxyz1, mxyz2) 
    47149 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47150 File
    47151 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47152 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    47153 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    47154 exclude=exclude) 
    47155 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47156 File
    47157 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47158 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    47159 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    47160 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47161 File
    47162 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47163 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    47164 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    47165 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47166 File
    47167 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47168 packages/chimerax/graphics/drawing.py", line 1108, in
    47169 _first_intercept_excluding_children 
    47170 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    47171 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47172 File
    47173 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47174 packages/chimerax/geometry/place.py", line 201, in inverse 
    47175 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    47176 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47177 File
    47178 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47179 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    47180 rinv[:, :] = matrix_inverse(r) 
    47181 ^^^^^^^^^^^^^^^^^ 
    47182 File
    47183 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47184 packages/numpy/linalg/linalg.py", line 561, in inv 
    47185 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    47186 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47187 File
    47188 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47189 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    47190 raise LinAlgError("Singular matrix") 
    47191 numpy.linalg.LinAlgError: Singular matrix 
    47192  
    47193 numpy.linalg.LinAlgError: Singular matrix 
    47194  
    47195 File
    47196 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47197 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    47198 raise LinAlgError("Singular matrix") 
    47199  
    47200 See log for complete Python traceback. 
    47201  
    47202 Traceback (most recent call last): 
    47203 File
    47204 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47205 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    47206 self.session.ui.mouse_modes.mouse_pause_tracking() 
    47207 File
    47208 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47209 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    47210 mouse_pause_tracking 
    47211 self._mouse_pause() 
    47212 File
    47213 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47214 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    47215 m.pause(self._mouse_pause_position) 
    47216 File
    47217 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47218 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    47219 p = self.view.picked_object(x, y) 
    47220 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47221 File
    47222 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47223 packages/chimerax/graphics/view.py", line 838, in picked_object 
    47224 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    47225 beyond, 
    47226 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47227 File
    47228 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47229 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    47230 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    47231 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47232 File
    47233 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47234 packages/chimerax/core/models.py", line 143, in first_intercept 
    47235 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    47236 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47237 File
    47238 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47239 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    47240 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    47241 exclude=exclude) 
    47242 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47243 File
    47244 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47245 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    47246 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    47247 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47248 File
    47249 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47250 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    47251 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    47252 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47253 File
    47254 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47255 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    47256 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    47257 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47258 File
    47259 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47260 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    47261 p = super().first_intercept(mxyz1, mxyz2) 
    47262 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47263 File
    47264 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47265 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    47266 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    47267 exclude=exclude) 
    47268 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47269 File
    47270 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47271 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    47272 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    47273 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47274 File
    47275 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47276 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    47277 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    47278 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47279 File
    47280 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47281 packages/chimerax/graphics/drawing.py", line 1108, in
    47282 _first_intercept_excluding_children 
    47283 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    47284 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47285 File
    47286 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47287 packages/chimerax/geometry/place.py", line 201, in inverse 
    47288 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    47289 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47290 File
    47291 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47292 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    47293 rinv[:, :] = matrix_inverse(r) 
    47294 ^^^^^^^^^^^^^^^^^ 
    47295 File
    47296 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47297 packages/numpy/linalg/linalg.py", line 561, in inv 
    47298 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    47299 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47300 File
    47301 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47302 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    47303 raise LinAlgError("Singular matrix") 
    47304 numpy.linalg.LinAlgError: Singular matrix 
    47305  
    47306 numpy.linalg.LinAlgError: Singular matrix 
    47307  
    47308 File
    47309 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47310 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    47311 raise LinAlgError("Singular matrix") 
    47312  
    47313 See log for complete Python traceback. 
    47314  
    47315 Traceback (most recent call last): 
    47316 File
    47317 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47318 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    47319 self.session.ui.mouse_modes.mouse_pause_tracking() 
    47320 File
    47321 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47322 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    47323 mouse_pause_tracking 
    47324 self._mouse_pause() 
    47325 File
    47326 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47327 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    47328 m.pause(self._mouse_pause_position) 
    47329 File
    47330 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47331 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    47332 p = self.view.picked_object(x, y) 
    47333 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47334 File
    47335 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47336 packages/chimerax/graphics/view.py", line 838, in picked_object 
    47337 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    47338 beyond, 
    47339 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47340 File
    47341 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47342 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    47343 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    47344 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47345 File
    47346 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47347 packages/chimerax/core/models.py", line 143, in first_intercept 
    47348 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    47349 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47350 File
    47351 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47352 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    47353 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    47354 exclude=exclude) 
    47355 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47356 File
    47357 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47358 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    47359 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    47360 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47361 File
    47362 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47363 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    47364 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    47365 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47366 File
    47367 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47368 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    47369 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    47370 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47371 File
    47372 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47373 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    47374 p = super().first_intercept(mxyz1, mxyz2) 
    47375 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47376 File
    47377 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47378 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    47379 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    47380 exclude=exclude) 
    47381 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47382 File
    47383 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47384 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    47385 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    47386 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47387 File
    47388 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47389 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    47390 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    47391 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47392 File
    47393 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47394 packages/chimerax/graphics/drawing.py", line 1108, in
    47395 _first_intercept_excluding_children 
    47396 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    47397 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47398 File
    47399 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47400 packages/chimerax/geometry/place.py", line 201, in inverse 
    47401 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    47402 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47403 File
    47404 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47405 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    47406 rinv[:, :] = matrix_inverse(r) 
    47407 ^^^^^^^^^^^^^^^^^ 
    47408 File
    47409 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47410 packages/numpy/linalg/linalg.py", line 561, in inv 
    47411 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    47412 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47413 File
    47414 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47415 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    47416 raise LinAlgError("Singular matrix") 
    47417 numpy.linalg.LinAlgError: Singular matrix 
    47418  
    47419 numpy.linalg.LinAlgError: Singular matrix 
    47420  
    47421 File
    47422 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47423 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    47424 raise LinAlgError("Singular matrix") 
    47425  
    47426 See log for complete Python traceback. 
    47427  
    47428 Traceback (most recent call last): 
    47429 File
    47430 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47431 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    47432 self.session.ui.mouse_modes.mouse_pause_tracking() 
    47433 File
    47434 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47435 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    47436 mouse_pause_tracking 
    47437 self._mouse_pause() 
    47438 File
    47439 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47440 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    47441 m.pause(self._mouse_pause_position) 
    47442 File
    47443 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47444 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    47445 p = self.view.picked_object(x, y) 
    47446 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47447 File
    47448 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47449 packages/chimerax/graphics/view.py", line 838, in picked_object 
    47450 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    47451 beyond, 
    47452 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47453 File
    47454 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47455 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    47456 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    47457 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47458 File
    47459 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47460 packages/chimerax/core/models.py", line 143, in first_intercept 
    47461 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    47462 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47463 File
    47464 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47465 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    47466 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    47467 exclude=exclude) 
    47468 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47469 File
    47470 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47471 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    47472 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    47473 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47474 File
    47475 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47476 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    47477 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    47478 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47479 File
    47480 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47481 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    47482 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    47483 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47484 File
    47485 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47486 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    47487 p = super().first_intercept(mxyz1, mxyz2) 
    47488 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47489 File
    47490 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47491 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    47492 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    47493 exclude=exclude) 
    47494 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47495 File
    47496 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47497 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    47498 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    47499 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47500 File
    47501 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47502 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    47503 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    47504 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47505 File
    47506 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47507 packages/chimerax/graphics/drawing.py", line 1108, in
    47508 _first_intercept_excluding_children 
    47509 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    47510 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47511 File
    47512 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47513 packages/chimerax/geometry/place.py", line 201, in inverse 
    47514 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    47515 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47516 File
    47517 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47518 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    47519 rinv[:, :] = matrix_inverse(r) 
    47520 ^^^^^^^^^^^^^^^^^ 
    47521 File
    47522 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47523 packages/numpy/linalg/linalg.py", line 561, in inv 
    47524 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    47525 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47526 File
    47527 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47528 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    47529 raise LinAlgError("Singular matrix") 
    47530 numpy.linalg.LinAlgError: Singular matrix 
    47531  
    47532 numpy.linalg.LinAlgError: Singular matrix 
    47533  
    47534 File
    47535 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47536 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    47537 raise LinAlgError("Singular matrix") 
    47538  
    47539 See log for complete Python traceback. 
    47540  
    47541 Traceback (most recent call last): 
    47542 File
    47543 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47544 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    47545 self.session.ui.mouse_modes.mouse_pause_tracking() 
    47546 File
    47547 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47548 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    47549 mouse_pause_tracking 
    47550 self._mouse_pause() 
    47551 File
    47552 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47553 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    47554 m.pause(self._mouse_pause_position) 
    47555 File
    47556 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47557 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    47558 p = self.view.picked_object(x, y) 
    47559 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47560 File
    47561 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47562 packages/chimerax/graphics/view.py", line 838, in picked_object 
    47563 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    47564 beyond, 
    47565 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47566 File
    47567 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47568 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    47569 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    47570 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47571 File
    47572 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47573 packages/chimerax/core/models.py", line 143, in first_intercept 
    47574 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    47575 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47576 File
    47577 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47578 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    47579 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    47580 exclude=exclude) 
    47581 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47582 File
    47583 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47584 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    47585 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    47586 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47587 File
    47588 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47589 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    47590 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    47591 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47592 File
    47593 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47594 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    47595 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    47596 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47597 File
    47598 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47599 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    47600 p = super().first_intercept(mxyz1, mxyz2) 
    47601 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47602 File
    47603 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47604 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    47605 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    47606 exclude=exclude) 
    47607 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47608 File
    47609 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47610 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    47611 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    47612 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47613 File
    47614 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47615 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    47616 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    47617 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47618 File
    47619 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47620 packages/chimerax/graphics/drawing.py", line 1108, in
    47621 _first_intercept_excluding_children 
    47622 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    47623 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47624 File
    47625 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47626 packages/chimerax/geometry/place.py", line 201, in inverse 
    47627 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    47628 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47629 File
    47630 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47631 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    47632 rinv[:, :] = matrix_inverse(r) 
    47633 ^^^^^^^^^^^^^^^^^ 
    47634 File
    47635 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47636 packages/numpy/linalg/linalg.py", line 561, in inv 
    47637 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    47638 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47639 File
    47640 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47641 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    47642 raise LinAlgError("Singular matrix") 
    47643 numpy.linalg.LinAlgError: Singular matrix 
    47644  
    47645 numpy.linalg.LinAlgError: Singular matrix 
    47646  
    47647 File
    47648 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47649 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    47650 raise LinAlgError("Singular matrix") 
    47651  
    47652 See log for complete Python traceback. 
    47653  
    47654 Traceback (most recent call last): 
    47655 File
    47656 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47657 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    47658 self.session.ui.mouse_modes.mouse_pause_tracking() 
    47659 File
    47660 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47661 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    47662 mouse_pause_tracking 
    47663 self._mouse_pause() 
    47664 File
    47665 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47666 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    47667 m.pause(self._mouse_pause_position) 
    47668 File
    47669 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47670 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    47671 p = self.view.picked_object(x, y) 
    47672 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47673 File
    47674 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47675 packages/chimerax/graphics/view.py", line 838, in picked_object 
    47676 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    47677 beyond, 
    47678 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47679 File
    47680 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47681 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    47682 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    47683 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47684 File
    47685 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47686 packages/chimerax/core/models.py", line 143, in first_intercept 
    47687 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    47688 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47689 File
    47690 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47691 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    47692 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    47693 exclude=exclude) 
    47694 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47695 File
    47696 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47697 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    47698 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    47699 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47700 File
    47701 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47702 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    47703 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    47704 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47705 File
    47706 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47707 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    47708 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    47709 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47710 File
    47711 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47712 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    47713 p = super().first_intercept(mxyz1, mxyz2) 
    47714 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47715 File
    47716 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47717 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    47718 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    47719 exclude=exclude) 
    47720 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47721 File
    47722 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47723 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    47724 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    47725 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47726 File
    47727 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47728 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    47729 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    47730 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47731 File
    47732 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47733 packages/chimerax/graphics/drawing.py", line 1108, in
    47734 _first_intercept_excluding_children 
    47735 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    47736 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47737 File
    47738 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47739 packages/chimerax/geometry/place.py", line 201, in inverse 
    47740 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    47741 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47742 File
    47743 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47744 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    47745 rinv[:, :] = matrix_inverse(r) 
    47746 ^^^^^^^^^^^^^^^^^ 
    47747 File
    47748 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47749 packages/numpy/linalg/linalg.py", line 561, in inv 
    47750 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    47751 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47752 File
    47753 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47754 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    47755 raise LinAlgError("Singular matrix") 
    47756 numpy.linalg.LinAlgError: Singular matrix 
    47757  
    47758 numpy.linalg.LinAlgError: Singular matrix 
    47759  
    47760 File
    47761 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47762 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    47763 raise LinAlgError("Singular matrix") 
    47764  
    47765 See log for complete Python traceback. 
    47766  
    47767 Traceback (most recent call last): 
    47768 File
    47769 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47770 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    47771 self.session.ui.mouse_modes.mouse_pause_tracking() 
    47772 File
    47773 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47774 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    47775 mouse_pause_tracking 
    47776 self._mouse_pause() 
    47777 File
    47778 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47779 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    47780 m.pause(self._mouse_pause_position) 
    47781 File
    47782 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47783 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    47784 p = self.view.picked_object(x, y) 
    47785 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47786 File
    47787 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47788 packages/chimerax/graphics/view.py", line 838, in picked_object 
    47789 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    47790 beyond, 
    47791 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47792 File
    47793 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47794 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    47795 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    47796 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47797 File
    47798 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47799 packages/chimerax/core/models.py", line 143, in first_intercept 
    47800 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    47801 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47802 File
    47803 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47804 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    47805 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    47806 exclude=exclude) 
    47807 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47808 File
    47809 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47810 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    47811 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    47812 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47813 File
    47814 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47815 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    47816 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    47817 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47818 File
    47819 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47820 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    47821 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    47822 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47823 File
    47824 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47825 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    47826 p = super().first_intercept(mxyz1, mxyz2) 
    47827 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47828 File
    47829 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47830 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    47831 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    47832 exclude=exclude) 
    47833 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47834 File
    47835 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47836 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    47837 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    47838 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47839 File
    47840 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47841 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    47842 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    47843 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47844 File
    47845 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47846 packages/chimerax/graphics/drawing.py", line 1108, in
    47847 _first_intercept_excluding_children 
    47848 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    47849 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47850 File
    47851 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47852 packages/chimerax/geometry/place.py", line 201, in inverse 
    47853 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    47854 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47855 File
    47856 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47857 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    47858 rinv[:, :] = matrix_inverse(r) 
    47859 ^^^^^^^^^^^^^^^^^ 
    47860 File
    47861 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47862 packages/numpy/linalg/linalg.py", line 561, in inv 
    47863 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    47864 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47865 File
    47866 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47867 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    47868 raise LinAlgError("Singular matrix") 
    47869 numpy.linalg.LinAlgError: Singular matrix 
    47870  
    47871 numpy.linalg.LinAlgError: Singular matrix 
    47872  
    47873 File
    47874 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47875 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    47876 raise LinAlgError("Singular matrix") 
    47877  
    47878 See log for complete Python traceback. 
    47879  
    47880 
    47881 > select add #1/D:511
    47882 
    47883 74 atoms, 64 bonds, 10 residues, 2 models selected 
    47884 
    47885 > select ~sel & ##selected
    47886 
    47887 34776 atoms, 35230 bonds, 162 pseudobonds, 4522 residues, 7 models selected 
    47888 
    47889 > select clear
    47890 
    47891 > select #1:509-510
    47892 
    47893 56 atoms, 52 bonds, 8 residues, 1 model selected 
    47894 
    47895 > show sel cartoons
    47896 
    47897 > select clear
    47898 
    47899 > select add #5/B:626
    47900 
    47901 7 atoms, 6 bonds, 1 residue, 1 model selected 
    47902 
    47903 > select add #5/A:22
    47904 
    47905 18 atoms, 17 bonds, 2 residues, 1 model selected 
    47906 
    47907 > select add #5/B:624
    47908 
    47909 26 atoms, 24 bonds, 3 residues, 1 model selected 
    47910 
    47911 > select add #5/B:542
    47912 
    47913 33 atoms, 31 bonds, 4 residues, 1 model selected 
    47914 
    47915 > select add #5/B:541
    47916 
    47917 42 atoms, 39 bonds, 5 residues, 1 model selected 
    47918 
    47919 > hide sel cartoons
    47920 
    47921 > select add #5/B:625
    47922 
    47923 49 atoms, 45 bonds, 6 residues, 1 model selected 
    47924 
    47925 > hide sel cartoons
    47926 
    47927 Traceback (most recent call last): 
    47928 File
    47929 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47930 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    47931 self.session.ui.mouse_modes.mouse_pause_tracking() 
    47932 File
    47933 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47934 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    47935 mouse_pause_tracking 
    47936 self._mouse_pause() 
    47937 File
    47938 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47939 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    47940 m.pause(self._mouse_pause_position) 
    47941 File
    47942 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47943 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    47944 p = self.view.picked_object(x, y) 
    47945 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47946 File
    47947 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47948 packages/chimerax/graphics/view.py", line 838, in picked_object 
    47949 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    47950 beyond, 
    47951 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47952 File
    47953 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47954 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    47955 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    47956 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47957 File
    47958 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47959 packages/chimerax/core/models.py", line 143, in first_intercept 
    47960 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    47961 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47962 File
    47963 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47964 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    47965 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    47966 exclude=exclude) 
    47967 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47968 File
    47969 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47970 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    47971 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    47972 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47973 File
    47974 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47975 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    47976 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    47977 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47978 File
    47979 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47980 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    47981 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    47982 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47983 File
    47984 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47985 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    47986 p = super().first_intercept(mxyz1, mxyz2) 
    47987 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47988 File
    47989 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47990 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    47991 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    47992 exclude=exclude) 
    47993 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47994 File
    47995 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    47996 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    47997 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    47998 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    47999 File
    48000 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48001 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    48002 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    48003 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48004 File
    48005 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48006 packages/chimerax/graphics/drawing.py", line 1108, in
    48007 _first_intercept_excluding_children 
    48008 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    48009 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48010 File
    48011 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48012 packages/chimerax/geometry/place.py", line 201, in inverse 
    48013 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    48014 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48015 File
    48016 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48017 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    48018 rinv[:, :] = matrix_inverse(r) 
    48019 ^^^^^^^^^^^^^^^^^ 
    48020 File
    48021 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48022 packages/numpy/linalg/linalg.py", line 561, in inv 
    48023 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    48024 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48025 File
    48026 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48027 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    48028 raise LinAlgError("Singular matrix") 
    48029 numpy.linalg.LinAlgError: Singular matrix 
    48030  
    48031 numpy.linalg.LinAlgError: Singular matrix 
    48032  
    48033 File
    48034 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48035 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    48036 raise LinAlgError("Singular matrix") 
    48037  
    48038 See log for complete Python traceback. 
    48039  
    48040 Traceback (most recent call last): 
    48041 File
    48042 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48043 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    48044 self.session.ui.mouse_modes.mouse_pause_tracking() 
    48045 File
    48046 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48047 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    48048 mouse_pause_tracking 
    48049 self._mouse_pause() 
    48050 File
    48051 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48052 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    48053 m.pause(self._mouse_pause_position) 
    48054 File
    48055 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48056 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    48057 p = self.view.picked_object(x, y) 
    48058 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48059 File
    48060 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48061 packages/chimerax/graphics/view.py", line 838, in picked_object 
    48062 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    48063 beyond, 
    48064 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48065 File
    48066 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48067 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    48068 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    48069 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48070 File
    48071 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48072 packages/chimerax/core/models.py", line 143, in first_intercept 
    48073 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    48074 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48075 File
    48076 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48077 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    48078 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    48079 exclude=exclude) 
    48080 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48081 File
    48082 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48083 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    48084 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    48085 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48086 File
    48087 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48088 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    48089 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    48090 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48091 File
    48092 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48093 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    48094 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    48095 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48096 File
    48097 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48098 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    48099 p = super().first_intercept(mxyz1, mxyz2) 
    48100 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48101 File
    48102 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48103 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    48104 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    48105 exclude=exclude) 
    48106 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48107 File
    48108 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48109 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    48110 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    48111 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48112 File
    48113 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48114 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    48115 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    48116 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48117 File
    48118 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48119 packages/chimerax/graphics/drawing.py", line 1108, in
    48120 _first_intercept_excluding_children 
    48121 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    48122 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48123 File
    48124 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48125 packages/chimerax/geometry/place.py", line 201, in inverse 
    48126 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    48127 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48128 File
    48129 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48130 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    48131 rinv[:, :] = matrix_inverse(r) 
    48132 ^^^^^^^^^^^^^^^^^ 
    48133 File
    48134 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48135 packages/numpy/linalg/linalg.py", line 561, in inv 
    48136 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    48137 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48138 File
    48139 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48140 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    48141 raise LinAlgError("Singular matrix") 
    48142 numpy.linalg.LinAlgError: Singular matrix 
    48143  
    48144 numpy.linalg.LinAlgError: Singular matrix 
    48145  
    48146 File
    48147 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48148 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    48149 raise LinAlgError("Singular matrix") 
    48150  
    48151 See log for complete Python traceback. 
    48152  
    48153 Traceback (most recent call last): 
    48154 File
    48155 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48156 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    48157 self.session.ui.mouse_modes.mouse_pause_tracking() 
    48158 File
    48159 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48160 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    48161 mouse_pause_tracking 
    48162 self._mouse_pause() 
    48163 File
    48164 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48165 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    48166 m.pause(self._mouse_pause_position) 
    48167 File
    48168 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48169 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    48170 p = self.view.picked_object(x, y) 
    48171 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48172 File
    48173 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48174 packages/chimerax/graphics/view.py", line 838, in picked_object 
    48175 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    48176 beyond, 
    48177 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48178 File
    48179 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48180 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    48181 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    48182 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48183 File
    48184 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48185 packages/chimerax/core/models.py", line 143, in first_intercept 
    48186 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    48187 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48188 File
    48189 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48190 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    48191 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    48192 exclude=exclude) 
    48193 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48194 File
    48195 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48196 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    48197 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    48198 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48199 File
    48200 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48201 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    48202 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    48203 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48204 File
    48205 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48206 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    48207 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    48208 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48209 File
    48210 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48211 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    48212 p = super().first_intercept(mxyz1, mxyz2) 
    48213 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48214 File
    48215 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48216 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    48217 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    48218 exclude=exclude) 
    48219 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48220 File
    48221 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48222 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    48223 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    48224 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48225 File
    48226 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48227 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    48228 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    48229 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48230 File
    48231 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48232 packages/chimerax/graphics/drawing.py", line 1108, in
    48233 _first_intercept_excluding_children 
    48234 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    48235 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48236 File
    48237 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48238 packages/chimerax/geometry/place.py", line 201, in inverse 
    48239 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    48240 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48241 File
    48242 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48243 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    48244 rinv[:, :] = matrix_inverse(r) 
    48245 ^^^^^^^^^^^^^^^^^ 
    48246 File
    48247 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48248 packages/numpy/linalg/linalg.py", line 561, in inv 
    48249 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    48250 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48251 File
    48252 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48253 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    48254 raise LinAlgError("Singular matrix") 
    48255 numpy.linalg.LinAlgError: Singular matrix 
    48256  
    48257 numpy.linalg.LinAlgError: Singular matrix 
    48258  
    48259 File
    48260 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48261 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    48262 raise LinAlgError("Singular matrix") 
    48263  
    48264 See log for complete Python traceback. 
    48265  
    48266 Traceback (most recent call last): 
    48267 File
    48268 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48269 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    48270 self.session.ui.mouse_modes.mouse_pause_tracking() 
    48271 File
    48272 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48273 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    48274 mouse_pause_tracking 
    48275 self._mouse_pause() 
    48276 File
    48277 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48278 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    48279 m.pause(self._mouse_pause_position) 
    48280 File
    48281 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48282 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    48283 p = self.view.picked_object(x, y) 
    48284 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48285 File
    48286 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48287 packages/chimerax/graphics/view.py", line 838, in picked_object 
    48288 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    48289 beyond, 
    48290 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48291 File
    48292 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48293 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    48294 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    48295 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48296 File
    48297 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48298 packages/chimerax/core/models.py", line 143, in first_intercept 
    48299 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    48300 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48301 File
    48302 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48303 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    48304 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    48305 exclude=exclude) 
    48306 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48307 File
    48308 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48309 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    48310 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    48311 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48312 File
    48313 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48314 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    48315 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    48316 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48317 File
    48318 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48319 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    48320 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    48321 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48322 File
    48323 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48324 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    48325 p = super().first_intercept(mxyz1, mxyz2) 
    48326 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48327 File
    48328 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48329 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    48330 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    48331 exclude=exclude) 
    48332 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48333 File
    48334 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48335 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    48336 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    48337 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48338 File
    48339 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48340 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    48341 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    48342 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48343 File
    48344 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48345 packages/chimerax/graphics/drawing.py", line 1108, in
    48346 _first_intercept_excluding_children 
    48347 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    48348 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48349 File
    48350 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48351 packages/chimerax/geometry/place.py", line 201, in inverse 
    48352 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    48353 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48354 File
    48355 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48356 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    48357 rinv[:, :] = matrix_inverse(r) 
    48358 ^^^^^^^^^^^^^^^^^ 
    48359 File
    48360 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48361 packages/numpy/linalg/linalg.py", line 561, in inv 
    48362 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    48363 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48364 File
    48365 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48366 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    48367 raise LinAlgError("Singular matrix") 
    48368 numpy.linalg.LinAlgError: Singular matrix 
    48369  
    48370 numpy.linalg.LinAlgError: Singular matrix 
    48371  
    48372 File
    48373 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48374 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    48375 raise LinAlgError("Singular matrix") 
    48376  
    48377 See log for complete Python traceback. 
    48378  
    48379 Traceback (most recent call last): 
    48380 File
    48381 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48382 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    48383 self.session.ui.mouse_modes.mouse_pause_tracking() 
    48384 File
    48385 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48386 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    48387 mouse_pause_tracking 
    48388 self._mouse_pause() 
    48389 File
    48390 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48391 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    48392 m.pause(self._mouse_pause_position) 
    48393 File
    48394 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48395 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    48396 p = self.view.picked_object(x, y) 
    48397 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48398 File
    48399 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48400 packages/chimerax/graphics/view.py", line 838, in picked_object 
    48401 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    48402 beyond, 
    48403 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48404 File
    48405 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48406 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    48407 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    48408 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48409 File
    48410 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48411 packages/chimerax/core/models.py", line 143, in first_intercept 
    48412 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    48413 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48414 File
    48415 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48416 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    48417 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    48418 exclude=exclude) 
    48419 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48420 File
    48421 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48422 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    48423 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    48424 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48425 File
    48426 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48427 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    48428 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    48429 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48430 File
    48431 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48432 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    48433 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    48434 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48435 File
    48436 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48437 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    48438 p = super().first_intercept(mxyz1, mxyz2) 
    48439 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48440 File
    48441 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48442 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    48443 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    48444 exclude=exclude) 
    48445 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48446 File
    48447 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48448 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    48449 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    48450 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48451 File
    48452 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48453 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    48454 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    48455 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48456 File
    48457 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48458 packages/chimerax/graphics/drawing.py", line 1108, in
    48459 _first_intercept_excluding_children 
    48460 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    48461 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48462 File
    48463 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48464 packages/chimerax/geometry/place.py", line 201, in inverse 
    48465 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    48466 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48467 File
    48468 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48469 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    48470 rinv[:, :] = matrix_inverse(r) 
    48471 ^^^^^^^^^^^^^^^^^ 
    48472 File
    48473 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48474 packages/numpy/linalg/linalg.py", line 561, in inv 
    48475 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    48476 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48477 File
    48478 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48479 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    48480 raise LinAlgError("Singular matrix") 
    48481 numpy.linalg.LinAlgError: Singular matrix 
    48482  
    48483 numpy.linalg.LinAlgError: Singular matrix 
    48484  
    48485 File
    48486 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48487 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    48488 raise LinAlgError("Singular matrix") 
    48489  
    48490 See log for complete Python traceback. 
    48491  
    48492 Traceback (most recent call last): 
    48493 File
    48494 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48495 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    48496 self.session.ui.mouse_modes.mouse_pause_tracking() 
    48497 File
    48498 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48499 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    48500 mouse_pause_tracking 
    48501 self._mouse_pause() 
    48502 File
    48503 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48504 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    48505 m.pause(self._mouse_pause_position) 
    48506 File
    48507 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48508 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    48509 p = self.view.picked_object(x, y) 
    48510 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48511 File
    48512 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48513 packages/chimerax/graphics/view.py", line 838, in picked_object 
    48514 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    48515 beyond, 
    48516 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48517 File
    48518 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48519 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    48520 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    48521 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48522 File
    48523 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48524 packages/chimerax/core/models.py", line 143, in first_intercept 
    48525 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    48526 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48527 File
    48528 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48529 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    48530 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    48531 exclude=exclude) 
    48532 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48533 File
    48534 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48535 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    48536 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    48537 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48538 File
    48539 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48540 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    48541 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    48542 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48543 File
    48544 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48545 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    48546 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    48547 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48548 File
    48549 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48550 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    48551 p = super().first_intercept(mxyz1, mxyz2) 
    48552 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48553 File
    48554 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48555 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    48556 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    48557 exclude=exclude) 
    48558 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48559 File
    48560 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48561 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    48562 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    48563 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48564 File
    48565 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48566 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    48567 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    48568 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48569 File
    48570 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48571 packages/chimerax/graphics/drawing.py", line 1108, in
    48572 _first_intercept_excluding_children 
    48573 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    48574 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48575 File
    48576 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48577 packages/chimerax/geometry/place.py", line 201, in inverse 
    48578 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    48579 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48580 File
    48581 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48582 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    48583 rinv[:, :] = matrix_inverse(r) 
    48584 ^^^^^^^^^^^^^^^^^ 
    48585 File
    48586 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48587 packages/numpy/linalg/linalg.py", line 561, in inv 
    48588 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    48589 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48590 File
    48591 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48592 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    48593 raise LinAlgError("Singular matrix") 
    48594 numpy.linalg.LinAlgError: Singular matrix 
    48595  
    48596 numpy.linalg.LinAlgError: Singular matrix 
    48597  
    48598 File
    48599 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48600 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    48601 raise LinAlgError("Singular matrix") 
    48602  
    48603 See log for complete Python traceback. 
    48604  
    48605 Traceback (most recent call last): 
    48606 File
    48607 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48608 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    48609 self.session.ui.mouse_modes.mouse_pause_tracking() 
    48610 File
    48611 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48612 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    48613 mouse_pause_tracking 
    48614 self._mouse_pause() 
    48615 File
    48616 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48617 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    48618 m.pause(self._mouse_pause_position) 
    48619 File
    48620 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48621 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    48622 p = self.view.picked_object(x, y) 
    48623 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48624 File
    48625 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48626 packages/chimerax/graphics/view.py", line 838, in picked_object 
    48627 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    48628 beyond, 
    48629 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48630 File
    48631 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48632 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    48633 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    48634 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48635 File
    48636 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48637 packages/chimerax/core/models.py", line 143, in first_intercept 
    48638 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    48639 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48640 File
    48641 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48642 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    48643 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    48644 exclude=exclude) 
    48645 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48646 File
    48647 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48648 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    48649 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    48650 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48651 File
    48652 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48653 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    48654 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    48655 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48656 File
    48657 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48658 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    48659 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    48660 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48661 File
    48662 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48663 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    48664 p = super().first_intercept(mxyz1, mxyz2) 
    48665 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48666 File
    48667 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48668 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    48669 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    48670 exclude=exclude) 
    48671 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48672 File
    48673 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48674 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    48675 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    48676 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48677 File
    48678 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48679 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    48680 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    48681 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48682 File
    48683 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48684 packages/chimerax/graphics/drawing.py", line 1108, in
    48685 _first_intercept_excluding_children 
    48686 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    48687 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48688 File
    48689 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48690 packages/chimerax/geometry/place.py", line 201, in inverse 
    48691 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    48692 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48693 File
    48694 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48695 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    48696 rinv[:, :] = matrix_inverse(r) 
    48697 ^^^^^^^^^^^^^^^^^ 
    48698 File
    48699 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48700 packages/numpy/linalg/linalg.py", line 561, in inv 
    48701 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    48702 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48703 File
    48704 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48705 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    48706 raise LinAlgError("Singular matrix") 
    48707 numpy.linalg.LinAlgError: Singular matrix 
    48708  
    48709 numpy.linalg.LinAlgError: Singular matrix 
    48710  
    48711 File
    48712 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48713 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    48714 raise LinAlgError("Singular matrix") 
    48715  
    48716 See log for complete Python traceback. 
    48717  
    48718 Traceback (most recent call last): 
    48719 File
    48720 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48721 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    48722 self.session.ui.mouse_modes.mouse_pause_tracking() 
    48723 File
    48724 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48725 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    48726 mouse_pause_tracking 
    48727 self._mouse_pause() 
    48728 File
    48729 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48730 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    48731 m.pause(self._mouse_pause_position) 
    48732 File
    48733 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48734 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    48735 p = self.view.picked_object(x, y) 
    48736 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48737 File
    48738 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48739 packages/chimerax/graphics/view.py", line 838, in picked_object 
    48740 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    48741 beyond, 
    48742 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48743 File
    48744 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48745 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    48746 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    48747 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48748 File
    48749 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48750 packages/chimerax/core/models.py", line 143, in first_intercept 
    48751 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    48752 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48753 File
    48754 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48755 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    48756 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    48757 exclude=exclude) 
    48758 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48759 File
    48760 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48761 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    48762 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    48763 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48764 File
    48765 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48766 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    48767 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    48768 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48769 File
    48770 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48771 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    48772 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    48773 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48774 File
    48775 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48776 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    48777 p = super().first_intercept(mxyz1, mxyz2) 
    48778 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48779 File
    48780 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48781 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    48782 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    48783 exclude=exclude) 
    48784 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48785 File
    48786 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48787 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    48788 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    48789 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48790 File
    48791 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48792 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    48793 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    48794 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48795 File
    48796 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48797 packages/chimerax/graphics/drawing.py", line 1108, in
    48798 _first_intercept_excluding_children 
    48799 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    48800 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48801 File
    48802 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48803 packages/chimerax/geometry/place.py", line 201, in inverse 
    48804 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    48805 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48806 File
    48807 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48808 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    48809 rinv[:, :] = matrix_inverse(r) 
    48810 ^^^^^^^^^^^^^^^^^ 
    48811 File
    48812 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48813 packages/numpy/linalg/linalg.py", line 561, in inv 
    48814 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    48815 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48816 File
    48817 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48818 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    48819 raise LinAlgError("Singular matrix") 
    48820 numpy.linalg.LinAlgError: Singular matrix 
    48821  
    48822 numpy.linalg.LinAlgError: Singular matrix 
    48823  
    48824 File
    48825 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48826 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    48827 raise LinAlgError("Singular matrix") 
    48828  
    48829 See log for complete Python traceback. 
    48830  
    48831 Traceback (most recent call last): 
    48832 File
    48833 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48834 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    48835 self.session.ui.mouse_modes.mouse_pause_tracking() 
    48836 File
    48837 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48838 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    48839 mouse_pause_tracking 
    48840 self._mouse_pause() 
    48841 File
    48842 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48843 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    48844 m.pause(self._mouse_pause_position) 
    48845 File
    48846 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48847 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    48848 p = self.view.picked_object(x, y) 
    48849 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48850 File
    48851 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48852 packages/chimerax/graphics/view.py", line 838, in picked_object 
    48853 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    48854 beyond, 
    48855 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48856 File
    48857 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48858 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    48859 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    48860 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48861 File
    48862 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48863 packages/chimerax/core/models.py", line 143, in first_intercept 
    48864 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    48865 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48866 File
    48867 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48868 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    48869 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    48870 exclude=exclude) 
    48871 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48872 File
    48873 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48874 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    48875 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    48876 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48877 File
    48878 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48879 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    48880 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    48881 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48882 File
    48883 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48884 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    48885 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    48886 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48887 File
    48888 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48889 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    48890 p = super().first_intercept(mxyz1, mxyz2) 
    48891 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48892 File
    48893 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48894 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    48895 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    48896 exclude=exclude) 
    48897 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48898 File
    48899 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48900 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    48901 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    48902 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48903 File
    48904 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48905 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    48906 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    48907 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48908 File
    48909 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48910 packages/chimerax/graphics/drawing.py", line 1108, in
    48911 _first_intercept_excluding_children 
    48912 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    48913 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48914 File
    48915 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48916 packages/chimerax/geometry/place.py", line 201, in inverse 
    48917 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    48918 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48919 File
    48920 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48921 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    48922 rinv[:, :] = matrix_inverse(r) 
    48923 ^^^^^^^^^^^^^^^^^ 
    48924 File
    48925 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48926 packages/numpy/linalg/linalg.py", line 561, in inv 
    48927 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    48928 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48929 File
    48930 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48931 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    48932 raise LinAlgError("Singular matrix") 
    48933 numpy.linalg.LinAlgError: Singular matrix 
    48934  
    48935 numpy.linalg.LinAlgError: Singular matrix 
    48936  
    48937 File
    48938 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48939 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    48940 raise LinAlgError("Singular matrix") 
    48941  
    48942 See log for complete Python traceback. 
    48943  
    48944 Traceback (most recent call last): 
    48945 File
    48946 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48947 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    48948 self.session.ui.mouse_modes.mouse_pause_tracking() 
    48949 File
    48950 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48951 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    48952 mouse_pause_tracking 
    48953 self._mouse_pause() 
    48954 File
    48955 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48956 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    48957 m.pause(self._mouse_pause_position) 
    48958 File
    48959 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48960 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    48961 p = self.view.picked_object(x, y) 
    48962 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48963 File
    48964 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48965 packages/chimerax/graphics/view.py", line 838, in picked_object 
    48966 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    48967 beyond, 
    48968 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48969 File
    48970 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48971 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    48972 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    48973 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48974 File
    48975 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48976 packages/chimerax/core/models.py", line 143, in first_intercept 
    48977 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    48978 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48979 File
    48980 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48981 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    48982 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    48983 exclude=exclude) 
    48984 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48985 File
    48986 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48987 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    48988 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    48989 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48990 File
    48991 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48992 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    48993 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    48994 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    48995 File
    48996 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    48997 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    48998 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    48999 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49000 File
    49001 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49002 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    49003 p = super().first_intercept(mxyz1, mxyz2) 
    49004 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49005 File
    49006 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49007 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    49008 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    49009 exclude=exclude) 
    49010 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49011 File
    49012 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49013 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    49014 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    49015 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49016 File
    49017 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49018 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    49019 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    49020 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49021 File
    49022 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49023 packages/chimerax/graphics/drawing.py", line 1108, in
    49024 _first_intercept_excluding_children 
    49025 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    49026 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49027 File
    49028 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49029 packages/chimerax/geometry/place.py", line 201, in inverse 
    49030 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    49031 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49032 File
    49033 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49034 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    49035 rinv[:, :] = matrix_inverse(r) 
    49036 ^^^^^^^^^^^^^^^^^ 
    49037 File
    49038 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49039 packages/numpy/linalg/linalg.py", line 561, in inv 
    49040 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    49041 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49042 File
    49043 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49044 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    49045 raise LinAlgError("Singular matrix") 
    49046 numpy.linalg.LinAlgError: Singular matrix 
    49047  
    49048 numpy.linalg.LinAlgError: Singular matrix 
    49049  
    49050 File
    49051 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49052 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    49053 raise LinAlgError("Singular matrix") 
    49054  
    49055 See log for complete Python traceback. 
    49056  
    49057 Traceback (most recent call last): 
    49058 File
    49059 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49060 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    49061 self.session.ui.mouse_modes.mouse_pause_tracking() 
    49062 File
    49063 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49064 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    49065 mouse_pause_tracking 
    49066 self._mouse_pause() 
    49067 File
    49068 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49069 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    49070 m.pause(self._mouse_pause_position) 
    49071 File
    49072 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49073 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    49074 p = self.view.picked_object(x, y) 
    49075 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49076 File
    49077 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49078 packages/chimerax/graphics/view.py", line 838, in picked_object 
    49079 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    49080 beyond, 
    49081 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49082 File
    49083 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49084 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    49085 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    49086 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49087 File
    49088 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49089 packages/chimerax/core/models.py", line 143, in first_intercept 
    49090 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    49091 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49092 File
    49093 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49094 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    49095 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    49096 exclude=exclude) 
    49097 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49098 File
    49099 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49100 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    49101 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    49102 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49103 File
    49104 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49105 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    49106 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    49107 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49108 File
    49109 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49110 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    49111 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    49112 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49113 File
    49114 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49115 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    49116 p = super().first_intercept(mxyz1, mxyz2) 
    49117 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49118 File
    49119 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49120 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    49121 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    49122 exclude=exclude) 
    49123 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49124 File
    49125 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49126 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    49127 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    49128 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49129 File
    49130 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49131 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    49132 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    49133 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49134 File
    49135 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49136 packages/chimerax/graphics/drawing.py", line 1108, in
    49137 _first_intercept_excluding_children 
    49138 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    49139 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49140 File
    49141 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49142 packages/chimerax/geometry/place.py", line 201, in inverse 
    49143 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    49144 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49145 File
    49146 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49147 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    49148 rinv[:, :] = matrix_inverse(r) 
    49149 ^^^^^^^^^^^^^^^^^ 
    49150 File
    49151 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49152 packages/numpy/linalg/linalg.py", line 561, in inv 
    49153 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    49154 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49155 File
    49156 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49157 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    49158 raise LinAlgError("Singular matrix") 
    49159 numpy.linalg.LinAlgError: Singular matrix 
    49160  
    49161 numpy.linalg.LinAlgError: Singular matrix 
    49162  
    49163 File
    49164 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49165 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    49166 raise LinAlgError("Singular matrix") 
    49167  
    49168 See log for complete Python traceback. 
    49169  
    49170 Traceback (most recent call last): 
    49171 File
    49172 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49173 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    49174 self.session.ui.mouse_modes.mouse_pause_tracking() 
    49175 File
    49176 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49177 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    49178 mouse_pause_tracking 
    49179 self._mouse_pause() 
    49180 File
    49181 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49182 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    49183 m.pause(self._mouse_pause_position) 
    49184 File
    49185 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49186 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    49187 p = self.view.picked_object(x, y) 
    49188 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49189 File
    49190 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49191 packages/chimerax/graphics/view.py", line 838, in picked_object 
    49192 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    49193 beyond, 
    49194 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49195 File
    49196 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49197 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    49198 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    49199 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49200 File
    49201 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49202 packages/chimerax/core/models.py", line 143, in first_intercept 
    49203 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    49204 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49205 File
    49206 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49207 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    49208 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    49209 exclude=exclude) 
    49210 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49211 File
    49212 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49213 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    49214 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    49215 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49216 File
    49217 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49218 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    49219 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    49220 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49221 File
    49222 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49223 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    49224 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    49225 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49226 File
    49227 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49228 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    49229 p = super().first_intercept(mxyz1, mxyz2) 
    49230 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49231 File
    49232 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49233 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    49234 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    49235 exclude=exclude) 
    49236 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49237 File
    49238 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49239 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    49240 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    49241 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49242 File
    49243 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49244 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    49245 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    49246 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49247 File
    49248 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49249 packages/chimerax/graphics/drawing.py", line 1108, in
    49250 _first_intercept_excluding_children 
    49251 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    49252 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49253 File
    49254 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49255 packages/chimerax/geometry/place.py", line 201, in inverse 
    49256 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    49257 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49258 File
    49259 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49260 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    49261 rinv[:, :] = matrix_inverse(r) 
    49262 ^^^^^^^^^^^^^^^^^ 
    49263 File
    49264 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49265 packages/numpy/linalg/linalg.py", line 561, in inv 
    49266 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    49267 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49268 File
    49269 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49270 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    49271 raise LinAlgError("Singular matrix") 
    49272 numpy.linalg.LinAlgError: Singular matrix 
    49273  
    49274 numpy.linalg.LinAlgError: Singular matrix 
    49275  
    49276 File
    49277 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49278 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    49279 raise LinAlgError("Singular matrix") 
    49280  
    49281 See log for complete Python traceback. 
    49282  
    49283 Traceback (most recent call last): 
    49284 File
    49285 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49286 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    49287 self.session.ui.mouse_modes.mouse_pause_tracking() 
    49288 File
    49289 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49290 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    49291 mouse_pause_tracking 
    49292 self._mouse_pause() 
    49293 File
    49294 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49295 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    49296 m.pause(self._mouse_pause_position) 
    49297 File
    49298 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49299 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    49300 p = self.view.picked_object(x, y) 
    49301 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49302 File
    49303 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49304 packages/chimerax/graphics/view.py", line 838, in picked_object 
    49305 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    49306 beyond, 
    49307 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49308 File
    49309 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49310 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    49311 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    49312 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49313 File
    49314 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49315 packages/chimerax/core/models.py", line 143, in first_intercept 
    49316 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    49317 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49318 File
    49319 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49320 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    49321 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    49322 exclude=exclude) 
    49323 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49324 File
    49325 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49326 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    49327 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    49328 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49329 File
    49330 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49331 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    49332 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    49333 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49334 File
    49335 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49336 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    49337 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    49338 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49339 File
    49340 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49341 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    49342 p = super().first_intercept(mxyz1, mxyz2) 
    49343 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49344 File
    49345 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49346 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    49347 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    49348 exclude=exclude) 
    49349 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49350 File
    49351 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49352 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    49353 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    49354 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49355 File
    49356 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49357 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    49358 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    49359 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49360 File
    49361 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49362 packages/chimerax/graphics/drawing.py", line 1108, in
    49363 _first_intercept_excluding_children 
    49364 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    49365 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49366 File
    49367 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49368 packages/chimerax/geometry/place.py", line 201, in inverse 
    49369 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    49370 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49371 File
    49372 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49373 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    49374 rinv[:, :] = matrix_inverse(r) 
    49375 ^^^^^^^^^^^^^^^^^ 
    49376 File
    49377 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49378 packages/numpy/linalg/linalg.py", line 561, in inv 
    49379 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    49380 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49381 File
    49382 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49383 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    49384 raise LinAlgError("Singular matrix") 
    49385 numpy.linalg.LinAlgError: Singular matrix 
    49386  
    49387 numpy.linalg.LinAlgError: Singular matrix 
    49388  
    49389 File
    49390 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49391 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    49392 raise LinAlgError("Singular matrix") 
    49393  
    49394 See log for complete Python traceback. 
    49395  
    49396 Traceback (most recent call last): 
    49397 File
    49398 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49399 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    49400 self.session.ui.mouse_modes.mouse_pause_tracking() 
    49401 File
    49402 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49403 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    49404 mouse_pause_tracking 
    49405 self._mouse_pause() 
    49406 File
    49407 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49408 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    49409 m.pause(self._mouse_pause_position) 
    49410 File
    49411 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49412 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    49413 p = self.view.picked_object(x, y) 
    49414 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49415 File
    49416 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49417 packages/chimerax/graphics/view.py", line 838, in picked_object 
    49418 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    49419 beyond, 
    49420 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49421 File
    49422 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49423 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    49424 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    49425 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49426 File
    49427 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49428 packages/chimerax/core/models.py", line 143, in first_intercept 
    49429 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    49430 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49431 File
    49432 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49433 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    49434 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    49435 exclude=exclude) 
    49436 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49437 File
    49438 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49439 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    49440 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    49441 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49442 File
    49443 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49444 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    49445 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    49446 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49447 File
    49448 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49449 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    49450 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    49451 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49452 File
    49453 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49454 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    49455 p = super().first_intercept(mxyz1, mxyz2) 
    49456 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49457 File
    49458 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49459 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    49460 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    49461 exclude=exclude) 
    49462 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49463 File
    49464 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49465 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    49466 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    49467 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49468 File
    49469 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49470 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    49471 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    49472 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49473 File
    49474 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49475 packages/chimerax/graphics/drawing.py", line 1108, in
    49476 _first_intercept_excluding_children 
    49477 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    49478 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49479 File
    49480 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49481 packages/chimerax/geometry/place.py", line 201, in inverse 
    49482 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    49483 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49484 File
    49485 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49486 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    49487 rinv[:, :] = matrix_inverse(r) 
    49488 ^^^^^^^^^^^^^^^^^ 
    49489 File
    49490 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49491 packages/numpy/linalg/linalg.py", line 561, in inv 
    49492 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    49493 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49494 File
    49495 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49496 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    49497 raise LinAlgError("Singular matrix") 
    49498 numpy.linalg.LinAlgError: Singular matrix 
    49499  
    49500 numpy.linalg.LinAlgError: Singular matrix 
    49501  
    49502 File
    49503 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49504 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    49505 raise LinAlgError("Singular matrix") 
    49506  
    49507 See log for complete Python traceback. 
    49508  
    49509 Traceback (most recent call last): 
    49510 File
    49511 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49512 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    49513 self.session.ui.mouse_modes.mouse_pause_tracking() 
    49514 File
    49515 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49516 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    49517 mouse_pause_tracking 
    49518 self._mouse_pause() 
    49519 File
    49520 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49521 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    49522 m.pause(self._mouse_pause_position) 
    49523 File
    49524 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49525 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    49526 p = self.view.picked_object(x, y) 
    49527 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49528 File
    49529 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49530 packages/chimerax/graphics/view.py", line 838, in picked_object 
    49531 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    49532 beyond, 
    49533 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49534 File
    49535 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49536 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    49537 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    49538 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49539 File
    49540 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49541 packages/chimerax/core/models.py", line 143, in first_intercept 
    49542 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    49543 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49544 File
    49545 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49546 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    49547 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    49548 exclude=exclude) 
    49549 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49550 File
    49551 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49552 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    49553 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    49554 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49555 File
    49556 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49557 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    49558 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    49559 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49560 File
    49561 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49562 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    49563 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    49564 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49565 File
    49566 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49567 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    49568 p = super().first_intercept(mxyz1, mxyz2) 
    49569 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49570 File
    49571 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49572 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    49573 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    49574 exclude=exclude) 
    49575 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49576 File
    49577 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49578 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    49579 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    49580 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49581 File
    49582 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49583 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    49584 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    49585 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49586 File
    49587 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49588 packages/chimerax/graphics/drawing.py", line 1108, in
    49589 _first_intercept_excluding_children 
    49590 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    49591 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49592 File
    49593 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49594 packages/chimerax/geometry/place.py", line 201, in inverse 
    49595 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    49596 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49597 File
    49598 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49599 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    49600 rinv[:, :] = matrix_inverse(r) 
    49601 ^^^^^^^^^^^^^^^^^ 
    49602 File
    49603 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49604 packages/numpy/linalg/linalg.py", line 561, in inv 
    49605 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    49606 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49607 File
    49608 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49609 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    49610 raise LinAlgError("Singular matrix") 
    49611 numpy.linalg.LinAlgError: Singular matrix 
    49612  
    49613 numpy.linalg.LinAlgError: Singular matrix 
    49614  
    49615 File
    49616 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49617 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    49618 raise LinAlgError("Singular matrix") 
    49619  
    49620 See log for complete Python traceback. 
    49621  
    49622 Traceback (most recent call last): 
    49623 File
    49624 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49625 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    49626 self.session.ui.mouse_modes.mouse_pause_tracking() 
    49627 File
    49628 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49629 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    49630 mouse_pause_tracking 
    49631 self._mouse_pause() 
    49632 File
    49633 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49634 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    49635 m.pause(self._mouse_pause_position) 
    49636 File
    49637 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49638 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    49639 p = self.view.picked_object(x, y) 
    49640 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49641 File
    49642 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49643 packages/chimerax/graphics/view.py", line 838, in picked_object 
    49644 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    49645 beyond, 
    49646 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49647 File
    49648 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49649 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    49650 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    49651 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49652 File
    49653 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49654 packages/chimerax/core/models.py", line 143, in first_intercept 
    49655 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    49656 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49657 File
    49658 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49659 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    49660 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    49661 exclude=exclude) 
    49662 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49663 File
    49664 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49665 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    49666 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    49667 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49668 File
    49669 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49670 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    49671 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    49672 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49673 File
    49674 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49675 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    49676 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    49677 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49678 File
    49679 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49680 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    49681 p = super().first_intercept(mxyz1, mxyz2) 
    49682 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49683 File
    49684 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49685 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    49686 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    49687 exclude=exclude) 
    49688 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49689 File
    49690 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49691 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    49692 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    49693 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49694 File
    49695 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49696 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    49697 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    49698 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49699 File
    49700 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49701 packages/chimerax/graphics/drawing.py", line 1108, in
    49702 _first_intercept_excluding_children 
    49703 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    49704 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49705 File
    49706 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49707 packages/chimerax/geometry/place.py", line 201, in inverse 
    49708 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    49709 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49710 File
    49711 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49712 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    49713 rinv[:, :] = matrix_inverse(r) 
    49714 ^^^^^^^^^^^^^^^^^ 
    49715 File
    49716 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49717 packages/numpy/linalg/linalg.py", line 561, in inv 
    49718 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    49719 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49720 File
    49721 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49722 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    49723 raise LinAlgError("Singular matrix") 
    49724 numpy.linalg.LinAlgError: Singular matrix 
    49725  
    49726 numpy.linalg.LinAlgError: Singular matrix 
    49727  
    49728 File
    49729 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49730 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    49731 raise LinAlgError("Singular matrix") 
    49732  
    49733 See log for complete Python traceback. 
    49734  
    49735 Traceback (most recent call last): 
    49736 File
    49737 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49738 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    49739 self.session.ui.mouse_modes.mouse_pause_tracking() 
    49740 File
    49741 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49742 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    49743 mouse_pause_tracking 
    49744 self._mouse_pause() 
    49745 File
    49746 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49747 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    49748 m.pause(self._mouse_pause_position) 
    49749 File
    49750 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49751 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    49752 p = self.view.picked_object(x, y) 
    49753 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49754 File
    49755 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49756 packages/chimerax/graphics/view.py", line 838, in picked_object 
    49757 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    49758 beyond, 
    49759 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49760 File
    49761 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49762 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    49763 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    49764 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49765 File
    49766 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49767 packages/chimerax/core/models.py", line 143, in first_intercept 
    49768 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    49769 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49770 File
    49771 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49772 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    49773 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    49774 exclude=exclude) 
    49775 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49776 File
    49777 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49778 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    49779 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    49780 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49781 File
    49782 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49783 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    49784 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    49785 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49786 File
    49787 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49788 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    49789 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    49790 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49791 File
    49792 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49793 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    49794 p = super().first_intercept(mxyz1, mxyz2) 
    49795 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49796 File
    49797 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49798 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    49799 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    49800 exclude=exclude) 
    49801 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49802 File
    49803 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49804 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    49805 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    49806 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49807 File
    49808 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49809 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    49810 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    49811 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49812 File
    49813 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49814 packages/chimerax/graphics/drawing.py", line 1108, in
    49815 _first_intercept_excluding_children 
    49816 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    49817 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49818 File
    49819 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49820 packages/chimerax/geometry/place.py", line 201, in inverse 
    49821 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    49822 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49823 File
    49824 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49825 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    49826 rinv[:, :] = matrix_inverse(r) 
    49827 ^^^^^^^^^^^^^^^^^ 
    49828 File
    49829 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49830 packages/numpy/linalg/linalg.py", line 561, in inv 
    49831 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    49832 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49833 File
    49834 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49835 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    49836 raise LinAlgError("Singular matrix") 
    49837 numpy.linalg.LinAlgError: Singular matrix 
    49838  
    49839 numpy.linalg.LinAlgError: Singular matrix 
    49840  
    49841 File
    49842 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49843 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    49844 raise LinAlgError("Singular matrix") 
    49845  
    49846 See log for complete Python traceback. 
    49847  
    49848 Traceback (most recent call last): 
    49849 File
    49850 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49851 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    49852 self.session.ui.mouse_modes.mouse_pause_tracking() 
    49853 File
    49854 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49855 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    49856 mouse_pause_tracking 
    49857 self._mouse_pause() 
    49858 File
    49859 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49860 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    49861 m.pause(self._mouse_pause_position) 
    49862 File
    49863 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49864 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    49865 p = self.view.picked_object(x, y) 
    49866 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49867 File
    49868 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49869 packages/chimerax/graphics/view.py", line 838, in picked_object 
    49870 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    49871 beyond, 
    49872 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49873 File
    49874 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49875 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    49876 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    49877 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49878 File
    49879 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49880 packages/chimerax/core/models.py", line 143, in first_intercept 
    49881 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    49882 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49883 File
    49884 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49885 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    49886 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    49887 exclude=exclude) 
    49888 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49889 File
    49890 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49891 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    49892 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    49893 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49894 File
    49895 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49896 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    49897 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    49898 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49899 File
    49900 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49901 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    49902 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    49903 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49904 File
    49905 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49906 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    49907 p = super().first_intercept(mxyz1, mxyz2) 
    49908 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49909 File
    49910 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49911 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    49912 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    49913 exclude=exclude) 
    49914 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49915 File
    49916 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49917 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    49918 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    49919 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49920 File
    49921 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49922 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    49923 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    49924 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49925 File
    49926 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49927 packages/chimerax/graphics/drawing.py", line 1108, in
    49928 _first_intercept_excluding_children 
    49929 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    49930 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49931 File
    49932 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49933 packages/chimerax/geometry/place.py", line 201, in inverse 
    49934 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    49935 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49936 File
    49937 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49938 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    49939 rinv[:, :] = matrix_inverse(r) 
    49940 ^^^^^^^^^^^^^^^^^ 
    49941 File
    49942 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49943 packages/numpy/linalg/linalg.py", line 561, in inv 
    49944 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    49945 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49946 File
    49947 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49948 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    49949 raise LinAlgError("Singular matrix") 
    49950 numpy.linalg.LinAlgError: Singular matrix 
    49951  
    49952 numpy.linalg.LinAlgError: Singular matrix 
    49953  
    49954 File
    49955 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49956 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    49957 raise LinAlgError("Singular matrix") 
    49958  
    49959 See log for complete Python traceback. 
    49960  
    49961 Traceback (most recent call last): 
    49962 File
    49963 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49964 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    49965 self.session.ui.mouse_modes.mouse_pause_tracking() 
    49966 File
    49967 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49968 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    49969 mouse_pause_tracking 
    49970 self._mouse_pause() 
    49971 File
    49972 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49973 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    49974 m.pause(self._mouse_pause_position) 
    49975 File
    49976 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49977 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    49978 p = self.view.picked_object(x, y) 
    49979 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49980 File
    49981 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49982 packages/chimerax/graphics/view.py", line 838, in picked_object 
    49983 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    49984 beyond, 
    49985 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49986 File
    49987 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49988 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    49989 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    49990 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49991 File
    49992 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49993 packages/chimerax/core/models.py", line 143, in first_intercept 
    49994 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    49995 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    49996 File
    49997 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    49998 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    49999 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    50000 exclude=exclude) 
    50001 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50002 File
    50003 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50004 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    50005 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    50006 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50007 File
    50008 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50009 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    50010 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    50011 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50012 File
    50013 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50014 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    50015 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    50016 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50017 File
    50018 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50019 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    50020 p = super().first_intercept(mxyz1, mxyz2) 
    50021 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50022 File
    50023 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50024 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    50025 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    50026 exclude=exclude) 
    50027 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50028 File
    50029 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50030 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    50031 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    50032 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50033 File
    50034 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50035 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    50036 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    50037 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50038 File
    50039 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50040 packages/chimerax/graphics/drawing.py", line 1108, in
    50041 _first_intercept_excluding_children 
    50042 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    50043 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50044 File
    50045 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50046 packages/chimerax/geometry/place.py", line 201, in inverse 
    50047 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    50048 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50049 File
    50050 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50051 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    50052 rinv[:, :] = matrix_inverse(r) 
    50053 ^^^^^^^^^^^^^^^^^ 
    50054 File
    50055 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50056 packages/numpy/linalg/linalg.py", line 561, in inv 
    50057 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    50058 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50059 File
    50060 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50061 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    50062 raise LinAlgError("Singular matrix") 
    50063 numpy.linalg.LinAlgError: Singular matrix 
    50064  
    50065 numpy.linalg.LinAlgError: Singular matrix 
    50066  
    50067 File
    50068 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50069 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    50070 raise LinAlgError("Singular matrix") 
    50071  
    50072 See log for complete Python traceback. 
    50073  
    50074 Traceback (most recent call last): 
    50075 File
    50076 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50077 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    50078 self.session.ui.mouse_modes.mouse_pause_tracking() 
    50079 File
    50080 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50081 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    50082 mouse_pause_tracking 
    50083 self._mouse_pause() 
    50084 File
    50085 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50086 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    50087 m.pause(self._mouse_pause_position) 
    50088 File
    50089 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50090 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    50091 p = self.view.picked_object(x, y) 
    50092 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50093 File
    50094 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50095 packages/chimerax/graphics/view.py", line 838, in picked_object 
    50096 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    50097 beyond, 
    50098 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50099 File
    50100 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50101 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    50102 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    50103 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50104 File
    50105 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50106 packages/chimerax/core/models.py", line 143, in first_intercept 
    50107 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    50108 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50109 File
    50110 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50111 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    50112 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    50113 exclude=exclude) 
    50114 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50115 File
    50116 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50117 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    50118 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    50119 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50120 File
    50121 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50122 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    50123 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    50124 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50125 File
    50126 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50127 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    50128 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    50129 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50130 File
    50131 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50132 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    50133 p = super().first_intercept(mxyz1, mxyz2) 
    50134 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50135 File
    50136 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50137 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    50138 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    50139 exclude=exclude) 
    50140 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50141 File
    50142 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50143 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    50144 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    50145 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50146 File
    50147 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50148 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    50149 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    50150 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50151 File
    50152 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50153 packages/chimerax/graphics/drawing.py", line 1108, in
    50154 _first_intercept_excluding_children 
    50155 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    50156 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50157 File
    50158 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50159 packages/chimerax/geometry/place.py", line 201, in inverse 
    50160 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    50161 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50162 File
    50163 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50164 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    50165 rinv[:, :] = matrix_inverse(r) 
    50166 ^^^^^^^^^^^^^^^^^ 
    50167 File
    50168 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50169 packages/numpy/linalg/linalg.py", line 561, in inv 
    50170 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    50171 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50172 File
    50173 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50174 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    50175 raise LinAlgError("Singular matrix") 
    50176 numpy.linalg.LinAlgError: Singular matrix 
    50177  
    50178 numpy.linalg.LinAlgError: Singular matrix 
    50179  
    50180 File
    50181 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50182 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    50183 raise LinAlgError("Singular matrix") 
    50184  
    50185 See log for complete Python traceback. 
    50186  
    50187 Traceback (most recent call last): 
    50188 File
    50189 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50190 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    50191 self.session.ui.mouse_modes.mouse_pause_tracking() 
    50192 File
    50193 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50194 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    50195 mouse_pause_tracking 
    50196 self._mouse_pause() 
    50197 File
    50198 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50199 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    50200 m.pause(self._mouse_pause_position) 
    50201 File
    50202 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50203 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    50204 p = self.view.picked_object(x, y) 
    50205 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50206 File
    50207 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50208 packages/chimerax/graphics/view.py", line 838, in picked_object 
    50209 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    50210 beyond, 
    50211 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50212 File
    50213 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50214 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    50215 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    50216 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50217 File
    50218 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50219 packages/chimerax/core/models.py", line 143, in first_intercept 
    50220 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    50221 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50222 File
    50223 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50224 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    50225 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    50226 exclude=exclude) 
    50227 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50228 File
    50229 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50230 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    50231 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    50232 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50233 File
    50234 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50235 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    50236 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    50237 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50238 File
    50239 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50240 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    50241 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    50242 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50243 File
    50244 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50245 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    50246 p = super().first_intercept(mxyz1, mxyz2) 
    50247 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50248 File
    50249 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50250 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    50251 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    50252 exclude=exclude) 
    50253 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50254 File
    50255 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50256 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    50257 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    50258 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50259 File
    50260 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50261 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    50262 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    50263 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50264 File
    50265 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50266 packages/chimerax/graphics/drawing.py", line 1108, in
    50267 _first_intercept_excluding_children 
    50268 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    50269 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50270 File
    50271 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50272 packages/chimerax/geometry/place.py", line 201, in inverse 
    50273 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    50274 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50275 File
    50276 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50277 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    50278 rinv[:, :] = matrix_inverse(r) 
    50279 ^^^^^^^^^^^^^^^^^ 
    50280 File
    50281 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50282 packages/numpy/linalg/linalg.py", line 561, in inv 
    50283 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    50284 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50285 File
    50286 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50287 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    50288 raise LinAlgError("Singular matrix") 
    50289 numpy.linalg.LinAlgError: Singular matrix 
    50290  
    50291 numpy.linalg.LinAlgError: Singular matrix 
    50292  
    50293 File
    50294 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50295 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    50296 raise LinAlgError("Singular matrix") 
    50297  
    50298 See log for complete Python traceback. 
    50299  
    50300 Traceback (most recent call last): 
    50301 File
    50302 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50303 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    50304 self.session.ui.mouse_modes.mouse_pause_tracking() 
    50305 File
    50306 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50307 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    50308 mouse_pause_tracking 
    50309 self._mouse_pause() 
    50310 File
    50311 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50312 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    50313 m.pause(self._mouse_pause_position) 
    50314 File
    50315 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50316 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    50317 p = self.view.picked_object(x, y) 
    50318 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50319 File
    50320 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50321 packages/chimerax/graphics/view.py", line 838, in picked_object 
    50322 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    50323 beyond, 
    50324 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50325 File
    50326 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50327 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    50328 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    50329 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50330 File
    50331 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50332 packages/chimerax/core/models.py", line 143, in first_intercept 
    50333 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    50334 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50335 File
    50336 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50337 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    50338 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    50339 exclude=exclude) 
    50340 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50341 File
    50342 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50343 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    50344 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    50345 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50346 File
    50347 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50348 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    50349 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    50350 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50351 File
    50352 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50353 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    50354 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    50355 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50356 File
    50357 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50358 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    50359 p = super().first_intercept(mxyz1, mxyz2) 
    50360 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50361 File
    50362 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50363 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    50364 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    50365 exclude=exclude) 
    50366 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50367 File
    50368 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50369 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    50370 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    50371 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50372 File
    50373 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50374 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    50375 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    50376 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50377 File
    50378 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50379 packages/chimerax/graphics/drawing.py", line 1108, in
    50380 _first_intercept_excluding_children 
    50381 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    50382 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50383 File
    50384 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50385 packages/chimerax/geometry/place.py", line 201, in inverse 
    50386 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    50387 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50388 File
    50389 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50390 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    50391 rinv[:, :] = matrix_inverse(r) 
    50392 ^^^^^^^^^^^^^^^^^ 
    50393 File
    50394 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50395 packages/numpy/linalg/linalg.py", line 561, in inv 
    50396 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    50397 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50398 File
    50399 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50400 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    50401 raise LinAlgError("Singular matrix") 
    50402 numpy.linalg.LinAlgError: Singular matrix 
    50403  
    50404 numpy.linalg.LinAlgError: Singular matrix 
    50405  
    50406 File
    50407 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50408 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    50409 raise LinAlgError("Singular matrix") 
    50410  
    50411 See log for complete Python traceback. 
    50412  
    50413 Traceback (most recent call last): 
    50414 File
    50415 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50416 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    50417 self.session.ui.mouse_modes.mouse_pause_tracking() 
    50418 File
    50419 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50420 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    50421 mouse_pause_tracking 
    50422 self._mouse_pause() 
    50423 File
    50424 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50425 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    50426 m.pause(self._mouse_pause_position) 
    50427 File
    50428 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50429 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    50430 p = self.view.picked_object(x, y) 
    50431 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50432 File
    50433 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50434 packages/chimerax/graphics/view.py", line 838, in picked_object 
    50435 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    50436 beyond, 
    50437 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50438 File
    50439 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50440 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    50441 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    50442 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50443 File
    50444 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50445 packages/chimerax/core/models.py", line 143, in first_intercept 
    50446 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    50447 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50448 File
    50449 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50450 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    50451 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    50452 exclude=exclude) 
    50453 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50454 File
    50455 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50456 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    50457 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    50458 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50459 File
    50460 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50461 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    50462 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    50463 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50464 File
    50465 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50466 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    50467 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    50468 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50469 File
    50470 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50471 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    50472 p = super().first_intercept(mxyz1, mxyz2) 
    50473 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50474 File
    50475 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50476 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    50477 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    50478 exclude=exclude) 
    50479 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50480 File
    50481 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50482 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    50483 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    50484 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50485 File
    50486 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50487 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    50488 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    50489 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50490 File
    50491 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50492 packages/chimerax/graphics/drawing.py", line 1108, in
    50493 _first_intercept_excluding_children 
    50494 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    50495 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50496 File
    50497 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50498 packages/chimerax/geometry/place.py", line 201, in inverse 
    50499 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    50500 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50501 File
    50502 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50503 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    50504 rinv[:, :] = matrix_inverse(r) 
    50505 ^^^^^^^^^^^^^^^^^ 
    50506 File
    50507 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50508 packages/numpy/linalg/linalg.py", line 561, in inv 
    50509 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    50510 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50511 File
    50512 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50513 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    50514 raise LinAlgError("Singular matrix") 
    50515 numpy.linalg.LinAlgError: Singular matrix 
    50516  
    50517 numpy.linalg.LinAlgError: Singular matrix 
    50518  
    50519 File
    50520 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50521 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    50522 raise LinAlgError("Singular matrix") 
    50523  
    50524 See log for complete Python traceback. 
    50525  
    50526 Traceback (most recent call last): 
    50527 File
    50528 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50529 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    50530 self.session.ui.mouse_modes.mouse_pause_tracking() 
    50531 File
    50532 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50533 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    50534 mouse_pause_tracking 
    50535 self._mouse_pause() 
    50536 File
    50537 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50538 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    50539 m.pause(self._mouse_pause_position) 
    50540 File
    50541 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50542 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    50543 p = self.view.picked_object(x, y) 
    50544 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50545 File
    50546 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50547 packages/chimerax/graphics/view.py", line 838, in picked_object 
    50548 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    50549 beyond, 
    50550 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50551 File
    50552 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50553 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    50554 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    50555 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50556 File
    50557 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50558 packages/chimerax/core/models.py", line 143, in first_intercept 
    50559 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    50560 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50561 File
    50562 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50563 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    50564 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    50565 exclude=exclude) 
    50566 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50567 File
    50568 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50569 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    50570 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    50571 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50572 File
    50573 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50574 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    50575 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    50576 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50577 File
    50578 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50579 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    50580 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    50581 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50582 File
    50583 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50584 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    50585 p = super().first_intercept(mxyz1, mxyz2) 
    50586 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50587 File
    50588 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50589 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    50590 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    50591 exclude=exclude) 
    50592 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50593 File
    50594 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50595 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    50596 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    50597 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50598 File
    50599 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50600 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    50601 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    50602 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50603 File
    50604 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50605 packages/chimerax/graphics/drawing.py", line 1108, in
    50606 _first_intercept_excluding_children 
    50607 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    50608 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50609 File
    50610 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50611 packages/chimerax/geometry/place.py", line 201, in inverse 
    50612 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    50613 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50614 File
    50615 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50616 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    50617 rinv[:, :] = matrix_inverse(r) 
    50618 ^^^^^^^^^^^^^^^^^ 
    50619 File
    50620 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50621 packages/numpy/linalg/linalg.py", line 561, in inv 
    50622 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    50623 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50624 File
    50625 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50626 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    50627 raise LinAlgError("Singular matrix") 
    50628 numpy.linalg.LinAlgError: Singular matrix 
    50629  
    50630 numpy.linalg.LinAlgError: Singular matrix 
    50631  
    50632 File
    50633 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50634 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    50635 raise LinAlgError("Singular matrix") 
    50636  
    50637 See log for complete Python traceback. 
    50638  
    50639 Traceback (most recent call last): 
    50640 File
    50641 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50642 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    50643 self.session.ui.mouse_modes.mouse_pause_tracking() 
    50644 File
    50645 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50646 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    50647 mouse_pause_tracking 
    50648 self._mouse_pause() 
    50649 File
    50650 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50651 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    50652 m.pause(self._mouse_pause_position) 
    50653 File
    50654 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50655 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    50656 p = self.view.picked_object(x, y) 
    50657 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50658 File
    50659 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50660 packages/chimerax/graphics/view.py", line 838, in picked_object 
    50661 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    50662 beyond, 
    50663 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50664 File
    50665 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50666 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    50667 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    50668 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50669 File
    50670 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50671 packages/chimerax/core/models.py", line 143, in first_intercept 
    50672 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    50673 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50674 File
    50675 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50676 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    50677 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    50678 exclude=exclude) 
    50679 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50680 File
    50681 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50682 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    50683 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    50684 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50685 File
    50686 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50687 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    50688 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    50689 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50690 File
    50691 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50692 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    50693 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    50694 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50695 File
    50696 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50697 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    50698 p = super().first_intercept(mxyz1, mxyz2) 
    50699 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50700 File
    50701 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50702 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    50703 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    50704 exclude=exclude) 
    50705 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50706 File
    50707 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50708 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    50709 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    50710 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50711 File
    50712 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50713 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    50714 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    50715 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50716 File
    50717 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50718 packages/chimerax/graphics/drawing.py", line 1108, in
    50719 _first_intercept_excluding_children 
    50720 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    50721 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50722 File
    50723 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50724 packages/chimerax/geometry/place.py", line 201, in inverse 
    50725 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    50726 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50727 File
    50728 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50729 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    50730 rinv[:, :] = matrix_inverse(r) 
    50731 ^^^^^^^^^^^^^^^^^ 
    50732 File
    50733 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50734 packages/numpy/linalg/linalg.py", line 561, in inv 
    50735 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    50736 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50737 File
    50738 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50739 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    50740 raise LinAlgError("Singular matrix") 
    50741 numpy.linalg.LinAlgError: Singular matrix 
    50742  
    50743 numpy.linalg.LinAlgError: Singular matrix 
    50744  
    50745 File
    50746 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50747 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    50748 raise LinAlgError("Singular matrix") 
    50749  
    50750 See log for complete Python traceback. 
    50751  
    50752 Traceback (most recent call last): 
    50753 File
    50754 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50755 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    50756 self.session.ui.mouse_modes.mouse_pause_tracking() 
    50757 File
    50758 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50759 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    50760 mouse_pause_tracking 
    50761 self._mouse_pause() 
    50762 File
    50763 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50764 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    50765 m.pause(self._mouse_pause_position) 
    50766 File
    50767 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50768 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    50769 p = self.view.picked_object(x, y) 
    50770 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50771 File
    50772 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50773 packages/chimerax/graphics/view.py", line 838, in picked_object 
    50774 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    50775 beyond, 
    50776 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50777 File
    50778 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50779 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    50780 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    50781 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50782 File
    50783 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50784 packages/chimerax/core/models.py", line 143, in first_intercept 
    50785 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    50786 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50787 File
    50788 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50789 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    50790 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    50791 exclude=exclude) 
    50792 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50793 File
    50794 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50795 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    50796 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    50797 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50798 File
    50799 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50800 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    50801 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    50802 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50803 File
    50804 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50805 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    50806 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    50807 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50808 File
    50809 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50810 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    50811 p = super().first_intercept(mxyz1, mxyz2) 
    50812 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50813 File
    50814 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50815 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    50816 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    50817 exclude=exclude) 
    50818 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50819 File
    50820 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50821 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    50822 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    50823 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50824 File
    50825 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50826 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    50827 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    50828 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50829 File
    50830 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50831 packages/chimerax/graphics/drawing.py", line 1108, in
    50832 _first_intercept_excluding_children 
    50833 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    50834 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50835 File
    50836 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50837 packages/chimerax/geometry/place.py", line 201, in inverse 
    50838 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    50839 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50840 File
    50841 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50842 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    50843 rinv[:, :] = matrix_inverse(r) 
    50844 ^^^^^^^^^^^^^^^^^ 
    50845 File
    50846 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50847 packages/numpy/linalg/linalg.py", line 561, in inv 
    50848 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    50849 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50850 File
    50851 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50852 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    50853 raise LinAlgError("Singular matrix") 
    50854 numpy.linalg.LinAlgError: Singular matrix 
    50855  
    50856 numpy.linalg.LinAlgError: Singular matrix 
    50857  
    50858 File
    50859 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50860 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    50861 raise LinAlgError("Singular matrix") 
    50862  
    50863 See log for complete Python traceback. 
    50864  
    50865 Traceback (most recent call last): 
    50866 File
    50867 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50868 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    50869 self.session.ui.mouse_modes.mouse_pause_tracking() 
    50870 File
    50871 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50872 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    50873 mouse_pause_tracking 
    50874 self._mouse_pause() 
    50875 File
    50876 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50877 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    50878 m.pause(self._mouse_pause_position) 
    50879 File
    50880 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50881 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    50882 p = self.view.picked_object(x, y) 
    50883 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50884 File
    50885 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50886 packages/chimerax/graphics/view.py", line 838, in picked_object 
    50887 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    50888 beyond, 
    50889 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50890 File
    50891 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50892 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    50893 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    50894 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50895 File
    50896 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50897 packages/chimerax/core/models.py", line 143, in first_intercept 
    50898 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    50899 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50900 File
    50901 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50902 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    50903 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    50904 exclude=exclude) 
    50905 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50906 File
    50907 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50908 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    50909 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    50910 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50911 File
    50912 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50913 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    50914 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    50915 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50916 File
    50917 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50918 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    50919 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    50920 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50921 File
    50922 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50923 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    50924 p = super().first_intercept(mxyz1, mxyz2) 
    50925 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50926 File
    50927 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50928 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    50929 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    50930 exclude=exclude) 
    50931 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50932 File
    50933 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50934 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    50935 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    50936 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50937 File
    50938 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50939 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    50940 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    50941 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50942 File
    50943 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50944 packages/chimerax/graphics/drawing.py", line 1108, in
    50945 _first_intercept_excluding_children 
    50946 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    50947 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50948 File
    50949 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50950 packages/chimerax/geometry/place.py", line 201, in inverse 
    50951 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    50952 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50953 File
    50954 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50955 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    50956 rinv[:, :] = matrix_inverse(r) 
    50957 ^^^^^^^^^^^^^^^^^ 
    50958 File
    50959 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50960 packages/numpy/linalg/linalg.py", line 561, in inv 
    50961 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    50962 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50963 File
    50964 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50965 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    50966 raise LinAlgError("Singular matrix") 
    50967 numpy.linalg.LinAlgError: Singular matrix 
    50968  
    50969 numpy.linalg.LinAlgError: Singular matrix 
    50970  
    50971 File
    50972 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50973 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    50974 raise LinAlgError("Singular matrix") 
    50975  
    50976 See log for complete Python traceback. 
    50977  
    50978 Traceback (most recent call last): 
    50979 File
    50980 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50981 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    50982 self.session.ui.mouse_modes.mouse_pause_tracking() 
    50983 File
    50984 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50985 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    50986 mouse_pause_tracking 
    50987 self._mouse_pause() 
    50988 File
    50989 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50990 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    50991 m.pause(self._mouse_pause_position) 
    50992 File
    50993 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50994 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    50995 p = self.view.picked_object(x, y) 
    50996 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    50997 File
    50998 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    50999 packages/chimerax/graphics/view.py", line 838, in picked_object 
    51000 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    51001 beyond, 
    51002 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51003 File
    51004 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51005 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    51006 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    51007 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51008 File
    51009 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51010 packages/chimerax/core/models.py", line 143, in first_intercept 
    51011 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    51012 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51013 File
    51014 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51015 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    51016 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    51017 exclude=exclude) 
    51018 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51019 File
    51020 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51021 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    51022 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    51023 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51024 File
    51025 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51026 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    51027 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    51028 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51029 File
    51030 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51031 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    51032 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    51033 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51034 File
    51035 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51036 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    51037 p = super().first_intercept(mxyz1, mxyz2) 
    51038 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51039 File
    51040 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51041 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    51042 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    51043 exclude=exclude) 
    51044 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51045 File
    51046 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51047 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    51048 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    51049 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51050 File
    51051 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51052 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    51053 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    51054 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51055 File
    51056 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51057 packages/chimerax/graphics/drawing.py", line 1108, in
    51058 _first_intercept_excluding_children 
    51059 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    51060 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51061 File
    51062 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51063 packages/chimerax/geometry/place.py", line 201, in inverse 
    51064 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    51065 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51066 File
    51067 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51068 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    51069 rinv[:, :] = matrix_inverse(r) 
    51070 ^^^^^^^^^^^^^^^^^ 
    51071 File
    51072 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51073 packages/numpy/linalg/linalg.py", line 561, in inv 
    51074 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    51075 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51076 File
    51077 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51078 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    51079 raise LinAlgError("Singular matrix") 
    51080 numpy.linalg.LinAlgError: Singular matrix 
    51081  
    51082 numpy.linalg.LinAlgError: Singular matrix 
    51083  
    51084 File
    51085 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51086 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    51087 raise LinAlgError("Singular matrix") 
    51088  
    51089 See log for complete Python traceback. 
    51090  
    51091 Traceback (most recent call last): 
    51092 File
    51093 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51094 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    51095 self.session.ui.mouse_modes.mouse_pause_tracking() 
    51096 File
    51097 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51098 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    51099 mouse_pause_tracking 
    51100 self._mouse_pause() 
    51101 File
    51102 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51103 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    51104 m.pause(self._mouse_pause_position) 
    51105 File
    51106 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51107 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    51108 p = self.view.picked_object(x, y) 
    51109 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51110 File
    51111 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51112 packages/chimerax/graphics/view.py", line 838, in picked_object 
    51113 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    51114 beyond, 
    51115 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51116 File
    51117 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51118 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    51119 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    51120 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51121 File
    51122 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51123 packages/chimerax/core/models.py", line 143, in first_intercept 
    51124 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    51125 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51126 File
    51127 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51128 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    51129 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    51130 exclude=exclude) 
    51131 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51132 File
    51133 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51134 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    51135 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    51136 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51137 File
    51138 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51139 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    51140 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    51141 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51142 File
    51143 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51144 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    51145 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    51146 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51147 File
    51148 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51149 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    51150 p = super().first_intercept(mxyz1, mxyz2) 
    51151 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51152 File
    51153 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51154 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    51155 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    51156 exclude=exclude) 
    51157 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51158 File
    51159 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51160 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    51161 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    51162 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51163 File
    51164 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51165 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    51166 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    51167 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51168 File
    51169 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51170 packages/chimerax/graphics/drawing.py", line 1108, in
    51171 _first_intercept_excluding_children 
    51172 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    51173 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51174 File
    51175 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51176 packages/chimerax/geometry/place.py", line 201, in inverse 
    51177 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    51178 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51179 File
    51180 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51181 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    51182 rinv[:, :] = matrix_inverse(r) 
    51183 ^^^^^^^^^^^^^^^^^ 
    51184 File
    51185 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51186 packages/numpy/linalg/linalg.py", line 561, in inv 
    51187 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    51188 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51189 File
    51190 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51191 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    51192 raise LinAlgError("Singular matrix") 
    51193 numpy.linalg.LinAlgError: Singular matrix 
    51194  
    51195 numpy.linalg.LinAlgError: Singular matrix 
    51196  
    51197 File
    51198 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51199 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    51200 raise LinAlgError("Singular matrix") 
    51201  
    51202 See log for complete Python traceback. 
    51203  
    51204 Traceback (most recent call last): 
    51205 File
    51206 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51207 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    51208 self.session.ui.mouse_modes.mouse_pause_tracking() 
    51209 File
    51210 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51211 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    51212 mouse_pause_tracking 
    51213 self._mouse_pause() 
    51214 File
    51215 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51216 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    51217 m.pause(self._mouse_pause_position) 
    51218 File
    51219 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51220 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    51221 p = self.view.picked_object(x, y) 
    51222 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51223 File
    51224 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51225 packages/chimerax/graphics/view.py", line 838, in picked_object 
    51226 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    51227 beyond, 
    51228 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51229 File
    51230 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51231 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    51232 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    51233 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51234 File
    51235 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51236 packages/chimerax/core/models.py", line 143, in first_intercept 
    51237 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    51238 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51239 File
    51240 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51241 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    51242 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    51243 exclude=exclude) 
    51244 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51245 File
    51246 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51247 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    51248 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    51249 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51250 File
    51251 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51252 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    51253 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    51254 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51255 File
    51256 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51257 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    51258 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    51259 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51260 File
    51261 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51262 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    51263 p = super().first_intercept(mxyz1, mxyz2) 
    51264 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51265 File
    51266 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51267 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    51268 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    51269 exclude=exclude) 
    51270 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51271 File
    51272 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51273 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    51274 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    51275 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51276 File
    51277 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51278 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    51279 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    51280 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51281 File
    51282 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51283 packages/chimerax/graphics/drawing.py", line 1108, in
    51284 _first_intercept_excluding_children 
    51285 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    51286 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51287 File
    51288 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51289 packages/chimerax/geometry/place.py", line 201, in inverse 
    51290 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    51291 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51292 File
    51293 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51294 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    51295 rinv[:, :] = matrix_inverse(r) 
    51296 ^^^^^^^^^^^^^^^^^ 
    51297 File
    51298 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51299 packages/numpy/linalg/linalg.py", line 561, in inv 
    51300 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    51301 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51302 File
    51303 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51304 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    51305 raise LinAlgError("Singular matrix") 
    51306 numpy.linalg.LinAlgError: Singular matrix 
    51307  
    51308 numpy.linalg.LinAlgError: Singular matrix 
    51309  
    51310 File
    51311 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51312 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    51313 raise LinAlgError("Singular matrix") 
    51314  
    51315 See log for complete Python traceback. 
    51316  
    51317 Traceback (most recent call last): 
    51318 File
    51319 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51320 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    51321 self.session.ui.mouse_modes.mouse_pause_tracking() 
    51322 File
    51323 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51324 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    51325 mouse_pause_tracking 
    51326 self._mouse_pause() 
    51327 File
    51328 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51329 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    51330 m.pause(self._mouse_pause_position) 
    51331 File
    51332 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51333 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    51334 p = self.view.picked_object(x, y) 
    51335 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51336 File
    51337 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51338 packages/chimerax/graphics/view.py", line 838, in picked_object 
    51339 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    51340 beyond, 
    51341 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51342 File
    51343 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51344 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    51345 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    51346 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51347 File
    51348 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51349 packages/chimerax/core/models.py", line 143, in first_intercept 
    51350 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    51351 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51352 File
    51353 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51354 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    51355 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    51356 exclude=exclude) 
    51357 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51358 File
    51359 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51360 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    51361 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    51362 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51363 File
    51364 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51365 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    51366 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    51367 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51368 File
    51369 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51370 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    51371 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    51372 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51373 File
    51374 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51375 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    51376 p = super().first_intercept(mxyz1, mxyz2) 
    51377 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51378 File
    51379 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51380 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    51381 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    51382 exclude=exclude) 
    51383 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51384 File
    51385 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51386 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    51387 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    51388 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51389 File
    51390 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51391 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    51392 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    51393 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51394 File
    51395 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51396 packages/chimerax/graphics/drawing.py", line 1108, in
    51397 _first_intercept_excluding_children 
    51398 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    51399 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51400 File
    51401 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51402 packages/chimerax/geometry/place.py", line 201, in inverse 
    51403 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    51404 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51405 File
    51406 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51407 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    51408 rinv[:, :] = matrix_inverse(r) 
    51409 ^^^^^^^^^^^^^^^^^ 
    51410 File
    51411 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51412 packages/numpy/linalg/linalg.py", line 561, in inv 
    51413 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    51414 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51415 File
    51416 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51417 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    51418 raise LinAlgError("Singular matrix") 
    51419 numpy.linalg.LinAlgError: Singular matrix 
    51420  
    51421 numpy.linalg.LinAlgError: Singular matrix 
    51422  
    51423 File
    51424 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51425 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    51426 raise LinAlgError("Singular matrix") 
    51427  
    51428 See log for complete Python traceback. 
    51429  
    51430 Traceback (most recent call last): 
    51431 File
    51432 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51433 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    51434 self.session.ui.mouse_modes.mouse_pause_tracking() 
    51435 File
    51436 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51437 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    51438 mouse_pause_tracking 
    51439 self._mouse_pause() 
    51440 File
    51441 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51442 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    51443 m.pause(self._mouse_pause_position) 
    51444 File
    51445 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51446 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    51447 p = self.view.picked_object(x, y) 
    51448 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51449 File
    51450 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51451 packages/chimerax/graphics/view.py", line 838, in picked_object 
    51452 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    51453 beyond, 
    51454 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51455 File
    51456 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51457 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    51458 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    51459 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51460 File
    51461 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51462 packages/chimerax/core/models.py", line 143, in first_intercept 
    51463 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    51464 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51465 File
    51466 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51467 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    51468 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    51469 exclude=exclude) 
    51470 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51471 File
    51472 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51473 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    51474 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    51475 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51476 File
    51477 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51478 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    51479 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    51480 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51481 File
    51482 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51483 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    51484 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    51485 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51486 File
    51487 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51488 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    51489 p = super().first_intercept(mxyz1, mxyz2) 
    51490 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51491 File
    51492 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51493 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    51494 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    51495 exclude=exclude) 
    51496 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51497 File
    51498 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51499 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    51500 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    51501 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51502 File
    51503 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51504 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    51505 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    51506 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51507 File
    51508 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51509 packages/chimerax/graphics/drawing.py", line 1108, in
    51510 _first_intercept_excluding_children 
    51511 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    51512 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51513 File
    51514 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51515 packages/chimerax/geometry/place.py", line 201, in inverse 
    51516 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    51517 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51518 File
    51519 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51520 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    51521 rinv[:, :] = matrix_inverse(r) 
    51522 ^^^^^^^^^^^^^^^^^ 
    51523 File
    51524 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51525 packages/numpy/linalg/linalg.py", line 561, in inv 
    51526 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    51527 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51528 File
    51529 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51530 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    51531 raise LinAlgError("Singular matrix") 
    51532 numpy.linalg.LinAlgError: Singular matrix 
    51533  
    51534 numpy.linalg.LinAlgError: Singular matrix 
    51535  
    51536 File
    51537 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51538 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    51539 raise LinAlgError("Singular matrix") 
    51540  
    51541 See log for complete Python traceback. 
    51542  
    51543 Traceback (most recent call last): 
    51544 File
    51545 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51546 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    51547 self.session.ui.mouse_modes.mouse_pause_tracking() 
    51548 File
    51549 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51550 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    51551 mouse_pause_tracking 
    51552 self._mouse_pause() 
    51553 File
    51554 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51555 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    51556 m.pause(self._mouse_pause_position) 
    51557 File
    51558 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51559 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    51560 p = self.view.picked_object(x, y) 
    51561 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51562 File
    51563 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51564 packages/chimerax/graphics/view.py", line 838, in picked_object 
    51565 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    51566 beyond, 
    51567 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51568 File
    51569 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51570 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    51571 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    51572 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51573 File
    51574 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51575 packages/chimerax/core/models.py", line 143, in first_intercept 
    51576 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    51577 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51578 File
    51579 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51580 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    51581 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    51582 exclude=exclude) 
    51583 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51584 File
    51585 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51586 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    51587 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    51588 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51589 File
    51590 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51591 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    51592 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    51593 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51594 File
    51595 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51596 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    51597 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    51598 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51599 File
    51600 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51601 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    51602 p = super().first_intercept(mxyz1, mxyz2) 
    51603 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51604 File
    51605 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51606 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    51607 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    51608 exclude=exclude) 
    51609 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51610 File
    51611 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51612 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    51613 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    51614 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51615 File
    51616 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51617 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    51618 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    51619 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51620 File
    51621 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51622 packages/chimerax/graphics/drawing.py", line 1108, in
    51623 _first_intercept_excluding_children 
    51624 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    51625 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51626 File
    51627 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51628 packages/chimerax/geometry/place.py", line 201, in inverse 
    51629 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    51630 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51631 File
    51632 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51633 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    51634 rinv[:, :] = matrix_inverse(r) 
    51635 ^^^^^^^^^^^^^^^^^ 
    51636 File
    51637 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51638 packages/numpy/linalg/linalg.py", line 561, in inv 
    51639 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    51640 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51641 File
    51642 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51643 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    51644 raise LinAlgError("Singular matrix") 
    51645 numpy.linalg.LinAlgError: Singular matrix 
    51646  
    51647 numpy.linalg.LinAlgError: Singular matrix 
    51648  
    51649 File
    51650 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51651 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    51652 raise LinAlgError("Singular matrix") 
    51653  
    51654 See log for complete Python traceback. 
    51655  
    51656 Traceback (most recent call last): 
    51657 File
    51658 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51659 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    51660 self.session.ui.mouse_modes.mouse_pause_tracking() 
    51661 File
    51662 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51663 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    51664 mouse_pause_tracking 
    51665 self._mouse_pause() 
    51666 File
    51667 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51668 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    51669 m.pause(self._mouse_pause_position) 
    51670 File
    51671 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51672 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    51673 p = self.view.picked_object(x, y) 
    51674 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51675 File
    51676 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51677 packages/chimerax/graphics/view.py", line 838, in picked_object 
    51678 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    51679 beyond, 
    51680 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51681 File
    51682 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51683 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    51684 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    51685 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51686 File
    51687 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51688 packages/chimerax/core/models.py", line 143, in first_intercept 
    51689 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    51690 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51691 File
    51692 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51693 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    51694 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    51695 exclude=exclude) 
    51696 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51697 File
    51698 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51699 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    51700 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    51701 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51702 File
    51703 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51704 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    51705 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    51706 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51707 File
    51708 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51709 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    51710 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    51711 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51712 File
    51713 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51714 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    51715 p = super().first_intercept(mxyz1, mxyz2) 
    51716 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51717 File
    51718 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51719 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    51720 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    51721 exclude=exclude) 
    51722 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51723 File
    51724 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51725 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    51726 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    51727 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51728 File
    51729 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51730 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    51731 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    51732 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51733 File
    51734 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51735 packages/chimerax/graphics/drawing.py", line 1108, in
    51736 _first_intercept_excluding_children 
    51737 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    51738 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51739 File
    51740 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51741 packages/chimerax/geometry/place.py", line 201, in inverse 
    51742 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    51743 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51744 File
    51745 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51746 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    51747 rinv[:, :] = matrix_inverse(r) 
    51748 ^^^^^^^^^^^^^^^^^ 
    51749 File
    51750 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51751 packages/numpy/linalg/linalg.py", line 561, in inv 
    51752 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    51753 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51754 File
    51755 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51756 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    51757 raise LinAlgError("Singular matrix") 
    51758 numpy.linalg.LinAlgError: Singular matrix 
    51759  
    51760 numpy.linalg.LinAlgError: Singular matrix 
    51761  
    51762 File
    51763 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51764 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    51765 raise LinAlgError("Singular matrix") 
    51766  
    51767 See log for complete Python traceback. 
    51768  
    51769 Traceback (most recent call last): 
    51770 File
    51771 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51772 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    51773 self.session.ui.mouse_modes.mouse_pause_tracking() 
    51774 File
    51775 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51776 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    51777 mouse_pause_tracking 
    51778 self._mouse_pause() 
    51779 File
    51780 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51781 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    51782 m.pause(self._mouse_pause_position) 
    51783 File
    51784 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51785 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    51786 p = self.view.picked_object(x, y) 
    51787 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51788 File
    51789 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51790 packages/chimerax/graphics/view.py", line 838, in picked_object 
    51791 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    51792 beyond, 
    51793 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51794 File
    51795 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51796 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    51797 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    51798 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51799 File
    51800 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51801 packages/chimerax/core/models.py", line 143, in first_intercept 
    51802 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    51803 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51804 File
    51805 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51806 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    51807 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    51808 exclude=exclude) 
    51809 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51810 File
    51811 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51812 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    51813 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    51814 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51815 File
    51816 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51817 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    51818 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    51819 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51820 File
    51821 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51822 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    51823 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    51824 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51825 File
    51826 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51827 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    51828 p = super().first_intercept(mxyz1, mxyz2) 
    51829 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51830 File
    51831 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51832 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    51833 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    51834 exclude=exclude) 
    51835 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51836 File
    51837 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51838 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    51839 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    51840 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51841 File
    51842 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51843 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    51844 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    51845 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51846 File
    51847 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51848 packages/chimerax/graphics/drawing.py", line 1108, in
    51849 _first_intercept_excluding_children 
    51850 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    51851 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51852 File
    51853 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51854 packages/chimerax/geometry/place.py", line 201, in inverse 
    51855 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    51856 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51857 File
    51858 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51859 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    51860 rinv[:, :] = matrix_inverse(r) 
    51861 ^^^^^^^^^^^^^^^^^ 
    51862 File
    51863 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51864 packages/numpy/linalg/linalg.py", line 561, in inv 
    51865 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    51866 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51867 File
    51868 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51869 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    51870 raise LinAlgError("Singular matrix") 
    51871 numpy.linalg.LinAlgError: Singular matrix 
    51872  
    51873 numpy.linalg.LinAlgError: Singular matrix 
    51874  
    51875 File
    51876 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51877 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    51878 raise LinAlgError("Singular matrix") 
    51879  
    51880 See log for complete Python traceback. 
    51881  
    51882 Traceback (most recent call last): 
    51883 File
    51884 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51885 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    51886 self.session.ui.mouse_modes.mouse_pause_tracking() 
    51887 File
    51888 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51889 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    51890 mouse_pause_tracking 
    51891 self._mouse_pause() 
    51892 File
    51893 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51894 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    51895 m.pause(self._mouse_pause_position) 
    51896 File
    51897 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51898 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    51899 p = self.view.picked_object(x, y) 
    51900 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51901 File
    51902 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51903 packages/chimerax/graphics/view.py", line 838, in picked_object 
    51904 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    51905 beyond, 
    51906 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51907 File
    51908 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51909 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    51910 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    51911 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51912 File
    51913 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51914 packages/chimerax/core/models.py", line 143, in first_intercept 
    51915 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    51916 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51917 File
    51918 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51919 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    51920 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    51921 exclude=exclude) 
    51922 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51923 File
    51924 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51925 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    51926 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    51927 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51928 File
    51929 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51930 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    51931 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    51932 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51933 File
    51934 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51935 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    51936 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    51937 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51938 File
    51939 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51940 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    51941 p = super().first_intercept(mxyz1, mxyz2) 
    51942 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51943 File
    51944 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51945 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    51946 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    51947 exclude=exclude) 
    51948 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51949 File
    51950 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51951 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    51952 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    51953 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51954 File
    51955 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51956 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    51957 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    51958 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51959 File
    51960 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51961 packages/chimerax/graphics/drawing.py", line 1108, in
    51962 _first_intercept_excluding_children 
    51963 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    51964 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51965 File
    51966 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51967 packages/chimerax/geometry/place.py", line 201, in inverse 
    51968 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    51969 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51970 File
    51971 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51972 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    51973 rinv[:, :] = matrix_inverse(r) 
    51974 ^^^^^^^^^^^^^^^^^ 
    51975 File
    51976 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51977 packages/numpy/linalg/linalg.py", line 561, in inv 
    51978 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    51979 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    51980 File
    51981 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51982 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    51983 raise LinAlgError("Singular matrix") 
    51984 numpy.linalg.LinAlgError: Singular matrix 
    51985  
    51986 numpy.linalg.LinAlgError: Singular matrix 
    51987  
    51988 File
    51989 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51990 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    51991 raise LinAlgError("Singular matrix") 
    51992  
    51993 See log for complete Python traceback. 
    51994  
    51995 Traceback (most recent call last): 
    51996 File
    51997 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    51998 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    51999 self.session.ui.mouse_modes.mouse_pause_tracking() 
    52000 File
    52001 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52002 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    52003 mouse_pause_tracking 
    52004 self._mouse_pause() 
    52005 File
    52006 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52007 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    52008 m.pause(self._mouse_pause_position) 
    52009 File
    52010 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52011 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    52012 p = self.view.picked_object(x, y) 
    52013 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52014 File
    52015 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52016 packages/chimerax/graphics/view.py", line 838, in picked_object 
    52017 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    52018 beyond, 
    52019 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52020 File
    52021 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52022 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    52023 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    52024 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52025 File
    52026 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52027 packages/chimerax/core/models.py", line 143, in first_intercept 
    52028 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    52029 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52030 File
    52031 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52032 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    52033 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    52034 exclude=exclude) 
    52035 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52036 File
    52037 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52038 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    52039 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    52040 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52041 File
    52042 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52043 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    52044 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    52045 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52046 File
    52047 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52048 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    52049 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    52050 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52051 File
    52052 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52053 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    52054 p = super().first_intercept(mxyz1, mxyz2) 
    52055 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52056 File
    52057 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52058 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    52059 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    52060 exclude=exclude) 
    52061 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52062 File
    52063 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52064 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    52065 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    52066 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52067 File
    52068 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52069 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    52070 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    52071 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52072 File
    52073 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52074 packages/chimerax/graphics/drawing.py", line 1108, in
    52075 _first_intercept_excluding_children 
    52076 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    52077 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52078 File
    52079 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52080 packages/chimerax/geometry/place.py", line 201, in inverse 
    52081 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    52082 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52083 File
    52084 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52085 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    52086 rinv[:, :] = matrix_inverse(r) 
    52087 ^^^^^^^^^^^^^^^^^ 
    52088 File
    52089 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52090 packages/numpy/linalg/linalg.py", line 561, in inv 
    52091 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    52092 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52093 File
    52094 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52095 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    52096 raise LinAlgError("Singular matrix") 
    52097 numpy.linalg.LinAlgError: Singular matrix 
    52098  
    52099 numpy.linalg.LinAlgError: Singular matrix 
    52100  
    52101 File
    52102 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52103 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    52104 raise LinAlgError("Singular matrix") 
    52105  
    52106 See log for complete Python traceback. 
    52107  
    52108 Traceback (most recent call last): 
    52109 File
    52110 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52111 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    52112 self.session.ui.mouse_modes.mouse_pause_tracking() 
    52113 File
    52114 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52115 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    52116 mouse_pause_tracking 
    52117 self._mouse_pause() 
    52118 File
    52119 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52120 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    52121 m.pause(self._mouse_pause_position) 
    52122 File
    52123 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52124 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    52125 p = self.view.picked_object(x, y) 
    52126 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52127 File
    52128 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52129 packages/chimerax/graphics/view.py", line 838, in picked_object 
    52130 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    52131 beyond, 
    52132 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52133 File
    52134 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52135 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    52136 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    52137 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52138 File
    52139 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52140 packages/chimerax/core/models.py", line 143, in first_intercept 
    52141 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    52142 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52143 File
    52144 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52145 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    52146 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    52147 exclude=exclude) 
    52148 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52149 File
    52150 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52151 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    52152 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    52153 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52154 File
    52155 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52156 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    52157 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    52158 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52159 File
    52160 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52161 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    52162 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    52163 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52164 File
    52165 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52166 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    52167 p = super().first_intercept(mxyz1, mxyz2) 
    52168 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52169 File
    52170 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52171 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    52172 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    52173 exclude=exclude) 
    52174 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52175 File
    52176 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52177 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    52178 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    52179 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52180 File
    52181 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52182 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    52183 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    52184 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52185 File
    52186 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52187 packages/chimerax/graphics/drawing.py", line 1108, in
    52188 _first_intercept_excluding_children 
    52189 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    52190 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52191 File
    52192 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52193 packages/chimerax/geometry/place.py", line 201, in inverse 
    52194 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    52195 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52196 File
    52197 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52198 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    52199 rinv[:, :] = matrix_inverse(r) 
    52200 ^^^^^^^^^^^^^^^^^ 
    52201 File
    52202 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52203 packages/numpy/linalg/linalg.py", line 561, in inv 
    52204 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    52205 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52206 File
    52207 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52208 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    52209 raise LinAlgError("Singular matrix") 
    52210 numpy.linalg.LinAlgError: Singular matrix 
    52211  
    52212 numpy.linalg.LinAlgError: Singular matrix 
    52213  
    52214 File
    52215 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52216 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    52217 raise LinAlgError("Singular matrix") 
    52218  
    52219 See log for complete Python traceback. 
    52220  
    52221 Traceback (most recent call last): 
    52222 File
    52223 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52224 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    52225 self.session.ui.mouse_modes.mouse_pause_tracking() 
    52226 File
    52227 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52228 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    52229 mouse_pause_tracking 
    52230 self._mouse_pause() 
    52231 File
    52232 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52233 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    52234 m.pause(self._mouse_pause_position) 
    52235 File
    52236 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52237 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    52238 p = self.view.picked_object(x, y) 
    52239 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52240 File
    52241 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52242 packages/chimerax/graphics/view.py", line 838, in picked_object 
    52243 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    52244 beyond, 
    52245 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52246 File
    52247 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52248 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    52249 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    52250 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52251 File
    52252 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52253 packages/chimerax/core/models.py", line 143, in first_intercept 
    52254 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    52255 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52256 File
    52257 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52258 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    52259 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    52260 exclude=exclude) 
    52261 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52262 File
    52263 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52264 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    52265 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    52266 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52267 File
    52268 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52269 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    52270 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    52271 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52272 File
    52273 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52274 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    52275 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    52276 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52277 File
    52278 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52279 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    52280 p = super().first_intercept(mxyz1, mxyz2) 
    52281 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52282 File
    52283 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52284 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    52285 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    52286 exclude=exclude) 
    52287 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52288 File
    52289 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52290 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    52291 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    52292 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52293 File
    52294 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52295 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    52296 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    52297 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52298 File
    52299 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52300 packages/chimerax/graphics/drawing.py", line 1108, in
    52301 _first_intercept_excluding_children 
    52302 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    52303 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52304 File
    52305 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52306 packages/chimerax/geometry/place.py", line 201, in inverse 
    52307 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    52308 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52309 File
    52310 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52311 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    52312 rinv[:, :] = matrix_inverse(r) 
    52313 ^^^^^^^^^^^^^^^^^ 
    52314 File
    52315 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52316 packages/numpy/linalg/linalg.py", line 561, in inv 
    52317 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    52318 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52319 File
    52320 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52321 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    52322 raise LinAlgError("Singular matrix") 
    52323 numpy.linalg.LinAlgError: Singular matrix 
    52324  
    52325 numpy.linalg.LinAlgError: Singular matrix 
    52326  
    52327 File
    52328 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52329 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    52330 raise LinAlgError("Singular matrix") 
    52331  
    52332 See log for complete Python traceback. 
    52333  
    52334 Traceback (most recent call last): 
    52335 File
    52336 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52337 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    52338 self.session.ui.mouse_modes.mouse_pause_tracking() 
    52339 File
    52340 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52341 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    52342 mouse_pause_tracking 
    52343 self._mouse_pause() 
    52344 File
    52345 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52346 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    52347 m.pause(self._mouse_pause_position) 
    52348 File
    52349 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52350 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    52351 p = self.view.picked_object(x, y) 
    52352 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52353 File
    52354 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52355 packages/chimerax/graphics/view.py", line 838, in picked_object 
    52356 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    52357 beyond, 
    52358 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52359 File
    52360 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52361 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    52362 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    52363 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52364 File
    52365 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52366 packages/chimerax/core/models.py", line 143, in first_intercept 
    52367 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    52368 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52369 File
    52370 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52371 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    52372 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    52373 exclude=exclude) 
    52374 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52375 File
    52376 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52377 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    52378 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    52379 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52380 File
    52381 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52382 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    52383 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    52384 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52385 File
    52386 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52387 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    52388 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    52389 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52390 File
    52391 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52392 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    52393 p = super().first_intercept(mxyz1, mxyz2) 
    52394 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52395 File
    52396 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52397 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    52398 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    52399 exclude=exclude) 
    52400 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52401 File
    52402 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52403 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    52404 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    52405 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52406 File
    52407 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52408 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    52409 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    52410 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52411 File
    52412 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52413 packages/chimerax/graphics/drawing.py", line 1108, in
    52414 _first_intercept_excluding_children 
    52415 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    52416 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52417 File
    52418 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52419 packages/chimerax/geometry/place.py", line 201, in inverse 
    52420 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    52421 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52422 File
    52423 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52424 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    52425 rinv[:, :] = matrix_inverse(r) 
    52426 ^^^^^^^^^^^^^^^^^ 
    52427 File
    52428 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52429 packages/numpy/linalg/linalg.py", line 561, in inv 
    52430 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    52431 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52432 File
    52433 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52434 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    52435 raise LinAlgError("Singular matrix") 
    52436 numpy.linalg.LinAlgError: Singular matrix 
    52437  
    52438 numpy.linalg.LinAlgError: Singular matrix 
    52439  
    52440 File
    52441 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52442 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    52443 raise LinAlgError("Singular matrix") 
    52444  
    52445 See log for complete Python traceback. 
    52446  
    52447 Traceback (most recent call last): 
    52448 File
    52449 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52450 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    52451 self.session.ui.mouse_modes.mouse_pause_tracking() 
    52452 File
    52453 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52454 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    52455 mouse_pause_tracking 
    52456 self._mouse_pause() 
    52457 File
    52458 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52459 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    52460 m.pause(self._mouse_pause_position) 
    52461 File
    52462 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52463 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    52464 p = self.view.picked_object(x, y) 
    52465 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52466 File
    52467 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52468 packages/chimerax/graphics/view.py", line 838, in picked_object 
    52469 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    52470 beyond, 
    52471 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52472 File
    52473 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52474 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    52475 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    52476 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52477 File
    52478 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52479 packages/chimerax/core/models.py", line 143, in first_intercept 
    52480 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    52481 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52482 File
    52483 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52484 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    52485 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    52486 exclude=exclude) 
    52487 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52488 File
    52489 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52490 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    52491 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    52492 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52493 File
    52494 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52495 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    52496 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    52497 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52498 File
    52499 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52500 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    52501 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    52502 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52503 File
    52504 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52505 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    52506 p = super().first_intercept(mxyz1, mxyz2) 
    52507 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52508 File
    52509 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52510 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    52511 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    52512 exclude=exclude) 
    52513 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52514 File
    52515 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52516 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    52517 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    52518 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52519 File
    52520 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52521 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    52522 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    52523 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52524 File
    52525 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52526 packages/chimerax/graphics/drawing.py", line 1108, in
    52527 _first_intercept_excluding_children 
    52528 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    52529 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52530 File
    52531 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52532 packages/chimerax/geometry/place.py", line 201, in inverse 
    52533 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    52534 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52535 File
    52536 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52537 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    52538 rinv[:, :] = matrix_inverse(r) 
    52539 ^^^^^^^^^^^^^^^^^ 
    52540 File
    52541 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52542 packages/numpy/linalg/linalg.py", line 561, in inv 
    52543 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    52544 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52545 File
    52546 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52547 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    52548 raise LinAlgError("Singular matrix") 
    52549 numpy.linalg.LinAlgError: Singular matrix 
    52550  
    52551 numpy.linalg.LinAlgError: Singular matrix 
    52552  
    52553 File
    52554 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52555 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    52556 raise LinAlgError("Singular matrix") 
    52557  
    52558 See log for complete Python traceback. 
    52559  
    52560 Traceback (most recent call last): 
    52561 File
    52562 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52563 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    52564 self.session.ui.mouse_modes.mouse_pause_tracking() 
    52565 File
    52566 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52567 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    52568 mouse_pause_tracking 
    52569 self._mouse_pause() 
    52570 File
    52571 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52572 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    52573 m.pause(self._mouse_pause_position) 
    52574 File
    52575 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52576 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    52577 p = self.view.picked_object(x, y) 
    52578 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52579 File
    52580 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52581 packages/chimerax/graphics/view.py", line 838, in picked_object 
    52582 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    52583 beyond, 
    52584 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52585 File
    52586 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52587 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    52588 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    52589 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52590 File
    52591 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52592 packages/chimerax/core/models.py", line 143, in first_intercept 
    52593 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    52594 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52595 File
    52596 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52597 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    52598 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    52599 exclude=exclude) 
    52600 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52601 File
    52602 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52603 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    52604 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    52605 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52606 File
    52607 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52608 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    52609 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    52610 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52611 File
    52612 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52613 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    52614 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    52615 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52616 File
    52617 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52618 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    52619 p = super().first_intercept(mxyz1, mxyz2) 
    52620 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52621 File
    52622 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52623 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    52624 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    52625 exclude=exclude) 
    52626 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52627 File
    52628 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52629 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    52630 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    52631 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52632 File
    52633 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52634 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    52635 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    52636 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52637 File
    52638 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52639 packages/chimerax/graphics/drawing.py", line 1108, in
    52640 _first_intercept_excluding_children 
    52641 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    52642 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52643 File
    52644 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52645 packages/chimerax/geometry/place.py", line 201, in inverse 
    52646 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    52647 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52648 File
    52649 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52650 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    52651 rinv[:, :] = matrix_inverse(r) 
    52652 ^^^^^^^^^^^^^^^^^ 
    52653 File
    52654 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52655 packages/numpy/linalg/linalg.py", line 561, in inv 
    52656 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    52657 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52658 File
    52659 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52660 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    52661 raise LinAlgError("Singular matrix") 
    52662 numpy.linalg.LinAlgError: Singular matrix 
    52663  
    52664 numpy.linalg.LinAlgError: Singular matrix 
    52665  
    52666 File
    52667 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52668 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    52669 raise LinAlgError("Singular matrix") 
    52670  
    52671 See log for complete Python traceback. 
    52672  
    52673 Traceback (most recent call last): 
    52674 File
    52675 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52676 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    52677 self.session.ui.mouse_modes.mouse_pause_tracking() 
    52678 File
    52679 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52680 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    52681 mouse_pause_tracking 
    52682 self._mouse_pause() 
    52683 File
    52684 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52685 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    52686 m.pause(self._mouse_pause_position) 
    52687 File
    52688 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52689 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    52690 p = self.view.picked_object(x, y) 
    52691 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52692 File
    52693 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52694 packages/chimerax/graphics/view.py", line 838, in picked_object 
    52695 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    52696 beyond, 
    52697 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52698 File
    52699 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52700 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    52701 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    52702 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52703 File
    52704 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52705 packages/chimerax/core/models.py", line 143, in first_intercept 
    52706 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    52707 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52708 File
    52709 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52710 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    52711 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    52712 exclude=exclude) 
    52713 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52714 File
    52715 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52716 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    52717 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    52718 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52719 File
    52720 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52721 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    52722 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    52723 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52724 File
    52725 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52726 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    52727 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    52728 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52729 File
    52730 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52731 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    52732 p = super().first_intercept(mxyz1, mxyz2) 
    52733 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52734 File
    52735 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52736 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    52737 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    52738 exclude=exclude) 
    52739 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52740 File
    52741 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52742 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    52743 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    52744 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52745 File
    52746 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52747 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    52748 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    52749 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52750 File
    52751 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52752 packages/chimerax/graphics/drawing.py", line 1108, in
    52753 _first_intercept_excluding_children 
    52754 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    52755 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52756 File
    52757 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52758 packages/chimerax/geometry/place.py", line 201, in inverse 
    52759 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    52760 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52761 File
    52762 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52763 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    52764 rinv[:, :] = matrix_inverse(r) 
    52765 ^^^^^^^^^^^^^^^^^ 
    52766 File
    52767 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52768 packages/numpy/linalg/linalg.py", line 561, in inv 
    52769 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    52770 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52771 File
    52772 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52773 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    52774 raise LinAlgError("Singular matrix") 
    52775 numpy.linalg.LinAlgError: Singular matrix 
    52776  
    52777 numpy.linalg.LinAlgError: Singular matrix 
    52778  
    52779 File
    52780 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52781 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    52782 raise LinAlgError("Singular matrix") 
    52783  
    52784 See log for complete Python traceback. 
    52785  
    52786 Traceback (most recent call last): 
    52787 File
    52788 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52789 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    52790 self.session.ui.mouse_modes.mouse_pause_tracking() 
    52791 File
    52792 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52793 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    52794 mouse_pause_tracking 
    52795 self._mouse_pause() 
    52796 File
    52797 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52798 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    52799 m.pause(self._mouse_pause_position) 
    52800 File
    52801 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52802 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    52803 p = self.view.picked_object(x, y) 
    52804 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52805 File
    52806 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52807 packages/chimerax/graphics/view.py", line 838, in picked_object 
    52808 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    52809 beyond, 
    52810 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52811 File
    52812 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52813 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    52814 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    52815 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52816 File
    52817 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52818 packages/chimerax/core/models.py", line 143, in first_intercept 
    52819 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    52820 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52821 File
    52822 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52823 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    52824 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    52825 exclude=exclude) 
    52826 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52827 File
    52828 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52829 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    52830 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    52831 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52832 File
    52833 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52834 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    52835 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    52836 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52837 File
    52838 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52839 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    52840 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    52841 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52842 File
    52843 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52844 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    52845 p = super().first_intercept(mxyz1, mxyz2) 
    52846 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52847 File
    52848 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52849 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    52850 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    52851 exclude=exclude) 
    52852 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52853 File
    52854 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52855 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    52856 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    52857 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52858 File
    52859 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52860 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    52861 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    52862 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52863 File
    52864 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52865 packages/chimerax/graphics/drawing.py", line 1108, in
    52866 _first_intercept_excluding_children 
    52867 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    52868 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52869 File
    52870 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52871 packages/chimerax/geometry/place.py", line 201, in inverse 
    52872 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    52873 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52874 File
    52875 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52876 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    52877 rinv[:, :] = matrix_inverse(r) 
    52878 ^^^^^^^^^^^^^^^^^ 
    52879 File
    52880 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52881 packages/numpy/linalg/linalg.py", line 561, in inv 
    52882 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    52883 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52884 File
    52885 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52886 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    52887 raise LinAlgError("Singular matrix") 
    52888 numpy.linalg.LinAlgError: Singular matrix 
    52889  
    52890 numpy.linalg.LinAlgError: Singular matrix 
    52891  
    52892 File
    52893 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52894 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    52895 raise LinAlgError("Singular matrix") 
    52896  
    52897 See log for complete Python traceback. 
    52898  
    52899 Traceback (most recent call last): 
    52900 File
    52901 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52902 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    52903 self.session.ui.mouse_modes.mouse_pause_tracking() 
    52904 File
    52905 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52906 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    52907 mouse_pause_tracking 
    52908 self._mouse_pause() 
    52909 File
    52910 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52911 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    52912 m.pause(self._mouse_pause_position) 
    52913 File
    52914 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52915 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    52916 p = self.view.picked_object(x, y) 
    52917 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52918 File
    52919 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52920 packages/chimerax/graphics/view.py", line 838, in picked_object 
    52921 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    52922 beyond, 
    52923 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52924 File
    52925 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52926 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    52927 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    52928 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52929 File
    52930 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52931 packages/chimerax/core/models.py", line 143, in first_intercept 
    52932 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    52933 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52934 File
    52935 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52936 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    52937 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    52938 exclude=exclude) 
    52939 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52940 File
    52941 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52942 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    52943 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    52944 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52945 File
    52946 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52947 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    52948 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    52949 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52950 File
    52951 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52952 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    52953 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    52954 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52955 File
    52956 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52957 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    52958 p = super().first_intercept(mxyz1, mxyz2) 
    52959 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52960 File
    52961 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52962 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    52963 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    52964 exclude=exclude) 
    52965 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52966 File
    52967 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52968 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    52969 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    52970 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52971 File
    52972 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52973 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    52974 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    52975 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52976 File
    52977 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52978 packages/chimerax/graphics/drawing.py", line 1108, in
    52979 _first_intercept_excluding_children 
    52980 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    52981 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52982 File
    52983 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52984 packages/chimerax/geometry/place.py", line 201, in inverse 
    52985 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    52986 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52987 File
    52988 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52989 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    52990 rinv[:, :] = matrix_inverse(r) 
    52991 ^^^^^^^^^^^^^^^^^ 
    52992 File
    52993 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52994 packages/numpy/linalg/linalg.py", line 561, in inv 
    52995 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    52996 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    52997 File
    52998 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    52999 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    53000 raise LinAlgError("Singular matrix") 
    53001 numpy.linalg.LinAlgError: Singular matrix 
    53002  
    53003 numpy.linalg.LinAlgError: Singular matrix 
    53004  
    53005 File
    53006 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53007 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    53008 raise LinAlgError("Singular matrix") 
    53009  
    53010 See log for complete Python traceback. 
    53011  
    53012 Traceback (most recent call last): 
    53013 File
    53014 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53015 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    53016 self.session.ui.mouse_modes.mouse_pause_tracking() 
    53017 File
    53018 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53019 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    53020 mouse_pause_tracking 
    53021 self._mouse_pause() 
    53022 File
    53023 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53024 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    53025 m.pause(self._mouse_pause_position) 
    53026 File
    53027 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53028 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    53029 p = self.view.picked_object(x, y) 
    53030 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53031 File
    53032 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53033 packages/chimerax/graphics/view.py", line 838, in picked_object 
    53034 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    53035 beyond, 
    53036 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53037 File
    53038 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53039 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    53040 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    53041 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53042 File
    53043 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53044 packages/chimerax/core/models.py", line 143, in first_intercept 
    53045 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    53046 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53047 File
    53048 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53049 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    53050 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    53051 exclude=exclude) 
    53052 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53053 File
    53054 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53055 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    53056 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    53057 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53058 File
    53059 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53060 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    53061 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    53062 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53063 File
    53064 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53065 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    53066 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    53067 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53068 File
    53069 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53070 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    53071 p = super().first_intercept(mxyz1, mxyz2) 
    53072 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53073 File
    53074 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53075 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    53076 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    53077 exclude=exclude) 
    53078 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53079 File
    53080 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53081 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    53082 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    53083 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53084 File
    53085 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53086 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    53087 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    53088 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53089 File
    53090 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53091 packages/chimerax/graphics/drawing.py", line 1108, in
    53092 _first_intercept_excluding_children 
    53093 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    53094 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53095 File
    53096 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53097 packages/chimerax/geometry/place.py", line 201, in inverse 
    53098 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    53099 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53100 File
    53101 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53102 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    53103 rinv[:, :] = matrix_inverse(r) 
    53104 ^^^^^^^^^^^^^^^^^ 
    53105 File
    53106 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53107 packages/numpy/linalg/linalg.py", line 561, in inv 
    53108 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    53109 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53110 File
    53111 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53112 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    53113 raise LinAlgError("Singular matrix") 
    53114 numpy.linalg.LinAlgError: Singular matrix 
    53115  
    53116 numpy.linalg.LinAlgError: Singular matrix 
    53117  
    53118 File
    53119 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53120 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    53121 raise LinAlgError("Singular matrix") 
    53122  
    53123 See log for complete Python traceback. 
    53124  
    53125 Traceback (most recent call last): 
    53126 File
    53127 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53128 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    53129 self.session.ui.mouse_modes.mouse_pause_tracking() 
    53130 File
    53131 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53132 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    53133 mouse_pause_tracking 
    53134 self._mouse_pause() 
    53135 File
    53136 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53137 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    53138 m.pause(self._mouse_pause_position) 
    53139 File
    53140 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53141 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    53142 p = self.view.picked_object(x, y) 
    53143 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53144 File
    53145 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53146 packages/chimerax/graphics/view.py", line 838, in picked_object 
    53147 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    53148 beyond, 
    53149 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53150 File
    53151 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53152 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    53153 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    53154 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53155 File
    53156 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53157 packages/chimerax/core/models.py", line 143, in first_intercept 
    53158 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    53159 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53160 File
    53161 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53162 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    53163 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    53164 exclude=exclude) 
    53165 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53166 File
    53167 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53168 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    53169 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    53170 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53171 File
    53172 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53173 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    53174 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    53175 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53176 File
    53177 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53178 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    53179 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    53180 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53181 File
    53182 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53183 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    53184 p = super().first_intercept(mxyz1, mxyz2) 
    53185 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53186 File
    53187 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53188 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    53189 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    53190 exclude=exclude) 
    53191 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53192 File
    53193 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53194 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    53195 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    53196 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53197 File
    53198 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53199 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    53200 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    53201 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53202 File
    53203 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53204 packages/chimerax/graphics/drawing.py", line 1108, in
    53205 _first_intercept_excluding_children 
    53206 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    53207 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53208 File
    53209 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53210 packages/chimerax/geometry/place.py", line 201, in inverse 
    53211 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    53212 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53213 File
    53214 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53215 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    53216 rinv[:, :] = matrix_inverse(r) 
    53217 ^^^^^^^^^^^^^^^^^ 
    53218 File
    53219 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53220 packages/numpy/linalg/linalg.py", line 561, in inv 
    53221 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    53222 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53223 File
    53224 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53225 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    53226 raise LinAlgError("Singular matrix") 
    53227 numpy.linalg.LinAlgError: Singular matrix 
    53228  
    53229 numpy.linalg.LinAlgError: Singular matrix 
    53230  
    53231 File
    53232 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53233 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    53234 raise LinAlgError("Singular matrix") 
    53235  
    53236 See log for complete Python traceback. 
    53237  
    53238 Traceback (most recent call last): 
    53239 File
    53240 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53241 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    53242 self.session.ui.mouse_modes.mouse_pause_tracking() 
    53243 File
    53244 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53245 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    53246 mouse_pause_tracking 
    53247 self._mouse_pause() 
    53248 File
    53249 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53250 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    53251 m.pause(self._mouse_pause_position) 
    53252 File
    53253 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53254 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    53255 p = self.view.picked_object(x, y) 
    53256 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53257 File
    53258 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53259 packages/chimerax/graphics/view.py", line 838, in picked_object 
    53260 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    53261 beyond, 
    53262 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53263 File
    53264 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53265 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    53266 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    53267 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53268 File
    53269 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53270 packages/chimerax/core/models.py", line 143, in first_intercept 
    53271 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    53272 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53273 File
    53274 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53275 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    53276 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    53277 exclude=exclude) 
    53278 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53279 File
    53280 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53281 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    53282 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    53283 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53284 File
    53285 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53286 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    53287 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    53288 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53289 File
    53290 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53291 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    53292 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    53293 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53294 File
    53295 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53296 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    53297 p = super().first_intercept(mxyz1, mxyz2) 
    53298 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53299 File
    53300 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53301 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    53302 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    53303 exclude=exclude) 
    53304 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53305 File
    53306 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53307 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    53308 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    53309 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53310 File
    53311 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53312 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    53313 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    53314 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53315 File
    53316 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53317 packages/chimerax/graphics/drawing.py", line 1108, in
    53318 _first_intercept_excluding_children 
    53319 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    53320 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53321 File
    53322 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53323 packages/chimerax/geometry/place.py", line 201, in inverse 
    53324 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    53325 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53326 File
    53327 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53328 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    53329 rinv[:, :] = matrix_inverse(r) 
    53330 ^^^^^^^^^^^^^^^^^ 
    53331 File
    53332 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53333 packages/numpy/linalg/linalg.py", line 561, in inv 
    53334 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    53335 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53336 File
    53337 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53338 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    53339 raise LinAlgError("Singular matrix") 
    53340 numpy.linalg.LinAlgError: Singular matrix 
    53341  
    53342 numpy.linalg.LinAlgError: Singular matrix 
    53343  
    53344 File
    53345 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53346 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    53347 raise LinAlgError("Singular matrix") 
    53348  
    53349 See log for complete Python traceback. 
    53350  
    53351 Traceback (most recent call last): 
    53352 File
    53353 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53354 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    53355 self.session.ui.mouse_modes.mouse_pause_tracking() 
    53356 File
    53357 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53358 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    53359 mouse_pause_tracking 
    53360 self._mouse_pause() 
    53361 File
    53362 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53363 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    53364 m.pause(self._mouse_pause_position) 
    53365 File
    53366 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53367 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    53368 p = self.view.picked_object(x, y) 
    53369 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53370 File
    53371 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53372 packages/chimerax/graphics/view.py", line 838, in picked_object 
    53373 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    53374 beyond, 
    53375 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53376 File
    53377 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53378 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    53379 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    53380 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53381 File
    53382 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53383 packages/chimerax/core/models.py", line 143, in first_intercept 
    53384 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    53385 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53386 File
    53387 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53388 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    53389 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    53390 exclude=exclude) 
    53391 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53392 File
    53393 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53394 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    53395 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    53396 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53397 File
    53398 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53399 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    53400 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    53401 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53402 File
    53403 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53404 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    53405 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    53406 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53407 File
    53408 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53409 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    53410 p = super().first_intercept(mxyz1, mxyz2) 
    53411 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53412 File
    53413 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53414 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    53415 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    53416 exclude=exclude) 
    53417 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53418 File
    53419 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53420 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    53421 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    53422 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53423 File
    53424 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53425 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    53426 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    53427 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53428 File
    53429 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53430 packages/chimerax/graphics/drawing.py", line 1108, in
    53431 _first_intercept_excluding_children 
    53432 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    53433 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53434 File
    53435 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53436 packages/chimerax/geometry/place.py", line 201, in inverse 
    53437 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    53438 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53439 File
    53440 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53441 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    53442 rinv[:, :] = matrix_inverse(r) 
    53443 ^^^^^^^^^^^^^^^^^ 
    53444 File
    53445 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53446 packages/numpy/linalg/linalg.py", line 561, in inv 
    53447 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    53448 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53449 File
    53450 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53451 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    53452 raise LinAlgError("Singular matrix") 
    53453 numpy.linalg.LinAlgError: Singular matrix 
    53454  
    53455 numpy.linalg.LinAlgError: Singular matrix 
    53456  
    53457 File
    53458 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53459 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    53460 raise LinAlgError("Singular matrix") 
    53461  
    53462 See log for complete Python traceback. 
    53463  
    53464 Traceback (most recent call last): 
    53465 File
    53466 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53467 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    53468 self.session.ui.mouse_modes.mouse_pause_tracking() 
    53469 File
    53470 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53471 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    53472 mouse_pause_tracking 
    53473 self._mouse_pause() 
    53474 File
    53475 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53476 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    53477 m.pause(self._mouse_pause_position) 
    53478 File
    53479 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53480 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    53481 p = self.view.picked_object(x, y) 
    53482 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53483 File
    53484 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53485 packages/chimerax/graphics/view.py", line 838, in picked_object 
    53486 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    53487 beyond, 
    53488 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53489 File
    53490 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53491 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    53492 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    53493 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53494 File
    53495 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53496 packages/chimerax/core/models.py", line 143, in first_intercept 
    53497 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    53498 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53499 File
    53500 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53501 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    53502 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    53503 exclude=exclude) 
    53504 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53505 File
    53506 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53507 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    53508 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    53509 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53510 File
    53511 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53512 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    53513 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    53514 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53515 File
    53516 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53517 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    53518 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    53519 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53520 File
    53521 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53522 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    53523 p = super().first_intercept(mxyz1, mxyz2) 
    53524 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53525 File
    53526 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53527 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    53528 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    53529 exclude=exclude) 
    53530 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53531 File
    53532 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53533 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    53534 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    53535 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53536 File
    53537 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53538 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    53539 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    53540 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53541 File
    53542 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53543 packages/chimerax/graphics/drawing.py", line 1108, in
    53544 _first_intercept_excluding_children 
    53545 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    53546 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53547 File
    53548 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53549 packages/chimerax/geometry/place.py", line 201, in inverse 
    53550 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    53551 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53552 File
    53553 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53554 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    53555 rinv[:, :] = matrix_inverse(r) 
    53556 ^^^^^^^^^^^^^^^^^ 
    53557 File
    53558 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53559 packages/numpy/linalg/linalg.py", line 561, in inv 
    53560 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    53561 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53562 File
    53563 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53564 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    53565 raise LinAlgError("Singular matrix") 
    53566 numpy.linalg.LinAlgError: Singular matrix 
    53567  
    53568 numpy.linalg.LinAlgError: Singular matrix 
    53569  
    53570 File
    53571 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53572 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    53573 raise LinAlgError("Singular matrix") 
    53574  
    53575 See log for complete Python traceback. 
    53576  
    53577 Traceback (most recent call last): 
    53578 File
    53579 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53580 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    53581 self.session.ui.mouse_modes.mouse_pause_tracking() 
    53582 File
    53583 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53584 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    53585 mouse_pause_tracking 
    53586 self._mouse_pause() 
    53587 File
    53588 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53589 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    53590 m.pause(self._mouse_pause_position) 
    53591 File
    53592 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53593 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    53594 p = self.view.picked_object(x, y) 
    53595 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53596 File
    53597 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53598 packages/chimerax/graphics/view.py", line 838, in picked_object 
    53599 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    53600 beyond, 
    53601 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53602 File
    53603 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53604 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    53605 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    53606 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53607 File
    53608 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53609 packages/chimerax/core/models.py", line 143, in first_intercept 
    53610 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    53611 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53612 File
    53613 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53614 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    53615 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    53616 exclude=exclude) 
    53617 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53618 File
    53619 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53620 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    53621 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    53622 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53623 File
    53624 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53625 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    53626 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    53627 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53628 File
    53629 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53630 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    53631 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    53632 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53633 File
    53634 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53635 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    53636 p = super().first_intercept(mxyz1, mxyz2) 
    53637 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53638 File
    53639 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53640 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    53641 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    53642 exclude=exclude) 
    53643 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53644 File
    53645 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53646 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    53647 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    53648 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53649 File
    53650 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53651 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    53652 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    53653 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53654 File
    53655 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53656 packages/chimerax/graphics/drawing.py", line 1108, in
    53657 _first_intercept_excluding_children 
    53658 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    53659 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53660 File
    53661 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53662 packages/chimerax/geometry/place.py", line 201, in inverse 
    53663 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    53664 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53665 File
    53666 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53667 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    53668 rinv[:, :] = matrix_inverse(r) 
    53669 ^^^^^^^^^^^^^^^^^ 
    53670 File
    53671 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53672 packages/numpy/linalg/linalg.py", line 561, in inv 
    53673 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    53674 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53675 File
    53676 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53677 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    53678 raise LinAlgError("Singular matrix") 
    53679 numpy.linalg.LinAlgError: Singular matrix 
    53680  
    53681 numpy.linalg.LinAlgError: Singular matrix 
    53682  
    53683 File
    53684 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53685 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    53686 raise LinAlgError("Singular matrix") 
    53687  
    53688 See log for complete Python traceback. 
    53689  
    53690 Traceback (most recent call last): 
    53691 File
    53692 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53693 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    53694 self.session.ui.mouse_modes.mouse_pause_tracking() 
    53695 File
    53696 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53697 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    53698 mouse_pause_tracking 
    53699 self._mouse_pause() 
    53700 File
    53701 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53702 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    53703 m.pause(self._mouse_pause_position) 
    53704 File
    53705 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53706 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    53707 p = self.view.picked_object(x, y) 
    53708 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53709 File
    53710 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53711 packages/chimerax/graphics/view.py", line 838, in picked_object 
    53712 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    53713 beyond, 
    53714 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53715 File
    53716 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53717 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    53718 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    53719 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53720 File
    53721 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53722 packages/chimerax/core/models.py", line 143, in first_intercept 
    53723 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    53724 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53725 File
    53726 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53727 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    53728 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    53729 exclude=exclude) 
    53730 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53731 File
    53732 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53733 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    53734 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    53735 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53736 File
    53737 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53738 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    53739 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    53740 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53741 File
    53742 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53743 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    53744 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    53745 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53746 File
    53747 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53748 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    53749 p = super().first_intercept(mxyz1, mxyz2) 
    53750 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53751 File
    53752 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53753 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    53754 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    53755 exclude=exclude) 
    53756 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53757 File
    53758 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53759 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    53760 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    53761 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53762 File
    53763 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53764 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    53765 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    53766 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53767 File
    53768 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53769 packages/chimerax/graphics/drawing.py", line 1108, in
    53770 _first_intercept_excluding_children 
    53771 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    53772 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53773 File
    53774 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53775 packages/chimerax/geometry/place.py", line 201, in inverse 
    53776 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    53777 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53778 File
    53779 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53780 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    53781 rinv[:, :] = matrix_inverse(r) 
    53782 ^^^^^^^^^^^^^^^^^ 
    53783 File
    53784 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53785 packages/numpy/linalg/linalg.py", line 561, in inv 
    53786 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    53787 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53788 File
    53789 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53790 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    53791 raise LinAlgError("Singular matrix") 
    53792 numpy.linalg.LinAlgError: Singular matrix 
    53793  
    53794 numpy.linalg.LinAlgError: Singular matrix 
    53795  
    53796 File
    53797 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53798 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    53799 raise LinAlgError("Singular matrix") 
    53800  
    53801 See log for complete Python traceback. 
    53802  
    53803 Traceback (most recent call last): 
    53804 File
    53805 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53806 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    53807 self.session.ui.mouse_modes.mouse_pause_tracking() 
    53808 File
    53809 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53810 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    53811 mouse_pause_tracking 
    53812 self._mouse_pause() 
    53813 File
    53814 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53815 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    53816 m.pause(self._mouse_pause_position) 
    53817 File
    53818 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53819 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    53820 p = self.view.picked_object(x, y) 
    53821 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53822 File
    53823 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53824 packages/chimerax/graphics/view.py", line 838, in picked_object 
    53825 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    53826 beyond, 
    53827 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53828 File
    53829 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53830 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    53831 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    53832 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53833 File
    53834 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53835 packages/chimerax/core/models.py", line 143, in first_intercept 
    53836 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    53837 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53838 File
    53839 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53840 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    53841 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    53842 exclude=exclude) 
    53843 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53844 File
    53845 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53846 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    53847 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    53848 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53849 File
    53850 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53851 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    53852 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    53853 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53854 File
    53855 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53856 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    53857 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    53858 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53859 File
    53860 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53861 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    53862 p = super().first_intercept(mxyz1, mxyz2) 
    53863 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53864 File
    53865 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53866 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    53867 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    53868 exclude=exclude) 
    53869 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53870 File
    53871 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53872 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    53873 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    53874 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53875 File
    53876 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53877 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    53878 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    53879 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53880 File
    53881 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53882 packages/chimerax/graphics/drawing.py", line 1108, in
    53883 _first_intercept_excluding_children 
    53884 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    53885 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53886 File
    53887 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53888 packages/chimerax/geometry/place.py", line 201, in inverse 
    53889 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    53890 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53891 File
    53892 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53893 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    53894 rinv[:, :] = matrix_inverse(r) 
    53895 ^^^^^^^^^^^^^^^^^ 
    53896 File
    53897 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53898 packages/numpy/linalg/linalg.py", line 561, in inv 
    53899 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    53900 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53901 File
    53902 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53903 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    53904 raise LinAlgError("Singular matrix") 
    53905 numpy.linalg.LinAlgError: Singular matrix 
    53906  
    53907 numpy.linalg.LinAlgError: Singular matrix 
    53908  
    53909 File
    53910 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53911 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    53912 raise LinAlgError("Singular matrix") 
    53913  
    53914 See log for complete Python traceback. 
    53915  
    53916 Traceback (most recent call last): 
    53917 File
    53918 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53919 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    53920 self.session.ui.mouse_modes.mouse_pause_tracking() 
    53921 File
    53922 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53923 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    53924 mouse_pause_tracking 
    53925 self._mouse_pause() 
    53926 File
    53927 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53928 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    53929 m.pause(self._mouse_pause_position) 
    53930 File
    53931 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53932 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    53933 p = self.view.picked_object(x, y) 
    53934 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53935 File
    53936 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53937 packages/chimerax/graphics/view.py", line 838, in picked_object 
    53938 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    53939 beyond, 
    53940 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53941 File
    53942 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53943 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    53944 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    53945 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53946 File
    53947 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53948 packages/chimerax/core/models.py", line 143, in first_intercept 
    53949 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    53950 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53951 File
    53952 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53953 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    53954 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    53955 exclude=exclude) 
    53956 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53957 File
    53958 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53959 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    53960 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    53961 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53962 File
    53963 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53964 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    53965 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    53966 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53967 File
    53968 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53969 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    53970 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    53971 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53972 File
    53973 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53974 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    53975 p = super().first_intercept(mxyz1, mxyz2) 
    53976 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53977 File
    53978 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53979 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    53980 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    53981 exclude=exclude) 
    53982 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53983 File
    53984 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53985 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    53986 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    53987 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53988 File
    53989 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53990 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    53991 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    53992 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53993 File
    53994 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    53995 packages/chimerax/graphics/drawing.py", line 1108, in
    53996 _first_intercept_excluding_children 
    53997 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    53998 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    53999 File
    54000 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54001 packages/chimerax/geometry/place.py", line 201, in inverse 
    54002 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    54003 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54004 File
    54005 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54006 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    54007 rinv[:, :] = matrix_inverse(r) 
    54008 ^^^^^^^^^^^^^^^^^ 
    54009 File
    54010 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54011 packages/numpy/linalg/linalg.py", line 561, in inv 
    54012 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    54013 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54014 File
    54015 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54016 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    54017 raise LinAlgError("Singular matrix") 
    54018 numpy.linalg.LinAlgError: Singular matrix 
    54019  
    54020 numpy.linalg.LinAlgError: Singular matrix 
    54021  
    54022 File
    54023 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54024 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    54025 raise LinAlgError("Singular matrix") 
    54026  
    54027 See log for complete Python traceback. 
    54028  
    54029 Traceback (most recent call last): 
    54030 File
    54031 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54032 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    54033 self.session.ui.mouse_modes.mouse_pause_tracking() 
    54034 File
    54035 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54036 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    54037 mouse_pause_tracking 
    54038 self._mouse_pause() 
    54039 File
    54040 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54041 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    54042 m.pause(self._mouse_pause_position) 
    54043 File
    54044 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54045 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    54046 p = self.view.picked_object(x, y) 
    54047 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54048 File
    54049 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54050 packages/chimerax/graphics/view.py", line 838, in picked_object 
    54051 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    54052 beyond, 
    54053 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54054 File
    54055 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54056 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    54057 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    54058 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54059 File
    54060 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54061 packages/chimerax/core/models.py", line 143, in first_intercept 
    54062 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    54063 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54064 File
    54065 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54066 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    54067 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    54068 exclude=exclude) 
    54069 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54070 File
    54071 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54072 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    54073 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    54074 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54075 File
    54076 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54077 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    54078 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    54079 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54080 File
    54081 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54082 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    54083 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    54084 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54085 File
    54086 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54087 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    54088 p = super().first_intercept(mxyz1, mxyz2) 
    54089 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54090 File
    54091 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54092 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    54093 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    54094 exclude=exclude) 
    54095 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54096 File
    54097 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54098 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    54099 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    54100 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54101 File
    54102 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54103 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    54104 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    54105 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54106 File
    54107 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54108 packages/chimerax/graphics/drawing.py", line 1108, in
    54109 _first_intercept_excluding_children 
    54110 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    54111 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54112 File
    54113 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54114 packages/chimerax/geometry/place.py", line 201, in inverse 
    54115 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    54116 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54117 File
    54118 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54119 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    54120 rinv[:, :] = matrix_inverse(r) 
    54121 ^^^^^^^^^^^^^^^^^ 
    54122 File
    54123 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54124 packages/numpy/linalg/linalg.py", line 561, in inv 
    54125 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    54126 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54127 File
    54128 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54129 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    54130 raise LinAlgError("Singular matrix") 
    54131 numpy.linalg.LinAlgError: Singular matrix 
    54132  
    54133 numpy.linalg.LinAlgError: Singular matrix 
    54134  
    54135 File
    54136 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54137 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    54138 raise LinAlgError("Singular matrix") 
    54139  
    54140 See log for complete Python traceback. 
    54141  
    54142 Traceback (most recent call last): 
    54143 File
    54144 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54145 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    54146 self.session.ui.mouse_modes.mouse_pause_tracking() 
    54147 File
    54148 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54149 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    54150 mouse_pause_tracking 
    54151 self._mouse_pause() 
    54152 File
    54153 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54154 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    54155 m.pause(self._mouse_pause_position) 
    54156 File
    54157 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54158 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    54159 p = self.view.picked_object(x, y) 
    54160 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54161 File
    54162 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54163 packages/chimerax/graphics/view.py", line 838, in picked_object 
    54164 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    54165 beyond, 
    54166 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54167 File
    54168 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54169 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    54170 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    54171 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54172 File
    54173 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54174 packages/chimerax/core/models.py", line 143, in first_intercept 
    54175 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    54176 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54177 File
    54178 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54179 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    54180 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    54181 exclude=exclude) 
    54182 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54183 File
    54184 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54185 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    54186 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    54187 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54188 File
    54189 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54190 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    54191 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    54192 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54193 File
    54194 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54195 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    54196 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    54197 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54198 File
    54199 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54200 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    54201 p = super().first_intercept(mxyz1, mxyz2) 
    54202 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54203 File
    54204 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54205 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    54206 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    54207 exclude=exclude) 
    54208 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54209 File
    54210 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54211 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    54212 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    54213 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54214 File
    54215 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54216 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    54217 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    54218 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54219 File
    54220 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54221 packages/chimerax/graphics/drawing.py", line 1108, in
    54222 _first_intercept_excluding_children 
    54223 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    54224 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54225 File
    54226 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54227 packages/chimerax/geometry/place.py", line 201, in inverse 
    54228 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    54229 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54230 File
    54231 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54232 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    54233 rinv[:, :] = matrix_inverse(r) 
    54234 ^^^^^^^^^^^^^^^^^ 
    54235 File
    54236 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54237 packages/numpy/linalg/linalg.py", line 561, in inv 
    54238 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    54239 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54240 File
    54241 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54242 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    54243 raise LinAlgError("Singular matrix") 
    54244 numpy.linalg.LinAlgError: Singular matrix 
    54245  
    54246 numpy.linalg.LinAlgError: Singular matrix 
    54247  
    54248 File
    54249 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54250 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    54251 raise LinAlgError("Singular matrix") 
    54252  
    54253 See log for complete Python traceback. 
    54254  
    54255 Traceback (most recent call last): 
    54256 File
    54257 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54258 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    54259 self.session.ui.mouse_modes.mouse_pause_tracking() 
    54260 File
    54261 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54262 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    54263 mouse_pause_tracking 
    54264 self._mouse_pause() 
    54265 File
    54266 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54267 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    54268 m.pause(self._mouse_pause_position) 
    54269 File
    54270 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54271 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    54272 p = self.view.picked_object(x, y) 
    54273 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54274 File
    54275 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54276 packages/chimerax/graphics/view.py", line 838, in picked_object 
    54277 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    54278 beyond, 
    54279 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54280 File
    54281 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54282 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    54283 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    54284 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54285 File
    54286 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54287 packages/chimerax/core/models.py", line 143, in first_intercept 
    54288 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    54289 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54290 File
    54291 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54292 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    54293 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    54294 exclude=exclude) 
    54295 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54296 File
    54297 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54298 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    54299 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    54300 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54301 File
    54302 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54303 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    54304 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    54305 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54306 File
    54307 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54308 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    54309 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    54310 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54311 File
    54312 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54313 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    54314 p = super().first_intercept(mxyz1, mxyz2) 
    54315 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54316 File
    54317 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54318 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    54319 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    54320 exclude=exclude) 
    54321 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54322 File
    54323 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54324 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    54325 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    54326 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54327 File
    54328 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54329 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    54330 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    54331 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54332 File
    54333 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54334 packages/chimerax/graphics/drawing.py", line 1108, in
    54335 _first_intercept_excluding_children 
    54336 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    54337 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54338 File
    54339 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54340 packages/chimerax/geometry/place.py", line 201, in inverse 
    54341 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    54342 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54343 File
    54344 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54345 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    54346 rinv[:, :] = matrix_inverse(r) 
    54347 ^^^^^^^^^^^^^^^^^ 
    54348 File
    54349 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54350 packages/numpy/linalg/linalg.py", line 561, in inv 
    54351 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    54352 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54353 File
    54354 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54355 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    54356 raise LinAlgError("Singular matrix") 
    54357 numpy.linalg.LinAlgError: Singular matrix 
    54358  
    54359 numpy.linalg.LinAlgError: Singular matrix 
    54360  
    54361 File
    54362 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54363 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    54364 raise LinAlgError("Singular matrix") 
    54365  
    54366 See log for complete Python traceback. 
    54367  
    54368 Traceback (most recent call last): 
    54369 File
    54370 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54371 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    54372 self.session.ui.mouse_modes.mouse_pause_tracking() 
    54373 File
    54374 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54375 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    54376 mouse_pause_tracking 
    54377 self._mouse_pause() 
    54378 File
    54379 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54380 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    54381 m.pause(self._mouse_pause_position) 
    54382 File
    54383 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54384 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    54385 p = self.view.picked_object(x, y) 
    54386 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54387 File
    54388 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54389 packages/chimerax/graphics/view.py", line 838, in picked_object 
    54390 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    54391 beyond, 
    54392 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54393 File
    54394 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54395 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    54396 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    54397 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54398 File
    54399 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54400 packages/chimerax/core/models.py", line 143, in first_intercept 
    54401 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    54402 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54403 File
    54404 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54405 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    54406 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    54407 exclude=exclude) 
    54408 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54409 File
    54410 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54411 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    54412 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    54413 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54414 File
    54415 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54416 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    54417 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    54418 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54419 File
    54420 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54421 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    54422 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    54423 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54424 File
    54425 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54426 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    54427 p = super().first_intercept(mxyz1, mxyz2) 
    54428 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54429 File
    54430 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54431 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    54432 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    54433 exclude=exclude) 
    54434 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54435 File
    54436 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54437 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    54438 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    54439 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54440 File
    54441 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54442 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    54443 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    54444 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54445 File
    54446 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54447 packages/chimerax/graphics/drawing.py", line 1108, in
    54448 _first_intercept_excluding_children 
    54449 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    54450 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54451 File
    54452 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54453 packages/chimerax/geometry/place.py", line 201, in inverse 
    54454 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    54455 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54456 File
    54457 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54458 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    54459 rinv[:, :] = matrix_inverse(r) 
    54460 ^^^^^^^^^^^^^^^^^ 
    54461 File
    54462 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54463 packages/numpy/linalg/linalg.py", line 561, in inv 
    54464 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    54465 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54466 File
    54467 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54468 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    54469 raise LinAlgError("Singular matrix") 
    54470 numpy.linalg.LinAlgError: Singular matrix 
    54471  
    54472 numpy.linalg.LinAlgError: Singular matrix 
    54473  
    54474 File
    54475 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54476 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    54477 raise LinAlgError("Singular matrix") 
    54478  
    54479 See log for complete Python traceback. 
    54480  
    54481 Traceback (most recent call last): 
    54482 File
    54483 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54484 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    54485 self.session.ui.mouse_modes.mouse_pause_tracking() 
    54486 File
    54487 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54488 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    54489 mouse_pause_tracking 
    54490 self._mouse_pause() 
    54491 File
    54492 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54493 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    54494 m.pause(self._mouse_pause_position) 
    54495 File
    54496 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54497 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    54498 p = self.view.picked_object(x, y) 
    54499 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54500 File
    54501 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54502 packages/chimerax/graphics/view.py", line 838, in picked_object 
    54503 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    54504 beyond, 
    54505 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54506 File
    54507 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54508 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    54509 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    54510 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54511 File
    54512 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54513 packages/chimerax/core/models.py", line 143, in first_intercept 
    54514 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    54515 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54516 File
    54517 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54518 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    54519 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    54520 exclude=exclude) 
    54521 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54522 File
    54523 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54524 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    54525 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    54526 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54527 File
    54528 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54529 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    54530 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    54531 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54532 File
    54533 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54534 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    54535 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    54536 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54537 File
    54538 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54539 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    54540 p = super().first_intercept(mxyz1, mxyz2) 
    54541 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54542 File
    54543 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54544 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    54545 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    54546 exclude=exclude) 
    54547 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54548 File
    54549 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54550 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    54551 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    54552 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54553 File
    54554 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54555 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    54556 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    54557 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54558 File
    54559 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54560 packages/chimerax/graphics/drawing.py", line 1108, in
    54561 _first_intercept_excluding_children 
    54562 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    54563 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54564 File
    54565 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54566 packages/chimerax/geometry/place.py", line 201, in inverse 
    54567 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    54568 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54569 File
    54570 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54571 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    54572 rinv[:, :] = matrix_inverse(r) 
    54573 ^^^^^^^^^^^^^^^^^ 
    54574 File
    54575 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54576 packages/numpy/linalg/linalg.py", line 561, in inv 
    54577 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    54578 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54579 File
    54580 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54581 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    54582 raise LinAlgError("Singular matrix") 
    54583 numpy.linalg.LinAlgError: Singular matrix 
    54584  
    54585 numpy.linalg.LinAlgError: Singular matrix 
    54586  
    54587 File
    54588 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54589 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    54590 raise LinAlgError("Singular matrix") 
    54591  
    54592 See log for complete Python traceback. 
    54593  
    54594 Traceback (most recent call last): 
    54595 File
    54596 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54597 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    54598 self.session.ui.mouse_modes.mouse_pause_tracking() 
    54599 File
    54600 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54601 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    54602 mouse_pause_tracking 
    54603 self._mouse_pause() 
    54604 File
    54605 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54606 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    54607 m.pause(self._mouse_pause_position) 
    54608 File
    54609 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54610 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    54611 p = self.view.picked_object(x, y) 
    54612 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54613 File
    54614 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54615 packages/chimerax/graphics/view.py", line 838, in picked_object 
    54616 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    54617 beyond, 
    54618 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54619 File
    54620 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54621 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    54622 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    54623 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54624 File
    54625 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54626 packages/chimerax/core/models.py", line 143, in first_intercept 
    54627 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    54628 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54629 File
    54630 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54631 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    54632 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    54633 exclude=exclude) 
    54634 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54635 File
    54636 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54637 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    54638 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    54639 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54640 File
    54641 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54642 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    54643 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    54644 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54645 File
    54646 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54647 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    54648 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    54649 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54650 File
    54651 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54652 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    54653 p = super().first_intercept(mxyz1, mxyz2) 
    54654 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54655 File
    54656 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54657 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    54658 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    54659 exclude=exclude) 
    54660 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54661 File
    54662 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54663 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    54664 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    54665 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54666 File
    54667 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54668 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    54669 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    54670 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54671 File
    54672 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54673 packages/chimerax/graphics/drawing.py", line 1108, in
    54674 _first_intercept_excluding_children 
    54675 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    54676 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54677 File
    54678 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54679 packages/chimerax/geometry/place.py", line 201, in inverse 
    54680 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    54681 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54682 File
    54683 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54684 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    54685 rinv[:, :] = matrix_inverse(r) 
    54686 ^^^^^^^^^^^^^^^^^ 
    54687 File
    54688 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54689 packages/numpy/linalg/linalg.py", line 561, in inv 
    54690 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    54691 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54692 File
    54693 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54694 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    54695 raise LinAlgError("Singular matrix") 
    54696 numpy.linalg.LinAlgError: Singular matrix 
    54697  
    54698 numpy.linalg.LinAlgError: Singular matrix 
    54699  
    54700 File
    54701 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54702 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    54703 raise LinAlgError("Singular matrix") 
    54704  
    54705 See log for complete Python traceback. 
    54706  
    54707 Traceback (most recent call last): 
    54708 File
    54709 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54710 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    54711 self.session.ui.mouse_modes.mouse_pause_tracking() 
    54712 File
    54713 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54714 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    54715 mouse_pause_tracking 
    54716 self._mouse_pause() 
    54717 File
    54718 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54719 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    54720 m.pause(self._mouse_pause_position) 
    54721 File
    54722 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54723 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    54724 p = self.view.picked_object(x, y) 
    54725 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54726 File
    54727 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54728 packages/chimerax/graphics/view.py", line 838, in picked_object 
    54729 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    54730 beyond, 
    54731 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54732 File
    54733 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54734 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    54735 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    54736 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54737 File
    54738 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54739 packages/chimerax/core/models.py", line 143, in first_intercept 
    54740 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    54741 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54742 File
    54743 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54744 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    54745 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    54746 exclude=exclude) 
    54747 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54748 File
    54749 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54750 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    54751 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    54752 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54753 File
    54754 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54755 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    54756 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    54757 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54758 File
    54759 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54760 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    54761 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    54762 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54763 File
    54764 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54765 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    54766 p = super().first_intercept(mxyz1, mxyz2) 
    54767 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54768 File
    54769 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54770 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    54771 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    54772 exclude=exclude) 
    54773 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54774 File
    54775 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54776 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    54777 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    54778 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54779 File
    54780 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54781 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    54782 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    54783 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54784 File
    54785 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54786 packages/chimerax/graphics/drawing.py", line 1108, in
    54787 _first_intercept_excluding_children 
    54788 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    54789 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54790 File
    54791 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54792 packages/chimerax/geometry/place.py", line 201, in inverse 
    54793 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    54794 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54795 File
    54796 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54797 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    54798 rinv[:, :] = matrix_inverse(r) 
    54799 ^^^^^^^^^^^^^^^^^ 
    54800 File
    54801 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54802 packages/numpy/linalg/linalg.py", line 561, in inv 
    54803 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    54804 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54805 File
    54806 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54807 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    54808 raise LinAlgError("Singular matrix") 
    54809 numpy.linalg.LinAlgError: Singular matrix 
    54810  
    54811 numpy.linalg.LinAlgError: Singular matrix 
    54812  
    54813 File
    54814 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54815 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    54816 raise LinAlgError("Singular matrix") 
    54817  
    54818 See log for complete Python traceback. 
    54819  
    54820 Traceback (most recent call last): 
    54821 File
    54822 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54823 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    54824 self.session.ui.mouse_modes.mouse_pause_tracking() 
    54825 File
    54826 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54827 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    54828 mouse_pause_tracking 
    54829 self._mouse_pause() 
    54830 File
    54831 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54832 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    54833 m.pause(self._mouse_pause_position) 
    54834 File
    54835 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54836 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    54837 p = self.view.picked_object(x, y) 
    54838 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54839 File
    54840 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54841 packages/chimerax/graphics/view.py", line 838, in picked_object 
    54842 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    54843 beyond, 
    54844 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54845 File
    54846 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54847 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    54848 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    54849 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54850 File
    54851 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54852 packages/chimerax/core/models.py", line 143, in first_intercept 
    54853 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    54854 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54855 File
    54856 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54857 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    54858 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    54859 exclude=exclude) 
    54860 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54861 File
    54862 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54863 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    54864 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    54865 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54866 File
    54867 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54868 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    54869 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    54870 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54871 File
    54872 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54873 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    54874 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    54875 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54876 File
    54877 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54878 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    54879 p = super().first_intercept(mxyz1, mxyz2) 
    54880 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54881 File
    54882 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54883 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    54884 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    54885 exclude=exclude) 
    54886 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54887 File
    54888 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54889 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    54890 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    54891 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54892 File
    54893 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54894 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    54895 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    54896 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54897 File
    54898 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54899 packages/chimerax/graphics/drawing.py", line 1108, in
    54900 _first_intercept_excluding_children 
    54901 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    54902 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54903 File
    54904 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54905 packages/chimerax/geometry/place.py", line 201, in inverse 
    54906 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    54907 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54908 File
    54909 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54910 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    54911 rinv[:, :] = matrix_inverse(r) 
    54912 ^^^^^^^^^^^^^^^^^ 
    54913 File
    54914 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54915 packages/numpy/linalg/linalg.py", line 561, in inv 
    54916 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    54917 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54918 File
    54919 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54920 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    54921 raise LinAlgError("Singular matrix") 
    54922 numpy.linalg.LinAlgError: Singular matrix 
    54923  
    54924 numpy.linalg.LinAlgError: Singular matrix 
    54925  
    54926 File
    54927 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54928 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    54929 raise LinAlgError("Singular matrix") 
    54930  
    54931 See log for complete Python traceback. 
    54932  
    54933 Traceback (most recent call last): 
    54934 File
    54935 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54936 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    54937 self.session.ui.mouse_modes.mouse_pause_tracking() 
    54938 File
    54939 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54940 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    54941 mouse_pause_tracking 
    54942 self._mouse_pause() 
    54943 File
    54944 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54945 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    54946 m.pause(self._mouse_pause_position) 
    54947 File
    54948 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54949 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    54950 p = self.view.picked_object(x, y) 
    54951 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54952 File
    54953 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54954 packages/chimerax/graphics/view.py", line 838, in picked_object 
    54955 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    54956 beyond, 
    54957 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54958 File
    54959 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54960 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    54961 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    54962 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54963 File
    54964 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54965 packages/chimerax/core/models.py", line 143, in first_intercept 
    54966 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    54967 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54968 File
    54969 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54970 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    54971 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    54972 exclude=exclude) 
    54973 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54974 File
    54975 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54976 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    54977 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    54978 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54979 File
    54980 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54981 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    54982 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    54983 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54984 File
    54985 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54986 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    54987 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    54988 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54989 File
    54990 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54991 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    54992 p = super().first_intercept(mxyz1, mxyz2) 
    54993 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    54994 File
    54995 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    54996 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    54997 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    54998 exclude=exclude) 
    54999 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55000 File
    55001 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55002 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    55003 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    55004 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55005 File
    55006 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55007 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    55008 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    55009 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55010 File
    55011 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55012 packages/chimerax/graphics/drawing.py", line 1108, in
    55013 _first_intercept_excluding_children 
    55014 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    55015 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55016 File
    55017 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55018 packages/chimerax/geometry/place.py", line 201, in inverse 
    55019 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    55020 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55021 File
    55022 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55023 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    55024 rinv[:, :] = matrix_inverse(r) 
    55025 ^^^^^^^^^^^^^^^^^ 
    55026 File
    55027 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55028 packages/numpy/linalg/linalg.py", line 561, in inv 
    55029 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    55030 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55031 File
    55032 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55033 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    55034 raise LinAlgError("Singular matrix") 
    55035 numpy.linalg.LinAlgError: Singular matrix 
    55036  
    55037 numpy.linalg.LinAlgError: Singular matrix 
    55038  
    55039 File
    55040 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55041 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    55042 raise LinAlgError("Singular matrix") 
    55043  
    55044 See log for complete Python traceback. 
    55045  
    55046 Traceback (most recent call last): 
    55047 File
    55048 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55049 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    55050 self.session.ui.mouse_modes.mouse_pause_tracking() 
    55051 File
    55052 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55053 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    55054 mouse_pause_tracking 
    55055 self._mouse_pause() 
    55056 File
    55057 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55058 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    55059 m.pause(self._mouse_pause_position) 
    55060 File
    55061 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55062 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    55063 p = self.view.picked_object(x, y) 
    55064 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55065 File
    55066 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55067 packages/chimerax/graphics/view.py", line 838, in picked_object 
    55068 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    55069 beyond, 
    55070 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55071 File
    55072 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55073 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    55074 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    55075 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55076 File
    55077 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55078 packages/chimerax/core/models.py", line 143, in first_intercept 
    55079 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    55080 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55081 File
    55082 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55083 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    55084 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    55085 exclude=exclude) 
    55086 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55087 File
    55088 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55089 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    55090 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    55091 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55092 File
    55093 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55094 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    55095 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    55096 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55097 File
    55098 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55099 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    55100 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    55101 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55102 File
    55103 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55104 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    55105 p = super().first_intercept(mxyz1, mxyz2) 
    55106 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55107 File
    55108 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55109 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    55110 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    55111 exclude=exclude) 
    55112 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55113 File
    55114 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55115 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    55116 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    55117 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55118 File
    55119 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55120 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    55121 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    55122 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55123 File
    55124 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55125 packages/chimerax/graphics/drawing.py", line 1108, in
    55126 _first_intercept_excluding_children 
    55127 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    55128 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55129 File
    55130 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55131 packages/chimerax/geometry/place.py", line 201, in inverse 
    55132 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    55133 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55134 File
    55135 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55136 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    55137 rinv[:, :] = matrix_inverse(r) 
    55138 ^^^^^^^^^^^^^^^^^ 
    55139 File
    55140 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55141 packages/numpy/linalg/linalg.py", line 561, in inv 
    55142 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    55143 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55144 File
    55145 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55146 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    55147 raise LinAlgError("Singular matrix") 
    55148 numpy.linalg.LinAlgError: Singular matrix 
    55149  
    55150 numpy.linalg.LinAlgError: Singular matrix 
    55151  
    55152 File
    55153 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55154 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    55155 raise LinAlgError("Singular matrix") 
    55156  
    55157 See log for complete Python traceback. 
    55158  
    55159 Traceback (most recent call last): 
    55160 File
    55161 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55162 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    55163 self.session.ui.mouse_modes.mouse_pause_tracking() 
    55164 File
    55165 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55166 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    55167 mouse_pause_tracking 
    55168 self._mouse_pause() 
    55169 File
    55170 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55171 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    55172 m.pause(self._mouse_pause_position) 
    55173 File
    55174 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55175 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    55176 p = self.view.picked_object(x, y) 
    55177 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55178 File
    55179 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55180 packages/chimerax/graphics/view.py", line 838, in picked_object 
    55181 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    55182 beyond, 
    55183 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55184 File
    55185 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55186 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    55187 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    55188 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55189 File
    55190 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55191 packages/chimerax/core/models.py", line 143, in first_intercept 
    55192 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    55193 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55194 File
    55195 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55196 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    55197 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    55198 exclude=exclude) 
    55199 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55200 File
    55201 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55202 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    55203 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    55204 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55205 File
    55206 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55207 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    55208 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    55209 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55210 File
    55211 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55212 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    55213 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    55214 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55215 File
    55216 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55217 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    55218 p = super().first_intercept(mxyz1, mxyz2) 
    55219 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55220 File
    55221 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55222 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    55223 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    55224 exclude=exclude) 
    55225 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55226 File
    55227 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55228 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    55229 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    55230 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55231 File
    55232 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55233 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    55234 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    55235 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55236 File
    55237 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55238 packages/chimerax/graphics/drawing.py", line 1108, in
    55239 _first_intercept_excluding_children 
    55240 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    55241 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55242 File
    55243 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55244 packages/chimerax/geometry/place.py", line 201, in inverse 
    55245 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    55246 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55247 File
    55248 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55249 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    55250 rinv[:, :] = matrix_inverse(r) 
    55251 ^^^^^^^^^^^^^^^^^ 
    55252 File
    55253 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55254 packages/numpy/linalg/linalg.py", line 561, in inv 
    55255 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    55256 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55257 File
    55258 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55259 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    55260 raise LinAlgError("Singular matrix") 
    55261 numpy.linalg.LinAlgError: Singular matrix 
    55262  
    55263 numpy.linalg.LinAlgError: Singular matrix 
    55264  
    55265 File
    55266 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55267 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    55268 raise LinAlgError("Singular matrix") 
    55269  
    55270 See log for complete Python traceback. 
    55271  
    55272 Traceback (most recent call last): 
    55273 File
    55274 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55275 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    55276 self.session.ui.mouse_modes.mouse_pause_tracking() 
    55277 File
    55278 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55279 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    55280 mouse_pause_tracking 
    55281 self._mouse_pause() 
    55282 File
    55283 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55284 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    55285 m.pause(self._mouse_pause_position) 
    55286 File
    55287 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55288 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    55289 p = self.view.picked_object(x, y) 
    55290 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55291 File
    55292 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55293 packages/chimerax/graphics/view.py", line 838, in picked_object 
    55294 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    55295 beyond, 
    55296 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55297 File
    55298 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55299 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    55300 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    55301 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55302 File
    55303 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55304 packages/chimerax/core/models.py", line 143, in first_intercept 
    55305 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    55306 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55307 File
    55308 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55309 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    55310 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    55311 exclude=exclude) 
    55312 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55313 File
    55314 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55315 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    55316 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    55317 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55318 File
    55319 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55320 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    55321 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    55322 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55323 File
    55324 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55325 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    55326 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    55327 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55328 File
    55329 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55330 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    55331 p = super().first_intercept(mxyz1, mxyz2) 
    55332 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55333 File
    55334 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55335 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    55336 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    55337 exclude=exclude) 
    55338 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55339 File
    55340 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55341 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    55342 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    55343 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55344 File
    55345 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55346 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    55347 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    55348 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55349 File
    55350 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55351 packages/chimerax/graphics/drawing.py", line 1108, in
    55352 _first_intercept_excluding_children 
    55353 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    55354 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55355 File
    55356 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55357 packages/chimerax/geometry/place.py", line 201, in inverse 
    55358 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    55359 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55360 File
    55361 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55362 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    55363 rinv[:, :] = matrix_inverse(r) 
    55364 ^^^^^^^^^^^^^^^^^ 
    55365 File
    55366 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55367 packages/numpy/linalg/linalg.py", line 561, in inv 
    55368 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    55369 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55370 File
    55371 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55372 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    55373 raise LinAlgError("Singular matrix") 
    55374 numpy.linalg.LinAlgError: Singular matrix 
    55375  
    55376 numpy.linalg.LinAlgError: Singular matrix 
    55377  
    55378 File
    55379 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55380 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    55381 raise LinAlgError("Singular matrix") 
    55382  
    55383 See log for complete Python traceback. 
    55384  
    55385 Traceback (most recent call last): 
    55386 File
    55387 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55388 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    55389 self.session.ui.mouse_modes.mouse_pause_tracking() 
    55390 File
    55391 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55392 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    55393 mouse_pause_tracking 
    55394 self._mouse_pause() 
    55395 File
    55396 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55397 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    55398 m.pause(self._mouse_pause_position) 
    55399 File
    55400 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55401 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    55402 p = self.view.picked_object(x, y) 
    55403 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55404 File
    55405 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55406 packages/chimerax/graphics/view.py", line 838, in picked_object 
    55407 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    55408 beyond, 
    55409 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55410 File
    55411 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55412 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    55413 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    55414 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55415 File
    55416 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55417 packages/chimerax/core/models.py", line 143, in first_intercept 
    55418 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    55419 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55420 File
    55421 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55422 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    55423 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    55424 exclude=exclude) 
    55425 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55426 File
    55427 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55428 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    55429 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    55430 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55431 File
    55432 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55433 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    55434 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    55435 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55436 File
    55437 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55438 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    55439 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    55440 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55441 File
    55442 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55443 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    55444 p = super().first_intercept(mxyz1, mxyz2) 
    55445 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55446 File
    55447 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55448 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    55449 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    55450 exclude=exclude) 
    55451 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55452 File
    55453 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55454 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    55455 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    55456 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55457 File
    55458 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55459 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    55460 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    55461 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55462 File
    55463 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55464 packages/chimerax/graphics/drawing.py", line 1108, in
    55465 _first_intercept_excluding_children 
    55466 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    55467 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55468 File
    55469 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55470 packages/chimerax/geometry/place.py", line 201, in inverse 
    55471 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    55472 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55473 File
    55474 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55475 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    55476 rinv[:, :] = matrix_inverse(r) 
    55477 ^^^^^^^^^^^^^^^^^ 
    55478 File
    55479 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55480 packages/numpy/linalg/linalg.py", line 561, in inv 
    55481 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    55482 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55483 File
    55484 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55485 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    55486 raise LinAlgError("Singular matrix") 
    55487 numpy.linalg.LinAlgError: Singular matrix 
    55488  
    55489 numpy.linalg.LinAlgError: Singular matrix 
    55490  
    55491 File
    55492 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55493 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    55494 raise LinAlgError("Singular matrix") 
    55495  
    55496 See log for complete Python traceback. 
    55497  
    55498 Traceback (most recent call last): 
    55499 File
    55500 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55501 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    55502 self.session.ui.mouse_modes.mouse_pause_tracking() 
    55503 File
    55504 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55505 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    55506 mouse_pause_tracking 
    55507 self._mouse_pause() 
    55508 File
    55509 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55510 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    55511 m.pause(self._mouse_pause_position) 
    55512 File
    55513 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55514 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    55515 p = self.view.picked_object(x, y) 
    55516 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55517 File
    55518 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55519 packages/chimerax/graphics/view.py", line 838, in picked_object 
    55520 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    55521 beyond, 
    55522 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55523 File
    55524 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55525 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    55526 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    55527 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55528 File
    55529 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55530 packages/chimerax/core/models.py", line 143, in first_intercept 
    55531 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    55532 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55533 File
    55534 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55535 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    55536 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    55537 exclude=exclude) 
    55538 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55539 File
    55540 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55541 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    55542 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    55543 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55544 File
    55545 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55546 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    55547 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    55548 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55549 File
    55550 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55551 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    55552 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    55553 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55554 File
    55555 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55556 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    55557 p = super().first_intercept(mxyz1, mxyz2) 
    55558 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55559 File
    55560 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55561 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    55562 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    55563 exclude=exclude) 
    55564 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55565 File
    55566 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55567 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    55568 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    55569 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55570 File
    55571 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55572 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    55573 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    55574 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55575 File
    55576 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55577 packages/chimerax/graphics/drawing.py", line 1108, in
    55578 _first_intercept_excluding_children 
    55579 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    55580 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55581 File
    55582 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55583 packages/chimerax/geometry/place.py", line 201, in inverse 
    55584 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    55585 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55586 File
    55587 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55588 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    55589 rinv[:, :] = matrix_inverse(r) 
    55590 ^^^^^^^^^^^^^^^^^ 
    55591 File
    55592 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55593 packages/numpy/linalg/linalg.py", line 561, in inv 
    55594 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    55595 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55596 File
    55597 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55598 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    55599 raise LinAlgError("Singular matrix") 
    55600 numpy.linalg.LinAlgError: Singular matrix 
    55601  
    55602 numpy.linalg.LinAlgError: Singular matrix 
    55603  
    55604 File
    55605 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55606 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    55607 raise LinAlgError("Singular matrix") 
    55608  
    55609 See log for complete Python traceback. 
    55610  
    55611 Traceback (most recent call last): 
    55612 File
    55613 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55614 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    55615 self.session.ui.mouse_modes.mouse_pause_tracking() 
    55616 File
    55617 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55618 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    55619 mouse_pause_tracking 
    55620 self._mouse_pause() 
    55621 File
    55622 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55623 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    55624 m.pause(self._mouse_pause_position) 
    55625 File
    55626 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55627 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    55628 p = self.view.picked_object(x, y) 
    55629 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55630 File
    55631 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55632 packages/chimerax/graphics/view.py", line 838, in picked_object 
    55633 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    55634 beyond, 
    55635 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55636 File
    55637 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55638 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    55639 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    55640 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55641 File
    55642 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55643 packages/chimerax/core/models.py", line 143, in first_intercept 
    55644 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    55645 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55646 File
    55647 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55648 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    55649 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    55650 exclude=exclude) 
    55651 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55652 File
    55653 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55654 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    55655 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    55656 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55657 File
    55658 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55659 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    55660 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    55661 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55662 File
    55663 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55664 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    55665 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    55666 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55667 File
    55668 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55669 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    55670 p = super().first_intercept(mxyz1, mxyz2) 
    55671 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55672 File
    55673 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55674 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    55675 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    55676 exclude=exclude) 
    55677 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55678 File
    55679 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55680 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    55681 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    55682 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55683 File
    55684 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55685 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    55686 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    55687 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55688 File
    55689 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55690 packages/chimerax/graphics/drawing.py", line 1108, in
    55691 _first_intercept_excluding_children 
    55692 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    55693 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55694 File
    55695 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55696 packages/chimerax/geometry/place.py", line 201, in inverse 
    55697 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    55698 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55699 File
    55700 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55701 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    55702 rinv[:, :] = matrix_inverse(r) 
    55703 ^^^^^^^^^^^^^^^^^ 
    55704 File
    55705 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55706 packages/numpy/linalg/linalg.py", line 561, in inv 
    55707 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    55708 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55709 File
    55710 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55711 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    55712 raise LinAlgError("Singular matrix") 
    55713 numpy.linalg.LinAlgError: Singular matrix 
    55714  
    55715 numpy.linalg.LinAlgError: Singular matrix 
    55716  
    55717 File
    55718 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55719 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    55720 raise LinAlgError("Singular matrix") 
    55721  
    55722 See log for complete Python traceback. 
    55723  
    55724 Traceback (most recent call last): 
    55725 File
    55726 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55727 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    55728 self.session.ui.mouse_modes.mouse_pause_tracking() 
    55729 File
    55730 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55731 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    55732 mouse_pause_tracking 
    55733 self._mouse_pause() 
    55734 File
    55735 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55736 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    55737 m.pause(self._mouse_pause_position) 
    55738 File
    55739 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55740 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    55741 p = self.view.picked_object(x, y) 
    55742 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55743 File
    55744 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55745 packages/chimerax/graphics/view.py", line 838, in picked_object 
    55746 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    55747 beyond, 
    55748 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55749 File
    55750 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55751 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    55752 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    55753 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55754 File
    55755 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55756 packages/chimerax/core/models.py", line 143, in first_intercept 
    55757 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    55758 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55759 File
    55760 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55761 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    55762 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    55763 exclude=exclude) 
    55764 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55765 File
    55766 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55767 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    55768 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    55769 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55770 File
    55771 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55772 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    55773 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    55774 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55775 File
    55776 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55777 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    55778 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    55779 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55780 File
    55781 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55782 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    55783 p = super().first_intercept(mxyz1, mxyz2) 
    55784 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55785 File
    55786 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55787 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    55788 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    55789 exclude=exclude) 
    55790 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55791 File
    55792 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55793 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    55794 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    55795 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55796 File
    55797 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55798 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    55799 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    55800 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55801 File
    55802 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55803 packages/chimerax/graphics/drawing.py", line 1108, in
    55804 _first_intercept_excluding_children 
    55805 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    55806 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55807 File
    55808 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55809 packages/chimerax/geometry/place.py", line 201, in inverse 
    55810 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    55811 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55812 File
    55813 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55814 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    55815 rinv[:, :] = matrix_inverse(r) 
    55816 ^^^^^^^^^^^^^^^^^ 
    55817 File
    55818 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55819 packages/numpy/linalg/linalg.py", line 561, in inv 
    55820 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    55821 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55822 File
    55823 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55824 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    55825 raise LinAlgError("Singular matrix") 
    55826 numpy.linalg.LinAlgError: Singular matrix 
    55827  
    55828 numpy.linalg.LinAlgError: Singular matrix 
    55829  
    55830 File
    55831 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55832 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    55833 raise LinAlgError("Singular matrix") 
    55834  
    55835 See log for complete Python traceback. 
    55836  
    55837 Traceback (most recent call last): 
    55838 File
    55839 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55840 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    55841 self.session.ui.mouse_modes.mouse_pause_tracking() 
    55842 File
    55843 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55844 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    55845 mouse_pause_tracking 
    55846 self._mouse_pause() 
    55847 File
    55848 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55849 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    55850 m.pause(self._mouse_pause_position) 
    55851 File
    55852 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55853 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    55854 p = self.view.picked_object(x, y) 
    55855 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55856 File
    55857 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55858 packages/chimerax/graphics/view.py", line 838, in picked_object 
    55859 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    55860 beyond, 
    55861 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55862 File
    55863 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55864 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    55865 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    55866 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55867 File
    55868 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55869 packages/chimerax/core/models.py", line 143, in first_intercept 
    55870 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    55871 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55872 File
    55873 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55874 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    55875 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    55876 exclude=exclude) 
    55877 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55878 File
    55879 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55880 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    55881 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    55882 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55883 File
    55884 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55885 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    55886 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    55887 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55888 File
    55889 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55890 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    55891 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    55892 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55893 File
    55894 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55895 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    55896 p = super().first_intercept(mxyz1, mxyz2) 
    55897 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55898 File
    55899 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55900 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    55901 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    55902 exclude=exclude) 
    55903 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55904 File
    55905 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55906 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    55907 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    55908 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55909 File
    55910 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55911 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    55912 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    55913 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55914 File
    55915 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55916 packages/chimerax/graphics/drawing.py", line 1108, in
    55917 _first_intercept_excluding_children 
    55918 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    55919 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55920 File
    55921 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55922 packages/chimerax/geometry/place.py", line 201, in inverse 
    55923 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    55924 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55925 File
    55926 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55927 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    55928 rinv[:, :] = matrix_inverse(r) 
    55929 ^^^^^^^^^^^^^^^^^ 
    55930 File
    55931 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55932 packages/numpy/linalg/linalg.py", line 561, in inv 
    55933 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    55934 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55935 File
    55936 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55937 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    55938 raise LinAlgError("Singular matrix") 
    55939 numpy.linalg.LinAlgError: Singular matrix 
    55940  
    55941 numpy.linalg.LinAlgError: Singular matrix 
    55942  
    55943 File
    55944 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55945 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    55946 raise LinAlgError("Singular matrix") 
    55947  
    55948 See log for complete Python traceback. 
    55949  
    55950 Traceback (most recent call last): 
    55951 File
    55952 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55953 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    55954 self.session.ui.mouse_modes.mouse_pause_tracking() 
    55955 File
    55956 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55957 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    55958 mouse_pause_tracking 
    55959 self._mouse_pause() 
    55960 File
    55961 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55962 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    55963 m.pause(self._mouse_pause_position) 
    55964 File
    55965 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55966 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    55967 p = self.view.picked_object(x, y) 
    55968 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55969 File
    55970 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55971 packages/chimerax/graphics/view.py", line 838, in picked_object 
    55972 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    55973 beyond, 
    55974 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55975 File
    55976 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55977 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    55978 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    55979 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55980 File
    55981 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55982 packages/chimerax/core/models.py", line 143, in first_intercept 
    55983 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    55984 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55985 File
    55986 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55987 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    55988 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    55989 exclude=exclude) 
    55990 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55991 File
    55992 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55993 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    55994 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    55995 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    55996 File
    55997 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    55998 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    55999 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    56000 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56001 File
    56002 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56003 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    56004 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    56005 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56006 File
    56007 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56008 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    56009 p = super().first_intercept(mxyz1, mxyz2) 
    56010 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56011 File
    56012 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56013 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    56014 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    56015 exclude=exclude) 
    56016 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56017 File
    56018 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56019 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    56020 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    56021 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56022 File
    56023 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56024 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    56025 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    56026 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56027 File
    56028 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56029 packages/chimerax/graphics/drawing.py", line 1108, in
    56030 _first_intercept_excluding_children 
    56031 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    56032 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56033 File
    56034 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56035 packages/chimerax/geometry/place.py", line 201, in inverse 
    56036 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    56037 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56038 File
    56039 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56040 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    56041 rinv[:, :] = matrix_inverse(r) 
    56042 ^^^^^^^^^^^^^^^^^ 
    56043 File
    56044 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56045 packages/numpy/linalg/linalg.py", line 561, in inv 
    56046 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    56047 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56048 File
    56049 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56050 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    56051 raise LinAlgError("Singular matrix") 
    56052 numpy.linalg.LinAlgError: Singular matrix 
    56053  
    56054 numpy.linalg.LinAlgError: Singular matrix 
    56055  
    56056 File
    56057 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56058 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    56059 raise LinAlgError("Singular matrix") 
    56060  
    56061 See log for complete Python traceback. 
    56062  
    56063 Traceback (most recent call last): 
    56064 File
    56065 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56066 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    56067 self.session.ui.mouse_modes.mouse_pause_tracking() 
    56068 File
    56069 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56070 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    56071 mouse_pause_tracking 
    56072 self._mouse_pause() 
    56073 File
    56074 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56075 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    56076 m.pause(self._mouse_pause_position) 
    56077 File
    56078 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56079 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    56080 p = self.view.picked_object(x, y) 
    56081 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56082 File
    56083 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56084 packages/chimerax/graphics/view.py", line 838, in picked_object 
    56085 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    56086 beyond, 
    56087 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56088 File
    56089 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56090 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    56091 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    56092 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56093 File
    56094 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56095 packages/chimerax/core/models.py", line 143, in first_intercept 
    56096 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    56097 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56098 File
    56099 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56100 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    56101 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    56102 exclude=exclude) 
    56103 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56104 File
    56105 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56106 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    56107 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    56108 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56109 File
    56110 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56111 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    56112 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    56113 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56114 File
    56115 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56116 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    56117 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    56118 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56119 File
    56120 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56121 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    56122 p = super().first_intercept(mxyz1, mxyz2) 
    56123 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56124 File
    56125 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56126 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    56127 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    56128 exclude=exclude) 
    56129 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56130 File
    56131 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56132 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    56133 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    56134 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56135 File
    56136 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56137 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    56138 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    56139 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56140 File
    56141 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56142 packages/chimerax/graphics/drawing.py", line 1108, in
    56143 _first_intercept_excluding_children 
    56144 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    56145 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56146 File
    56147 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56148 packages/chimerax/geometry/place.py", line 201, in inverse 
    56149 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    56150 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56151 File
    56152 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56153 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    56154 rinv[:, :] = matrix_inverse(r) 
    56155 ^^^^^^^^^^^^^^^^^ 
    56156 File
    56157 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56158 packages/numpy/linalg/linalg.py", line 561, in inv 
    56159 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    56160 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56161 File
    56162 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56163 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    56164 raise LinAlgError("Singular matrix") 
    56165 numpy.linalg.LinAlgError: Singular matrix 
    56166  
    56167 numpy.linalg.LinAlgError: Singular matrix 
    56168  
    56169 File
    56170 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56171 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    56172 raise LinAlgError("Singular matrix") 
    56173  
    56174 See log for complete Python traceback. 
    56175  
    56176 Traceback (most recent call last): 
    56177 File
    56178 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56179 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    56180 self.session.ui.mouse_modes.mouse_pause_tracking() 
    56181 File
    56182 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56183 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    56184 mouse_pause_tracking 
    56185 self._mouse_pause() 
    56186 File
    56187 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56188 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    56189 m.pause(self._mouse_pause_position) 
    56190 File
    56191 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56192 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    56193 p = self.view.picked_object(x, y) 
    56194 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56195 File
    56196 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56197 packages/chimerax/graphics/view.py", line 838, in picked_object 
    56198 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    56199 beyond, 
    56200 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56201 File
    56202 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56203 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    56204 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    56205 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56206 File
    56207 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56208 packages/chimerax/core/models.py", line 143, in first_intercept 
    56209 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    56210 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56211 File
    56212 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56213 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    56214 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    56215 exclude=exclude) 
    56216 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56217 File
    56218 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56219 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    56220 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    56221 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56222 File
    56223 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56224 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    56225 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    56226 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56227 File
    56228 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56229 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    56230 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    56231 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56232 File
    56233 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56234 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    56235 p = super().first_intercept(mxyz1, mxyz2) 
    56236 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56237 File
    56238 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56239 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    56240 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    56241 exclude=exclude) 
    56242 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56243 File
    56244 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56245 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    56246 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    56247 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56248 File
    56249 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56250 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    56251 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    56252 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56253 File
    56254 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56255 packages/chimerax/graphics/drawing.py", line 1108, in
    56256 _first_intercept_excluding_children 
    56257 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    56258 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56259 File
    56260 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56261 packages/chimerax/geometry/place.py", line 201, in inverse 
    56262 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    56263 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56264 File
    56265 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56266 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    56267 rinv[:, :] = matrix_inverse(r) 
    56268 ^^^^^^^^^^^^^^^^^ 
    56269 File
    56270 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56271 packages/numpy/linalg/linalg.py", line 561, in inv 
    56272 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    56273 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56274 File
    56275 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56276 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    56277 raise LinAlgError("Singular matrix") 
    56278 numpy.linalg.LinAlgError: Singular matrix 
    56279  
    56280 numpy.linalg.LinAlgError: Singular matrix 
    56281  
    56282 File
    56283 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56284 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    56285 raise LinAlgError("Singular matrix") 
    56286  
    56287 See log for complete Python traceback. 
    56288  
    56289 Traceback (most recent call last): 
    56290 File
    56291 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56292 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    56293 self.session.ui.mouse_modes.mouse_pause_tracking() 
    56294 File
    56295 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56296 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    56297 mouse_pause_tracking 
    56298 self._mouse_pause() 
    56299 File
    56300 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56301 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    56302 m.pause(self._mouse_pause_position) 
    56303 File
    56304 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56305 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    56306 p = self.view.picked_object(x, y) 
    56307 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56308 File
    56309 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56310 packages/chimerax/graphics/view.py", line 838, in picked_object 
    56311 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    56312 beyond, 
    56313 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56314 File
    56315 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56316 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    56317 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    56318 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56319 File
    56320 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56321 packages/chimerax/core/models.py", line 143, in first_intercept 
    56322 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    56323 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56324 File
    56325 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56326 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    56327 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    56328 exclude=exclude) 
    56329 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56330 File
    56331 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56332 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    56333 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    56334 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56335 File
    56336 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56337 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    56338 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    56339 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56340 File
    56341 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56342 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    56343 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    56344 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56345 File
    56346 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56347 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    56348 p = super().first_intercept(mxyz1, mxyz2) 
    56349 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56350 File
    56351 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56352 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    56353 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    56354 exclude=exclude) 
    56355 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56356 File
    56357 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56358 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    56359 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    56360 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56361 File
    56362 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56363 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    56364 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    56365 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56366 File
    56367 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56368 packages/chimerax/graphics/drawing.py", line 1108, in
    56369 _first_intercept_excluding_children 
    56370 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    56371 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56372 File
    56373 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56374 packages/chimerax/geometry/place.py", line 201, in inverse 
    56375 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    56376 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56377 File
    56378 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56379 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    56380 rinv[:, :] = matrix_inverse(r) 
    56381 ^^^^^^^^^^^^^^^^^ 
    56382 File
    56383 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56384 packages/numpy/linalg/linalg.py", line 561, in inv 
    56385 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    56386 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56387 File
    56388 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56389 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    56390 raise LinAlgError("Singular matrix") 
    56391 numpy.linalg.LinAlgError: Singular matrix 
    56392  
    56393 numpy.linalg.LinAlgError: Singular matrix 
    56394  
    56395 File
    56396 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56397 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    56398 raise LinAlgError("Singular matrix") 
    56399  
    56400 See log for complete Python traceback. 
    56401  
    56402 Traceback (most recent call last): 
    56403 File
    56404 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56405 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    56406 self.session.ui.mouse_modes.mouse_pause_tracking() 
    56407 File
    56408 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56409 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    56410 mouse_pause_tracking 
    56411 self._mouse_pause() 
    56412 File
    56413 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56414 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    56415 m.pause(self._mouse_pause_position) 
    56416 File
    56417 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56418 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    56419 p = self.view.picked_object(x, y) 
    56420 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56421 File
    56422 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56423 packages/chimerax/graphics/view.py", line 838, in picked_object 
    56424 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    56425 beyond, 
    56426 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56427 File
    56428 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56429 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    56430 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    56431 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56432 File
    56433 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56434 packages/chimerax/core/models.py", line 143, in first_intercept 
    56435 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    56436 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56437 File
    56438 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56439 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    56440 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    56441 exclude=exclude) 
    56442 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56443 File
    56444 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56445 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    56446 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    56447 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56448 File
    56449 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56450 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    56451 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    56452 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56453 File
    56454 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56455 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    56456 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    56457 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56458 File
    56459 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56460 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    56461 p = super().first_intercept(mxyz1, mxyz2) 
    56462 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56463 File
    56464 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56465 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    56466 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    56467 exclude=exclude) 
    56468 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56469 File
    56470 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56471 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    56472 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    56473 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56474 File
    56475 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56476 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    56477 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    56478 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56479 File
    56480 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56481 packages/chimerax/graphics/drawing.py", line 1108, in
    56482 _first_intercept_excluding_children 
    56483 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    56484 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56485 File
    56486 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56487 packages/chimerax/geometry/place.py", line 201, in inverse 
    56488 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    56489 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56490 File
    56491 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56492 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    56493 rinv[:, :] = matrix_inverse(r) 
    56494 ^^^^^^^^^^^^^^^^^ 
    56495 File
    56496 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56497 packages/numpy/linalg/linalg.py", line 561, in inv 
    56498 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    56499 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56500 File
    56501 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56502 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    56503 raise LinAlgError("Singular matrix") 
    56504 numpy.linalg.LinAlgError: Singular matrix 
    56505  
    56506 numpy.linalg.LinAlgError: Singular matrix 
    56507  
    56508 File
    56509 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56510 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    56511 raise LinAlgError("Singular matrix") 
    56512  
    56513 See log for complete Python traceback. 
    56514  
    56515 Traceback (most recent call last): 
    56516 File
    56517 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56518 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    56519 self.session.ui.mouse_modes.mouse_pause_tracking() 
    56520 File
    56521 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56522 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    56523 mouse_pause_tracking 
    56524 self._mouse_pause() 
    56525 File
    56526 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56527 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    56528 m.pause(self._mouse_pause_position) 
    56529 File
    56530 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56531 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    56532 p = self.view.picked_object(x, y) 
    56533 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56534 File
    56535 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56536 packages/chimerax/graphics/view.py", line 838, in picked_object 
    56537 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    56538 beyond, 
    56539 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56540 File
    56541 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56542 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    56543 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    56544 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56545 File
    56546 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56547 packages/chimerax/core/models.py", line 143, in first_intercept 
    56548 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    56549 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56550 File
    56551 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56552 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    56553 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    56554 exclude=exclude) 
    56555 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56556 File
    56557 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56558 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    56559 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    56560 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56561 File
    56562 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56563 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    56564 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    56565 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56566 File
    56567 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56568 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    56569 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    56570 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56571 File
    56572 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56573 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    56574 p = super().first_intercept(mxyz1, mxyz2) 
    56575 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56576 File
    56577 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56578 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    56579 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    56580 exclude=exclude) 
    56581 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56582 File
    56583 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56584 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    56585 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    56586 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56587 File
    56588 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56589 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    56590 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    56591 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56592 File
    56593 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56594 packages/chimerax/graphics/drawing.py", line 1108, in
    56595 _first_intercept_excluding_children 
    56596 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    56597 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56598 File
    56599 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56600 packages/chimerax/geometry/place.py", line 201, in inverse 
    56601 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    56602 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56603 File
    56604 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56605 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    56606 rinv[:, :] = matrix_inverse(r) 
    56607 ^^^^^^^^^^^^^^^^^ 
    56608 File
    56609 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56610 packages/numpy/linalg/linalg.py", line 561, in inv 
    56611 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    56612 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56613 File
    56614 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56615 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    56616 raise LinAlgError("Singular matrix") 
    56617 numpy.linalg.LinAlgError: Singular matrix 
    56618  
    56619 numpy.linalg.LinAlgError: Singular matrix 
    56620  
    56621 File
    56622 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56623 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    56624 raise LinAlgError("Singular matrix") 
    56625  
    56626 See log for complete Python traceback. 
    56627  
    56628 Traceback (most recent call last): 
    56629 File
    56630 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56631 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    56632 self.session.ui.mouse_modes.mouse_pause_tracking() 
    56633 File
    56634 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56635 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    56636 mouse_pause_tracking 
    56637 self._mouse_pause() 
    56638 File
    56639 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56640 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    56641 m.pause(self._mouse_pause_position) 
    56642 File
    56643 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56644 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    56645 p = self.view.picked_object(x, y) 
    56646 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56647 File
    56648 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56649 packages/chimerax/graphics/view.py", line 838, in picked_object 
    56650 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    56651 beyond, 
    56652 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56653 File
    56654 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56655 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    56656 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    56657 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56658 File
    56659 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56660 packages/chimerax/core/models.py", line 143, in first_intercept 
    56661 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    56662 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56663 File
    56664 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56665 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    56666 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    56667 exclude=exclude) 
    56668 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56669 File
    56670 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56671 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    56672 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    56673 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56674 File
    56675 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56676 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    56677 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    56678 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56679 File
    56680 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56681 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    56682 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    56683 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56684 File
    56685 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56686 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    56687 p = super().first_intercept(mxyz1, mxyz2) 
    56688 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56689 File
    56690 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56691 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    56692 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    56693 exclude=exclude) 
    56694 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56695 File
    56696 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56697 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    56698 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    56699 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56700 File
    56701 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56702 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    56703 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    56704 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56705 File
    56706 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56707 packages/chimerax/graphics/drawing.py", line 1108, in
    56708 _first_intercept_excluding_children 
    56709 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    56710 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56711 File
    56712 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56713 packages/chimerax/geometry/place.py", line 201, in inverse 
    56714 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    56715 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56716 File
    56717 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56718 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    56719 rinv[:, :] = matrix_inverse(r) 
    56720 ^^^^^^^^^^^^^^^^^ 
    56721 File
    56722 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56723 packages/numpy/linalg/linalg.py", line 561, in inv 
    56724 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    56725 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56726 File
    56727 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56728 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    56729 raise LinAlgError("Singular matrix") 
    56730 numpy.linalg.LinAlgError: Singular matrix 
    56731  
    56732 numpy.linalg.LinAlgError: Singular matrix 
    56733  
    56734 File
    56735 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56736 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    56737 raise LinAlgError("Singular matrix") 
    56738  
    56739 See log for complete Python traceback. 
    56740  
    56741 Traceback (most recent call last): 
    56742 File
    56743 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56744 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    56745 self.session.ui.mouse_modes.mouse_pause_tracking() 
    56746 File
    56747 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56748 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    56749 mouse_pause_tracking 
    56750 self._mouse_pause() 
    56751 File
    56752 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56753 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    56754 m.pause(self._mouse_pause_position) 
    56755 File
    56756 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56757 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    56758 p = self.view.picked_object(x, y) 
    56759 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56760 File
    56761 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56762 packages/chimerax/graphics/view.py", line 838, in picked_object 
    56763 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    56764 beyond, 
    56765 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56766 File
    56767 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56768 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    56769 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    56770 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56771 File
    56772 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56773 packages/chimerax/core/models.py", line 143, in first_intercept 
    56774 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    56775 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56776 File
    56777 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56778 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    56779 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    56780 exclude=exclude) 
    56781 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56782 File
    56783 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56784 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    56785 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    56786 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56787 File
    56788 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56789 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    56790 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    56791 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56792 File
    56793 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56794 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    56795 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    56796 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56797 File
    56798 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56799 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    56800 p = super().first_intercept(mxyz1, mxyz2) 
    56801 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56802 File
    56803 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56804 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    56805 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    56806 exclude=exclude) 
    56807 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56808 File
    56809 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56810 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    56811 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    56812 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56813 File
    56814 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56815 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    56816 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    56817 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56818 File
    56819 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56820 packages/chimerax/graphics/drawing.py", line 1108, in
    56821 _first_intercept_excluding_children 
    56822 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    56823 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56824 File
    56825 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56826 packages/chimerax/geometry/place.py", line 201, in inverse 
    56827 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    56828 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56829 File
    56830 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56831 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    56832 rinv[:, :] = matrix_inverse(r) 
    56833 ^^^^^^^^^^^^^^^^^ 
    56834 File
    56835 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56836 packages/numpy/linalg/linalg.py", line 561, in inv 
    56837 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    56838 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56839 File
    56840 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56841 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    56842 raise LinAlgError("Singular matrix") 
    56843 numpy.linalg.LinAlgError: Singular matrix 
    56844  
    56845 numpy.linalg.LinAlgError: Singular matrix 
    56846  
    56847 File
    56848 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56849 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    56850 raise LinAlgError("Singular matrix") 
    56851  
    56852 See log for complete Python traceback. 
    56853  
    56854 Traceback (most recent call last): 
    56855 File
    56856 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56857 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    56858 self.session.ui.mouse_modes.mouse_pause_tracking() 
    56859 File
    56860 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56861 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    56862 mouse_pause_tracking 
    56863 self._mouse_pause() 
    56864 File
    56865 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56866 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    56867 m.pause(self._mouse_pause_position) 
    56868 File
    56869 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56870 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    56871 p = self.view.picked_object(x, y) 
    56872 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56873 File
    56874 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56875 packages/chimerax/graphics/view.py", line 838, in picked_object 
    56876 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    56877 beyond, 
    56878 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56879 File
    56880 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56881 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    56882 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    56883 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56884 File
    56885 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56886 packages/chimerax/core/models.py", line 143, in first_intercept 
    56887 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    56888 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56889 File
    56890 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56891 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    56892 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    56893 exclude=exclude) 
    56894 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56895 File
    56896 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56897 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    56898 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    56899 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56900 File
    56901 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56902 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    56903 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    56904 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56905 File
    56906 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56907 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    56908 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    56909 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56910 File
    56911 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56912 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    56913 p = super().first_intercept(mxyz1, mxyz2) 
    56914 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56915 File
    56916 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56917 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    56918 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    56919 exclude=exclude) 
    56920 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56921 File
    56922 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56923 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    56924 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    56925 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56926 File
    56927 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56928 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    56929 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    56930 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56931 File
    56932 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56933 packages/chimerax/graphics/drawing.py", line 1108, in
    56934 _first_intercept_excluding_children 
    56935 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    56936 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56937 File
    56938 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56939 packages/chimerax/geometry/place.py", line 201, in inverse 
    56940 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    56941 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56942 File
    56943 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56944 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    56945 rinv[:, :] = matrix_inverse(r) 
    56946 ^^^^^^^^^^^^^^^^^ 
    56947 File
    56948 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56949 packages/numpy/linalg/linalg.py", line 561, in inv 
    56950 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    56951 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56952 File
    56953 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56954 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    56955 raise LinAlgError("Singular matrix") 
    56956 numpy.linalg.LinAlgError: Singular matrix 
    56957  
    56958 numpy.linalg.LinAlgError: Singular matrix 
    56959  
    56960 File
    56961 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56962 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    56963 raise LinAlgError("Singular matrix") 
    56964  
    56965 See log for complete Python traceback. 
    56966  
    56967 Traceback (most recent call last): 
    56968 File
    56969 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56970 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    56971 self.session.ui.mouse_modes.mouse_pause_tracking() 
    56972 File
    56973 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56974 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    56975 mouse_pause_tracking 
    56976 self._mouse_pause() 
    56977 File
    56978 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56979 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    56980 m.pause(self._mouse_pause_position) 
    56981 File
    56982 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56983 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    56984 p = self.view.picked_object(x, y) 
    56985 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56986 File
    56987 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56988 packages/chimerax/graphics/view.py", line 838, in picked_object 
    56989 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    56990 beyond, 
    56991 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56992 File
    56993 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56994 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    56995 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    56996 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    56997 File
    56998 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    56999 packages/chimerax/core/models.py", line 143, in first_intercept 
    57000 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    57001 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57002 File
    57003 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57004 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    57005 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    57006 exclude=exclude) 
    57007 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57008 File
    57009 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57010 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    57011 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    57012 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57013 File
    57014 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57015 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    57016 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    57017 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57018 File
    57019 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57020 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    57021 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    57022 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57023 File
    57024 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57025 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    57026 p = super().first_intercept(mxyz1, mxyz2) 
    57027 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57028 File
    57029 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57030 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    57031 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    57032 exclude=exclude) 
    57033 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57034 File
    57035 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57036 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    57037 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    57038 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57039 File
    57040 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57041 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    57042 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    57043 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57044 File
    57045 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57046 packages/chimerax/graphics/drawing.py", line 1108, in
    57047 _first_intercept_excluding_children 
    57048 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    57049 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57050 File
    57051 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57052 packages/chimerax/geometry/place.py", line 201, in inverse 
    57053 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    57054 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57055 File
    57056 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57057 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    57058 rinv[:, :] = matrix_inverse(r) 
    57059 ^^^^^^^^^^^^^^^^^ 
    57060 File
    57061 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57062 packages/numpy/linalg/linalg.py", line 561, in inv 
    57063 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    57064 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57065 File
    57066 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57067 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    57068 raise LinAlgError("Singular matrix") 
    57069 numpy.linalg.LinAlgError: Singular matrix 
    57070  
    57071 numpy.linalg.LinAlgError: Singular matrix 
    57072  
    57073 File
    57074 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57075 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    57076 raise LinAlgError("Singular matrix") 
    57077  
    57078 See log for complete Python traceback. 
    57079  
    57080 Traceback (most recent call last): 
    57081 File
    57082 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57083 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    57084 self.session.ui.mouse_modes.mouse_pause_tracking() 
    57085 File
    57086 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57087 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    57088 mouse_pause_tracking 
    57089 self._mouse_pause() 
    57090 File
    57091 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57092 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    57093 m.pause(self._mouse_pause_position) 
    57094 File
    57095 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57096 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    57097 p = self.view.picked_object(x, y) 
    57098 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57099 File
    57100 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57101 packages/chimerax/graphics/view.py", line 838, in picked_object 
    57102 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    57103 beyond, 
    57104 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57105 File
    57106 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57107 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    57108 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    57109 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57110 File
    57111 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57112 packages/chimerax/core/models.py", line 143, in first_intercept 
    57113 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    57114 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57115 File
    57116 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57117 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    57118 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    57119 exclude=exclude) 
    57120 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57121 File
    57122 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57123 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    57124 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    57125 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57126 File
    57127 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57128 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    57129 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    57130 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57131 File
    57132 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57133 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    57134 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    57135 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57136 File
    57137 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57138 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    57139 p = super().first_intercept(mxyz1, mxyz2) 
    57140 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57141 File
    57142 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57143 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    57144 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    57145 exclude=exclude) 
    57146 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57147 File
    57148 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57149 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    57150 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    57151 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57152 File
    57153 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57154 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    57155 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    57156 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57157 File
    57158 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57159 packages/chimerax/graphics/drawing.py", line 1108, in
    57160 _first_intercept_excluding_children 
    57161 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    57162 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57163 File
    57164 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57165 packages/chimerax/geometry/place.py", line 201, in inverse 
    57166 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    57167 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57168 File
    57169 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57170 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    57171 rinv[:, :] = matrix_inverse(r) 
    57172 ^^^^^^^^^^^^^^^^^ 
    57173 File
    57174 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57175 packages/numpy/linalg/linalg.py", line 561, in inv 
    57176 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    57177 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57178 File
    57179 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57180 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    57181 raise LinAlgError("Singular matrix") 
    57182 numpy.linalg.LinAlgError: Singular matrix 
    57183  
    57184 numpy.linalg.LinAlgError: Singular matrix 
    57185  
    57186 File
    57187 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57188 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    57189 raise LinAlgError("Singular matrix") 
    57190  
    57191 See log for complete Python traceback. 
    57192  
    57193 Traceback (most recent call last): 
    57194 File
    57195 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57196 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    57197 self.session.ui.mouse_modes.mouse_pause_tracking() 
    57198 File
    57199 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57200 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    57201 mouse_pause_tracking 
    57202 self._mouse_pause() 
    57203 File
    57204 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57205 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    57206 m.pause(self._mouse_pause_position) 
    57207 File
    57208 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57209 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    57210 p = self.view.picked_object(x, y) 
    57211 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57212 File
    57213 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57214 packages/chimerax/graphics/view.py", line 838, in picked_object 
    57215 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    57216 beyond, 
    57217 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57218 File
    57219 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57220 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    57221 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    57222 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57223 File
    57224 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57225 packages/chimerax/core/models.py", line 143, in first_intercept 
    57226 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    57227 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57228 File
    57229 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57230 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    57231 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    57232 exclude=exclude) 
    57233 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57234 File
    57235 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57236 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    57237 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    57238 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57239 File
    57240 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57241 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    57242 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    57243 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57244 File
    57245 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57246 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    57247 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    57248 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57249 File
    57250 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57251 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    57252 p = super().first_intercept(mxyz1, mxyz2) 
    57253 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57254 File
    57255 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57256 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    57257 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    57258 exclude=exclude) 
    57259 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57260 File
    57261 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57262 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    57263 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    57264 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57265 File
    57266 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57267 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    57268 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    57269 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57270 File
    57271 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57272 packages/chimerax/graphics/drawing.py", line 1108, in
    57273 _first_intercept_excluding_children 
    57274 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    57275 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57276 File
    57277 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57278 packages/chimerax/geometry/place.py", line 201, in inverse 
    57279 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    57280 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57281 File
    57282 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57283 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    57284 rinv[:, :] = matrix_inverse(r) 
    57285 ^^^^^^^^^^^^^^^^^ 
    57286 File
    57287 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57288 packages/numpy/linalg/linalg.py", line 561, in inv 
    57289 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    57290 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57291 File
    57292 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57293 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    57294 raise LinAlgError("Singular matrix") 
    57295 numpy.linalg.LinAlgError: Singular matrix 
    57296  
    57297 numpy.linalg.LinAlgError: Singular matrix 
    57298  
    57299 File
    57300 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57301 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    57302 raise LinAlgError("Singular matrix") 
    57303  
    57304 See log for complete Python traceback. 
    57305  
    57306 Traceback (most recent call last): 
    57307 File
    57308 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57309 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    57310 self.session.ui.mouse_modes.mouse_pause_tracking() 
    57311 File
    57312 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57313 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    57314 mouse_pause_tracking 
    57315 self._mouse_pause() 
    57316 File
    57317 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57318 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    57319 m.pause(self._mouse_pause_position) 
    57320 File
    57321 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57322 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    57323 p = self.view.picked_object(x, y) 
    57324 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57325 File
    57326 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57327 packages/chimerax/graphics/view.py", line 838, in picked_object 
    57328 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    57329 beyond, 
    57330 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57331 File
    57332 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57333 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    57334 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    57335 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57336 File
    57337 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57338 packages/chimerax/core/models.py", line 143, in first_intercept 
    57339 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    57340 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57341 File
    57342 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57343 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    57344 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    57345 exclude=exclude) 
    57346 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57347 File
    57348 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57349 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    57350 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    57351 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57352 File
    57353 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57354 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    57355 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    57356 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57357 File
    57358 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57359 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    57360 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    57361 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57362 File
    57363 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57364 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    57365 p = super().first_intercept(mxyz1, mxyz2) 
    57366 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57367 File
    57368 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57369 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    57370 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    57371 exclude=exclude) 
    57372 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57373 File
    57374 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57375 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    57376 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    57377 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57378 File
    57379 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57380 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    57381 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    57382 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57383 File
    57384 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57385 packages/chimerax/graphics/drawing.py", line 1108, in
    57386 _first_intercept_excluding_children 
    57387 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    57388 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57389 File
    57390 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57391 packages/chimerax/geometry/place.py", line 201, in inverse 
    57392 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    57393 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57394 File
    57395 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57396 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    57397 rinv[:, :] = matrix_inverse(r) 
    57398 ^^^^^^^^^^^^^^^^^ 
    57399 File
    57400 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57401 packages/numpy/linalg/linalg.py", line 561, in inv 
    57402 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    57403 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57404 File
    57405 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57406 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    57407 raise LinAlgError("Singular matrix") 
    57408 numpy.linalg.LinAlgError: Singular matrix 
    57409  
    57410 numpy.linalg.LinAlgError: Singular matrix 
    57411  
    57412 File
    57413 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57414 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    57415 raise LinAlgError("Singular matrix") 
    57416  
    57417 See log for complete Python traceback. 
    57418  
    57419 Traceback (most recent call last): 
    57420 File
    57421 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57422 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    57423 self.session.ui.mouse_modes.mouse_pause_tracking() 
    57424 File
    57425 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57426 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    57427 mouse_pause_tracking 
    57428 self._mouse_pause() 
    57429 File
    57430 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57431 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    57432 m.pause(self._mouse_pause_position) 
    57433 File
    57434 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57435 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    57436 p = self.view.picked_object(x, y) 
    57437 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57438 File
    57439 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57440 packages/chimerax/graphics/view.py", line 838, in picked_object 
    57441 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    57442 beyond, 
    57443 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57444 File
    57445 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57446 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    57447 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    57448 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57449 File
    57450 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57451 packages/chimerax/core/models.py", line 143, in first_intercept 
    57452 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    57453 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57454 File
    57455 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57456 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    57457 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    57458 exclude=exclude) 
    57459 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57460 File
    57461 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57462 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    57463 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    57464 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57465 File
    57466 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57467 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    57468 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    57469 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57470 File
    57471 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57472 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    57473 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    57474 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57475 File
    57476 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57477 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    57478 p = super().first_intercept(mxyz1, mxyz2) 
    57479 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57480 File
    57481 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57482 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    57483 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    57484 exclude=exclude) 
    57485 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57486 File
    57487 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57488 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    57489 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    57490 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57491 File
    57492 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57493 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    57494 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    57495 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57496 File
    57497 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57498 packages/chimerax/graphics/drawing.py", line 1108, in
    57499 _first_intercept_excluding_children 
    57500 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    57501 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57502 File
    57503 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57504 packages/chimerax/geometry/place.py", line 201, in inverse 
    57505 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    57506 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57507 File
    57508 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57509 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    57510 rinv[:, :] = matrix_inverse(r) 
    57511 ^^^^^^^^^^^^^^^^^ 
    57512 File
    57513 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57514 packages/numpy/linalg/linalg.py", line 561, in inv 
    57515 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    57516 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57517 File
    57518 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57519 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    57520 raise LinAlgError("Singular matrix") 
    57521 numpy.linalg.LinAlgError: Singular matrix 
    57522  
    57523 numpy.linalg.LinAlgError: Singular matrix 
    57524  
    57525 File
    57526 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57527 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    57528 raise LinAlgError("Singular matrix") 
    57529  
    57530 See log for complete Python traceback. 
    57531  
    57532 Traceback (most recent call last): 
    57533 File
    57534 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57535 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    57536 self.session.ui.mouse_modes.mouse_pause_tracking() 
    57537 File
    57538 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57539 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    57540 mouse_pause_tracking 
    57541 self._mouse_pause() 
    57542 File
    57543 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57544 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    57545 m.pause(self._mouse_pause_position) 
    57546 File
    57547 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57548 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    57549 p = self.view.picked_object(x, y) 
    57550 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57551 File
    57552 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57553 packages/chimerax/graphics/view.py", line 838, in picked_object 
    57554 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    57555 beyond, 
    57556 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57557 File
    57558 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57559 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    57560 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    57561 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57562 File
    57563 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57564 packages/chimerax/core/models.py", line 143, in first_intercept 
    57565 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    57566 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57567 File
    57568 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57569 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    57570 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    57571 exclude=exclude) 
    57572 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57573 File
    57574 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57575 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    57576 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    57577 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57578 File
    57579 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57580 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    57581 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    57582 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57583 File
    57584 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57585 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    57586 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    57587 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57588 File
    57589 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57590 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    57591 p = super().first_intercept(mxyz1, mxyz2) 
    57592 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57593 File
    57594 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57595 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    57596 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    57597 exclude=exclude) 
    57598 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57599 File
    57600 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57601 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    57602 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    57603 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57604 File
    57605 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57606 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    57607 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    57608 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57609 File
    57610 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57611 packages/chimerax/graphics/drawing.py", line 1108, in
    57612 _first_intercept_excluding_children 
    57613 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    57614 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57615 File
    57616 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57617 packages/chimerax/geometry/place.py", line 201, in inverse 
    57618 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    57619 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57620 File
    57621 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57622 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    57623 rinv[:, :] = matrix_inverse(r) 
    57624 ^^^^^^^^^^^^^^^^^ 
    57625 File
    57626 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57627 packages/numpy/linalg/linalg.py", line 561, in inv 
    57628 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    57629 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57630 File
    57631 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57632 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    57633 raise LinAlgError("Singular matrix") 
    57634 numpy.linalg.LinAlgError: Singular matrix 
    57635  
    57636 numpy.linalg.LinAlgError: Singular matrix 
    57637  
    57638 File
    57639 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57640 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    57641 raise LinAlgError("Singular matrix") 
    57642  
    57643 See log for complete Python traceback. 
    57644  
    57645 Traceback (most recent call last): 
    57646 File
    57647 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57648 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    57649 self.session.ui.mouse_modes.mouse_pause_tracking() 
    57650 File
    57651 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57652 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    57653 mouse_pause_tracking 
    57654 self._mouse_pause() 
    57655 File
    57656 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57657 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    57658 m.pause(self._mouse_pause_position) 
    57659 File
    57660 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57661 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    57662 p = self.view.picked_object(x, y) 
    57663 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57664 File
    57665 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57666 packages/chimerax/graphics/view.py", line 838, in picked_object 
    57667 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    57668 beyond, 
    57669 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57670 File
    57671 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57672 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    57673 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    57674 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57675 File
    57676 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57677 packages/chimerax/core/models.py", line 143, in first_intercept 
    57678 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    57679 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57680 File
    57681 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57682 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    57683 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    57684 exclude=exclude) 
    57685 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57686 File
    57687 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57688 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    57689 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    57690 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57691 File
    57692 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57693 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    57694 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    57695 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57696 File
    57697 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57698 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    57699 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    57700 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57701 File
    57702 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57703 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    57704 p = super().first_intercept(mxyz1, mxyz2) 
    57705 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57706 File
    57707 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57708 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    57709 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    57710 exclude=exclude) 
    57711 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57712 File
    57713 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57714 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    57715 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    57716 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57717 File
    57718 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57719 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    57720 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    57721 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57722 File
    57723 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57724 packages/chimerax/graphics/drawing.py", line 1108, in
    57725 _first_intercept_excluding_children 
    57726 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    57727 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57728 File
    57729 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57730 packages/chimerax/geometry/place.py", line 201, in inverse 
    57731 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    57732 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57733 File
    57734 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57735 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    57736 rinv[:, :] = matrix_inverse(r) 
    57737 ^^^^^^^^^^^^^^^^^ 
    57738 File
    57739 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57740 packages/numpy/linalg/linalg.py", line 561, in inv 
    57741 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    57742 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57743 File
    57744 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57745 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    57746 raise LinAlgError("Singular matrix") 
    57747 numpy.linalg.LinAlgError: Singular matrix 
    57748  
    57749 numpy.linalg.LinAlgError: Singular matrix 
    57750  
    57751 File
    57752 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57753 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    57754 raise LinAlgError("Singular matrix") 
    57755  
    57756 See log for complete Python traceback. 
    57757  
    57758 Traceback (most recent call last): 
    57759 File
    57760 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57761 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    57762 self.session.ui.mouse_modes.mouse_pause_tracking() 
    57763 File
    57764 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57765 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    57766 mouse_pause_tracking 
    57767 self._mouse_pause() 
    57768 File
    57769 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57770 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    57771 m.pause(self._mouse_pause_position) 
    57772 File
    57773 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57774 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    57775 p = self.view.picked_object(x, y) 
    57776 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57777 File
    57778 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57779 packages/chimerax/graphics/view.py", line 838, in picked_object 
    57780 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    57781 beyond, 
    57782 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57783 File
    57784 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57785 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    57786 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    57787 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57788 File
    57789 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57790 packages/chimerax/core/models.py", line 143, in first_intercept 
    57791 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    57792 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57793 File
    57794 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57795 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    57796 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    57797 exclude=exclude) 
    57798 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57799 File
    57800 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57801 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    57802 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    57803 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57804 File
    57805 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57806 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    57807 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    57808 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57809 File
    57810 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57811 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    57812 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    57813 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57814 File
    57815 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57816 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    57817 p = super().first_intercept(mxyz1, mxyz2) 
    57818 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57819 File
    57820 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57821 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    57822 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    57823 exclude=exclude) 
    57824 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57825 File
    57826 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57827 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    57828 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    57829 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57830 File
    57831 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57832 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    57833 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    57834 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57835 File
    57836 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57837 packages/chimerax/graphics/drawing.py", line 1108, in
    57838 _first_intercept_excluding_children 
    57839 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    57840 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57841 File
    57842 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57843 packages/chimerax/geometry/place.py", line 201, in inverse 
    57844 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    57845 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57846 File
    57847 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57848 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    57849 rinv[:, :] = matrix_inverse(r) 
    57850 ^^^^^^^^^^^^^^^^^ 
    57851 File
    57852 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57853 packages/numpy/linalg/linalg.py", line 561, in inv 
    57854 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    57855 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57856 File
    57857 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57858 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    57859 raise LinAlgError("Singular matrix") 
    57860 numpy.linalg.LinAlgError: Singular matrix 
    57861  
    57862 numpy.linalg.LinAlgError: Singular matrix 
    57863  
    57864 File
    57865 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57866 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    57867 raise LinAlgError("Singular matrix") 
    57868  
    57869 See log for complete Python traceback. 
    57870  
    57871 Traceback (most recent call last): 
    57872 File
    57873 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57874 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    57875 self.session.ui.mouse_modes.mouse_pause_tracking() 
    57876 File
    57877 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57878 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    57879 mouse_pause_tracking 
    57880 self._mouse_pause() 
    57881 File
    57882 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57883 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    57884 m.pause(self._mouse_pause_position) 
    57885 File
    57886 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57887 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    57888 p = self.view.picked_object(x, y) 
    57889 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57890 File
    57891 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57892 packages/chimerax/graphics/view.py", line 838, in picked_object 
    57893 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    57894 beyond, 
    57895 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57896 File
    57897 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57898 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    57899 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    57900 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57901 File
    57902 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57903 packages/chimerax/core/models.py", line 143, in first_intercept 
    57904 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    57905 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57906 File
    57907 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57908 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    57909 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    57910 exclude=exclude) 
    57911 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57912 File
    57913 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57914 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    57915 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    57916 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57917 File
    57918 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57919 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    57920 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    57921 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57922 File
    57923 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57924 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    57925 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    57926 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57927 File
    57928 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57929 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    57930 p = super().first_intercept(mxyz1, mxyz2) 
    57931 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57932 File
    57933 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57934 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    57935 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    57936 exclude=exclude) 
    57937 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57938 File
    57939 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57940 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    57941 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    57942 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57943 File
    57944 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57945 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    57946 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    57947 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57948 File
    57949 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57950 packages/chimerax/graphics/drawing.py", line 1108, in
    57951 _first_intercept_excluding_children 
    57952 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    57953 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57954 File
    57955 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57956 packages/chimerax/geometry/place.py", line 201, in inverse 
    57957 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    57958 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57959 File
    57960 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57961 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    57962 rinv[:, :] = matrix_inverse(r) 
    57963 ^^^^^^^^^^^^^^^^^ 
    57964 File
    57965 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57966 packages/numpy/linalg/linalg.py", line 561, in inv 
    57967 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    57968 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    57969 File
    57970 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57971 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    57972 raise LinAlgError("Singular matrix") 
    57973 numpy.linalg.LinAlgError: Singular matrix 
    57974  
    57975 numpy.linalg.LinAlgError: Singular matrix 
    57976  
    57977 File
    57978 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57979 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    57980 raise LinAlgError("Singular matrix") 
    57981  
    57982 See log for complete Python traceback. 
    57983  
    57984 Traceback (most recent call last): 
    57985 File
    57986 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57987 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    57988 self.session.ui.mouse_modes.mouse_pause_tracking() 
    57989 File
    57990 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57991 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    57992 mouse_pause_tracking 
    57993 self._mouse_pause() 
    57994 File
    57995 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    57996 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    57997 m.pause(self._mouse_pause_position) 
    57998 File
    57999 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58000 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    58001 p = self.view.picked_object(x, y) 
    58002 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58003 File
    58004 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58005 packages/chimerax/graphics/view.py", line 838, in picked_object 
    58006 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    58007 beyond, 
    58008 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58009 File
    58010 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58011 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    58012 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    58013 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58014 File
    58015 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58016 packages/chimerax/core/models.py", line 143, in first_intercept 
    58017 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    58018 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58019 File
    58020 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58021 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    58022 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    58023 exclude=exclude) 
    58024 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58025 File
    58026 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58027 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    58028 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    58029 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58030 File
    58031 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58032 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    58033 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    58034 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58035 File
    58036 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58037 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    58038 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    58039 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58040 File
    58041 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58042 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    58043 p = super().first_intercept(mxyz1, mxyz2) 
    58044 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58045 File
    58046 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58047 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    58048 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    58049 exclude=exclude) 
    58050 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58051 File
    58052 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58053 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    58054 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    58055 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58056 File
    58057 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58058 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    58059 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    58060 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58061 File
    58062 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58063 packages/chimerax/graphics/drawing.py", line 1108, in
    58064 _first_intercept_excluding_children 
    58065 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    58066 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58067 File
    58068 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58069 packages/chimerax/geometry/place.py", line 201, in inverse 
    58070 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    58071 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58072 File
    58073 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58074 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    58075 rinv[:, :] = matrix_inverse(r) 
    58076 ^^^^^^^^^^^^^^^^^ 
    58077 File
    58078 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58079 packages/numpy/linalg/linalg.py", line 561, in inv 
    58080 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    58081 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58082 File
    58083 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58084 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    58085 raise LinAlgError("Singular matrix") 
    58086 numpy.linalg.LinAlgError: Singular matrix 
    58087  
    58088 numpy.linalg.LinAlgError: Singular matrix 
    58089  
    58090 File
    58091 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58092 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    58093 raise LinAlgError("Singular matrix") 
    58094  
    58095 See log for complete Python traceback. 
    58096  
    58097 Traceback (most recent call last): 
    58098 File
    58099 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58100 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    58101 self.session.ui.mouse_modes.mouse_pause_tracking() 
    58102 File
    58103 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58104 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    58105 mouse_pause_tracking 
    58106 self._mouse_pause() 
    58107 File
    58108 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58109 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    58110 m.pause(self._mouse_pause_position) 
    58111 File
    58112 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58113 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    58114 p = self.view.picked_object(x, y) 
    58115 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58116 File
    58117 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58118 packages/chimerax/graphics/view.py", line 838, in picked_object 
    58119 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    58120 beyond, 
    58121 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58122 File
    58123 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58124 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    58125 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    58126 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58127 File
    58128 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58129 packages/chimerax/core/models.py", line 143, in first_intercept 
    58130 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    58131 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58132 File
    58133 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58134 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    58135 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    58136 exclude=exclude) 
    58137 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58138 File
    58139 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58140 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    58141 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    58142 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58143 File
    58144 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58145 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    58146 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    58147 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58148 File
    58149 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58150 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    58151 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    58152 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58153 File
    58154 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58155 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    58156 p = super().first_intercept(mxyz1, mxyz2) 
    58157 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58158 File
    58159 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58160 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    58161 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    58162 exclude=exclude) 
    58163 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58164 File
    58165 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58166 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    58167 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    58168 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58169 File
    58170 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58171 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    58172 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    58173 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58174 File
    58175 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58176 packages/chimerax/graphics/drawing.py", line 1108, in
    58177 _first_intercept_excluding_children 
    58178 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    58179 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58180 File
    58181 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58182 packages/chimerax/geometry/place.py", line 201, in inverse 
    58183 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    58184 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58185 File
    58186 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58187 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    58188 rinv[:, :] = matrix_inverse(r) 
    58189 ^^^^^^^^^^^^^^^^^ 
    58190 File
    58191 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58192 packages/numpy/linalg/linalg.py", line 561, in inv 
    58193 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    58194 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58195 File
    58196 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58197 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    58198 raise LinAlgError("Singular matrix") 
    58199 numpy.linalg.LinAlgError: Singular matrix 
    58200  
    58201 numpy.linalg.LinAlgError: Singular matrix 
    58202  
    58203 File
    58204 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58205 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    58206 raise LinAlgError("Singular matrix") 
    58207  
    58208 See log for complete Python traceback. 
    58209  
    58210 Traceback (most recent call last): 
    58211 File
    58212 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58213 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    58214 self.session.ui.mouse_modes.mouse_pause_tracking() 
    58215 File
    58216 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58217 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    58218 mouse_pause_tracking 
    58219 self._mouse_pause() 
    58220 File
    58221 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58222 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    58223 m.pause(self._mouse_pause_position) 
    58224 File
    58225 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58226 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    58227 p = self.view.picked_object(x, y) 
    58228 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58229 File
    58230 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58231 packages/chimerax/graphics/view.py", line 838, in picked_object 
    58232 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    58233 beyond, 
    58234 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58235 File
    58236 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58237 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    58238 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    58239 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58240 File
    58241 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58242 packages/chimerax/core/models.py", line 143, in first_intercept 
    58243 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    58244 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58245 File
    58246 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58247 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    58248 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    58249 exclude=exclude) 
    58250 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58251 File
    58252 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58253 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    58254 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    58255 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58256 File
    58257 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58258 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    58259 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    58260 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58261 File
    58262 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58263 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    58264 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    58265 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58266 File
    58267 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58268 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    58269 p = super().first_intercept(mxyz1, mxyz2) 
    58270 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58271 File
    58272 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58273 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    58274 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    58275 exclude=exclude) 
    58276 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58277 File
    58278 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58279 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    58280 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    58281 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58282 File
    58283 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58284 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    58285 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    58286 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58287 File
    58288 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58289 packages/chimerax/graphics/drawing.py", line 1108, in
    58290 _first_intercept_excluding_children 
    58291 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    58292 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58293 File
    58294 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58295 packages/chimerax/geometry/place.py", line 201, in inverse 
    58296 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    58297 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58298 File
    58299 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58300 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    58301 rinv[:, :] = matrix_inverse(r) 
    58302 ^^^^^^^^^^^^^^^^^ 
    58303 File
    58304 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58305 packages/numpy/linalg/linalg.py", line 561, in inv 
    58306 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    58307 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58308 File
    58309 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58310 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    58311 raise LinAlgError("Singular matrix") 
    58312 numpy.linalg.LinAlgError: Singular matrix 
    58313  
    58314 numpy.linalg.LinAlgError: Singular matrix 
    58315  
    58316 File
    58317 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58318 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    58319 raise LinAlgError("Singular matrix") 
    58320  
    58321 See log for complete Python traceback. 
    58322  
    58323 Traceback (most recent call last): 
    58324 File
    58325 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58326 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    58327 self.session.ui.mouse_modes.mouse_pause_tracking() 
    58328 File
    58329 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58330 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    58331 mouse_pause_tracking 
    58332 self._mouse_pause() 
    58333 File
    58334 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58335 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    58336 m.pause(self._mouse_pause_position) 
    58337 File
    58338 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58339 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    58340 p = self.view.picked_object(x, y) 
    58341 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58342 File
    58343 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58344 packages/chimerax/graphics/view.py", line 838, in picked_object 
    58345 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    58346 beyond, 
    58347 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58348 File
    58349 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58350 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    58351 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    58352 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58353 File
    58354 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58355 packages/chimerax/core/models.py", line 143, in first_intercept 
    58356 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    58357 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58358 File
    58359 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58360 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    58361 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    58362 exclude=exclude) 
    58363 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58364 File
    58365 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58366 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    58367 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    58368 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58369 File
    58370 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58371 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    58372 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    58373 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58374 File
    58375 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58376 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    58377 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    58378 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58379 File
    58380 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58381 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    58382 p = super().first_intercept(mxyz1, mxyz2) 
    58383 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58384 File
    58385 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58386 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    58387 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    58388 exclude=exclude) 
    58389 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58390 File
    58391 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58392 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    58393 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    58394 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58395 File
    58396 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58397 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    58398 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    58399 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58400 File
    58401 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58402 packages/chimerax/graphics/drawing.py", line 1108, in
    58403 _first_intercept_excluding_children 
    58404 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    58405 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58406 File
    58407 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58408 packages/chimerax/geometry/place.py", line 201, in inverse 
    58409 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    58410 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58411 File
    58412 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58413 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    58414 rinv[:, :] = matrix_inverse(r) 
    58415 ^^^^^^^^^^^^^^^^^ 
    58416 File
    58417 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58418 packages/numpy/linalg/linalg.py", line 561, in inv 
    58419 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    58420 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58421 File
    58422 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58423 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    58424 raise LinAlgError("Singular matrix") 
    58425 numpy.linalg.LinAlgError: Singular matrix 
    58426  
    58427 numpy.linalg.LinAlgError: Singular matrix 
    58428  
    58429 File
    58430 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58431 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    58432 raise LinAlgError("Singular matrix") 
    58433  
    58434 See log for complete Python traceback. 
    58435  
    58436 Traceback (most recent call last): 
    58437 File
    58438 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58439 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    58440 self.session.ui.mouse_modes.mouse_pause_tracking() 
    58441 File
    58442 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58443 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    58444 mouse_pause_tracking 
    58445 self._mouse_pause() 
    58446 File
    58447 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58448 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    58449 m.pause(self._mouse_pause_position) 
    58450 File
    58451 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58452 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    58453 p = self.view.picked_object(x, y) 
    58454 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58455 File
    58456 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58457 packages/chimerax/graphics/view.py", line 838, in picked_object 
    58458 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    58459 beyond, 
    58460 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58461 File
    58462 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58463 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    58464 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    58465 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58466 File
    58467 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58468 packages/chimerax/core/models.py", line 143, in first_intercept 
    58469 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    58470 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58471 File
    58472 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58473 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    58474 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    58475 exclude=exclude) 
    58476 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58477 File
    58478 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58479 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    58480 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    58481 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58482 File
    58483 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58484 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    58485 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    58486 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58487 File
    58488 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58489 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    58490 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    58491 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58492 File
    58493 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58494 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    58495 p = super().first_intercept(mxyz1, mxyz2) 
    58496 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58497 File
    58498 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58499 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    58500 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    58501 exclude=exclude) 
    58502 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58503 File
    58504 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58505 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    58506 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    58507 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58508 File
    58509 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58510 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    58511 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    58512 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58513 File
    58514 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58515 packages/chimerax/graphics/drawing.py", line 1108, in
    58516 _first_intercept_excluding_children 
    58517 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    58518 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58519 File
    58520 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58521 packages/chimerax/geometry/place.py", line 201, in inverse 
    58522 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    58523 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58524 File
    58525 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58526 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    58527 rinv[:, :] = matrix_inverse(r) 
    58528 ^^^^^^^^^^^^^^^^^ 
    58529 File
    58530 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58531 packages/numpy/linalg/linalg.py", line 561, in inv 
    58532 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    58533 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58534 File
    58535 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58536 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    58537 raise LinAlgError("Singular matrix") 
    58538 numpy.linalg.LinAlgError: Singular matrix 
    58539  
    58540 numpy.linalg.LinAlgError: Singular matrix 
    58541  
    58542 File
    58543 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58544 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    58545 raise LinAlgError("Singular matrix") 
    58546  
    58547 See log for complete Python traceback. 
    58548  
    58549 Traceback (most recent call last): 
    58550 File
    58551 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58552 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    58553 self.session.ui.mouse_modes.mouse_pause_tracking() 
    58554 File
    58555 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58556 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    58557 mouse_pause_tracking 
    58558 self._mouse_pause() 
    58559 File
    58560 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58561 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    58562 m.pause(self._mouse_pause_position) 
    58563 File
    58564 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58565 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    58566 p = self.view.picked_object(x, y) 
    58567 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58568 File
    58569 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58570 packages/chimerax/graphics/view.py", line 838, in picked_object 
    58571 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    58572 beyond, 
    58573 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58574 File
    58575 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58576 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    58577 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    58578 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58579 File
    58580 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58581 packages/chimerax/core/models.py", line 143, in first_intercept 
    58582 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    58583 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58584 File
    58585 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58586 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    58587 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    58588 exclude=exclude) 
    58589 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58590 File
    58591 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58592 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    58593 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    58594 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58595 File
    58596 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58597 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    58598 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    58599 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58600 File
    58601 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58602 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    58603 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    58604 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58605 File
    58606 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58607 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    58608 p = super().first_intercept(mxyz1, mxyz2) 
    58609 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58610 File
    58611 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58612 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    58613 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    58614 exclude=exclude) 
    58615 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58616 File
    58617 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58618 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    58619 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    58620 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58621 File
    58622 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58623 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    58624 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    58625 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58626 File
    58627 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58628 packages/chimerax/graphics/drawing.py", line 1108, in
    58629 _first_intercept_excluding_children 
    58630 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    58631 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58632 File
    58633 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58634 packages/chimerax/geometry/place.py", line 201, in inverse 
    58635 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    58636 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58637 File
    58638 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58639 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    58640 rinv[:, :] = matrix_inverse(r) 
    58641 ^^^^^^^^^^^^^^^^^ 
    58642 File
    58643 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58644 packages/numpy/linalg/linalg.py", line 561, in inv 
    58645 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    58646 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58647 File
    58648 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58649 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    58650 raise LinAlgError("Singular matrix") 
    58651 numpy.linalg.LinAlgError: Singular matrix 
    58652  
    58653 numpy.linalg.LinAlgError: Singular matrix 
    58654  
    58655 File
    58656 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58657 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    58658 raise LinAlgError("Singular matrix") 
    58659  
    58660 See log for complete Python traceback. 
    58661  
    58662 Traceback (most recent call last): 
    58663 File
    58664 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58665 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    58666 self.session.ui.mouse_modes.mouse_pause_tracking() 
    58667 File
    58668 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58669 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    58670 mouse_pause_tracking 
    58671 self._mouse_pause() 
    58672 File
    58673 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58674 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    58675 m.pause(self._mouse_pause_position) 
    58676 File
    58677 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58678 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    58679 p = self.view.picked_object(x, y) 
    58680 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58681 File
    58682 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58683 packages/chimerax/graphics/view.py", line 838, in picked_object 
    58684 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    58685 beyond, 
    58686 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58687 File
    58688 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58689 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    58690 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    58691 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58692 File
    58693 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58694 packages/chimerax/core/models.py", line 143, in first_intercept 
    58695 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    58696 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58697 File
    58698 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58699 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    58700 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    58701 exclude=exclude) 
    58702 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58703 File
    58704 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58705 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    58706 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    58707 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58708 File
    58709 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58710 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    58711 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    58712 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58713 File
    58714 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58715 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    58716 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    58717 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58718 File
    58719 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58720 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    58721 p = super().first_intercept(mxyz1, mxyz2) 
    58722 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58723 File
    58724 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58725 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    58726 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    58727 exclude=exclude) 
    58728 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58729 File
    58730 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58731 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    58732 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    58733 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58734 File
    58735 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58736 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    58737 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    58738 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58739 File
    58740 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58741 packages/chimerax/graphics/drawing.py", line 1108, in
    58742 _first_intercept_excluding_children 
    58743 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    58744 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58745 File
    58746 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58747 packages/chimerax/geometry/place.py", line 201, in inverse 
    58748 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    58749 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58750 File
    58751 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58752 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    58753 rinv[:, :] = matrix_inverse(r) 
    58754 ^^^^^^^^^^^^^^^^^ 
    58755 File
    58756 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58757 packages/numpy/linalg/linalg.py", line 561, in inv 
    58758 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    58759 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58760 File
    58761 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58762 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    58763 raise LinAlgError("Singular matrix") 
    58764 numpy.linalg.LinAlgError: Singular matrix 
    58765  
    58766 numpy.linalg.LinAlgError: Singular matrix 
    58767  
    58768 File
    58769 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58770 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    58771 raise LinAlgError("Singular matrix") 
    58772  
    58773 See log for complete Python traceback. 
    58774  
    58775 Traceback (most recent call last): 
    58776 File
    58777 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58778 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    58779 self.session.ui.mouse_modes.mouse_pause_tracking() 
    58780 File
    58781 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58782 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    58783 mouse_pause_tracking 
    58784 self._mouse_pause() 
    58785 File
    58786 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58787 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    58788 m.pause(self._mouse_pause_position) 
    58789 File
    58790 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58791 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    58792 p = self.view.picked_object(x, y) 
    58793 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58794 File
    58795 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58796 packages/chimerax/graphics/view.py", line 838, in picked_object 
    58797 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    58798 beyond, 
    58799 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58800 File
    58801 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58802 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    58803 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    58804 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58805 File
    58806 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58807 packages/chimerax/core/models.py", line 143, in first_intercept 
    58808 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    58809 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58810 File
    58811 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58812 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    58813 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    58814 exclude=exclude) 
    58815 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58816 File
    58817 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58818 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    58819 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    58820 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58821 File
    58822 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58823 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    58824 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    58825 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58826 File
    58827 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58828 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    58829 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    58830 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58831 File
    58832 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58833 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    58834 p = super().first_intercept(mxyz1, mxyz2) 
    58835 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58836 File
    58837 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58838 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    58839 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    58840 exclude=exclude) 
    58841 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58842 File
    58843 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58844 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    58845 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    58846 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58847 File
    58848 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58849 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    58850 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    58851 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58852 File
    58853 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58854 packages/chimerax/graphics/drawing.py", line 1108, in
    58855 _first_intercept_excluding_children 
    58856 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    58857 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58858 File
    58859 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58860 packages/chimerax/geometry/place.py", line 201, in inverse 
    58861 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    58862 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58863 File
    58864 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58865 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    58866 rinv[:, :] = matrix_inverse(r) 
    58867 ^^^^^^^^^^^^^^^^^ 
    58868 File
    58869 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58870 packages/numpy/linalg/linalg.py", line 561, in inv 
    58871 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    58872 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58873 File
    58874 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58875 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    58876 raise LinAlgError("Singular matrix") 
    58877 numpy.linalg.LinAlgError: Singular matrix 
    58878  
    58879 numpy.linalg.LinAlgError: Singular matrix 
    58880  
    58881 File
    58882 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58883 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    58884 raise LinAlgError("Singular matrix") 
    58885  
    58886 See log for complete Python traceback. 
    58887  
    58888 Traceback (most recent call last): 
    58889 File
    58890 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58891 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    58892 self.session.ui.mouse_modes.mouse_pause_tracking() 
    58893 File
    58894 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58895 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    58896 mouse_pause_tracking 
    58897 self._mouse_pause() 
    58898 File
    58899 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58900 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    58901 m.pause(self._mouse_pause_position) 
    58902 File
    58903 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58904 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    58905 p = self.view.picked_object(x, y) 
    58906 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58907 File
    58908 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58909 packages/chimerax/graphics/view.py", line 838, in picked_object 
    58910 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    58911 beyond, 
    58912 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58913 File
    58914 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58915 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    58916 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    58917 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58918 File
    58919 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58920 packages/chimerax/core/models.py", line 143, in first_intercept 
    58921 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    58922 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58923 File
    58924 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58925 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    58926 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    58927 exclude=exclude) 
    58928 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58929 File
    58930 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58931 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    58932 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    58933 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58934 File
    58935 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58936 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    58937 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    58938 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58939 File
    58940 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58941 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    58942 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    58943 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58944 File
    58945 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58946 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    58947 p = super().first_intercept(mxyz1, mxyz2) 
    58948 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58949 File
    58950 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58951 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    58952 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    58953 exclude=exclude) 
    58954 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58955 File
    58956 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58957 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    58958 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    58959 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58960 File
    58961 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58962 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    58963 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    58964 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58965 File
    58966 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58967 packages/chimerax/graphics/drawing.py", line 1108, in
    58968 _first_intercept_excluding_children 
    58969 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    58970 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58971 File
    58972 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58973 packages/chimerax/geometry/place.py", line 201, in inverse 
    58974 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    58975 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58976 File
    58977 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58978 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    58979 rinv[:, :] = matrix_inverse(r) 
    58980 ^^^^^^^^^^^^^^^^^ 
    58981 File
    58982 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58983 packages/numpy/linalg/linalg.py", line 561, in inv 
    58984 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    58985 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    58986 File
    58987 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58988 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    58989 raise LinAlgError("Singular matrix") 
    58990 numpy.linalg.LinAlgError: Singular matrix 
    58991  
    58992 numpy.linalg.LinAlgError: Singular matrix 
    58993  
    58994 File
    58995 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    58996 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    58997 raise LinAlgError("Singular matrix") 
    58998  
    58999 See log for complete Python traceback. 
    59000  
    59001 Traceback (most recent call last): 
    59002 File
    59003 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59004 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    59005 self.session.ui.mouse_modes.mouse_pause_tracking() 
    59006 File
    59007 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59008 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    59009 mouse_pause_tracking 
    59010 self._mouse_pause() 
    59011 File
    59012 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59013 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    59014 m.pause(self._mouse_pause_position) 
    59015 File
    59016 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59017 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    59018 p = self.view.picked_object(x, y) 
    59019 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59020 File
    59021 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59022 packages/chimerax/graphics/view.py", line 838, in picked_object 
    59023 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    59024 beyond, 
    59025 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59026 File
    59027 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59028 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    59029 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    59030 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59031 File
    59032 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59033 packages/chimerax/core/models.py", line 143, in first_intercept 
    59034 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    59035 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59036 File
    59037 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59038 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    59039 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    59040 exclude=exclude) 
    59041 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59042 File
    59043 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59044 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    59045 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    59046 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59047 File
    59048 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59049 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    59050 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    59051 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59052 File
    59053 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59054 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    59055 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    59056 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59057 File
    59058 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59059 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    59060 p = super().first_intercept(mxyz1, mxyz2) 
    59061 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59062 File
    59063 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59064 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    59065 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    59066 exclude=exclude) 
    59067 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59068 File
    59069 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59070 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    59071 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    59072 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59073 File
    59074 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59075 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    59076 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    59077 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59078 File
    59079 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59080 packages/chimerax/graphics/drawing.py", line 1108, in
    59081 _first_intercept_excluding_children 
    59082 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    59083 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59084 File
    59085 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59086 packages/chimerax/geometry/place.py", line 201, in inverse 
    59087 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    59088 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59089 File
    59090 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59091 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    59092 rinv[:, :] = matrix_inverse(r) 
    59093 ^^^^^^^^^^^^^^^^^ 
    59094 File
    59095 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59096 packages/numpy/linalg/linalg.py", line 561, in inv 
    59097 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    59098 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59099 File
    59100 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59101 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    59102 raise LinAlgError("Singular matrix") 
    59103 numpy.linalg.LinAlgError: Singular matrix 
    59104  
    59105 numpy.linalg.LinAlgError: Singular matrix 
    59106  
    59107 File
    59108 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59109 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    59110 raise LinAlgError("Singular matrix") 
    59111  
    59112 See log for complete Python traceback. 
    59113  
    59114 Traceback (most recent call last): 
    59115 File
    59116 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59117 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    59118 self.session.ui.mouse_modes.mouse_pause_tracking() 
    59119 File
    59120 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59121 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    59122 mouse_pause_tracking 
    59123 self._mouse_pause() 
    59124 File
    59125 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59126 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    59127 m.pause(self._mouse_pause_position) 
    59128 File
    59129 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59130 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    59131 p = self.view.picked_object(x, y) 
    59132 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59133 File
    59134 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59135 packages/chimerax/graphics/view.py", line 838, in picked_object 
    59136 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    59137 beyond, 
    59138 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59139 File
    59140 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59141 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    59142 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    59143 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59144 File
    59145 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59146 packages/chimerax/core/models.py", line 143, in first_intercept 
    59147 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    59148 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59149 File
    59150 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59151 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    59152 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    59153 exclude=exclude) 
    59154 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59155 File
    59156 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59157 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    59158 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    59159 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59160 File
    59161 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59162 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    59163 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    59164 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59165 File
    59166 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59167 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    59168 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    59169 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59170 File
    59171 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59172 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    59173 p = super().first_intercept(mxyz1, mxyz2) 
    59174 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59175 File
    59176 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59177 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    59178 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    59179 exclude=exclude) 
    59180 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59181 File
    59182 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59183 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    59184 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    59185 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59186 File
    59187 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59188 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    59189 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    59190 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59191 File
    59192 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59193 packages/chimerax/graphics/drawing.py", line 1108, in
    59194 _first_intercept_excluding_children 
    59195 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    59196 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59197 File
    59198 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59199 packages/chimerax/geometry/place.py", line 201, in inverse 
    59200 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    59201 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59202 File
    59203 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59204 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    59205 rinv[:, :] = matrix_inverse(r) 
    59206 ^^^^^^^^^^^^^^^^^ 
    59207 File
    59208 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59209 packages/numpy/linalg/linalg.py", line 561, in inv 
    59210 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    59211 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59212 File
    59213 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59214 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    59215 raise LinAlgError("Singular matrix") 
    59216 numpy.linalg.LinAlgError: Singular matrix 
    59217  
    59218 numpy.linalg.LinAlgError: Singular matrix 
    59219  
    59220 File
    59221 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59222 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    59223 raise LinAlgError("Singular matrix") 
    59224  
    59225 See log for complete Python traceback. 
    59226  
    59227 Traceback (most recent call last): 
    59228 File
    59229 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59230 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    59231 self.session.ui.mouse_modes.mouse_pause_tracking() 
    59232 File
    59233 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59234 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    59235 mouse_pause_tracking 
    59236 self._mouse_pause() 
    59237 File
    59238 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59239 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    59240 m.pause(self._mouse_pause_position) 
    59241 File
    59242 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59243 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    59244 p = self.view.picked_object(x, y) 
    59245 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59246 File
    59247 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59248 packages/chimerax/graphics/view.py", line 838, in picked_object 
    59249 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    59250 beyond, 
    59251 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59252 File
    59253 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59254 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    59255 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    59256 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59257 File
    59258 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59259 packages/chimerax/core/models.py", line 143, in first_intercept 
    59260 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    59261 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59262 File
    59263 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59264 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    59265 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    59266 exclude=exclude) 
    59267 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59268 File
    59269 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59270 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    59271 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    59272 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59273 File
    59274 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59275 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    59276 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    59277 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59278 File
    59279 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59280 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    59281 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    59282 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59283 File
    59284 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59285 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    59286 p = super().first_intercept(mxyz1, mxyz2) 
    59287 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59288 File
    59289 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59290 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    59291 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    59292 exclude=exclude) 
    59293 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59294 File
    59295 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59296 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    59297 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    59298 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59299 File
    59300 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59301 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    59302 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    59303 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59304 File
    59305 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59306 packages/chimerax/graphics/drawing.py", line 1108, in
    59307 _first_intercept_excluding_children 
    59308 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    59309 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59310 File
    59311 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59312 packages/chimerax/geometry/place.py", line 201, in inverse 
    59313 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    59314 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59315 File
    59316 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59317 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    59318 rinv[:, :] = matrix_inverse(r) 
    59319 ^^^^^^^^^^^^^^^^^ 
    59320 File
    59321 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59322 packages/numpy/linalg/linalg.py", line 561, in inv 
    59323 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    59324 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59325 File
    59326 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59327 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    59328 raise LinAlgError("Singular matrix") 
    59329 numpy.linalg.LinAlgError: Singular matrix 
    59330  
    59331 numpy.linalg.LinAlgError: Singular matrix 
    59332  
    59333 File
    59334 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59335 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    59336 raise LinAlgError("Singular matrix") 
    59337  
    59338 See log for complete Python traceback. 
    59339  
    59340 Traceback (most recent call last): 
    59341 File
    59342 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59343 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    59344 self.session.ui.mouse_modes.mouse_pause_tracking() 
    59345 File
    59346 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59347 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    59348 mouse_pause_tracking 
    59349 self._mouse_pause() 
    59350 File
    59351 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59352 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    59353 m.pause(self._mouse_pause_position) 
    59354 File
    59355 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59356 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    59357 p = self.view.picked_object(x, y) 
    59358 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59359 File
    59360 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59361 packages/chimerax/graphics/view.py", line 838, in picked_object 
    59362 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    59363 beyond, 
    59364 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59365 File
    59366 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59367 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    59368 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    59369 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59370 File
    59371 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59372 packages/chimerax/core/models.py", line 143, in first_intercept 
    59373 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    59374 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59375 File
    59376 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59377 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    59378 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    59379 exclude=exclude) 
    59380 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59381 File
    59382 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59383 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    59384 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    59385 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59386 File
    59387 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59388 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    59389 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    59390 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59391 File
    59392 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59393 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    59394 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    59395 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59396 File
    59397 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59398 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    59399 p = super().first_intercept(mxyz1, mxyz2) 
    59400 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59401 File
    59402 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59403 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    59404 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    59405 exclude=exclude) 
    59406 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59407 File
    59408 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59409 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    59410 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    59411 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59412 File
    59413 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59414 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    59415 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    59416 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59417 File
    59418 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59419 packages/chimerax/graphics/drawing.py", line 1108, in
    59420 _first_intercept_excluding_children 
    59421 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    59422 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59423 File
    59424 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59425 packages/chimerax/geometry/place.py", line 201, in inverse 
    59426 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    59427 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59428 File
    59429 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59430 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    59431 rinv[:, :] = matrix_inverse(r) 
    59432 ^^^^^^^^^^^^^^^^^ 
    59433 File
    59434 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59435 packages/numpy/linalg/linalg.py", line 561, in inv 
    59436 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    59437 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59438 File
    59439 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59440 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    59441 raise LinAlgError("Singular matrix") 
    59442 numpy.linalg.LinAlgError: Singular matrix 
    59443  
    59444 numpy.linalg.LinAlgError: Singular matrix 
    59445  
    59446 File
    59447 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59448 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    59449 raise LinAlgError("Singular matrix") 
    59450  
    59451 See log for complete Python traceback. 
    59452  
    59453 Traceback (most recent call last): 
    59454 File
    59455 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59456 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    59457 self.session.ui.mouse_modes.mouse_pause_tracking() 
    59458 File
    59459 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59460 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    59461 mouse_pause_tracking 
    59462 self._mouse_pause() 
    59463 File
    59464 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59465 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    59466 m.pause(self._mouse_pause_position) 
    59467 File
    59468 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59469 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    59470 p = self.view.picked_object(x, y) 
    59471 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59472 File
    59473 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59474 packages/chimerax/graphics/view.py", line 838, in picked_object 
    59475 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    59476 beyond, 
    59477 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59478 File
    59479 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59480 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    59481 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    59482 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59483 File
    59484 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59485 packages/chimerax/core/models.py", line 143, in first_intercept 
    59486 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    59487 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59488 File
    59489 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59490 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    59491 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    59492 exclude=exclude) 
    59493 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59494 File
    59495 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59496 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    59497 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    59498 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59499 File
    59500 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59501 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    59502 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    59503 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59504 File
    59505 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59506 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    59507 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    59508 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59509 File
    59510 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59511 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    59512 p = super().first_intercept(mxyz1, mxyz2) 
    59513 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59514 File
    59515 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59516 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    59517 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    59518 exclude=exclude) 
    59519 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59520 File
    59521 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59522 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    59523 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    59524 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59525 File
    59526 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59527 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    59528 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    59529 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59530 File
    59531 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59532 packages/chimerax/graphics/drawing.py", line 1108, in
    59533 _first_intercept_excluding_children 
    59534 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    59535 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59536 File
    59537 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59538 packages/chimerax/geometry/place.py", line 201, in inverse 
    59539 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    59540 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59541 File
    59542 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59543 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    59544 rinv[:, :] = matrix_inverse(r) 
    59545 ^^^^^^^^^^^^^^^^^ 
    59546 File
    59547 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59548 packages/numpy/linalg/linalg.py", line 561, in inv 
    59549 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    59550 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59551 File
    59552 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59553 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    59554 raise LinAlgError("Singular matrix") 
    59555 numpy.linalg.LinAlgError: Singular matrix 
    59556  
    59557 numpy.linalg.LinAlgError: Singular matrix 
    59558  
    59559 File
    59560 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59561 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    59562 raise LinAlgError("Singular matrix") 
    59563  
    59564 See log for complete Python traceback. 
    59565  
    59566 Traceback (most recent call last): 
    59567 File
    59568 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59569 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    59570 self.session.ui.mouse_modes.mouse_pause_tracking() 
    59571 File
    59572 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59573 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    59574 mouse_pause_tracking 
    59575 self._mouse_pause() 
    59576 File
    59577 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59578 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    59579 m.pause(self._mouse_pause_position) 
    59580 File
    59581 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59582 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    59583 p = self.view.picked_object(x, y) 
    59584 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59585 File
    59586 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59587 packages/chimerax/graphics/view.py", line 838, in picked_object 
    59588 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    59589 beyond, 
    59590 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59591 File
    59592 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59593 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    59594 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    59595 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59596 File
    59597 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59598 packages/chimerax/core/models.py", line 143, in first_intercept 
    59599 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    59600 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59601 File
    59602 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59603 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    59604 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    59605 exclude=exclude) 
    59606 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59607 File
    59608 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59609 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    59610 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    59611 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59612 File
    59613 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59614 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    59615 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    59616 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59617 File
    59618 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59619 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    59620 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    59621 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59622 File
    59623 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59624 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    59625 p = super().first_intercept(mxyz1, mxyz2) 
    59626 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59627 File
    59628 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59629 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    59630 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    59631 exclude=exclude) 
    59632 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59633 File
    59634 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59635 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    59636 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    59637 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59638 File
    59639 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59640 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    59641 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    59642 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59643 File
    59644 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59645 packages/chimerax/graphics/drawing.py", line 1108, in
    59646 _first_intercept_excluding_children 
    59647 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    59648 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59649 File
    59650 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59651 packages/chimerax/geometry/place.py", line 201, in inverse 
    59652 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    59653 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59654 File
    59655 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59656 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    59657 rinv[:, :] = matrix_inverse(r) 
    59658 ^^^^^^^^^^^^^^^^^ 
    59659 File
    59660 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59661 packages/numpy/linalg/linalg.py", line 561, in inv 
    59662 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    59663 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59664 File
    59665 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59666 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    59667 raise LinAlgError("Singular matrix") 
    59668 numpy.linalg.LinAlgError: Singular matrix 
    59669  
    59670 numpy.linalg.LinAlgError: Singular matrix 
    59671  
    59672 File
    59673 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59674 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    59675 raise LinAlgError("Singular matrix") 
    59676  
    59677 See log for complete Python traceback. 
    59678  
    59679 Traceback (most recent call last): 
    59680 File
    59681 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59682 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    59683 self.session.ui.mouse_modes.mouse_pause_tracking() 
    59684 File
    59685 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59686 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    59687 mouse_pause_tracking 
    59688 self._mouse_pause() 
    59689 File
    59690 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59691 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    59692 m.pause(self._mouse_pause_position) 
    59693 File
    59694 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59695 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    59696 p = self.view.picked_object(x, y) 
    59697 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59698 File
    59699 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59700 packages/chimerax/graphics/view.py", line 838, in picked_object 
    59701 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    59702 beyond, 
    59703 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59704 File
    59705 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59706 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    59707 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    59708 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59709 File
    59710 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59711 packages/chimerax/core/models.py", line 143, in first_intercept 
    59712 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    59713 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59714 File
    59715 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59716 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    59717 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    59718 exclude=exclude) 
    59719 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59720 File
    59721 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59722 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    59723 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    59724 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59725 File
    59726 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59727 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    59728 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    59729 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59730 File
    59731 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59732 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    59733 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    59734 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59735 File
    59736 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59737 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    59738 p = super().first_intercept(mxyz1, mxyz2) 
    59739 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59740 File
    59741 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59742 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    59743 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    59744 exclude=exclude) 
    59745 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59746 File
    59747 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59748 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    59749 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    59750 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59751 File
    59752 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59753 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    59754 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    59755 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59756 File
    59757 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59758 packages/chimerax/graphics/drawing.py", line 1108, in
    59759 _first_intercept_excluding_children 
    59760 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    59761 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59762 File
    59763 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59764 packages/chimerax/geometry/place.py", line 201, in inverse 
    59765 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    59766 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59767 File
    59768 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59769 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    59770 rinv[:, :] = matrix_inverse(r) 
    59771 ^^^^^^^^^^^^^^^^^ 
    59772 File
    59773 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59774 packages/numpy/linalg/linalg.py", line 561, in inv 
    59775 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    59776 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59777 File
    59778 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59779 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    59780 raise LinAlgError("Singular matrix") 
    59781 numpy.linalg.LinAlgError: Singular matrix 
    59782  
    59783 numpy.linalg.LinAlgError: Singular matrix 
    59784  
    59785 File
    59786 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59787 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    59788 raise LinAlgError("Singular matrix") 
    59789  
    59790 See log for complete Python traceback. 
    59791  
    59792 Traceback (most recent call last): 
    59793 File
    59794 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59795 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    59796 self.session.ui.mouse_modes.mouse_pause_tracking() 
    59797 File
    59798 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59799 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    59800 mouse_pause_tracking 
    59801 self._mouse_pause() 
    59802 File
    59803 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59804 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    59805 m.pause(self._mouse_pause_position) 
    59806 File
    59807 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59808 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    59809 p = self.view.picked_object(x, y) 
    59810 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59811 File
    59812 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59813 packages/chimerax/graphics/view.py", line 838, in picked_object 
    59814 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    59815 beyond, 
    59816 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59817 File
    59818 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59819 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    59820 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    59821 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59822 File
    59823 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59824 packages/chimerax/core/models.py", line 143, in first_intercept 
    59825 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    59826 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59827 File
    59828 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59829 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    59830 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    59831 exclude=exclude) 
    59832 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59833 File
    59834 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59835 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    59836 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    59837 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59838 File
    59839 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59840 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    59841 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    59842 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59843 File
    59844 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59845 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    59846 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    59847 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59848 File
    59849 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59850 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    59851 p = super().first_intercept(mxyz1, mxyz2) 
    59852 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59853 File
    59854 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59855 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    59856 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    59857 exclude=exclude) 
    59858 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59859 File
    59860 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59861 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    59862 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    59863 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59864 File
    59865 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59866 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    59867 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    59868 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59869 File
    59870 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59871 packages/chimerax/graphics/drawing.py", line 1108, in
    59872 _first_intercept_excluding_children 
    59873 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    59874 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59875 File
    59876 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59877 packages/chimerax/geometry/place.py", line 201, in inverse 
    59878 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    59879 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59880 File
    59881 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59882 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    59883 rinv[:, :] = matrix_inverse(r) 
    59884 ^^^^^^^^^^^^^^^^^ 
    59885 File
    59886 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59887 packages/numpy/linalg/linalg.py", line 561, in inv 
    59888 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    59889 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59890 File
    59891 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59892 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    59893 raise LinAlgError("Singular matrix") 
    59894 numpy.linalg.LinAlgError: Singular matrix 
    59895  
    59896 numpy.linalg.LinAlgError: Singular matrix 
    59897  
    59898 File
    59899 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59900 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    59901 raise LinAlgError("Singular matrix") 
    59902  
    59903 See log for complete Python traceback. 
    59904  
    59905 Traceback (most recent call last): 
    59906 File
    59907 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59908 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    59909 self.session.ui.mouse_modes.mouse_pause_tracking() 
    59910 File
    59911 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59912 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    59913 mouse_pause_tracking 
    59914 self._mouse_pause() 
    59915 File
    59916 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59917 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    59918 m.pause(self._mouse_pause_position) 
    59919 File
    59920 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59921 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    59922 p = self.view.picked_object(x, y) 
    59923 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59924 File
    59925 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59926 packages/chimerax/graphics/view.py", line 838, in picked_object 
    59927 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    59928 beyond, 
    59929 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59930 File
    59931 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59932 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    59933 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    59934 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59935 File
    59936 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59937 packages/chimerax/core/models.py", line 143, in first_intercept 
    59938 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    59939 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59940 File
    59941 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59942 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    59943 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    59944 exclude=exclude) 
    59945 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59946 File
    59947 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59948 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    59949 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    59950 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59951 File
    59952 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59953 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    59954 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    59955 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59956 File
    59957 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59958 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    59959 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    59960 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59961 File
    59962 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59963 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    59964 p = super().first_intercept(mxyz1, mxyz2) 
    59965 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59966 File
    59967 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59968 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    59969 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    59970 exclude=exclude) 
    59971 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59972 File
    59973 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59974 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    59975 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    59976 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59977 File
    59978 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59979 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    59980 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    59981 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59982 File
    59983 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59984 packages/chimerax/graphics/drawing.py", line 1108, in
    59985 _first_intercept_excluding_children 
    59986 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    59987 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59988 File
    59989 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59990 packages/chimerax/geometry/place.py", line 201, in inverse 
    59991 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    59992 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    59993 File
    59994 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    59995 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    59996 rinv[:, :] = matrix_inverse(r) 
    59997 ^^^^^^^^^^^^^^^^^ 
    59998 File
    59999 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60000 packages/numpy/linalg/linalg.py", line 561, in inv 
    60001 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    60002 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60003 File
    60004 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60005 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    60006 raise LinAlgError("Singular matrix") 
    60007 numpy.linalg.LinAlgError: Singular matrix 
    60008  
    60009 numpy.linalg.LinAlgError: Singular matrix 
    60010  
    60011 File
    60012 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60013 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    60014 raise LinAlgError("Singular matrix") 
    60015  
    60016 See log for complete Python traceback. 
    60017  
    60018 Traceback (most recent call last): 
    60019 File
    60020 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60021 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    60022 self.session.ui.mouse_modes.mouse_pause_tracking() 
    60023 File
    60024 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60025 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    60026 mouse_pause_tracking 
    60027 self._mouse_pause() 
    60028 File
    60029 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60030 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    60031 m.pause(self._mouse_pause_position) 
    60032 File
    60033 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60034 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    60035 p = self.view.picked_object(x, y) 
    60036 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60037 File
    60038 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60039 packages/chimerax/graphics/view.py", line 838, in picked_object 
    60040 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    60041 beyond, 
    60042 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60043 File
    60044 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60045 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    60046 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    60047 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60048 File
    60049 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60050 packages/chimerax/core/models.py", line 143, in first_intercept 
    60051 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    60052 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60053 File
    60054 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60055 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    60056 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    60057 exclude=exclude) 
    60058 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60059 File
    60060 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60061 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    60062 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    60063 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60064 File
    60065 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60066 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    60067 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    60068 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60069 File
    60070 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60071 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    60072 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    60073 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60074 File
    60075 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60076 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    60077 p = super().first_intercept(mxyz1, mxyz2) 
    60078 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60079 File
    60080 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60081 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    60082 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    60083 exclude=exclude) 
    60084 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60085 File
    60086 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60087 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    60088 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    60089 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60090 File
    60091 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60092 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    60093 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    60094 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60095 File
    60096 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60097 packages/chimerax/graphics/drawing.py", line 1108, in
    60098 _first_intercept_excluding_children 
    60099 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    60100 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60101 File
    60102 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60103 packages/chimerax/geometry/place.py", line 201, in inverse 
    60104 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    60105 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60106 File
    60107 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60108 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    60109 rinv[:, :] = matrix_inverse(r) 
    60110 ^^^^^^^^^^^^^^^^^ 
    60111 File
    60112 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60113 packages/numpy/linalg/linalg.py", line 561, in inv 
    60114 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    60115 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60116 File
    60117 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60118 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    60119 raise LinAlgError("Singular matrix") 
    60120 numpy.linalg.LinAlgError: Singular matrix 
    60121  
    60122 numpy.linalg.LinAlgError: Singular matrix 
    60123  
    60124 File
    60125 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60126 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    60127 raise LinAlgError("Singular matrix") 
    60128  
    60129 See log for complete Python traceback. 
    60130  
    60131 Traceback (most recent call last): 
    60132 File
    60133 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60134 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    60135 self.session.ui.mouse_modes.mouse_pause_tracking() 
    60136 File
    60137 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60138 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    60139 mouse_pause_tracking 
    60140 self._mouse_pause() 
    60141 File
    60142 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60143 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    60144 m.pause(self._mouse_pause_position) 
    60145 File
    60146 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60147 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    60148 p = self.view.picked_object(x, y) 
    60149 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60150 File
    60151 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60152 packages/chimerax/graphics/view.py", line 838, in picked_object 
    60153 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    60154 beyond, 
    60155 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60156 File
    60157 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60158 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    60159 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    60160 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60161 File
    60162 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60163 packages/chimerax/core/models.py", line 143, in first_intercept 
    60164 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    60165 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60166 File
    60167 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60168 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    60169 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    60170 exclude=exclude) 
    60171 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60172 File
    60173 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60174 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    60175 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    60176 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60177 File
    60178 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60179 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    60180 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    60181 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60182 File
    60183 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60184 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    60185 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    60186 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60187 File
    60188 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60189 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    60190 p = super().first_intercept(mxyz1, mxyz2) 
    60191 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60192 File
    60193 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60194 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    60195 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    60196 exclude=exclude) 
    60197 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60198 File
    60199 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60200 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    60201 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    60202 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60203 File
    60204 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60205 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    60206 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    60207 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60208 File
    60209 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60210 packages/chimerax/graphics/drawing.py", line 1108, in
    60211 _first_intercept_excluding_children 
    60212 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    60213 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60214 File
    60215 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60216 packages/chimerax/geometry/place.py", line 201, in inverse 
    60217 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    60218 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60219 File
    60220 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60221 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    60222 rinv[:, :] = matrix_inverse(r) 
    60223 ^^^^^^^^^^^^^^^^^ 
    60224 File
    60225 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60226 packages/numpy/linalg/linalg.py", line 561, in inv 
    60227 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    60228 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60229 File
    60230 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60231 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    60232 raise LinAlgError("Singular matrix") 
    60233 numpy.linalg.LinAlgError: Singular matrix 
    60234  
    60235 numpy.linalg.LinAlgError: Singular matrix 
    60236  
    60237 File
    60238 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60239 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    60240 raise LinAlgError("Singular matrix") 
    60241  
    60242 See log for complete Python traceback. 
    60243  
    60244 Traceback (most recent call last): 
    60245 File
    60246 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60247 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    60248 self.session.ui.mouse_modes.mouse_pause_tracking() 
    60249 File
    60250 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60251 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    60252 mouse_pause_tracking 
    60253 self._mouse_pause() 
    60254 File
    60255 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60256 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    60257 m.pause(self._mouse_pause_position) 
    60258 File
    60259 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60260 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    60261 p = self.view.picked_object(x, y) 
    60262 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60263 File
    60264 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60265 packages/chimerax/graphics/view.py", line 838, in picked_object 
    60266 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    60267 beyond, 
    60268 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60269 File
    60270 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60271 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    60272 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    60273 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60274 File
    60275 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60276 packages/chimerax/core/models.py", line 143, in first_intercept 
    60277 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    60278 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60279 File
    60280 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60281 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    60282 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    60283 exclude=exclude) 
    60284 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60285 File
    60286 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60287 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    60288 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    60289 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60290 File
    60291 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60292 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    60293 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    60294 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60295 File
    60296 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60297 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    60298 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    60299 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60300 File
    60301 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60302 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    60303 p = super().first_intercept(mxyz1, mxyz2) 
    60304 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60305 File
    60306 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60307 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    60308 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    60309 exclude=exclude) 
    60310 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60311 File
    60312 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60313 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    60314 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    60315 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60316 File
    60317 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60318 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    60319 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    60320 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60321 File
    60322 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60323 packages/chimerax/graphics/drawing.py", line 1108, in
    60324 _first_intercept_excluding_children 
    60325 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    60326 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60327 File
    60328 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60329 packages/chimerax/geometry/place.py", line 201, in inverse 
    60330 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    60331 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60332 File
    60333 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60334 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    60335 rinv[:, :] = matrix_inverse(r) 
    60336 ^^^^^^^^^^^^^^^^^ 
    60337 File
    60338 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60339 packages/numpy/linalg/linalg.py", line 561, in inv 
    60340 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    60341 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60342 File
    60343 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60344 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    60345 raise LinAlgError("Singular matrix") 
    60346 numpy.linalg.LinAlgError: Singular matrix 
    60347  
    60348 numpy.linalg.LinAlgError: Singular matrix 
    60349  
    60350 File
    60351 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60352 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    60353 raise LinAlgError("Singular matrix") 
    60354  
    60355 See log for complete Python traceback. 
    60356  
    60357 Traceback (most recent call last): 
    60358 File
    60359 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60360 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    60361 self.session.ui.mouse_modes.mouse_pause_tracking() 
    60362 File
    60363 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60364 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    60365 mouse_pause_tracking 
    60366 self._mouse_pause() 
    60367 File
    60368 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60369 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    60370 m.pause(self._mouse_pause_position) 
    60371 File
    60372 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60373 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    60374 p = self.view.picked_object(x, y) 
    60375 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60376 File
    60377 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60378 packages/chimerax/graphics/view.py", line 838, in picked_object 
    60379 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    60380 beyond, 
    60381 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60382 File
    60383 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60384 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    60385 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    60386 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60387 File
    60388 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60389 packages/chimerax/core/models.py", line 143, in first_intercept 
    60390 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    60391 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60392 File
    60393 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60394 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    60395 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    60396 exclude=exclude) 
    60397 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60398 File
    60399 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60400 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    60401 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    60402 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60403 File
    60404 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60405 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    60406 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    60407 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60408 File
    60409 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60410 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    60411 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    60412 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60413 File
    60414 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60415 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    60416 p = super().first_intercept(mxyz1, mxyz2) 
    60417 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60418 File
    60419 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60420 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    60421 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    60422 exclude=exclude) 
    60423 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60424 File
    60425 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60426 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    60427 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    60428 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60429 File
    60430 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60431 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    60432 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    60433 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60434 File
    60435 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60436 packages/chimerax/graphics/drawing.py", line 1108, in
    60437 _first_intercept_excluding_children 
    60438 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    60439 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60440 File
    60441 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60442 packages/chimerax/geometry/place.py", line 201, in inverse 
    60443 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    60444 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60445 File
    60446 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60447 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    60448 rinv[:, :] = matrix_inverse(r) 
    60449 ^^^^^^^^^^^^^^^^^ 
    60450 File
    60451 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60452 packages/numpy/linalg/linalg.py", line 561, in inv 
    60453 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    60454 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60455 File
    60456 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60457 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    60458 raise LinAlgError("Singular matrix") 
    60459 numpy.linalg.LinAlgError: Singular matrix 
    60460  
    60461 numpy.linalg.LinAlgError: Singular matrix 
    60462  
    60463 File
    60464 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60465 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    60466 raise LinAlgError("Singular matrix") 
    60467  
    60468 See log for complete Python traceback. 
    60469  
    60470 Traceback (most recent call last): 
    60471 File
    60472 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60473 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    60474 self.session.ui.mouse_modes.mouse_pause_tracking() 
    60475 File
    60476 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60477 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    60478 mouse_pause_tracking 
    60479 self._mouse_pause() 
    60480 File
    60481 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60482 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    60483 m.pause(self._mouse_pause_position) 
    60484 File
    60485 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60486 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    60487 p = self.view.picked_object(x, y) 
    60488 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60489 File
    60490 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60491 packages/chimerax/graphics/view.py", line 838, in picked_object 
    60492 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    60493 beyond, 
    60494 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60495 File
    60496 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60497 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    60498 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    60499 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60500 File
    60501 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60502 packages/chimerax/core/models.py", line 143, in first_intercept 
    60503 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    60504 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60505 File
    60506 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60507 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    60508 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    60509 exclude=exclude) 
    60510 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60511 File
    60512 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60513 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    60514 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    60515 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60516 File
    60517 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60518 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    60519 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    60520 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60521 File
    60522 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60523 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    60524 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    60525 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60526 File
    60527 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60528 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    60529 p = super().first_intercept(mxyz1, mxyz2) 
    60530 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60531 File
    60532 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60533 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    60534 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    60535 exclude=exclude) 
    60536 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60537 File
    60538 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60539 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    60540 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    60541 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60542 File
    60543 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60544 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    60545 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    60546 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60547 File
    60548 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60549 packages/chimerax/graphics/drawing.py", line 1108, in
    60550 _first_intercept_excluding_children 
    60551 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    60552 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60553 File
    60554 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60555 packages/chimerax/geometry/place.py", line 201, in inverse 
    60556 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    60557 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60558 File
    60559 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60560 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    60561 rinv[:, :] = matrix_inverse(r) 
    60562 ^^^^^^^^^^^^^^^^^ 
    60563 File
    60564 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60565 packages/numpy/linalg/linalg.py", line 561, in inv 
    60566 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    60567 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60568 File
    60569 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60570 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    60571 raise LinAlgError("Singular matrix") 
    60572 numpy.linalg.LinAlgError: Singular matrix 
    60573  
    60574 numpy.linalg.LinAlgError: Singular matrix 
    60575  
    60576 File
    60577 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60578 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    60579 raise LinAlgError("Singular matrix") 
    60580  
    60581 See log for complete Python traceback. 
    60582  
    60583 Traceback (most recent call last): 
    60584 File
    60585 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60586 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    60587 self.session.ui.mouse_modes.mouse_pause_tracking() 
    60588 File
    60589 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60590 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    60591 mouse_pause_tracking 
    60592 self._mouse_pause() 
    60593 File
    60594 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60595 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    60596 m.pause(self._mouse_pause_position) 
    60597 File
    60598 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60599 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    60600 p = self.view.picked_object(x, y) 
    60601 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60602 File
    60603 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60604 packages/chimerax/graphics/view.py", line 838, in picked_object 
    60605 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    60606 beyond, 
    60607 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60608 File
    60609 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60610 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    60611 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    60612 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60613 File
    60614 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60615 packages/chimerax/core/models.py", line 143, in first_intercept 
    60616 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    60617 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60618 File
    60619 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60620 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    60621 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    60622 exclude=exclude) 
    60623 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60624 File
    60625 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60626 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    60627 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    60628 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60629 File
    60630 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60631 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    60632 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    60633 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60634 File
    60635 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60636 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    60637 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    60638 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60639 File
    60640 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60641 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    60642 p = super().first_intercept(mxyz1, mxyz2) 
    60643 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60644 File
    60645 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60646 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    60647 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    60648 exclude=exclude) 
    60649 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60650 File
    60651 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60652 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    60653 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    60654 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60655 File
    60656 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60657 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    60658 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    60659 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60660 File
    60661 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60662 packages/chimerax/graphics/drawing.py", line 1108, in
    60663 _first_intercept_excluding_children 
    60664 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    60665 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60666 File
    60667 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60668 packages/chimerax/geometry/place.py", line 201, in inverse 
    60669 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    60670 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60671 File
    60672 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60673 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    60674 rinv[:, :] = matrix_inverse(r) 
    60675 ^^^^^^^^^^^^^^^^^ 
    60676 File
    60677 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60678 packages/numpy/linalg/linalg.py", line 561, in inv 
    60679 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    60680 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60681 File
    60682 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60683 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    60684 raise LinAlgError("Singular matrix") 
    60685 numpy.linalg.LinAlgError: Singular matrix 
    60686  
    60687 numpy.linalg.LinAlgError: Singular matrix 
    60688  
    60689 File
    60690 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60691 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    60692 raise LinAlgError("Singular matrix") 
    60693  
    60694 See log for complete Python traceback. 
    60695  
    60696 Traceback (most recent call last): 
    60697 File
    60698 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60699 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    60700 self.session.ui.mouse_modes.mouse_pause_tracking() 
    60701 File
    60702 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60703 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    60704 mouse_pause_tracking 
    60705 self._mouse_pause() 
    60706 File
    60707 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60708 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    60709 m.pause(self._mouse_pause_position) 
    60710 File
    60711 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60712 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    60713 p = self.view.picked_object(x, y) 
    60714 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60715 File
    60716 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60717 packages/chimerax/graphics/view.py", line 838, in picked_object 
    60718 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    60719 beyond, 
    60720 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60721 File
    60722 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60723 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    60724 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    60725 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60726 File
    60727 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60728 packages/chimerax/core/models.py", line 143, in first_intercept 
    60729 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    60730 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60731 File
    60732 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60733 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    60734 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    60735 exclude=exclude) 
    60736 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60737 File
    60738 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60739 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    60740 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    60741 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60742 File
    60743 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60744 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    60745 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    60746 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60747 File
    60748 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60749 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    60750 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    60751 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60752 File
    60753 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60754 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    60755 p = super().first_intercept(mxyz1, mxyz2) 
    60756 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60757 File
    60758 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60759 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    60760 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    60761 exclude=exclude) 
    60762 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60763 File
    60764 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60765 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    60766 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    60767 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60768 File
    60769 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60770 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    60771 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    60772 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60773 File
    60774 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60775 packages/chimerax/graphics/drawing.py", line 1108, in
    60776 _first_intercept_excluding_children 
    60777 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    60778 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60779 File
    60780 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60781 packages/chimerax/geometry/place.py", line 201, in inverse 
    60782 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    60783 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60784 File
    60785 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60786 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    60787 rinv[:, :] = matrix_inverse(r) 
    60788 ^^^^^^^^^^^^^^^^^ 
    60789 File
    60790 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60791 packages/numpy/linalg/linalg.py", line 561, in inv 
    60792 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    60793 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60794 File
    60795 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60796 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    60797 raise LinAlgError("Singular matrix") 
    60798 numpy.linalg.LinAlgError: Singular matrix 
    60799  
    60800 numpy.linalg.LinAlgError: Singular matrix 
    60801  
    60802 File
    60803 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60804 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    60805 raise LinAlgError("Singular matrix") 
    60806  
    60807 See log for complete Python traceback. 
    60808  
    60809 Traceback (most recent call last): 
    60810 File
    60811 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60812 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    60813 self.session.ui.mouse_modes.mouse_pause_tracking() 
    60814 File
    60815 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60816 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    60817 mouse_pause_tracking 
    60818 self._mouse_pause() 
    60819 File
    60820 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60821 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    60822 m.pause(self._mouse_pause_position) 
    60823 File
    60824 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60825 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    60826 p = self.view.picked_object(x, y) 
    60827 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60828 File
    60829 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60830 packages/chimerax/graphics/view.py", line 838, in picked_object 
    60831 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    60832 beyond, 
    60833 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60834 File
    60835 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60836 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    60837 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    60838 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60839 File
    60840 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60841 packages/chimerax/core/models.py", line 143, in first_intercept 
    60842 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    60843 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60844 File
    60845 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60846 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    60847 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    60848 exclude=exclude) 
    60849 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60850 File
    60851 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60852 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    60853 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    60854 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60855 File
    60856 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60857 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    60858 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    60859 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60860 File
    60861 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60862 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    60863 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    60864 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60865 File
    60866 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60867 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    60868 p = super().first_intercept(mxyz1, mxyz2) 
    60869 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60870 File
    60871 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60872 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    60873 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    60874 exclude=exclude) 
    60875 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60876 File
    60877 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60878 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    60879 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    60880 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60881 File
    60882 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60883 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    60884 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    60885 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60886 File
    60887 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60888 packages/chimerax/graphics/drawing.py", line 1108, in
    60889 _first_intercept_excluding_children 
    60890 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    60891 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60892 File
    60893 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60894 packages/chimerax/geometry/place.py", line 201, in inverse 
    60895 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    60896 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60897 File
    60898 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60899 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    60900 rinv[:, :] = matrix_inverse(r) 
    60901 ^^^^^^^^^^^^^^^^^ 
    60902 File
    60903 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60904 packages/numpy/linalg/linalg.py", line 561, in inv 
    60905 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    60906 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60907 File
    60908 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60909 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    60910 raise LinAlgError("Singular matrix") 
    60911 numpy.linalg.LinAlgError: Singular matrix 
    60912  
    60913 numpy.linalg.LinAlgError: Singular matrix 
    60914  
    60915 File
    60916 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60917 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    60918 raise LinAlgError("Singular matrix") 
    60919  
    60920 See log for complete Python traceback. 
    60921  
    60922 Traceback (most recent call last): 
    60923 File
    60924 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60925 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    60926 self.session.ui.mouse_modes.mouse_pause_tracking() 
    60927 File
    60928 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60929 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    60930 mouse_pause_tracking 
    60931 self._mouse_pause() 
    60932 File
    60933 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60934 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    60935 m.pause(self._mouse_pause_position) 
    60936 File
    60937 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60938 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    60939 p = self.view.picked_object(x, y) 
    60940 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60941 File
    60942 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60943 packages/chimerax/graphics/view.py", line 838, in picked_object 
    60944 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    60945 beyond, 
    60946 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60947 File
    60948 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60949 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    60950 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    60951 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60952 File
    60953 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60954 packages/chimerax/core/models.py", line 143, in first_intercept 
    60955 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    60956 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60957 File
    60958 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60959 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    60960 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    60961 exclude=exclude) 
    60962 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60963 File
    60964 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60965 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    60966 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    60967 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60968 File
    60969 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60970 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    60971 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    60972 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60973 File
    60974 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60975 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    60976 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    60977 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60978 File
    60979 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60980 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    60981 p = super().first_intercept(mxyz1, mxyz2) 
    60982 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60983 File
    60984 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60985 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    60986 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    60987 exclude=exclude) 
    60988 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60989 File
    60990 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60991 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    60992 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    60993 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60994 File
    60995 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    60996 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    60997 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    60998 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    60999 File
    61000 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61001 packages/chimerax/graphics/drawing.py", line 1108, in
    61002 _first_intercept_excluding_children 
    61003 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    61004 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61005 File
    61006 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61007 packages/chimerax/geometry/place.py", line 201, in inverse 
    61008 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    61009 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61010 File
    61011 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61012 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    61013 rinv[:, :] = matrix_inverse(r) 
    61014 ^^^^^^^^^^^^^^^^^ 
    61015 File
    61016 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61017 packages/numpy/linalg/linalg.py", line 561, in inv 
    61018 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    61019 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61020 File
    61021 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61022 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    61023 raise LinAlgError("Singular matrix") 
    61024 numpy.linalg.LinAlgError: Singular matrix 
    61025  
    61026 numpy.linalg.LinAlgError: Singular matrix 
    61027  
    61028 File
    61029 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61030 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    61031 raise LinAlgError("Singular matrix") 
    61032  
    61033 See log for complete Python traceback. 
    61034  
    61035 Traceback (most recent call last): 
    61036 File
    61037 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61038 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    61039 self.session.ui.mouse_modes.mouse_pause_tracking() 
    61040 File
    61041 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61042 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    61043 mouse_pause_tracking 
    61044 self._mouse_pause() 
    61045 File
    61046 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61047 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    61048 m.pause(self._mouse_pause_position) 
    61049 File
    61050 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61051 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    61052 p = self.view.picked_object(x, y) 
    61053 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61054 File
    61055 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61056 packages/chimerax/graphics/view.py", line 838, in picked_object 
    61057 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    61058 beyond, 
    61059 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61060 File
    61061 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61062 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    61063 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    61064 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61065 File
    61066 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61067 packages/chimerax/core/models.py", line 143, in first_intercept 
    61068 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    61069 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61070 File
    61071 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61072 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    61073 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    61074 exclude=exclude) 
    61075 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61076 File
    61077 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61078 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    61079 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    61080 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61081 File
    61082 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61083 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    61084 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    61085 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61086 File
    61087 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61088 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    61089 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    61090 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61091 File
    61092 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61093 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    61094 p = super().first_intercept(mxyz1, mxyz2) 
    61095 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61096 File
    61097 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61098 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    61099 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    61100 exclude=exclude) 
    61101 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61102 File
    61103 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61104 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    61105 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    61106 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61107 File
    61108 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61109 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    61110 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    61111 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61112 File
    61113 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61114 packages/chimerax/graphics/drawing.py", line 1108, in
    61115 _first_intercept_excluding_children 
    61116 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    61117 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61118 File
    61119 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61120 packages/chimerax/geometry/place.py", line 201, in inverse 
    61121 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    61122 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61123 File
    61124 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61125 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    61126 rinv[:, :] = matrix_inverse(r) 
    61127 ^^^^^^^^^^^^^^^^^ 
    61128 File
    61129 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61130 packages/numpy/linalg/linalg.py", line 561, in inv 
    61131 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    61132 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61133 File
    61134 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61135 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    61136 raise LinAlgError("Singular matrix") 
    61137 numpy.linalg.LinAlgError: Singular matrix 
    61138  
    61139 numpy.linalg.LinAlgError: Singular matrix 
    61140  
    61141 File
    61142 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61143 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    61144 raise LinAlgError("Singular matrix") 
    61145  
    61146 See log for complete Python traceback. 
    61147  
    61148 Traceback (most recent call last): 
    61149 File
    61150 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61151 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    61152 self.session.ui.mouse_modes.mouse_pause_tracking() 
    61153 File
    61154 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61155 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    61156 mouse_pause_tracking 
    61157 self._mouse_pause() 
    61158 File
    61159 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61160 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    61161 m.pause(self._mouse_pause_position) 
    61162 File
    61163 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61164 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    61165 p = self.view.picked_object(x, y) 
    61166 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61167 File
    61168 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61169 packages/chimerax/graphics/view.py", line 838, in picked_object 
    61170 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    61171 beyond, 
    61172 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61173 File
    61174 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61175 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    61176 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    61177 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61178 File
    61179 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61180 packages/chimerax/core/models.py", line 143, in first_intercept 
    61181 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    61182 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61183 File
    61184 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61185 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    61186 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    61187 exclude=exclude) 
    61188 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61189 File
    61190 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61191 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    61192 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    61193 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61194 File
    61195 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61196 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    61197 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    61198 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61199 File
    61200 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61201 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    61202 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    61203 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61204 File
    61205 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61206 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    61207 p = super().first_intercept(mxyz1, mxyz2) 
    61208 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61209 File
    61210 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61211 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    61212 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    61213 exclude=exclude) 
    61214 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61215 File
    61216 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61217 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    61218 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    61219 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61220 File
    61221 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61222 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    61223 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    61224 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61225 File
    61226 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61227 packages/chimerax/graphics/drawing.py", line 1108, in
    61228 _first_intercept_excluding_children 
    61229 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    61230 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61231 File
    61232 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61233 packages/chimerax/geometry/place.py", line 201, in inverse 
    61234 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    61235 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61236 File
    61237 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61238 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    61239 rinv[:, :] = matrix_inverse(r) 
    61240 ^^^^^^^^^^^^^^^^^ 
    61241 File
    61242 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61243 packages/numpy/linalg/linalg.py", line 561, in inv 
    61244 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    61245 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61246 File
    61247 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61248 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    61249 raise LinAlgError("Singular matrix") 
    61250 numpy.linalg.LinAlgError: Singular matrix 
    61251  
    61252 numpy.linalg.LinAlgError: Singular matrix 
    61253  
    61254 File
    61255 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61256 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    61257 raise LinAlgError("Singular matrix") 
    61258  
    61259 See log for complete Python traceback. 
    61260  
    61261 Traceback (most recent call last): 
    61262 File
    61263 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61264 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    61265 self.session.ui.mouse_modes.mouse_pause_tracking() 
    61266 File
    61267 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61268 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    61269 mouse_pause_tracking 
    61270 self._mouse_pause() 
    61271 File
    61272 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61273 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    61274 m.pause(self._mouse_pause_position) 
    61275 File
    61276 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61277 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    61278 p = self.view.picked_object(x, y) 
    61279 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61280 File
    61281 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61282 packages/chimerax/graphics/view.py", line 838, in picked_object 
    61283 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    61284 beyond, 
    61285 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61286 File
    61287 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61288 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    61289 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    61290 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61291 File
    61292 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61293 packages/chimerax/core/models.py", line 143, in first_intercept 
    61294 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    61295 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61296 File
    61297 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61298 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    61299 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    61300 exclude=exclude) 
    61301 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61302 File
    61303 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61304 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    61305 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    61306 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61307 File
    61308 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61309 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    61310 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    61311 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61312 File
    61313 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61314 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    61315 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    61316 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61317 File
    61318 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61319 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    61320 p = super().first_intercept(mxyz1, mxyz2) 
    61321 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61322 File
    61323 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61324 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    61325 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    61326 exclude=exclude) 
    61327 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61328 File
    61329 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61330 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    61331 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    61332 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61333 File
    61334 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61335 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    61336 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    61337 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61338 File
    61339 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61340 packages/chimerax/graphics/drawing.py", line 1108, in
    61341 _first_intercept_excluding_children 
    61342 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    61343 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61344 File
    61345 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61346 packages/chimerax/geometry/place.py", line 201, in inverse 
    61347 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    61348 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61349 File
    61350 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61351 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    61352 rinv[:, :] = matrix_inverse(r) 
    61353 ^^^^^^^^^^^^^^^^^ 
    61354 File
    61355 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61356 packages/numpy/linalg/linalg.py", line 561, in inv 
    61357 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    61358 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61359 File
    61360 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61361 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    61362 raise LinAlgError("Singular matrix") 
    61363 numpy.linalg.LinAlgError: Singular matrix 
    61364  
    61365 numpy.linalg.LinAlgError: Singular matrix 
    61366  
    61367 File
    61368 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61369 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    61370 raise LinAlgError("Singular matrix") 
    61371  
    61372 See log for complete Python traceback. 
    61373  
    61374 Traceback (most recent call last): 
    61375 File
    61376 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61377 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    61378 self.session.ui.mouse_modes.mouse_pause_tracking() 
    61379 File
    61380 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61381 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    61382 mouse_pause_tracking 
    61383 self._mouse_pause() 
    61384 File
    61385 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61386 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    61387 m.pause(self._mouse_pause_position) 
    61388 File
    61389 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61390 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    61391 p = self.view.picked_object(x, y) 
    61392 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61393 File
    61394 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61395 packages/chimerax/graphics/view.py", line 838, in picked_object 
    61396 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    61397 beyond, 
    61398 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61399 File
    61400 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61401 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    61402 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    61403 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61404 File
    61405 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61406 packages/chimerax/core/models.py", line 143, in first_intercept 
    61407 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    61408 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61409 File
    61410 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61411 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    61412 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    61413 exclude=exclude) 
    61414 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61415 File
    61416 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61417 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    61418 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    61419 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61420 File
    61421 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61422 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    61423 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    61424 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61425 File
    61426 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61427 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    61428 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    61429 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61430 File
    61431 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61432 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    61433 p = super().first_intercept(mxyz1, mxyz2) 
    61434 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61435 File
    61436 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61437 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    61438 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    61439 exclude=exclude) 
    61440 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61441 File
    61442 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61443 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    61444 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    61445 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61446 File
    61447 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61448 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    61449 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    61450 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61451 File
    61452 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61453 packages/chimerax/graphics/drawing.py", line 1108, in
    61454 _first_intercept_excluding_children 
    61455 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    61456 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61457 File
    61458 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61459 packages/chimerax/geometry/place.py", line 201, in inverse 
    61460 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    61461 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61462 File
    61463 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61464 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    61465 rinv[:, :] = matrix_inverse(r) 
    61466 ^^^^^^^^^^^^^^^^^ 
    61467 File
    61468 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61469 packages/numpy/linalg/linalg.py", line 561, in inv 
    61470 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    61471 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61472 File
    61473 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61474 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    61475 raise LinAlgError("Singular matrix") 
    61476 numpy.linalg.LinAlgError: Singular matrix 
    61477  
    61478 numpy.linalg.LinAlgError: Singular matrix 
    61479  
    61480 File
    61481 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61482 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    61483 raise LinAlgError("Singular matrix") 
    61484  
    61485 See log for complete Python traceback. 
    61486  
    61487 Traceback (most recent call last): 
    61488 File
    61489 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61490 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    61491 self.session.ui.mouse_modes.mouse_pause_tracking() 
    61492 File
    61493 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61494 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    61495 mouse_pause_tracking 
    61496 self._mouse_pause() 
    61497 File
    61498 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61499 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    61500 m.pause(self._mouse_pause_position) 
    61501 File
    61502 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61503 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    61504 p = self.view.picked_object(x, y) 
    61505 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61506 File
    61507 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61508 packages/chimerax/graphics/view.py", line 838, in picked_object 
    61509 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    61510 beyond, 
    61511 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61512 File
    61513 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61514 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    61515 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    61516 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61517 File
    61518 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61519 packages/chimerax/core/models.py", line 143, in first_intercept 
    61520 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    61521 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61522 File
    61523 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61524 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    61525 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    61526 exclude=exclude) 
    61527 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61528 File
    61529 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61530 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    61531 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    61532 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61533 File
    61534 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61535 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    61536 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    61537 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61538 File
    61539 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61540 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    61541 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    61542 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61543 File
    61544 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61545 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    61546 p = super().first_intercept(mxyz1, mxyz2) 
    61547 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61548 File
    61549 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61550 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    61551 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    61552 exclude=exclude) 
    61553 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61554 File
    61555 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61556 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    61557 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    61558 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61559 File
    61560 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61561 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    61562 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    61563 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61564 File
    61565 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61566 packages/chimerax/graphics/drawing.py", line 1108, in
    61567 _first_intercept_excluding_children 
    61568 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    61569 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61570 File
    61571 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61572 packages/chimerax/geometry/place.py", line 201, in inverse 
    61573 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    61574 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61575 File
    61576 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61577 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    61578 rinv[:, :] = matrix_inverse(r) 
    61579 ^^^^^^^^^^^^^^^^^ 
    61580 File
    61581 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61582 packages/numpy/linalg/linalg.py", line 561, in inv 
    61583 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    61584 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61585 File
    61586 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61587 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    61588 raise LinAlgError("Singular matrix") 
    61589 numpy.linalg.LinAlgError: Singular matrix 
    61590  
    61591 numpy.linalg.LinAlgError: Singular matrix 
    61592  
    61593 File
    61594 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61595 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    61596 raise LinAlgError("Singular matrix") 
    61597  
    61598 See log for complete Python traceback. 
    61599  
    61600 Traceback (most recent call last): 
    61601 File
    61602 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61603 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    61604 self.session.ui.mouse_modes.mouse_pause_tracking() 
    61605 File
    61606 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61607 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    61608 mouse_pause_tracking 
    61609 self._mouse_pause() 
    61610 File
    61611 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61612 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    61613 m.pause(self._mouse_pause_position) 
    61614 File
    61615 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61616 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    61617 p = self.view.picked_object(x, y) 
    61618 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61619 File
    61620 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61621 packages/chimerax/graphics/view.py", line 838, in picked_object 
    61622 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    61623 beyond, 
    61624 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61625 File
    61626 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61627 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    61628 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    61629 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61630 File
    61631 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61632 packages/chimerax/core/models.py", line 143, in first_intercept 
    61633 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    61634 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61635 File
    61636 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61637 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    61638 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    61639 exclude=exclude) 
    61640 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61641 File
    61642 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61643 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    61644 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    61645 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61646 File
    61647 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61648 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    61649 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    61650 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61651 File
    61652 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61653 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    61654 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    61655 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61656 File
    61657 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61658 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    61659 p = super().first_intercept(mxyz1, mxyz2) 
    61660 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61661 File
    61662 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61663 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    61664 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    61665 exclude=exclude) 
    61666 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61667 File
    61668 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61669 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    61670 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    61671 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61672 File
    61673 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61674 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    61675 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    61676 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61677 File
    61678 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61679 packages/chimerax/graphics/drawing.py", line 1108, in
    61680 _first_intercept_excluding_children 
    61681 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    61682 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61683 File
    61684 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61685 packages/chimerax/geometry/place.py", line 201, in inverse 
    61686 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    61687 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61688 File
    61689 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61690 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    61691 rinv[:, :] = matrix_inverse(r) 
    61692 ^^^^^^^^^^^^^^^^^ 
    61693 File
    61694 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61695 packages/numpy/linalg/linalg.py", line 561, in inv 
    61696 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    61697 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61698 File
    61699 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61700 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    61701 raise LinAlgError("Singular matrix") 
    61702 numpy.linalg.LinAlgError: Singular matrix 
    61703  
    61704 numpy.linalg.LinAlgError: Singular matrix 
    61705  
    61706 File
    61707 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61708 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    61709 raise LinAlgError("Singular matrix") 
    61710  
    61711 See log for complete Python traceback. 
    61712  
    61713 Traceback (most recent call last): 
    61714 File
    61715 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61716 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    61717 self.session.ui.mouse_modes.mouse_pause_tracking() 
    61718 File
    61719 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61720 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    61721 mouse_pause_tracking 
    61722 self._mouse_pause() 
    61723 File
    61724 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61725 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    61726 m.pause(self._mouse_pause_position) 
    61727 File
    61728 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61729 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    61730 p = self.view.picked_object(x, y) 
    61731 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61732 File
    61733 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61734 packages/chimerax/graphics/view.py", line 838, in picked_object 
    61735 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    61736 beyond, 
    61737 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61738 File
    61739 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61740 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    61741 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    61742 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61743 File
    61744 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61745 packages/chimerax/core/models.py", line 143, in first_intercept 
    61746 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    61747 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61748 File
    61749 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61750 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    61751 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    61752 exclude=exclude) 
    61753 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61754 File
    61755 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61756 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    61757 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    61758 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61759 File
    61760 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61761 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    61762 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    61763 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61764 File
    61765 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61766 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    61767 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    61768 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61769 File
    61770 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61771 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    61772 p = super().first_intercept(mxyz1, mxyz2) 
    61773 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61774 File
    61775 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61776 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    61777 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    61778 exclude=exclude) 
    61779 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61780 File
    61781 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61782 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    61783 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    61784 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61785 File
    61786 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61787 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    61788 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    61789 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61790 File
    61791 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61792 packages/chimerax/graphics/drawing.py", line 1108, in
    61793 _first_intercept_excluding_children 
    61794 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    61795 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61796 File
    61797 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61798 packages/chimerax/geometry/place.py", line 201, in inverse 
    61799 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    61800 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61801 File
    61802 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61803 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    61804 rinv[:, :] = matrix_inverse(r) 
    61805 ^^^^^^^^^^^^^^^^^ 
    61806 File
    61807 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61808 packages/numpy/linalg/linalg.py", line 561, in inv 
    61809 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    61810 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61811 File
    61812 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61813 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    61814 raise LinAlgError("Singular matrix") 
    61815 numpy.linalg.LinAlgError: Singular matrix 
    61816  
    61817 numpy.linalg.LinAlgError: Singular matrix 
    61818  
    61819 File
    61820 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61821 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    61822 raise LinAlgError("Singular matrix") 
    61823  
    61824 See log for complete Python traceback. 
    61825  
    61826 Traceback (most recent call last): 
    61827 File
    61828 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61829 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    61830 self.session.ui.mouse_modes.mouse_pause_tracking() 
    61831 File
    61832 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61833 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    61834 mouse_pause_tracking 
    61835 self._mouse_pause() 
    61836 File
    61837 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61838 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    61839 m.pause(self._mouse_pause_position) 
    61840 File
    61841 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61842 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    61843 p = self.view.picked_object(x, y) 
    61844 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61845 File
    61846 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61847 packages/chimerax/graphics/view.py", line 838, in picked_object 
    61848 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    61849 beyond, 
    61850 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61851 File
    61852 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61853 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    61854 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    61855 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61856 File
    61857 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61858 packages/chimerax/core/models.py", line 143, in first_intercept 
    61859 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    61860 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61861 File
    61862 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61863 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    61864 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    61865 exclude=exclude) 
    61866 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61867 File
    61868 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61869 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    61870 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    61871 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61872 File
    61873 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61874 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    61875 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    61876 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61877 File
    61878 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61879 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    61880 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    61881 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61882 File
    61883 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61884 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    61885 p = super().first_intercept(mxyz1, mxyz2) 
    61886 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61887 File
    61888 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61889 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    61890 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    61891 exclude=exclude) 
    61892 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61893 File
    61894 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61895 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    61896 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    61897 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61898 File
    61899 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61900 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    61901 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    61902 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61903 File
    61904 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61905 packages/chimerax/graphics/drawing.py", line 1108, in
    61906 _first_intercept_excluding_children 
    61907 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    61908 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61909 File
    61910 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61911 packages/chimerax/geometry/place.py", line 201, in inverse 
    61912 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    61913 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61914 File
    61915 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61916 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    61917 rinv[:, :] = matrix_inverse(r) 
    61918 ^^^^^^^^^^^^^^^^^ 
    61919 File
    61920 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61921 packages/numpy/linalg/linalg.py", line 561, in inv 
    61922 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    61923 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61924 File
    61925 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61926 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    61927 raise LinAlgError("Singular matrix") 
    61928 numpy.linalg.LinAlgError: Singular matrix 
    61929  
    61930 numpy.linalg.LinAlgError: Singular matrix 
    61931  
    61932 File
    61933 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61934 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    61935 raise LinAlgError("Singular matrix") 
    61936  
    61937 See log for complete Python traceback. 
    61938  
    61939 Traceback (most recent call last): 
    61940 File
    61941 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61942 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    61943 self.session.ui.mouse_modes.mouse_pause_tracking() 
    61944 File
    61945 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61946 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    61947 mouse_pause_tracking 
    61948 self._mouse_pause() 
    61949 File
    61950 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61951 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    61952 m.pause(self._mouse_pause_position) 
    61953 File
    61954 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61955 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    61956 p = self.view.picked_object(x, y) 
    61957 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61958 File
    61959 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61960 packages/chimerax/graphics/view.py", line 838, in picked_object 
    61961 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    61962 beyond, 
    61963 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61964 File
    61965 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61966 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    61967 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    61968 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61969 File
    61970 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61971 packages/chimerax/core/models.py", line 143, in first_intercept 
    61972 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    61973 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61974 File
    61975 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61976 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    61977 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    61978 exclude=exclude) 
    61979 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61980 File
    61981 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61982 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    61983 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    61984 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61985 File
    61986 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61987 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    61988 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    61989 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61990 File
    61991 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61992 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    61993 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    61994 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    61995 File
    61996 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    61997 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    61998 p = super().first_intercept(mxyz1, mxyz2) 
    61999 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62000 File
    62001 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62002 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    62003 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    62004 exclude=exclude) 
    62005 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62006 File
    62007 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62008 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    62009 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    62010 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62011 File
    62012 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62013 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    62014 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    62015 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62016 File
    62017 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62018 packages/chimerax/graphics/drawing.py", line 1108, in
    62019 _first_intercept_excluding_children 
    62020 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    62021 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62022 File
    62023 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62024 packages/chimerax/geometry/place.py", line 201, in inverse 
    62025 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    62026 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62027 File
    62028 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62029 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    62030 rinv[:, :] = matrix_inverse(r) 
    62031 ^^^^^^^^^^^^^^^^^ 
    62032 File
    62033 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62034 packages/numpy/linalg/linalg.py", line 561, in inv 
    62035 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    62036 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62037 File
    62038 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62039 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    62040 raise LinAlgError("Singular matrix") 
    62041 numpy.linalg.LinAlgError: Singular matrix 
    62042  
    62043 numpy.linalg.LinAlgError: Singular matrix 
    62044  
    62045 File
    62046 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62047 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    62048 raise LinAlgError("Singular matrix") 
    62049  
    62050 See log for complete Python traceback. 
    62051  
    62052 Traceback (most recent call last): 
    62053 File
    62054 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62055 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    62056 self.session.ui.mouse_modes.mouse_pause_tracking() 
    62057 File
    62058 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62059 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    62060 mouse_pause_tracking 
    62061 self._mouse_pause() 
    62062 File
    62063 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62064 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    62065 m.pause(self._mouse_pause_position) 
    62066 File
    62067 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62068 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    62069 p = self.view.picked_object(x, y) 
    62070 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62071 File
    62072 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62073 packages/chimerax/graphics/view.py", line 838, in picked_object 
    62074 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    62075 beyond, 
    62076 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62077 File
    62078 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62079 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    62080 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    62081 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62082 File
    62083 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62084 packages/chimerax/core/models.py", line 143, in first_intercept 
    62085 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    62086 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62087 File
    62088 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62089 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    62090 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    62091 exclude=exclude) 
    62092 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62093 File
    62094 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62095 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    62096 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    62097 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62098 File
    62099 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62100 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    62101 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    62102 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62103 File
    62104 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62105 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    62106 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    62107 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62108 File
    62109 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62110 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    62111 p = super().first_intercept(mxyz1, mxyz2) 
    62112 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62113 File
    62114 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62115 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    62116 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    62117 exclude=exclude) 
    62118 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62119 File
    62120 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62121 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    62122 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    62123 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62124 File
    62125 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62126 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    62127 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    62128 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62129 File
    62130 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62131 packages/chimerax/graphics/drawing.py", line 1108, in
    62132 _first_intercept_excluding_children 
    62133 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    62134 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62135 File
    62136 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62137 packages/chimerax/geometry/place.py", line 201, in inverse 
    62138 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    62139 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62140 File
    62141 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62142 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    62143 rinv[:, :] = matrix_inverse(r) 
    62144 ^^^^^^^^^^^^^^^^^ 
    62145 File
    62146 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62147 packages/numpy/linalg/linalg.py", line 561, in inv 
    62148 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    62149 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62150 File
    62151 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62152 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    62153 raise LinAlgError("Singular matrix") 
    62154 numpy.linalg.LinAlgError: Singular matrix 
    62155  
    62156 numpy.linalg.LinAlgError: Singular matrix 
    62157  
    62158 File
    62159 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62160 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    62161 raise LinAlgError("Singular matrix") 
    62162  
    62163 See log for complete Python traceback. 
    62164  
    62165 Traceback (most recent call last): 
    62166 File
    62167 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62168 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    62169 self.session.ui.mouse_modes.mouse_pause_tracking() 
    62170 File
    62171 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62172 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    62173 mouse_pause_tracking 
    62174 self._mouse_pause() 
    62175 File
    62176 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62177 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    62178 m.pause(self._mouse_pause_position) 
    62179 File
    62180 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62181 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    62182 p = self.view.picked_object(x, y) 
    62183 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62184 File
    62185 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62186 packages/chimerax/graphics/view.py", line 838, in picked_object 
    62187 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    62188 beyond, 
    62189 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62190 File
    62191 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62192 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    62193 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    62194 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62195 File
    62196 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62197 packages/chimerax/core/models.py", line 143, in first_intercept 
    62198 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    62199 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62200 File
    62201 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62202 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    62203 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    62204 exclude=exclude) 
    62205 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62206 File
    62207 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62208 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    62209 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    62210 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62211 File
    62212 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62213 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    62214 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    62215 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62216 File
    62217 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62218 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    62219 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    62220 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62221 File
    62222 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62223 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    62224 p = super().first_intercept(mxyz1, mxyz2) 
    62225 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62226 File
    62227 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62228 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    62229 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    62230 exclude=exclude) 
    62231 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62232 File
    62233 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62234 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    62235 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    62236 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62237 File
    62238 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62239 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    62240 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    62241 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62242 File
    62243 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62244 packages/chimerax/graphics/drawing.py", line 1108, in
    62245 _first_intercept_excluding_children 
    62246 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    62247 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62248 File
    62249 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62250 packages/chimerax/geometry/place.py", line 201, in inverse 
    62251 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    62252 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62253 File
    62254 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62255 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    62256 rinv[:, :] = matrix_inverse(r) 
    62257 ^^^^^^^^^^^^^^^^^ 
    62258 File
    62259 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62260 packages/numpy/linalg/linalg.py", line 561, in inv 
    62261 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    62262 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62263 File
    62264 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62265 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    62266 raise LinAlgError("Singular matrix") 
    62267 numpy.linalg.LinAlgError: Singular matrix 
    62268  
    62269 numpy.linalg.LinAlgError: Singular matrix 
    62270  
    62271 File
    62272 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62273 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    62274 raise LinAlgError("Singular matrix") 
    62275  
    62276 See log for complete Python traceback. 
    62277  
    62278 Traceback (most recent call last): 
    62279 File
    62280 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62281 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    62282 self.session.ui.mouse_modes.mouse_pause_tracking() 
    62283 File
    62284 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62285 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    62286 mouse_pause_tracking 
    62287 self._mouse_pause() 
    62288 File
    62289 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62290 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    62291 m.pause(self._mouse_pause_position) 
    62292 File
    62293 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62294 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    62295 p = self.view.picked_object(x, y) 
    62296 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62297 File
    62298 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62299 packages/chimerax/graphics/view.py", line 838, in picked_object 
    62300 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    62301 beyond, 
    62302 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62303 File
    62304 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62305 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    62306 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    62307 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62308 File
    62309 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62310 packages/chimerax/core/models.py", line 143, in first_intercept 
    62311 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    62312 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62313 File
    62314 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62315 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    62316 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    62317 exclude=exclude) 
    62318 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62319 File
    62320 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62321 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    62322 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    62323 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62324 File
    62325 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62326 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    62327 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    62328 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62329 File
    62330 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62331 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    62332 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    62333 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62334 File
    62335 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62336 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    62337 p = super().first_intercept(mxyz1, mxyz2) 
    62338 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62339 File
    62340 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62341 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    62342 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    62343 exclude=exclude) 
    62344 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62345 File
    62346 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62347 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    62348 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    62349 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62350 File
    62351 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62352 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    62353 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    62354 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62355 File
    62356 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62357 packages/chimerax/graphics/drawing.py", line 1108, in
    62358 _first_intercept_excluding_children 
    62359 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    62360 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62361 File
    62362 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62363 packages/chimerax/geometry/place.py", line 201, in inverse 
    62364 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    62365 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62366 File
    62367 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62368 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    62369 rinv[:, :] = matrix_inverse(r) 
    62370 ^^^^^^^^^^^^^^^^^ 
    62371 File
    62372 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62373 packages/numpy/linalg/linalg.py", line 561, in inv 
    62374 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    62375 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62376 File
    62377 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62378 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    62379 raise LinAlgError("Singular matrix") 
    62380 numpy.linalg.LinAlgError: Singular matrix 
    62381  
    62382 numpy.linalg.LinAlgError: Singular matrix 
    62383  
    62384 File
    62385 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62386 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    62387 raise LinAlgError("Singular matrix") 
    62388  
    62389 See log for complete Python traceback. 
    62390  
    62391 Traceback (most recent call last): 
    62392 File
    62393 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62394 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    62395 self.session.ui.mouse_modes.mouse_pause_tracking() 
    62396 File
    62397 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62398 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    62399 mouse_pause_tracking 
    62400 self._mouse_pause() 
    62401 File
    62402 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62403 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    62404 m.pause(self._mouse_pause_position) 
    62405 File
    62406 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62407 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    62408 p = self.view.picked_object(x, y) 
    62409 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62410 File
    62411 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62412 packages/chimerax/graphics/view.py", line 838, in picked_object 
    62413 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    62414 beyond, 
    62415 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62416 File
    62417 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62418 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    62419 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    62420 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62421 File
    62422 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62423 packages/chimerax/core/models.py", line 143, in first_intercept 
    62424 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    62425 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62426 File
    62427 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62428 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    62429 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    62430 exclude=exclude) 
    62431 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62432 File
    62433 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62434 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    62435 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    62436 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62437 File
    62438 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62439 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    62440 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    62441 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62442 File
    62443 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62444 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    62445 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    62446 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62447 File
    62448 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62449 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    62450 p = super().first_intercept(mxyz1, mxyz2) 
    62451 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62452 File
    62453 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62454 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    62455 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    62456 exclude=exclude) 
    62457 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62458 File
    62459 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62460 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    62461 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    62462 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62463 File
    62464 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62465 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    62466 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    62467 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62468 File
    62469 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62470 packages/chimerax/graphics/drawing.py", line 1108, in
    62471 _first_intercept_excluding_children 
    62472 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    62473 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62474 File
    62475 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62476 packages/chimerax/geometry/place.py", line 201, in inverse 
    62477 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    62478 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62479 File
    62480 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62481 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    62482 rinv[:, :] = matrix_inverse(r) 
    62483 ^^^^^^^^^^^^^^^^^ 
    62484 File
    62485 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62486 packages/numpy/linalg/linalg.py", line 561, in inv 
    62487 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    62488 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62489 File
    62490 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62491 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    62492 raise LinAlgError("Singular matrix") 
    62493 numpy.linalg.LinAlgError: Singular matrix 
    62494  
    62495 numpy.linalg.LinAlgError: Singular matrix 
    62496  
    62497 File
    62498 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62499 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    62500 raise LinAlgError("Singular matrix") 
    62501  
    62502 See log for complete Python traceback. 
    62503  
    62504 Traceback (most recent call last): 
    62505 File
    62506 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62507 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    62508 self.session.ui.mouse_modes.mouse_pause_tracking() 
    62509 File
    62510 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62511 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    62512 mouse_pause_tracking 
    62513 self._mouse_pause() 
    62514 File
    62515 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62516 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    62517 m.pause(self._mouse_pause_position) 
    62518 File
    62519 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62520 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    62521 p = self.view.picked_object(x, y) 
    62522 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62523 File
    62524 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62525 packages/chimerax/graphics/view.py", line 838, in picked_object 
    62526 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    62527 beyond, 
    62528 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62529 File
    62530 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62531 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    62532 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    62533 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62534 File
    62535 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62536 packages/chimerax/core/models.py", line 143, in first_intercept 
    62537 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    62538 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62539 File
    62540 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62541 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    62542 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    62543 exclude=exclude) 
    62544 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62545 File
    62546 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62547 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    62548 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    62549 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62550 File
    62551 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62552 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    62553 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    62554 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62555 File
    62556 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62557 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    62558 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    62559 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62560 File
    62561 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62562 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    62563 p = super().first_intercept(mxyz1, mxyz2) 
    62564 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62565 File
    62566 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62567 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    62568 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    62569 exclude=exclude) 
    62570 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62571 File
    62572 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62573 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    62574 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    62575 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62576 File
    62577 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62578 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    62579 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    62580 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62581 File
    62582 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62583 packages/chimerax/graphics/drawing.py", line 1108, in
    62584 _first_intercept_excluding_children 
    62585 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    62586 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62587 File
    62588 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62589 packages/chimerax/geometry/place.py", line 201, in inverse 
    62590 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    62591 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62592 File
    62593 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62594 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    62595 rinv[:, :] = matrix_inverse(r) 
    62596 ^^^^^^^^^^^^^^^^^ 
    62597 File
    62598 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62599 packages/numpy/linalg/linalg.py", line 561, in inv 
    62600 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    62601 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62602 File
    62603 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62604 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    62605 raise LinAlgError("Singular matrix") 
    62606 numpy.linalg.LinAlgError: Singular matrix 
    62607  
    62608 numpy.linalg.LinAlgError: Singular matrix 
    62609  
    62610 File
    62611 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62612 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    62613 raise LinAlgError("Singular matrix") 
    62614  
    62615 See log for complete Python traceback. 
    62616  
    62617 Traceback (most recent call last): 
    62618 File
    62619 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62620 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    62621 self.session.ui.mouse_modes.mouse_pause_tracking() 
    62622 File
    62623 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62624 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    62625 mouse_pause_tracking 
    62626 self._mouse_pause() 
    62627 File
    62628 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62629 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    62630 m.pause(self._mouse_pause_position) 
    62631 File
    62632 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62633 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    62634 p = self.view.picked_object(x, y) 
    62635 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62636 File
    62637 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62638 packages/chimerax/graphics/view.py", line 838, in picked_object 
    62639 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    62640 beyond, 
    62641 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62642 File
    62643 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62644 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    62645 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    62646 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62647 File
    62648 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62649 packages/chimerax/core/models.py", line 143, in first_intercept 
    62650 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    62651 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62652 File
    62653 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62654 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    62655 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    62656 exclude=exclude) 
    62657 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62658 File
    62659 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62660 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    62661 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    62662 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62663 File
    62664 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62665 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    62666 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    62667 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62668 File
    62669 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62670 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    62671 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    62672 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62673 File
    62674 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62675 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    62676 p = super().first_intercept(mxyz1, mxyz2) 
    62677 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62678 File
    62679 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62680 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    62681 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    62682 exclude=exclude) 
    62683 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62684 File
    62685 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62686 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    62687 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    62688 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62689 File
    62690 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62691 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    62692 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    62693 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62694 File
    62695 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62696 packages/chimerax/graphics/drawing.py", line 1108, in
    62697 _first_intercept_excluding_children 
    62698 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    62699 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62700 File
    62701 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62702 packages/chimerax/geometry/place.py", line 201, in inverse 
    62703 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    62704 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62705 File
    62706 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62707 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    62708 rinv[:, :] = matrix_inverse(r) 
    62709 ^^^^^^^^^^^^^^^^^ 
    62710 File
    62711 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62712 packages/numpy/linalg/linalg.py", line 561, in inv 
    62713 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    62714 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62715 File
    62716 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62717 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    62718 raise LinAlgError("Singular matrix") 
    62719 numpy.linalg.LinAlgError: Singular matrix 
    62720  
    62721 numpy.linalg.LinAlgError: Singular matrix 
    62722  
    62723 File
    62724 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62725 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    62726 raise LinAlgError("Singular matrix") 
    62727  
    62728 See log for complete Python traceback. 
    62729  
    62730 Traceback (most recent call last): 
    62731 File
    62732 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62733 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    62734 self.session.ui.mouse_modes.mouse_pause_tracking() 
    62735 File
    62736 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62737 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    62738 mouse_pause_tracking 
    62739 self._mouse_pause() 
    62740 File
    62741 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62742 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    62743 m.pause(self._mouse_pause_position) 
    62744 File
    62745 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62746 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    62747 p = self.view.picked_object(x, y) 
    62748 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62749 File
    62750 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62751 packages/chimerax/graphics/view.py", line 838, in picked_object 
    62752 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    62753 beyond, 
    62754 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62755 File
    62756 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62757 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    62758 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    62759 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62760 File
    62761 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62762 packages/chimerax/core/models.py", line 143, in first_intercept 
    62763 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    62764 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62765 File
    62766 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62767 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    62768 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    62769 exclude=exclude) 
    62770 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62771 File
    62772 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62773 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    62774 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    62775 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62776 File
    62777 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62778 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    62779 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    62780 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62781 File
    62782 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62783 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    62784 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    62785 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62786 File
    62787 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62788 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    62789 p = super().first_intercept(mxyz1, mxyz2) 
    62790 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62791 File
    62792 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62793 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    62794 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    62795 exclude=exclude) 
    62796 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62797 File
    62798 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62799 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    62800 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    62801 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62802 File
    62803 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62804 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    62805 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    62806 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62807 File
    62808 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62809 packages/chimerax/graphics/drawing.py", line 1108, in
    62810 _first_intercept_excluding_children 
    62811 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    62812 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62813 File
    62814 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62815 packages/chimerax/geometry/place.py", line 201, in inverse 
    62816 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    62817 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62818 File
    62819 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62820 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    62821 rinv[:, :] = matrix_inverse(r) 
    62822 ^^^^^^^^^^^^^^^^^ 
    62823 File
    62824 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62825 packages/numpy/linalg/linalg.py", line 561, in inv 
    62826 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    62827 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62828 File
    62829 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62830 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    62831 raise LinAlgError("Singular matrix") 
    62832 numpy.linalg.LinAlgError: Singular matrix 
    62833  
    62834 numpy.linalg.LinAlgError: Singular matrix 
    62835  
    62836 File
    62837 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62838 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    62839 raise LinAlgError("Singular matrix") 
    62840  
    62841 See log for complete Python traceback. 
    62842  
    62843 Traceback (most recent call last): 
    62844 File
    62845 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62846 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    62847 self.session.ui.mouse_modes.mouse_pause_tracking() 
    62848 File
    62849 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62850 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    62851 mouse_pause_tracking 
    62852 self._mouse_pause() 
    62853 File
    62854 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62855 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    62856 m.pause(self._mouse_pause_position) 
    62857 File
    62858 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62859 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    62860 p = self.view.picked_object(x, y) 
    62861 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62862 File
    62863 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62864 packages/chimerax/graphics/view.py", line 838, in picked_object 
    62865 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    62866 beyond, 
    62867 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62868 File
    62869 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62870 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    62871 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    62872 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62873 File
    62874 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62875 packages/chimerax/core/models.py", line 143, in first_intercept 
    62876 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    62877 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62878 File
    62879 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62880 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    62881 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    62882 exclude=exclude) 
    62883 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62884 File
    62885 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62886 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    62887 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    62888 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62889 File
    62890 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62891 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    62892 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    62893 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62894 File
    62895 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62896 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    62897 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    62898 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62899 File
    62900 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62901 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    62902 p = super().first_intercept(mxyz1, mxyz2) 
    62903 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62904 File
    62905 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62906 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    62907 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    62908 exclude=exclude) 
    62909 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62910 File
    62911 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62912 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    62913 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    62914 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62915 File
    62916 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62917 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    62918 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    62919 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62920 File
    62921 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62922 packages/chimerax/graphics/drawing.py", line 1108, in
    62923 _first_intercept_excluding_children 
    62924 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    62925 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62926 File
    62927 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62928 packages/chimerax/geometry/place.py", line 201, in inverse 
    62929 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    62930 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62931 File
    62932 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62933 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    62934 rinv[:, :] = matrix_inverse(r) 
    62935 ^^^^^^^^^^^^^^^^^ 
    62936 File
    62937 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62938 packages/numpy/linalg/linalg.py", line 561, in inv 
    62939 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    62940 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62941 File
    62942 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62943 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    62944 raise LinAlgError("Singular matrix") 
    62945 numpy.linalg.LinAlgError: Singular matrix 
    62946  
    62947 numpy.linalg.LinAlgError: Singular matrix 
    62948  
    62949 File
    62950 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62951 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    62952 raise LinAlgError("Singular matrix") 
    62953  
    62954 See log for complete Python traceback. 
    62955  
    62956 Traceback (most recent call last): 
    62957 File
    62958 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62959 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    62960 self.session.ui.mouse_modes.mouse_pause_tracking() 
    62961 File
    62962 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62963 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    62964 mouse_pause_tracking 
    62965 self._mouse_pause() 
    62966 File
    62967 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62968 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    62969 m.pause(self._mouse_pause_position) 
    62970 File
    62971 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62972 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    62973 p = self.view.picked_object(x, y) 
    62974 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62975 File
    62976 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62977 packages/chimerax/graphics/view.py", line 838, in picked_object 
    62978 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    62979 beyond, 
    62980 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62981 File
    62982 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62983 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    62984 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    62985 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62986 File
    62987 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62988 packages/chimerax/core/models.py", line 143, in first_intercept 
    62989 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    62990 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62991 File
    62992 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62993 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    62994 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    62995 exclude=exclude) 
    62996 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    62997 File
    62998 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    62999 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    63000 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    63001 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63002 File
    63003 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63004 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    63005 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    63006 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63007 File
    63008 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63009 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    63010 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    63011 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63012 File
    63013 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63014 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    63015 p = super().first_intercept(mxyz1, mxyz2) 
    63016 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63017 File
    63018 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63019 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    63020 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    63021 exclude=exclude) 
    63022 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63023 File
    63024 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63025 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    63026 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    63027 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63028 File
    63029 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63030 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    63031 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    63032 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63033 File
    63034 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63035 packages/chimerax/graphics/drawing.py", line 1108, in
    63036 _first_intercept_excluding_children 
    63037 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    63038 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63039 File
    63040 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63041 packages/chimerax/geometry/place.py", line 201, in inverse 
    63042 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    63043 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63044 File
    63045 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63046 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    63047 rinv[:, :] = matrix_inverse(r) 
    63048 ^^^^^^^^^^^^^^^^^ 
    63049 File
    63050 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63051 packages/numpy/linalg/linalg.py", line 561, in inv 
    63052 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    63053 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63054 File
    63055 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63056 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    63057 raise LinAlgError("Singular matrix") 
    63058 numpy.linalg.LinAlgError: Singular matrix 
    63059  
    63060 numpy.linalg.LinAlgError: Singular matrix 
    63061  
    63062 File
    63063 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63064 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    63065 raise LinAlgError("Singular matrix") 
    63066  
    63067 See log for complete Python traceback. 
    63068  
    63069 Traceback (most recent call last): 
    63070 File
    63071 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63072 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    63073 self.session.ui.mouse_modes.mouse_pause_tracking() 
    63074 File
    63075 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63076 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    63077 mouse_pause_tracking 
    63078 self._mouse_pause() 
    63079 File
    63080 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63081 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    63082 m.pause(self._mouse_pause_position) 
    63083 File
    63084 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63085 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    63086 p = self.view.picked_object(x, y) 
    63087 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63088 File
    63089 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63090 packages/chimerax/graphics/view.py", line 838, in picked_object 
    63091 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    63092 beyond, 
    63093 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63094 File
    63095 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63096 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    63097 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    63098 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63099 File
    63100 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63101 packages/chimerax/core/models.py", line 143, in first_intercept 
    63102 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    63103 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63104 File
    63105 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63106 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    63107 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    63108 exclude=exclude) 
    63109 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63110 File
    63111 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63112 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    63113 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    63114 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63115 File
    63116 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63117 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    63118 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    63119 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63120 File
    63121 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63122 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    63123 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    63124 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63125 File
    63126 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63127 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    63128 p = super().first_intercept(mxyz1, mxyz2) 
    63129 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63130 File
    63131 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63132 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    63133 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    63134 exclude=exclude) 
    63135 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63136 File
    63137 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63138 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    63139 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    63140 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63141 File
    63142 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63143 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    63144 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    63145 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63146 File
    63147 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63148 packages/chimerax/graphics/drawing.py", line 1108, in
    63149 _first_intercept_excluding_children 
    63150 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    63151 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63152 File
    63153 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63154 packages/chimerax/geometry/place.py", line 201, in inverse 
    63155 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    63156 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63157 File
    63158 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63159 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    63160 rinv[:, :] = matrix_inverse(r) 
    63161 ^^^^^^^^^^^^^^^^^ 
    63162 File
    63163 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63164 packages/numpy/linalg/linalg.py", line 561, in inv 
    63165 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    63166 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63167 File
    63168 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63169 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    63170 raise LinAlgError("Singular matrix") 
    63171 numpy.linalg.LinAlgError: Singular matrix 
    63172  
    63173 numpy.linalg.LinAlgError: Singular matrix 
    63174  
    63175 File
    63176 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63177 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    63178 raise LinAlgError("Singular matrix") 
    63179  
    63180 See log for complete Python traceback. 
    63181  
    63182 
    63183 > color #5.2 #160711ff models
    63184 
    63185 > color #5.2 #cea62dff models
    63186 
    63187 > color #5.2 #d67325ff models
    63188 
    63189 > select #5/E/F
    63190 
    63191 907 atoms, 972 bonds, 51 pseudobonds, 82 residues, 4 models selected 
    63192 
    63193 > color sel slate gray
    63194 
    63195 > lighting full
    63196 
    63197 > lighting simple
    63198 
    63199 > color sel silver
    63200 
    63201 > color sel tan
    63202 
    63203 > color sel olive
    63204 
    63205 > color sel peru
    63206 
    63207 > color sel sadle brown
    63208 
    63209 Expected a color or one of 'byatom', 'bychain', 'byelement', 'byhetero',
    63210 'byidentity', 'bymodel', 'bynucleotide', 'bypolymer', 'fromatoms',
    63211 'fromcartoons', 'fromribbons', or 'random' or a keyword 
    63212 
    63213 > lighting full
    63214 
    63215 > lighting simple
    63216 
    63217 > lighting soft
    63218 
    63219 > lighting simple
    63220 
    63221 > lighting soft
    63222 
    63223 > lighting full
    63224 
    63225 > lighting soft
    63226 
    63227 > lighting simple
    63228 
    63229 > color sel alice blue
    63230 
    63231 > color sel mint cream
    63232 
    63233 > color sel lavender
    63234 
    63235 > color sel thistle
    63236 
    63237 > color sel light steel blue
    63238 
    63239 > color sel dark khaki
    63240 
    63241 > color sel dark olive green
    63242 
    63243 > color sel darkred see green
    63244 
    63245 Expected a collection of one of 'All', 'atoms', 'bonds', 'cartoons', 'labels',
    63246 'models', 'pseudobonds', 'ribbons', 'rings', or 'surfaces' or a keyword 
    63247 
    63248 > color sel dark sea green
    63249 
    63250 > color sel cadet blue
    63251 
    63252 > select #1:510
    63253 
    63254 24 atoms, 20 bonds, 4 residues, 1 model selected 
    63255 
    63256 > select #1:513
    63257 
    63258 32 atoms, 28 bonds, 4 residues, 1 model selected 
    63259 
    63260 > color sel blue
    63261 
    63262 > color sel byhetero
    63263 
    63264 > select #1:511
    63265 
    63266 34 atoms, 30 bonds, 4 residues, 1 model selected 
    63267 
    63268 > color sel blue
    63269 
    63270 > color sel byhetero
    63271 
    63272 > select clear
    63273 
    63274 Traceback (most recent call last): 
    63275 File
    63276 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63277 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    63278 self.session.ui.mouse_modes.mouse_pause_tracking() 
    63279 File
    63280 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63281 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    63282 mouse_pause_tracking 
    63283 self._mouse_pause() 
    63284 File
    63285 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63286 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    63287 m.pause(self._mouse_pause_position) 
    63288 File
    63289 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63290 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    63291 p = self.view.picked_object(x, y) 
    63292 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63293 File
    63294 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63295 packages/chimerax/graphics/view.py", line 838, in picked_object 
    63296 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    63297 beyond, 
    63298 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63299 File
    63300 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63301 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    63302 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    63303 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63304 File
    63305 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63306 packages/chimerax/core/models.py", line 143, in first_intercept 
    63307 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    63308 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63309 File
    63310 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63311 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    63312 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    63313 exclude=exclude) 
    63314 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63315 File
    63316 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63317 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    63318 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    63319 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63320 File
    63321 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63322 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    63323 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    63324 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63325 File
    63326 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63327 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    63328 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    63329 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63330 File
    63331 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63332 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    63333 p = super().first_intercept(mxyz1, mxyz2) 
    63334 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63335 File
    63336 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63337 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    63338 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    63339 exclude=exclude) 
    63340 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63341 File
    63342 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63343 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    63344 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    63345 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63346 File
    63347 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63348 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    63349 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    63350 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63351 File
    63352 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63353 packages/chimerax/graphics/drawing.py", line 1108, in
    63354 _first_intercept_excluding_children 
    63355 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    63356 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63357 File
    63358 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63359 packages/chimerax/geometry/place.py", line 201, in inverse 
    63360 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    63361 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63362 File
    63363 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63364 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    63365 rinv[:, :] = matrix_inverse(r) 
    63366 ^^^^^^^^^^^^^^^^^ 
    63367 File
    63368 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63369 packages/numpy/linalg/linalg.py", line 561, in inv 
    63370 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    63371 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63372 File
    63373 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63374 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    63375 raise LinAlgError("Singular matrix") 
    63376 numpy.linalg.LinAlgError: Singular matrix 
    63377  
    63378 numpy.linalg.LinAlgError: Singular matrix 
    63379  
    63380 File
    63381 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63382 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    63383 raise LinAlgError("Singular matrix") 
    63384  
    63385 See log for complete Python traceback. 
    63386  
    63387 Traceback (most recent call last): 
    63388 File
    63389 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63390 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    63391 self.session.ui.mouse_modes.mouse_pause_tracking() 
    63392 File
    63393 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63394 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    63395 mouse_pause_tracking 
    63396 self._mouse_pause() 
    63397 File
    63398 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63399 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    63400 m.pause(self._mouse_pause_position) 
    63401 File
    63402 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63403 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    63404 p = self.view.picked_object(x, y) 
    63405 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63406 File
    63407 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63408 packages/chimerax/graphics/view.py", line 838, in picked_object 
    63409 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    63410 beyond, 
    63411 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63412 File
    63413 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63414 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    63415 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    63416 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63417 File
    63418 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63419 packages/chimerax/core/models.py", line 143, in first_intercept 
    63420 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    63421 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63422 File
    63423 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63424 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    63425 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    63426 exclude=exclude) 
    63427 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63428 File
    63429 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63430 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    63431 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    63432 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63433 File
    63434 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63435 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    63436 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    63437 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63438 File
    63439 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63440 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    63441 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    63442 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63443 File
    63444 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63445 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    63446 p = super().first_intercept(mxyz1, mxyz2) 
    63447 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63448 File
    63449 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63450 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    63451 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    63452 exclude=exclude) 
    63453 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63454 File
    63455 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63456 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    63457 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    63458 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63459 File
    63460 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63461 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    63462 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    63463 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63464 File
    63465 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63466 packages/chimerax/graphics/drawing.py", line 1108, in
    63467 _first_intercept_excluding_children 
    63468 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    63469 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63470 File
    63471 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63472 packages/chimerax/geometry/place.py", line 201, in inverse 
    63473 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    63474 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63475 File
    63476 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63477 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    63478 rinv[:, :] = matrix_inverse(r) 
    63479 ^^^^^^^^^^^^^^^^^ 
    63480 File
    63481 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63482 packages/numpy/linalg/linalg.py", line 561, in inv 
    63483 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    63484 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63485 File
    63486 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63487 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    63488 raise LinAlgError("Singular matrix") 
    63489 numpy.linalg.LinAlgError: Singular matrix 
    63490  
    63491 numpy.linalg.LinAlgError: Singular matrix 
    63492  
    63493 File
    63494 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63495 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    63496 raise LinAlgError("Singular matrix") 
    63497  
    63498 See log for complete Python traceback. 
    63499  
    63500 Traceback (most recent call last): 
    63501 File
    63502 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63503 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    63504 self.session.ui.mouse_modes.mouse_pause_tracking() 
    63505 File
    63506 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63507 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    63508 mouse_pause_tracking 
    63509 self._mouse_pause() 
    63510 File
    63511 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63512 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    63513 m.pause(self._mouse_pause_position) 
    63514 File
    63515 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63516 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    63517 p = self.view.picked_object(x, y) 
    63518 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63519 File
    63520 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63521 packages/chimerax/graphics/view.py", line 838, in picked_object 
    63522 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    63523 beyond, 
    63524 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63525 File
    63526 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63527 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    63528 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    63529 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63530 File
    63531 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63532 packages/chimerax/core/models.py", line 143, in first_intercept 
    63533 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    63534 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63535 File
    63536 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63537 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    63538 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    63539 exclude=exclude) 
    63540 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63541 File
    63542 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63543 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    63544 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    63545 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63546 File
    63547 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63548 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    63549 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    63550 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63551 File
    63552 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63553 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    63554 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    63555 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63556 File
    63557 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63558 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    63559 p = super().first_intercept(mxyz1, mxyz2) 
    63560 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63561 File
    63562 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63563 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    63564 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    63565 exclude=exclude) 
    63566 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63567 File
    63568 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63569 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    63570 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    63571 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63572 File
    63573 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63574 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    63575 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    63576 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63577 File
    63578 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63579 packages/chimerax/graphics/drawing.py", line 1108, in
    63580 _first_intercept_excluding_children 
    63581 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    63582 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63583 File
    63584 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63585 packages/chimerax/geometry/place.py", line 201, in inverse 
    63586 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    63587 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63588 File
    63589 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63590 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    63591 rinv[:, :] = matrix_inverse(r) 
    63592 ^^^^^^^^^^^^^^^^^ 
    63593 File
    63594 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63595 packages/numpy/linalg/linalg.py", line 561, in inv 
    63596 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    63597 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63598 File
    63599 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63600 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    63601 raise LinAlgError("Singular matrix") 
    63602 numpy.linalg.LinAlgError: Singular matrix 
    63603  
    63604 numpy.linalg.LinAlgError: Singular matrix 
    63605  
    63606 File
    63607 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63608 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    63609 raise LinAlgError("Singular matrix") 
    63610  
    63611 See log for complete Python traceback. 
    63612  
    63613 Traceback (most recent call last): 
    63614 File
    63615 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63616 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    63617 self.session.ui.mouse_modes.mouse_pause_tracking() 
    63618 File
    63619 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63620 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    63621 mouse_pause_tracking 
    63622 self._mouse_pause() 
    63623 File
    63624 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63625 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    63626 m.pause(self._mouse_pause_position) 
    63627 File
    63628 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63629 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    63630 p = self.view.picked_object(x, y) 
    63631 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63632 File
    63633 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63634 packages/chimerax/graphics/view.py", line 838, in picked_object 
    63635 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    63636 beyond, 
    63637 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63638 File
    63639 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63640 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    63641 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    63642 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63643 File
    63644 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63645 packages/chimerax/core/models.py", line 143, in first_intercept 
    63646 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    63647 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63648 File
    63649 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63650 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    63651 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    63652 exclude=exclude) 
    63653 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63654 File
    63655 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63656 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    63657 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    63658 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63659 File
    63660 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63661 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    63662 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    63663 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63664 File
    63665 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63666 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    63667 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    63668 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63669 File
    63670 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63671 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    63672 p = super().first_intercept(mxyz1, mxyz2) 
    63673 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63674 File
    63675 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63676 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    63677 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    63678 exclude=exclude) 
    63679 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63680 File
    63681 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63682 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    63683 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    63684 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63685 File
    63686 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63687 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    63688 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    63689 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63690 File
    63691 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63692 packages/chimerax/graphics/drawing.py", line 1108, in
    63693 _first_intercept_excluding_children 
    63694 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    63695 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63696 File
    63697 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63698 packages/chimerax/geometry/place.py", line 201, in inverse 
    63699 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    63700 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63701 File
    63702 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63703 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    63704 rinv[:, :] = matrix_inverse(r) 
    63705 ^^^^^^^^^^^^^^^^^ 
    63706 File
    63707 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63708 packages/numpy/linalg/linalg.py", line 561, in inv 
    63709 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    63710 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63711 File
    63712 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63713 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    63714 raise LinAlgError("Singular matrix") 
    63715 numpy.linalg.LinAlgError: Singular matrix 
    63716  
    63717 numpy.linalg.LinAlgError: Singular matrix 
    63718  
    63719 File
    63720 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63721 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    63722 raise LinAlgError("Singular matrix") 
    63723  
    63724 See log for complete Python traceback. 
    63725  
    63726 Traceback (most recent call last): 
    63727 File
    63728 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63729 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    63730 self.session.ui.mouse_modes.mouse_pause_tracking() 
    63731 File
    63732 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63733 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    63734 mouse_pause_tracking 
    63735 self._mouse_pause() 
    63736 File
    63737 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63738 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    63739 m.pause(self._mouse_pause_position) 
    63740 File
    63741 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63742 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    63743 p = self.view.picked_object(x, y) 
    63744 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63745 File
    63746 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63747 packages/chimerax/graphics/view.py", line 838, in picked_object 
    63748 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    63749 beyond, 
    63750 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63751 File
    63752 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63753 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    63754 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    63755 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63756 File
    63757 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63758 packages/chimerax/core/models.py", line 143, in first_intercept 
    63759 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    63760 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63761 File
    63762 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63763 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    63764 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    63765 exclude=exclude) 
    63766 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63767 File
    63768 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63769 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    63770 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    63771 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63772 File
    63773 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63774 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    63775 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    63776 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63777 File
    63778 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63779 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    63780 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    63781 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63782 File
    63783 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63784 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    63785 p = super().first_intercept(mxyz1, mxyz2) 
    63786 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63787 File
    63788 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63789 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    63790 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    63791 exclude=exclude) 
    63792 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63793 File
    63794 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63795 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    63796 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    63797 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63798 File
    63799 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63800 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    63801 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    63802 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63803 File
    63804 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63805 packages/chimerax/graphics/drawing.py", line 1108, in
    63806 _first_intercept_excluding_children 
    63807 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    63808 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63809 File
    63810 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63811 packages/chimerax/geometry/place.py", line 201, in inverse 
    63812 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    63813 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63814 File
    63815 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63816 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    63817 rinv[:, :] = matrix_inverse(r) 
    63818 ^^^^^^^^^^^^^^^^^ 
    63819 File
    63820 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63821 packages/numpy/linalg/linalg.py", line 561, in inv 
    63822 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    63823 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63824 File
    63825 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63826 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    63827 raise LinAlgError("Singular matrix") 
    63828 numpy.linalg.LinAlgError: Singular matrix 
    63829  
    63830 numpy.linalg.LinAlgError: Singular matrix 
    63831  
    63832 File
    63833 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63834 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    63835 raise LinAlgError("Singular matrix") 
    63836  
    63837 See log for complete Python traceback. 
    63838  
    63839 Traceback (most recent call last): 
    63840 File
    63841 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63842 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    63843 self.session.ui.mouse_modes.mouse_pause_tracking() 
    63844 File
    63845 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63846 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    63847 mouse_pause_tracking 
    63848 self._mouse_pause() 
    63849 File
    63850 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63851 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    63852 m.pause(self._mouse_pause_position) 
    63853 File
    63854 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63855 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    63856 p = self.view.picked_object(x, y) 
    63857 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63858 File
    63859 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63860 packages/chimerax/graphics/view.py", line 838, in picked_object 
    63861 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    63862 beyond, 
    63863 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63864 File
    63865 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63866 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    63867 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    63868 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63869 File
    63870 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63871 packages/chimerax/core/models.py", line 143, in first_intercept 
    63872 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    63873 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63874 File
    63875 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63876 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    63877 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    63878 exclude=exclude) 
    63879 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63880 File
    63881 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63882 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    63883 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    63884 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63885 File
    63886 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63887 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    63888 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    63889 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63890 File
    63891 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63892 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    63893 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    63894 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63895 File
    63896 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63897 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    63898 p = super().first_intercept(mxyz1, mxyz2) 
    63899 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63900 File
    63901 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63902 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    63903 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    63904 exclude=exclude) 
    63905 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63906 File
    63907 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63908 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    63909 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    63910 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63911 File
    63912 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63913 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    63914 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    63915 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63916 File
    63917 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63918 packages/chimerax/graphics/drawing.py", line 1108, in
    63919 _first_intercept_excluding_children 
    63920 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    63921 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63922 File
    63923 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63924 packages/chimerax/geometry/place.py", line 201, in inverse 
    63925 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    63926 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63927 File
    63928 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63929 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    63930 rinv[:, :] = matrix_inverse(r) 
    63931 ^^^^^^^^^^^^^^^^^ 
    63932 File
    63933 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63934 packages/numpy/linalg/linalg.py", line 561, in inv 
    63935 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    63936 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63937 File
    63938 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63939 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    63940 raise LinAlgError("Singular matrix") 
    63941 numpy.linalg.LinAlgError: Singular matrix 
    63942  
    63943 numpy.linalg.LinAlgError: Singular matrix 
    63944  
    63945 File
    63946 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63947 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    63948 raise LinAlgError("Singular matrix") 
    63949  
    63950 See log for complete Python traceback. 
    63951  
    63952 Traceback (most recent call last): 
    63953 File
    63954 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63955 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    63956 self.session.ui.mouse_modes.mouse_pause_tracking() 
    63957 File
    63958 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63959 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    63960 mouse_pause_tracking 
    63961 self._mouse_pause() 
    63962 File
    63963 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63964 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    63965 m.pause(self._mouse_pause_position) 
    63966 File
    63967 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63968 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    63969 p = self.view.picked_object(x, y) 
    63970 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63971 File
    63972 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63973 packages/chimerax/graphics/view.py", line 838, in picked_object 
    63974 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    63975 beyond, 
    63976 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63977 File
    63978 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63979 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    63980 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    63981 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63982 File
    63983 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63984 packages/chimerax/core/models.py", line 143, in first_intercept 
    63985 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    63986 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63987 File
    63988 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63989 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    63990 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    63991 exclude=exclude) 
    63992 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63993 File
    63994 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    63995 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    63996 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    63997 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    63998 File
    63999 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64000 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    64001 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    64002 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64003 File
    64004 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64005 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    64006 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    64007 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64008 File
    64009 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64010 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    64011 p = super().first_intercept(mxyz1, mxyz2) 
    64012 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64013 File
    64014 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64015 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    64016 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    64017 exclude=exclude) 
    64018 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64019 File
    64020 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64021 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    64022 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    64023 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64024 File
    64025 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64026 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    64027 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    64028 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64029 File
    64030 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64031 packages/chimerax/graphics/drawing.py", line 1108, in
    64032 _first_intercept_excluding_children 
    64033 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    64034 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64035 File
    64036 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64037 packages/chimerax/geometry/place.py", line 201, in inverse 
    64038 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    64039 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64040 File
    64041 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64042 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    64043 rinv[:, :] = matrix_inverse(r) 
    64044 ^^^^^^^^^^^^^^^^^ 
    64045 File
    64046 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64047 packages/numpy/linalg/linalg.py", line 561, in inv 
    64048 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    64049 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64050 File
    64051 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64052 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    64053 raise LinAlgError("Singular matrix") 
    64054 numpy.linalg.LinAlgError: Singular matrix 
    64055  
    64056 numpy.linalg.LinAlgError: Singular matrix 
    64057  
    64058 File
    64059 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64060 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    64061 raise LinAlgError("Singular matrix") 
    64062  
    64063 See log for complete Python traceback. 
    64064  
    64065 Traceback (most recent call last): 
    64066 File
    64067 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64068 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    64069 self.session.ui.mouse_modes.mouse_pause_tracking() 
    64070 File
    64071 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64072 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    64073 mouse_pause_tracking 
    64074 self._mouse_pause() 
    64075 File
    64076 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64077 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    64078 m.pause(self._mouse_pause_position) 
    64079 File
    64080 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64081 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    64082 p = self.view.picked_object(x, y) 
    64083 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64084 File
    64085 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64086 packages/chimerax/graphics/view.py", line 838, in picked_object 
    64087 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    64088 beyond, 
    64089 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64090 File
    64091 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64092 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    64093 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    64094 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64095 File
    64096 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64097 packages/chimerax/core/models.py", line 143, in first_intercept 
    64098 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    64099 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64100 File
    64101 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64102 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    64103 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    64104 exclude=exclude) 
    64105 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64106 File
    64107 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64108 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    64109 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    64110 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64111 File
    64112 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64113 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    64114 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    64115 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64116 File
    64117 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64118 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    64119 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    64120 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64121 File
    64122 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64123 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    64124 p = super().first_intercept(mxyz1, mxyz2) 
    64125 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64126 File
    64127 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64128 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    64129 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    64130 exclude=exclude) 
    64131 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64132 File
    64133 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64134 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    64135 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    64136 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64137 File
    64138 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64139 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    64140 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    64141 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64142 File
    64143 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64144 packages/chimerax/graphics/drawing.py", line 1108, in
    64145 _first_intercept_excluding_children 
    64146 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    64147 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64148 File
    64149 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64150 packages/chimerax/geometry/place.py", line 201, in inverse 
    64151 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    64152 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64153 File
    64154 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64155 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    64156 rinv[:, :] = matrix_inverse(r) 
    64157 ^^^^^^^^^^^^^^^^^ 
    64158 File
    64159 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64160 packages/numpy/linalg/linalg.py", line 561, in inv 
    64161 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    64162 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64163 File
    64164 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64165 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    64166 raise LinAlgError("Singular matrix") 
    64167 numpy.linalg.LinAlgError: Singular matrix 
    64168  
    64169 numpy.linalg.LinAlgError: Singular matrix 
    64170  
    64171 File
    64172 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64173 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    64174 raise LinAlgError("Singular matrix") 
    64175  
    64176 See log for complete Python traceback. 
    64177  
    64178 Traceback (most recent call last): 
    64179 File
    64180 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64181 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    64182 self.session.ui.mouse_modes.mouse_pause_tracking() 
    64183 File
    64184 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64185 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    64186 mouse_pause_tracking 
    64187 self._mouse_pause() 
    64188 File
    64189 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64190 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    64191 m.pause(self._mouse_pause_position) 
    64192 File
    64193 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64194 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    64195 p = self.view.picked_object(x, y) 
    64196 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64197 File
    64198 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64199 packages/chimerax/graphics/view.py", line 838, in picked_object 
    64200 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    64201 beyond, 
    64202 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64203 File
    64204 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64205 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    64206 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    64207 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64208 File
    64209 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64210 packages/chimerax/core/models.py", line 143, in first_intercept 
    64211 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    64212 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64213 File
    64214 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64215 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    64216 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    64217 exclude=exclude) 
    64218 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64219 File
    64220 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64221 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    64222 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    64223 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64224 File
    64225 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64226 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    64227 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    64228 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64229 File
    64230 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64231 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    64232 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    64233 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64234 File
    64235 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64236 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    64237 p = super().first_intercept(mxyz1, mxyz2) 
    64238 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64239 File
    64240 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64241 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    64242 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    64243 exclude=exclude) 
    64244 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64245 File
    64246 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64247 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    64248 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    64249 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64250 File
    64251 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64252 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    64253 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    64254 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64255 File
    64256 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64257 packages/chimerax/graphics/drawing.py", line 1108, in
    64258 _first_intercept_excluding_children 
    64259 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    64260 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64261 File
    64262 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64263 packages/chimerax/geometry/place.py", line 201, in inverse 
    64264 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    64265 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64266 File
    64267 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64268 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    64269 rinv[:, :] = matrix_inverse(r) 
    64270 ^^^^^^^^^^^^^^^^^ 
    64271 File
    64272 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64273 packages/numpy/linalg/linalg.py", line 561, in inv 
    64274 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    64275 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64276 File
    64277 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64278 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    64279 raise LinAlgError("Singular matrix") 
    64280 numpy.linalg.LinAlgError: Singular matrix 
    64281  
    64282 numpy.linalg.LinAlgError: Singular matrix 
    64283  
    64284 File
    64285 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64286 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    64287 raise LinAlgError("Singular matrix") 
    64288  
    64289 See log for complete Python traceback. 
    64290  
    64291 Traceback (most recent call last): 
    64292 File
    64293 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64294 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    64295 self.session.ui.mouse_modes.mouse_pause_tracking() 
    64296 File
    64297 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64298 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    64299 mouse_pause_tracking 
    64300 self._mouse_pause() 
    64301 File
    64302 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64303 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    64304 m.pause(self._mouse_pause_position) 
    64305 File
    64306 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64307 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    64308 p = self.view.picked_object(x, y) 
    64309 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64310 File
    64311 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64312 packages/chimerax/graphics/view.py", line 838, in picked_object 
    64313 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    64314 beyond, 
    64315 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64316 File
    64317 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64318 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    64319 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    64320 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64321 File
    64322 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64323 packages/chimerax/core/models.py", line 143, in first_intercept 
    64324 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    64325 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64326 File
    64327 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64328 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    64329 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    64330 exclude=exclude) 
    64331 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64332 File
    64333 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64334 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    64335 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    64336 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64337 File
    64338 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64339 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    64340 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    64341 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64342 File
    64343 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64344 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    64345 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    64346 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64347 File
    64348 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64349 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    64350 p = super().first_intercept(mxyz1, mxyz2) 
    64351 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64352 File
    64353 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64354 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    64355 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    64356 exclude=exclude) 
    64357 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64358 File
    64359 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64360 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    64361 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    64362 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64363 File
    64364 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64365 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    64366 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    64367 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64368 File
    64369 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64370 packages/chimerax/graphics/drawing.py", line 1108, in
    64371 _first_intercept_excluding_children 
    64372 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    64373 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64374 File
    64375 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64376 packages/chimerax/geometry/place.py", line 201, in inverse 
    64377 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    64378 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64379 File
    64380 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64381 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    64382 rinv[:, :] = matrix_inverse(r) 
    64383 ^^^^^^^^^^^^^^^^^ 
    64384 File
    64385 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64386 packages/numpy/linalg/linalg.py", line 561, in inv 
    64387 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    64388 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64389 File
    64390 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64391 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    64392 raise LinAlgError("Singular matrix") 
    64393 numpy.linalg.LinAlgError: Singular matrix 
    64394  
    64395 numpy.linalg.LinAlgError: Singular matrix 
    64396  
    64397 File
    64398 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64399 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    64400 raise LinAlgError("Singular matrix") 
    64401  
    64402 See log for complete Python traceback. 
    64403  
    64404 Traceback (most recent call last): 
    64405 File
    64406 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64407 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    64408 self.session.ui.mouse_modes.mouse_pause_tracking() 
    64409 File
    64410 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64411 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    64412 mouse_pause_tracking 
    64413 self._mouse_pause() 
    64414 File
    64415 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64416 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    64417 m.pause(self._mouse_pause_position) 
    64418 File
    64419 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64420 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    64421 p = self.view.picked_object(x, y) 
    64422 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64423 File
    64424 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64425 packages/chimerax/graphics/view.py", line 838, in picked_object 
    64426 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    64427 beyond, 
    64428 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64429 File
    64430 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64431 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    64432 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    64433 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64434 File
    64435 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64436 packages/chimerax/core/models.py", line 143, in first_intercept 
    64437 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    64438 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64439 File
    64440 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64441 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    64442 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    64443 exclude=exclude) 
    64444 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64445 File
    64446 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64447 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    64448 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    64449 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64450 File
    64451 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64452 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    64453 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    64454 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64455 File
    64456 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64457 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    64458 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    64459 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64460 File
    64461 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64462 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    64463 p = super().first_intercept(mxyz1, mxyz2) 
    64464 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64465 File
    64466 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64467 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    64468 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    64469 exclude=exclude) 
    64470 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64471 File
    64472 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64473 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    64474 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    64475 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64476 File
    64477 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64478 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    64479 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    64480 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64481 File
    64482 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64483 packages/chimerax/graphics/drawing.py", line 1108, in
    64484 _first_intercept_excluding_children 
    64485 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    64486 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64487 File
    64488 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64489 packages/chimerax/geometry/place.py", line 201, in inverse 
    64490 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    64491 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64492 File
    64493 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64494 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    64495 rinv[:, :] = matrix_inverse(r) 
    64496 ^^^^^^^^^^^^^^^^^ 
    64497 File
    64498 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64499 packages/numpy/linalg/linalg.py", line 561, in inv 
    64500 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    64501 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64502 File
    64503 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64504 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    64505 raise LinAlgError("Singular matrix") 
    64506 numpy.linalg.LinAlgError: Singular matrix 
    64507  
    64508 numpy.linalg.LinAlgError: Singular matrix 
    64509  
    64510 File
    64511 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64512 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    64513 raise LinAlgError("Singular matrix") 
    64514  
    64515 See log for complete Python traceback. 
    64516  
    64517 Traceback (most recent call last): 
    64518 File
    64519 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64520 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    64521 self.session.ui.mouse_modes.mouse_pause_tracking() 
    64522 File
    64523 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64524 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    64525 mouse_pause_tracking 
    64526 self._mouse_pause() 
    64527 File
    64528 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64529 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    64530 m.pause(self._mouse_pause_position) 
    64531 File
    64532 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64533 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    64534 p = self.view.picked_object(x, y) 
    64535 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64536 File
    64537 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64538 packages/chimerax/graphics/view.py", line 838, in picked_object 
    64539 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    64540 beyond, 
    64541 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64542 File
    64543 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64544 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    64545 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    64546 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64547 File
    64548 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64549 packages/chimerax/core/models.py", line 143, in first_intercept 
    64550 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    64551 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64552 File
    64553 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64554 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    64555 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    64556 exclude=exclude) 
    64557 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64558 File
    64559 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64560 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    64561 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    64562 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64563 File
    64564 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64565 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    64566 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    64567 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64568 File
    64569 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64570 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    64571 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    64572 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64573 File
    64574 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64575 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    64576 p = super().first_intercept(mxyz1, mxyz2) 
    64577 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64578 File
    64579 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64580 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    64581 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    64582 exclude=exclude) 
    64583 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64584 File
    64585 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64586 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    64587 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    64588 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64589 File
    64590 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64591 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    64592 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    64593 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64594 File
    64595 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64596 packages/chimerax/graphics/drawing.py", line 1108, in
    64597 _first_intercept_excluding_children 
    64598 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    64599 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64600 File
    64601 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64602 packages/chimerax/geometry/place.py", line 201, in inverse 
    64603 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    64604 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64605 File
    64606 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64607 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    64608 rinv[:, :] = matrix_inverse(r) 
    64609 ^^^^^^^^^^^^^^^^^ 
    64610 File
    64611 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64612 packages/numpy/linalg/linalg.py", line 561, in inv 
    64613 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    64614 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64615 File
    64616 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64617 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    64618 raise LinAlgError("Singular matrix") 
    64619 numpy.linalg.LinAlgError: Singular matrix 
    64620  
    64621 numpy.linalg.LinAlgError: Singular matrix 
    64622  
    64623 File
    64624 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64625 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    64626 raise LinAlgError("Singular matrix") 
    64627  
    64628 See log for complete Python traceback. 
    64629  
    64630 Traceback (most recent call last): 
    64631 File
    64632 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64633 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    64634 self.session.ui.mouse_modes.mouse_pause_tracking() 
    64635 File
    64636 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64637 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    64638 mouse_pause_tracking 
    64639 self._mouse_pause() 
    64640 File
    64641 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64642 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    64643 m.pause(self._mouse_pause_position) 
    64644 File
    64645 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64646 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    64647 p = self.view.picked_object(x, y) 
    64648 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64649 File
    64650 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64651 packages/chimerax/graphics/view.py", line 838, in picked_object 
    64652 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    64653 beyond, 
    64654 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64655 File
    64656 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64657 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    64658 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    64659 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64660 File
    64661 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64662 packages/chimerax/core/models.py", line 143, in first_intercept 
    64663 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    64664 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64665 File
    64666 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64667 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    64668 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    64669 exclude=exclude) 
    64670 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64671 File
    64672 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64673 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    64674 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    64675 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64676 File
    64677 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64678 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    64679 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    64680 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64681 File
    64682 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64683 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    64684 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    64685 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64686 File
    64687 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64688 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    64689 p = super().first_intercept(mxyz1, mxyz2) 
    64690 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64691 File
    64692 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64693 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    64694 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    64695 exclude=exclude) 
    64696 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64697 File
    64698 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64699 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    64700 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    64701 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64702 File
    64703 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64704 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    64705 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    64706 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64707 File
    64708 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64709 packages/chimerax/graphics/drawing.py", line 1108, in
    64710 _first_intercept_excluding_children 
    64711 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    64712 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64713 File
    64714 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64715 packages/chimerax/geometry/place.py", line 201, in inverse 
    64716 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    64717 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64718 File
    64719 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64720 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    64721 rinv[:, :] = matrix_inverse(r) 
    64722 ^^^^^^^^^^^^^^^^^ 
    64723 File
    64724 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64725 packages/numpy/linalg/linalg.py", line 561, in inv 
    64726 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    64727 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64728 File
    64729 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64730 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    64731 raise LinAlgError("Singular matrix") 
    64732 numpy.linalg.LinAlgError: Singular matrix 
    64733  
    64734 numpy.linalg.LinAlgError: Singular matrix 
    64735  
    64736 File
    64737 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64738 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    64739 raise LinAlgError("Singular matrix") 
    64740  
    64741 See log for complete Python traceback. 
    64742  
    64743 Traceback (most recent call last): 
    64744 File
    64745 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64746 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    64747 self.session.ui.mouse_modes.mouse_pause_tracking() 
    64748 File
    64749 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64750 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    64751 mouse_pause_tracking 
    64752 self._mouse_pause() 
    64753 File
    64754 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64755 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    64756 m.pause(self._mouse_pause_position) 
    64757 File
    64758 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64759 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    64760 p = self.view.picked_object(x, y) 
    64761 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64762 File
    64763 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64764 packages/chimerax/graphics/view.py", line 838, in picked_object 
    64765 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    64766 beyond, 
    64767 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64768 File
    64769 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64770 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    64771 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    64772 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64773 File
    64774 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64775 packages/chimerax/core/models.py", line 143, in first_intercept 
    64776 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    64777 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64778 File
    64779 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64780 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    64781 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    64782 exclude=exclude) 
    64783 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64784 File
    64785 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64786 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    64787 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    64788 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64789 File
    64790 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64791 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    64792 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    64793 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64794 File
    64795 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64796 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    64797 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    64798 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64799 File
    64800 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64801 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    64802 p = super().first_intercept(mxyz1, mxyz2) 
    64803 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64804 File
    64805 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64806 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    64807 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    64808 exclude=exclude) 
    64809 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64810 File
    64811 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64812 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    64813 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    64814 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64815 File
    64816 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64817 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    64818 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    64819 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64820 File
    64821 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64822 packages/chimerax/graphics/drawing.py", line 1108, in
    64823 _first_intercept_excluding_children 
    64824 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    64825 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64826 File
    64827 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64828 packages/chimerax/geometry/place.py", line 201, in inverse 
    64829 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    64830 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64831 File
    64832 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64833 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    64834 rinv[:, :] = matrix_inverse(r) 
    64835 ^^^^^^^^^^^^^^^^^ 
    64836 File
    64837 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64838 packages/numpy/linalg/linalg.py", line 561, in inv 
    64839 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    64840 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64841 File
    64842 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64843 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    64844 raise LinAlgError("Singular matrix") 
    64845 numpy.linalg.LinAlgError: Singular matrix 
    64846  
    64847 numpy.linalg.LinAlgError: Singular matrix 
    64848  
    64849 File
    64850 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64851 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    64852 raise LinAlgError("Singular matrix") 
    64853  
    64854 See log for complete Python traceback. 
    64855  
    64856 Traceback (most recent call last): 
    64857 File
    64858 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64859 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    64860 self.session.ui.mouse_modes.mouse_pause_tracking() 
    64861 File
    64862 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64863 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    64864 mouse_pause_tracking 
    64865 self._mouse_pause() 
    64866 File
    64867 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64868 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    64869 m.pause(self._mouse_pause_position) 
    64870 File
    64871 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64872 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    64873 p = self.view.picked_object(x, y) 
    64874 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64875 File
    64876 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64877 packages/chimerax/graphics/view.py", line 838, in picked_object 
    64878 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    64879 beyond, 
    64880 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64881 File
    64882 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64883 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    64884 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    64885 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64886 File
    64887 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64888 packages/chimerax/core/models.py", line 143, in first_intercept 
    64889 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    64890 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64891 File
    64892 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64893 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    64894 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    64895 exclude=exclude) 
    64896 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64897 File
    64898 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64899 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    64900 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    64901 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64902 File
    64903 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64904 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    64905 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    64906 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64907 File
    64908 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64909 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    64910 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    64911 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64912 File
    64913 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64914 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    64915 p = super().first_intercept(mxyz1, mxyz2) 
    64916 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64917 File
    64918 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64919 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    64920 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    64921 exclude=exclude) 
    64922 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64923 File
    64924 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64925 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    64926 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    64927 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64928 File
    64929 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64930 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    64931 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    64932 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64933 File
    64934 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64935 packages/chimerax/graphics/drawing.py", line 1108, in
    64936 _first_intercept_excluding_children 
    64937 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    64938 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64939 File
    64940 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64941 packages/chimerax/geometry/place.py", line 201, in inverse 
    64942 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    64943 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64944 File
    64945 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64946 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    64947 rinv[:, :] = matrix_inverse(r) 
    64948 ^^^^^^^^^^^^^^^^^ 
    64949 File
    64950 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64951 packages/numpy/linalg/linalg.py", line 561, in inv 
    64952 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    64953 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64954 File
    64955 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64956 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    64957 raise LinAlgError("Singular matrix") 
    64958 numpy.linalg.LinAlgError: Singular matrix 
    64959  
    64960 numpy.linalg.LinAlgError: Singular matrix 
    64961  
    64962 File
    64963 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64964 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    64965 raise LinAlgError("Singular matrix") 
    64966  
    64967 See log for complete Python traceback. 
    64968  
    64969 Traceback (most recent call last): 
    64970 File
    64971 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64972 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    64973 self.session.ui.mouse_modes.mouse_pause_tracking() 
    64974 File
    64975 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64976 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    64977 mouse_pause_tracking 
    64978 self._mouse_pause() 
    64979 File
    64980 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64981 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    64982 m.pause(self._mouse_pause_position) 
    64983 File
    64984 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64985 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    64986 p = self.view.picked_object(x, y) 
    64987 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64988 File
    64989 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64990 packages/chimerax/graphics/view.py", line 838, in picked_object 
    64991 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    64992 beyond, 
    64993 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64994 File
    64995 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    64996 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    64997 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    64998 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    64999 File
    65000 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65001 packages/chimerax/core/models.py", line 143, in first_intercept 
    65002 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    65003 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65004 File
    65005 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65006 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    65007 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    65008 exclude=exclude) 
    65009 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65010 File
    65011 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65012 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    65013 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    65014 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65015 File
    65016 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65017 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    65018 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    65019 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65020 File
    65021 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65022 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    65023 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    65024 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65025 File
    65026 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65027 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    65028 p = super().first_intercept(mxyz1, mxyz2) 
    65029 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65030 File
    65031 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65032 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    65033 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    65034 exclude=exclude) 
    65035 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65036 File
    65037 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65038 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    65039 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    65040 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65041 File
    65042 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65043 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    65044 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    65045 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65046 File
    65047 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65048 packages/chimerax/graphics/drawing.py", line 1108, in
    65049 _first_intercept_excluding_children 
    65050 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    65051 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65052 File
    65053 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65054 packages/chimerax/geometry/place.py", line 201, in inverse 
    65055 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    65056 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65057 File
    65058 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65059 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    65060 rinv[:, :] = matrix_inverse(r) 
    65061 ^^^^^^^^^^^^^^^^^ 
    65062 File
    65063 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65064 packages/numpy/linalg/linalg.py", line 561, in inv 
    65065 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    65066 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65067 File
    65068 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65069 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    65070 raise LinAlgError("Singular matrix") 
    65071 numpy.linalg.LinAlgError: Singular matrix 
    65072  
    65073 numpy.linalg.LinAlgError: Singular matrix 
    65074  
    65075 File
    65076 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65077 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    65078 raise LinAlgError("Singular matrix") 
    65079  
    65080 See log for complete Python traceback. 
    65081  
    65082 Traceback (most recent call last): 
    65083 File
    65084 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65085 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    65086 self.session.ui.mouse_modes.mouse_pause_tracking() 
    65087 File
    65088 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65089 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    65090 mouse_pause_tracking 
    65091 self._mouse_pause() 
    65092 File
    65093 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65094 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    65095 m.pause(self._mouse_pause_position) 
    65096 File
    65097 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65098 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    65099 p = self.view.picked_object(x, y) 
    65100 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65101 File
    65102 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65103 packages/chimerax/graphics/view.py", line 838, in picked_object 
    65104 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    65105 beyond, 
    65106 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65107 File
    65108 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65109 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    65110 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    65111 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65112 File
    65113 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65114 packages/chimerax/core/models.py", line 143, in first_intercept 
    65115 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    65116 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65117 File
    65118 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65119 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    65120 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    65121 exclude=exclude) 
    65122 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65123 File
    65124 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65125 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    65126 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    65127 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65128 File
    65129 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65130 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    65131 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    65132 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65133 File
    65134 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65135 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    65136 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    65137 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65138 File
    65139 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65140 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    65141 p = super().first_intercept(mxyz1, mxyz2) 
    65142 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65143 File
    65144 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65145 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    65146 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    65147 exclude=exclude) 
    65148 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65149 File
    65150 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65151 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    65152 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    65153 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65154 File
    65155 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65156 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    65157 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    65158 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65159 File
    65160 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65161 packages/chimerax/graphics/drawing.py", line 1108, in
    65162 _first_intercept_excluding_children 
    65163 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    65164 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65165 File
    65166 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65167 packages/chimerax/geometry/place.py", line 201, in inverse 
    65168 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    65169 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65170 File
    65171 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65172 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    65173 rinv[:, :] = matrix_inverse(r) 
    65174 ^^^^^^^^^^^^^^^^^ 
    65175 File
    65176 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65177 packages/numpy/linalg/linalg.py", line 561, in inv 
    65178 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    65179 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65180 File
    65181 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65182 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    65183 raise LinAlgError("Singular matrix") 
    65184 numpy.linalg.LinAlgError: Singular matrix 
    65185  
    65186 numpy.linalg.LinAlgError: Singular matrix 
    65187  
    65188 File
    65189 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65190 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    65191 raise LinAlgError("Singular matrix") 
    65192  
    65193 See log for complete Python traceback. 
    65194  
    65195 Traceback (most recent call last): 
    65196 File
    65197 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65198 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    65199 self.session.ui.mouse_modes.mouse_pause_tracking() 
    65200 File
    65201 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65202 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    65203 mouse_pause_tracking 
    65204 self._mouse_pause() 
    65205 File
    65206 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65207 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    65208 m.pause(self._mouse_pause_position) 
    65209 File
    65210 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65211 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    65212 p = self.view.picked_object(x, y) 
    65213 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65214 File
    65215 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65216 packages/chimerax/graphics/view.py", line 838, in picked_object 
    65217 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    65218 beyond, 
    65219 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65220 File
    65221 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65222 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    65223 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    65224 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65225 File
    65226 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65227 packages/chimerax/core/models.py", line 143, in first_intercept 
    65228 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    65229 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65230 File
    65231 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65232 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    65233 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    65234 exclude=exclude) 
    65235 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65236 File
    65237 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65238 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    65239 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    65240 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65241 File
    65242 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65243 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    65244 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    65245 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65246 File
    65247 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65248 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    65249 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    65250 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65251 File
    65252 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65253 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    65254 p = super().first_intercept(mxyz1, mxyz2) 
    65255 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65256 File
    65257 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65258 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    65259 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    65260 exclude=exclude) 
    65261 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65262 File
    65263 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65264 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    65265 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    65266 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65267 File
    65268 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65269 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    65270 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    65271 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65272 File
    65273 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65274 packages/chimerax/graphics/drawing.py", line 1108, in
    65275 _first_intercept_excluding_children 
    65276 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    65277 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65278 File
    65279 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65280 packages/chimerax/geometry/place.py", line 201, in inverse 
    65281 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    65282 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65283 File
    65284 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65285 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    65286 rinv[:, :] = matrix_inverse(r) 
    65287 ^^^^^^^^^^^^^^^^^ 
    65288 File
    65289 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65290 packages/numpy/linalg/linalg.py", line 561, in inv 
    65291 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    65292 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65293 File
    65294 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65295 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    65296 raise LinAlgError("Singular matrix") 
    65297 numpy.linalg.LinAlgError: Singular matrix 
    65298  
    65299 numpy.linalg.LinAlgError: Singular matrix 
    65300  
    65301 File
    65302 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65303 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    65304 raise LinAlgError("Singular matrix") 
    65305  
    65306 See log for complete Python traceback. 
    65307  
    65308 Traceback (most recent call last): 
    65309 File
    65310 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65311 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    65312 self.session.ui.mouse_modes.mouse_pause_tracking() 
    65313 File
    65314 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65315 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    65316 mouse_pause_tracking 
    65317 self._mouse_pause() 
    65318 File
    65319 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65320 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    65321 m.pause(self._mouse_pause_position) 
    65322 File
    65323 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65324 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    65325 p = self.view.picked_object(x, y) 
    65326 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65327 File
    65328 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65329 packages/chimerax/graphics/view.py", line 838, in picked_object 
    65330 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    65331 beyond, 
    65332 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65333 File
    65334 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65335 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    65336 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    65337 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65338 File
    65339 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65340 packages/chimerax/core/models.py", line 143, in first_intercept 
    65341 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    65342 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65343 File
    65344 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65345 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    65346 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    65347 exclude=exclude) 
    65348 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65349 File
    65350 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65351 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    65352 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    65353 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65354 File
    65355 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65356 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    65357 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    65358 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65359 File
    65360 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65361 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    65362 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    65363 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65364 File
    65365 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65366 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    65367 p = super().first_intercept(mxyz1, mxyz2) 
    65368 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65369 File
    65370 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65371 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    65372 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    65373 exclude=exclude) 
    65374 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65375 File
    65376 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65377 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    65378 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    65379 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65380 File
    65381 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65382 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    65383 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    65384 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65385 File
    65386 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65387 packages/chimerax/graphics/drawing.py", line 1108, in
    65388 _first_intercept_excluding_children 
    65389 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    65390 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65391 File
    65392 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65393 packages/chimerax/geometry/place.py", line 201, in inverse 
    65394 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    65395 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65396 File
    65397 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65398 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    65399 rinv[:, :] = matrix_inverse(r) 
    65400 ^^^^^^^^^^^^^^^^^ 
    65401 File
    65402 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65403 packages/numpy/linalg/linalg.py", line 561, in inv 
    65404 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    65405 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65406 File
    65407 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65408 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    65409 raise LinAlgError("Singular matrix") 
    65410 numpy.linalg.LinAlgError: Singular matrix 
    65411  
    65412 numpy.linalg.LinAlgError: Singular matrix 
    65413  
    65414 File
    65415 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65416 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    65417 raise LinAlgError("Singular matrix") 
    65418  
    65419 See log for complete Python traceback. 
    65420  
    65421 Traceback (most recent call last): 
    65422 File
    65423 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65424 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    65425 self.session.ui.mouse_modes.mouse_pause_tracking() 
    65426 File
    65427 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65428 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    65429 mouse_pause_tracking 
    65430 self._mouse_pause() 
    65431 File
    65432 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65433 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    65434 m.pause(self._mouse_pause_position) 
    65435 File
    65436 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65437 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    65438 p = self.view.picked_object(x, y) 
    65439 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65440 File
    65441 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65442 packages/chimerax/graphics/view.py", line 838, in picked_object 
    65443 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    65444 beyond, 
    65445 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65446 File
    65447 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65448 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    65449 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    65450 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65451 File
    65452 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65453 packages/chimerax/core/models.py", line 143, in first_intercept 
    65454 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    65455 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65456 File
    65457 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65458 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    65459 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    65460 exclude=exclude) 
    65461 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65462 File
    65463 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65464 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    65465 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    65466 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65467 File
    65468 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65469 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    65470 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    65471 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65472 File
    65473 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65474 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    65475 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    65476 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65477 File
    65478 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65479 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    65480 p = super().first_intercept(mxyz1, mxyz2) 
    65481 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65482 File
    65483 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65484 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    65485 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    65486 exclude=exclude) 
    65487 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65488 File
    65489 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65490 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    65491 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    65492 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65493 File
    65494 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65495 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    65496 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    65497 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65498 File
    65499 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65500 packages/chimerax/graphics/drawing.py", line 1108, in
    65501 _first_intercept_excluding_children 
    65502 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    65503 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65504 File
    65505 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65506 packages/chimerax/geometry/place.py", line 201, in inverse 
    65507 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    65508 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65509 File
    65510 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65511 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    65512 rinv[:, :] = matrix_inverse(r) 
    65513 ^^^^^^^^^^^^^^^^^ 
    65514 File
    65515 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65516 packages/numpy/linalg/linalg.py", line 561, in inv 
    65517 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    65518 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65519 File
    65520 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65521 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    65522 raise LinAlgError("Singular matrix") 
    65523 numpy.linalg.LinAlgError: Singular matrix 
    65524  
    65525 numpy.linalg.LinAlgError: Singular matrix 
    65526  
    65527 File
    65528 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65529 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    65530 raise LinAlgError("Singular matrix") 
    65531  
    65532 See log for complete Python traceback. 
    65533  
    65534 Traceback (most recent call last): 
    65535 File
    65536 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65537 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    65538 self.session.ui.mouse_modes.mouse_pause_tracking() 
    65539 File
    65540 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65541 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    65542 mouse_pause_tracking 
    65543 self._mouse_pause() 
    65544 File
    65545 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65546 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    65547 m.pause(self._mouse_pause_position) 
    65548 File
    65549 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65550 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    65551 p = self.view.picked_object(x, y) 
    65552 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65553 File
    65554 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65555 packages/chimerax/graphics/view.py", line 838, in picked_object 
    65556 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    65557 beyond, 
    65558 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65559 File
    65560 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65561 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    65562 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    65563 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65564 File
    65565 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65566 packages/chimerax/core/models.py", line 143, in first_intercept 
    65567 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    65568 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65569 File
    65570 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65571 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    65572 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    65573 exclude=exclude) 
    65574 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65575 File
    65576 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65577 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    65578 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    65579 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65580 File
    65581 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65582 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    65583 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    65584 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65585 File
    65586 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65587 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    65588 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    65589 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65590 File
    65591 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65592 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    65593 p = super().first_intercept(mxyz1, mxyz2) 
    65594 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65595 File
    65596 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65597 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    65598 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    65599 exclude=exclude) 
    65600 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65601 File
    65602 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65603 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    65604 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    65605 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65606 File
    65607 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65608 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    65609 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    65610 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65611 File
    65612 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65613 packages/chimerax/graphics/drawing.py", line 1108, in
    65614 _first_intercept_excluding_children 
    65615 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    65616 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65617 File
    65618 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65619 packages/chimerax/geometry/place.py", line 201, in inverse 
    65620 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    65621 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65622 File
    65623 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65624 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    65625 rinv[:, :] = matrix_inverse(r) 
    65626 ^^^^^^^^^^^^^^^^^ 
    65627 File
    65628 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65629 packages/numpy/linalg/linalg.py", line 561, in inv 
    65630 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    65631 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65632 File
    65633 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65634 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    65635 raise LinAlgError("Singular matrix") 
    65636 numpy.linalg.LinAlgError: Singular matrix 
    65637  
    65638 numpy.linalg.LinAlgError: Singular matrix 
    65639  
    65640 File
    65641 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65642 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    65643 raise LinAlgError("Singular matrix") 
    65644  
    65645 See log for complete Python traceback. 
    65646  
    65647 Traceback (most recent call last): 
    65648 File
    65649 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65650 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    65651 self.session.ui.mouse_modes.mouse_pause_tracking() 
    65652 File
    65653 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65654 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    65655 mouse_pause_tracking 
    65656 self._mouse_pause() 
    65657 File
    65658 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65659 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    65660 m.pause(self._mouse_pause_position) 
    65661 File
    65662 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65663 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    65664 p = self.view.picked_object(x, y) 
    65665 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65666 File
    65667 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65668 packages/chimerax/graphics/view.py", line 838, in picked_object 
    65669 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    65670 beyond, 
    65671 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65672 File
    65673 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65674 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    65675 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    65676 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65677 File
    65678 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65679 packages/chimerax/core/models.py", line 143, in first_intercept 
    65680 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    65681 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65682 File
    65683 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65684 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    65685 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    65686 exclude=exclude) 
    65687 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65688 File
    65689 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65690 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    65691 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    65692 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65693 File
    65694 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65695 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    65696 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    65697 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65698 File
    65699 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65700 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    65701 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    65702 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65703 File
    65704 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65705 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    65706 p = super().first_intercept(mxyz1, mxyz2) 
    65707 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65708 File
    65709 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65710 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    65711 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    65712 exclude=exclude) 
    65713 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65714 File
    65715 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65716 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    65717 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    65718 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65719 File
    65720 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65721 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    65722 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    65723 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65724 File
    65725 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65726 packages/chimerax/graphics/drawing.py", line 1108, in
    65727 _first_intercept_excluding_children 
    65728 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    65729 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65730 File
    65731 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65732 packages/chimerax/geometry/place.py", line 201, in inverse 
    65733 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    65734 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65735 File
    65736 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65737 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    65738 rinv[:, :] = matrix_inverse(r) 
    65739 ^^^^^^^^^^^^^^^^^ 
    65740 File
    65741 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65742 packages/numpy/linalg/linalg.py", line 561, in inv 
    65743 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    65744 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65745 File
    65746 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65747 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    65748 raise LinAlgError("Singular matrix") 
    65749 numpy.linalg.LinAlgError: Singular matrix 
    65750  
    65751 numpy.linalg.LinAlgError: Singular matrix 
    65752  
    65753 File
    65754 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65755 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    65756 raise LinAlgError("Singular matrix") 
    65757  
    65758 See log for complete Python traceback. 
    65759  
    65760 Traceback (most recent call last): 
    65761 File
    65762 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65763 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    65764 self.session.ui.mouse_modes.mouse_pause_tracking() 
    65765 File
    65766 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65767 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    65768 mouse_pause_tracking 
    65769 self._mouse_pause() 
    65770 File
    65771 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65772 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    65773 m.pause(self._mouse_pause_position) 
    65774 File
    65775 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65776 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    65777 p = self.view.picked_object(x, y) 
    65778 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65779 File
    65780 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65781 packages/chimerax/graphics/view.py", line 838, in picked_object 
    65782 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    65783 beyond, 
    65784 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65785 File
    65786 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65787 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    65788 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    65789 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65790 File
    65791 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65792 packages/chimerax/core/models.py", line 143, in first_intercept 
    65793 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    65794 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65795 File
    65796 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65797 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    65798 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    65799 exclude=exclude) 
    65800 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65801 File
    65802 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65803 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    65804 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    65805 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65806 File
    65807 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65808 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    65809 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    65810 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65811 File
    65812 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65813 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    65814 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    65815 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65816 File
    65817 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65818 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    65819 p = super().first_intercept(mxyz1, mxyz2) 
    65820 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65821 File
    65822 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65823 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    65824 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    65825 exclude=exclude) 
    65826 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65827 File
    65828 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65829 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    65830 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    65831 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65832 File
    65833 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65834 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    65835 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    65836 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65837 File
    65838 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65839 packages/chimerax/graphics/drawing.py", line 1108, in
    65840 _first_intercept_excluding_children 
    65841 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    65842 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65843 File
    65844 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65845 packages/chimerax/geometry/place.py", line 201, in inverse 
    65846 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    65847 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65848 File
    65849 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65850 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    65851 rinv[:, :] = matrix_inverse(r) 
    65852 ^^^^^^^^^^^^^^^^^ 
    65853 File
    65854 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65855 packages/numpy/linalg/linalg.py", line 561, in inv 
    65856 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    65857 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65858 File
    65859 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65860 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    65861 raise LinAlgError("Singular matrix") 
    65862 numpy.linalg.LinAlgError: Singular matrix 
    65863  
    65864 numpy.linalg.LinAlgError: Singular matrix 
    65865  
    65866 File
    65867 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65868 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    65869 raise LinAlgError("Singular matrix") 
    65870  
    65871 See log for complete Python traceback. 
    65872  
    65873 Traceback (most recent call last): 
    65874 File
    65875 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65876 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    65877 self.session.ui.mouse_modes.mouse_pause_tracking() 
    65878 File
    65879 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65880 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    65881 mouse_pause_tracking 
    65882 self._mouse_pause() 
    65883 File
    65884 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65885 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    65886 m.pause(self._mouse_pause_position) 
    65887 File
    65888 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65889 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    65890 p = self.view.picked_object(x, y) 
    65891 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65892 File
    65893 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65894 packages/chimerax/graphics/view.py", line 838, in picked_object 
    65895 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    65896 beyond, 
    65897 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65898 File
    65899 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65900 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    65901 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    65902 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65903 File
    65904 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65905 packages/chimerax/core/models.py", line 143, in first_intercept 
    65906 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    65907 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65908 File
    65909 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65910 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    65911 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    65912 exclude=exclude) 
    65913 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65914 File
    65915 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65916 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    65917 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    65918 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65919 File
    65920 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65921 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    65922 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    65923 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65924 File
    65925 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65926 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    65927 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    65928 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65929 File
    65930 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65931 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    65932 p = super().first_intercept(mxyz1, mxyz2) 
    65933 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65934 File
    65935 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65936 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    65937 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    65938 exclude=exclude) 
    65939 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65940 File
    65941 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65942 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    65943 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    65944 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65945 File
    65946 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65947 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    65948 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    65949 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65950 File
    65951 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65952 packages/chimerax/graphics/drawing.py", line 1108, in
    65953 _first_intercept_excluding_children 
    65954 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    65955 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65956 File
    65957 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65958 packages/chimerax/geometry/place.py", line 201, in inverse 
    65959 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    65960 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65961 File
    65962 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65963 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    65964 rinv[:, :] = matrix_inverse(r) 
    65965 ^^^^^^^^^^^^^^^^^ 
    65966 File
    65967 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65968 packages/numpy/linalg/linalg.py", line 561, in inv 
    65969 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    65970 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    65971 File
    65972 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65973 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    65974 raise LinAlgError("Singular matrix") 
    65975 numpy.linalg.LinAlgError: Singular matrix 
    65976  
    65977 numpy.linalg.LinAlgError: Singular matrix 
    65978  
    65979 File
    65980 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65981 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    65982 raise LinAlgError("Singular matrix") 
    65983  
    65984 See log for complete Python traceback. 
    65985  
    65986 Traceback (most recent call last): 
    65987 File
    65988 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65989 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    65990 self.session.ui.mouse_modes.mouse_pause_tracking() 
    65991 File
    65992 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65993 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    65994 mouse_pause_tracking 
    65995 self._mouse_pause() 
    65996 File
    65997 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    65998 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    65999 m.pause(self._mouse_pause_position) 
    66000 File
    66001 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66002 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    66003 p = self.view.picked_object(x, y) 
    66004 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66005 File
    66006 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66007 packages/chimerax/graphics/view.py", line 838, in picked_object 
    66008 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    66009 beyond, 
    66010 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66011 File
    66012 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66013 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    66014 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    66015 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66016 File
    66017 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66018 packages/chimerax/core/models.py", line 143, in first_intercept 
    66019 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    66020 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66021 File
    66022 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66023 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    66024 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    66025 exclude=exclude) 
    66026 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66027 File
    66028 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66029 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    66030 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    66031 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66032 File
    66033 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66034 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    66035 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    66036 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66037 File
    66038 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66039 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    66040 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    66041 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66042 File
    66043 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66044 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    66045 p = super().first_intercept(mxyz1, mxyz2) 
    66046 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66047 File
    66048 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66049 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    66050 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    66051 exclude=exclude) 
    66052 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66053 File
    66054 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66055 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    66056 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    66057 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66058 File
    66059 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66060 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    66061 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    66062 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66063 File
    66064 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66065 packages/chimerax/graphics/drawing.py", line 1108, in
    66066 _first_intercept_excluding_children 
    66067 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    66068 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66069 File
    66070 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66071 packages/chimerax/geometry/place.py", line 201, in inverse 
    66072 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    66073 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66074 File
    66075 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66076 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    66077 rinv[:, :] = matrix_inverse(r) 
    66078 ^^^^^^^^^^^^^^^^^ 
    66079 File
    66080 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66081 packages/numpy/linalg/linalg.py", line 561, in inv 
    66082 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    66083 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66084 File
    66085 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66086 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    66087 raise LinAlgError("Singular matrix") 
    66088 numpy.linalg.LinAlgError: Singular matrix 
    66089  
    66090 numpy.linalg.LinAlgError: Singular matrix 
    66091  
    66092 File
    66093 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66094 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    66095 raise LinAlgError("Singular matrix") 
    66096  
    66097 See log for complete Python traceback. 
    66098  
    66099 Traceback (most recent call last): 
    66100 File
    66101 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66102 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    66103 self.session.ui.mouse_modes.mouse_pause_tracking() 
    66104 File
    66105 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66106 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    66107 mouse_pause_tracking 
    66108 self._mouse_pause() 
    66109 File
    66110 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66111 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    66112 m.pause(self._mouse_pause_position) 
    66113 File
    66114 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66115 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    66116 p = self.view.picked_object(x, y) 
    66117 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66118 File
    66119 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66120 packages/chimerax/graphics/view.py", line 838, in picked_object 
    66121 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    66122 beyond, 
    66123 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66124 File
    66125 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66126 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    66127 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    66128 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66129 File
    66130 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66131 packages/chimerax/core/models.py", line 143, in first_intercept 
    66132 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    66133 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66134 File
    66135 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66136 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    66137 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    66138 exclude=exclude) 
    66139 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66140 File
    66141 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66142 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    66143 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    66144 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66145 File
    66146 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66147 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    66148 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    66149 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66150 File
    66151 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66152 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    66153 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    66154 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66155 File
    66156 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66157 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    66158 p = super().first_intercept(mxyz1, mxyz2) 
    66159 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66160 File
    66161 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66162 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    66163 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    66164 exclude=exclude) 
    66165 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66166 File
    66167 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66168 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    66169 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    66170 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66171 File
    66172 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66173 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    66174 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    66175 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66176 File
    66177 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66178 packages/chimerax/graphics/drawing.py", line 1108, in
    66179 _first_intercept_excluding_children 
    66180 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    66181 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66182 File
    66183 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66184 packages/chimerax/geometry/place.py", line 201, in inverse 
    66185 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    66186 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66187 File
    66188 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66189 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    66190 rinv[:, :] = matrix_inverse(r) 
    66191 ^^^^^^^^^^^^^^^^^ 
    66192 File
    66193 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66194 packages/numpy/linalg/linalg.py", line 561, in inv 
    66195 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    66196 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66197 File
    66198 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66199 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    66200 raise LinAlgError("Singular matrix") 
    66201 numpy.linalg.LinAlgError: Singular matrix 
    66202  
    66203 numpy.linalg.LinAlgError: Singular matrix 
    66204  
    66205 File
    66206 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66207 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    66208 raise LinAlgError("Singular matrix") 
    66209  
    66210 See log for complete Python traceback. 
    66211  
    66212 Traceback (most recent call last): 
    66213 File
    66214 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66215 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    66216 self.session.ui.mouse_modes.mouse_pause_tracking() 
    66217 File
    66218 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66219 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    66220 mouse_pause_tracking 
    66221 self._mouse_pause() 
    66222 File
    66223 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66224 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    66225 m.pause(self._mouse_pause_position) 
    66226 File
    66227 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66228 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    66229 p = self.view.picked_object(x, y) 
    66230 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66231 File
    66232 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66233 packages/chimerax/graphics/view.py", line 838, in picked_object 
    66234 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    66235 beyond, 
    66236 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66237 File
    66238 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66239 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    66240 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    66241 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66242 File
    66243 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66244 packages/chimerax/core/models.py", line 143, in first_intercept 
    66245 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    66246 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66247 File
    66248 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66249 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    66250 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    66251 exclude=exclude) 
    66252 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66253 File
    66254 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66255 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    66256 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    66257 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66258 File
    66259 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66260 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    66261 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    66262 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66263 File
    66264 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66265 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    66266 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    66267 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66268 File
    66269 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66270 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    66271 p = super().first_intercept(mxyz1, mxyz2) 
    66272 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66273 File
    66274 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66275 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    66276 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    66277 exclude=exclude) 
    66278 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66279 File
    66280 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66281 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    66282 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    66283 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66284 File
    66285 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66286 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    66287 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    66288 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66289 File
    66290 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66291 packages/chimerax/graphics/drawing.py", line 1108, in
    66292 _first_intercept_excluding_children 
    66293 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    66294 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66295 File
    66296 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66297 packages/chimerax/geometry/place.py", line 201, in inverse 
    66298 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    66299 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66300 File
    66301 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66302 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    66303 rinv[:, :] = matrix_inverse(r) 
    66304 ^^^^^^^^^^^^^^^^^ 
    66305 File
    66306 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66307 packages/numpy/linalg/linalg.py", line 561, in inv 
    66308 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    66309 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66310 File
    66311 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66312 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    66313 raise LinAlgError("Singular matrix") 
    66314 numpy.linalg.LinAlgError: Singular matrix 
    66315  
    66316 numpy.linalg.LinAlgError: Singular matrix 
    66317  
    66318 File
    66319 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66320 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    66321 raise LinAlgError("Singular matrix") 
    66322  
    66323 See log for complete Python traceback. 
    66324  
    66325 Traceback (most recent call last): 
    66326 File
    66327 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66328 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    66329 self.session.ui.mouse_modes.mouse_pause_tracking() 
    66330 File
    66331 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66332 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    66333 mouse_pause_tracking 
    66334 self._mouse_pause() 
    66335 File
    66336 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66337 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    66338 m.pause(self._mouse_pause_position) 
    66339 File
    66340 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66341 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    66342 p = self.view.picked_object(x, y) 
    66343 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66344 File
    66345 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66346 packages/chimerax/graphics/view.py", line 838, in picked_object 
    66347 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    66348 beyond, 
    66349 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66350 File
    66351 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66352 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    66353 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    66354 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66355 File
    66356 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66357 packages/chimerax/core/models.py", line 143, in first_intercept 
    66358 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    66359 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66360 File
    66361 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66362 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    66363 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    66364 exclude=exclude) 
    66365 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66366 File
    66367 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66368 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    66369 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    66370 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66371 File
    66372 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66373 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    66374 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    66375 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66376 File
    66377 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66378 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    66379 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    66380 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66381 File
    66382 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66383 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    66384 p = super().first_intercept(mxyz1, mxyz2) 
    66385 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66386 File
    66387 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66388 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    66389 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    66390 exclude=exclude) 
    66391 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66392 File
    66393 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66394 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    66395 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    66396 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66397 File
    66398 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66399 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    66400 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    66401 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66402 File
    66403 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66404 packages/chimerax/graphics/drawing.py", line 1108, in
    66405 _first_intercept_excluding_children 
    66406 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    66407 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66408 File
    66409 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66410 packages/chimerax/geometry/place.py", line 201, in inverse 
    66411 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    66412 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66413 File
    66414 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66415 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    66416 rinv[:, :] = matrix_inverse(r) 
    66417 ^^^^^^^^^^^^^^^^^ 
    66418 File
    66419 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66420 packages/numpy/linalg/linalg.py", line 561, in inv 
    66421 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    66422 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66423 File
    66424 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66425 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    66426 raise LinAlgError("Singular matrix") 
    66427 numpy.linalg.LinAlgError: Singular matrix 
    66428  
    66429 numpy.linalg.LinAlgError: Singular matrix 
    66430  
    66431 File
    66432 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66433 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    66434 raise LinAlgError("Singular matrix") 
    66435  
    66436 See log for complete Python traceback. 
    66437  
    66438 Traceback (most recent call last): 
    66439 File
    66440 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66441 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    66442 self.session.ui.mouse_modes.mouse_pause_tracking() 
    66443 File
    66444 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66445 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    66446 mouse_pause_tracking 
    66447 self._mouse_pause() 
    66448 File
    66449 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66450 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    66451 m.pause(self._mouse_pause_position) 
    66452 File
    66453 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66454 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    66455 p = self.view.picked_object(x, y) 
    66456 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66457 File
    66458 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66459 packages/chimerax/graphics/view.py", line 838, in picked_object 
    66460 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    66461 beyond, 
    66462 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66463 File
    66464 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66465 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    66466 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    66467 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66468 File
    66469 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66470 packages/chimerax/core/models.py", line 143, in first_intercept 
    66471 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    66472 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66473 File
    66474 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66475 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    66476 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    66477 exclude=exclude) 
    66478 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66479 File
    66480 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66481 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    66482 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    66483 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66484 File
    66485 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66486 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    66487 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    66488 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66489 File
    66490 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66491 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    66492 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    66493 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66494 File
    66495 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66496 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    66497 p = super().first_intercept(mxyz1, mxyz2) 
    66498 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66499 File
    66500 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66501 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    66502 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    66503 exclude=exclude) 
    66504 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66505 File
    66506 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66507 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    66508 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    66509 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66510 File
    66511 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66512 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    66513 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    66514 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66515 File
    66516 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66517 packages/chimerax/graphics/drawing.py", line 1108, in
    66518 _first_intercept_excluding_children 
    66519 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    66520 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66521 File
    66522 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66523 packages/chimerax/geometry/place.py", line 201, in inverse 
    66524 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    66525 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66526 File
    66527 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66528 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    66529 rinv[:, :] = matrix_inverse(r) 
    66530 ^^^^^^^^^^^^^^^^^ 
    66531 File
    66532 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66533 packages/numpy/linalg/linalg.py", line 561, in inv 
    66534 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    66535 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66536 File
    66537 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66538 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    66539 raise LinAlgError("Singular matrix") 
    66540 numpy.linalg.LinAlgError: Singular matrix 
    66541  
    66542 numpy.linalg.LinAlgError: Singular matrix 
    66543  
    66544 File
    66545 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66546 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    66547 raise LinAlgError("Singular matrix") 
    66548  
    66549 See log for complete Python traceback. 
    66550  
    66551 Traceback (most recent call last): 
    66552 File
    66553 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66554 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    66555 self.session.ui.mouse_modes.mouse_pause_tracking() 
    66556 File
    66557 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66558 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    66559 mouse_pause_tracking 
    66560 self._mouse_pause() 
    66561 File
    66562 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66563 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    66564 m.pause(self._mouse_pause_position) 
    66565 File
    66566 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66567 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    66568 p = self.view.picked_object(x, y) 
    66569 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66570 File
    66571 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66572 packages/chimerax/graphics/view.py", line 838, in picked_object 
    66573 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    66574 beyond, 
    66575 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66576 File
    66577 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66578 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    66579 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    66580 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66581 File
    66582 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66583 packages/chimerax/core/models.py", line 143, in first_intercept 
    66584 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    66585 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66586 File
    66587 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66588 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    66589 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    66590 exclude=exclude) 
    66591 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66592 File
    66593 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66594 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    66595 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    66596 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66597 File
    66598 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66599 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    66600 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    66601 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66602 File
    66603 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66604 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    66605 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    66606 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66607 File
    66608 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66609 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    66610 p = super().first_intercept(mxyz1, mxyz2) 
    66611 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66612 File
    66613 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66614 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    66615 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    66616 exclude=exclude) 
    66617 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66618 File
    66619 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66620 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    66621 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    66622 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66623 File
    66624 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66625 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    66626 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    66627 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66628 File
    66629 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66630 packages/chimerax/graphics/drawing.py", line 1108, in
    66631 _first_intercept_excluding_children 
    66632 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    66633 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66634 File
    66635 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66636 packages/chimerax/geometry/place.py", line 201, in inverse 
    66637 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    66638 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66639 File
    66640 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66641 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    66642 rinv[:, :] = matrix_inverse(r) 
    66643 ^^^^^^^^^^^^^^^^^ 
    66644 File
    66645 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66646 packages/numpy/linalg/linalg.py", line 561, in inv 
    66647 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    66648 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66649 File
    66650 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66651 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    66652 raise LinAlgError("Singular matrix") 
    66653 numpy.linalg.LinAlgError: Singular matrix 
    66654  
    66655 numpy.linalg.LinAlgError: Singular matrix 
    66656  
    66657 File
    66658 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66659 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    66660 raise LinAlgError("Singular matrix") 
    66661  
    66662 See log for complete Python traceback. 
    66663  
    66664 Traceback (most recent call last): 
    66665 File
    66666 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66667 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    66668 self.session.ui.mouse_modes.mouse_pause_tracking() 
    66669 File
    66670 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66671 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    66672 mouse_pause_tracking 
    66673 self._mouse_pause() 
    66674 File
    66675 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66676 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    66677 m.pause(self._mouse_pause_position) 
    66678 File
    66679 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66680 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    66681 p = self.view.picked_object(x, y) 
    66682 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66683 File
    66684 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66685 packages/chimerax/graphics/view.py", line 838, in picked_object 
    66686 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    66687 beyond, 
    66688 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66689 File
    66690 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66691 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    66692 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    66693 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66694 File
    66695 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66696 packages/chimerax/core/models.py", line 143, in first_intercept 
    66697 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    66698 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66699 File
    66700 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66701 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    66702 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    66703 exclude=exclude) 
    66704 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66705 File
    66706 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66707 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    66708 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    66709 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66710 File
    66711 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66712 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    66713 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    66714 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66715 File
    66716 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66717 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    66718 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    66719 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66720 File
    66721 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66722 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    66723 p = super().first_intercept(mxyz1, mxyz2) 
    66724 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66725 File
    66726 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66727 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    66728 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    66729 exclude=exclude) 
    66730 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66731 File
    66732 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66733 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    66734 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    66735 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66736 File
    66737 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66738 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    66739 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    66740 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66741 File
    66742 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66743 packages/chimerax/graphics/drawing.py", line 1108, in
    66744 _first_intercept_excluding_children 
    66745 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    66746 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66747 File
    66748 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66749 packages/chimerax/geometry/place.py", line 201, in inverse 
    66750 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    66751 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66752 File
    66753 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66754 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    66755 rinv[:, :] = matrix_inverse(r) 
    66756 ^^^^^^^^^^^^^^^^^ 
    66757 File
    66758 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66759 packages/numpy/linalg/linalg.py", line 561, in inv 
    66760 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    66761 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66762 File
    66763 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66764 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    66765 raise LinAlgError("Singular matrix") 
    66766 numpy.linalg.LinAlgError: Singular matrix 
    66767  
    66768 numpy.linalg.LinAlgError: Singular matrix 
    66769  
    66770 File
    66771 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66772 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    66773 raise LinAlgError("Singular matrix") 
    66774  
    66775 See log for complete Python traceback. 
    66776  
    66777 Traceback (most recent call last): 
    66778 File
    66779 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66780 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    66781 self.session.ui.mouse_modes.mouse_pause_tracking() 
    66782 File
    66783 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66784 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    66785 mouse_pause_tracking 
    66786 self._mouse_pause() 
    66787 File
    66788 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66789 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    66790 m.pause(self._mouse_pause_position) 
    66791 File
    66792 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66793 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    66794 p = self.view.picked_object(x, y) 
    66795 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66796 File
    66797 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66798 packages/chimerax/graphics/view.py", line 838, in picked_object 
    66799 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    66800 beyond, 
    66801 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66802 File
    66803 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66804 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    66805 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    66806 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66807 File
    66808 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66809 packages/chimerax/core/models.py", line 143, in first_intercept 
    66810 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    66811 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66812 File
    66813 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66814 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    66815 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    66816 exclude=exclude) 
    66817 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66818 File
    66819 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66820 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    66821 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    66822 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66823 File
    66824 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66825 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    66826 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    66827 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66828 File
    66829 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66830 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    66831 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    66832 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66833 File
    66834 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66835 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    66836 p = super().first_intercept(mxyz1, mxyz2) 
    66837 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66838 File
    66839 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66840 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    66841 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    66842 exclude=exclude) 
    66843 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66844 File
    66845 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66846 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    66847 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    66848 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66849 File
    66850 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66851 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    66852 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    66853 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66854 File
    66855 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66856 packages/chimerax/graphics/drawing.py", line 1108, in
    66857 _first_intercept_excluding_children 
    66858 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    66859 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66860 File
    66861 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66862 packages/chimerax/geometry/place.py", line 201, in inverse 
    66863 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    66864 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66865 File
    66866 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66867 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    66868 rinv[:, :] = matrix_inverse(r) 
    66869 ^^^^^^^^^^^^^^^^^ 
    66870 File
    66871 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66872 packages/numpy/linalg/linalg.py", line 561, in inv 
    66873 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    66874 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66875 File
    66876 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66877 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    66878 raise LinAlgError("Singular matrix") 
    66879 numpy.linalg.LinAlgError: Singular matrix 
    66880  
    66881 numpy.linalg.LinAlgError: Singular matrix 
    66882  
    66883 File
    66884 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66885 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    66886 raise LinAlgError("Singular matrix") 
    66887  
    66888 See log for complete Python traceback. 
    66889  
    66890 Traceback (most recent call last): 
    66891 File
    66892 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66893 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    66894 self.session.ui.mouse_modes.mouse_pause_tracking() 
    66895 File
    66896 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66897 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    66898 mouse_pause_tracking 
    66899 self._mouse_pause() 
    66900 File
    66901 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66902 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    66903 m.pause(self._mouse_pause_position) 
    66904 File
    66905 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66906 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    66907 p = self.view.picked_object(x, y) 
    66908 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66909 File
    66910 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66911 packages/chimerax/graphics/view.py", line 838, in picked_object 
    66912 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    66913 beyond, 
    66914 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66915 File
    66916 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66917 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    66918 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    66919 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66920 File
    66921 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66922 packages/chimerax/core/models.py", line 143, in first_intercept 
    66923 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    66924 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66925 File
    66926 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66927 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    66928 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    66929 exclude=exclude) 
    66930 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66931 File
    66932 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66933 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    66934 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    66935 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66936 File
    66937 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66938 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    66939 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    66940 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66941 File
    66942 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66943 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    66944 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    66945 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66946 File
    66947 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66948 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    66949 p = super().first_intercept(mxyz1, mxyz2) 
    66950 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66951 File
    66952 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66953 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    66954 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    66955 exclude=exclude) 
    66956 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66957 File
    66958 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66959 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    66960 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    66961 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66962 File
    66963 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66964 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    66965 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    66966 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66967 File
    66968 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66969 packages/chimerax/graphics/drawing.py", line 1108, in
    66970 _first_intercept_excluding_children 
    66971 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    66972 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66973 File
    66974 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66975 packages/chimerax/geometry/place.py", line 201, in inverse 
    66976 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    66977 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66978 File
    66979 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66980 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    66981 rinv[:, :] = matrix_inverse(r) 
    66982 ^^^^^^^^^^^^^^^^^ 
    66983 File
    66984 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66985 packages/numpy/linalg/linalg.py", line 561, in inv 
    66986 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    66987 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    66988 File
    66989 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66990 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    66991 raise LinAlgError("Singular matrix") 
    66992 numpy.linalg.LinAlgError: Singular matrix 
    66993  
    66994 numpy.linalg.LinAlgError: Singular matrix 
    66995  
    66996 File
    66997 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    66998 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    66999 raise LinAlgError("Singular matrix") 
    67000  
    67001 See log for complete Python traceback. 
    67002  
    67003 Traceback (most recent call last): 
    67004 File
    67005 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67006 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    67007 self.session.ui.mouse_modes.mouse_pause_tracking() 
    67008 File
    67009 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67010 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    67011 mouse_pause_tracking 
    67012 self._mouse_pause() 
    67013 File
    67014 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67015 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    67016 m.pause(self._mouse_pause_position) 
    67017 File
    67018 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67019 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    67020 p = self.view.picked_object(x, y) 
    67021 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67022 File
    67023 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67024 packages/chimerax/graphics/view.py", line 838, in picked_object 
    67025 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    67026 beyond, 
    67027 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67028 File
    67029 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67030 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    67031 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    67032 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67033 File
    67034 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67035 packages/chimerax/core/models.py", line 143, in first_intercept 
    67036 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    67037 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67038 File
    67039 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67040 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    67041 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    67042 exclude=exclude) 
    67043 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67044 File
    67045 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67046 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    67047 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    67048 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67049 File
    67050 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67051 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    67052 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    67053 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67054 File
    67055 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67056 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    67057 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    67058 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67059 File
    67060 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67061 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    67062 p = super().first_intercept(mxyz1, mxyz2) 
    67063 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67064 File
    67065 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67066 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    67067 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    67068 exclude=exclude) 
    67069 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67070 File
    67071 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67072 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    67073 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    67074 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67075 File
    67076 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67077 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    67078 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    67079 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67080 File
    67081 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67082 packages/chimerax/graphics/drawing.py", line 1108, in
    67083 _first_intercept_excluding_children 
    67084 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    67085 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67086 File
    67087 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67088 packages/chimerax/geometry/place.py", line 201, in inverse 
    67089 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    67090 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67091 File
    67092 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67093 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    67094 rinv[:, :] = matrix_inverse(r) 
    67095 ^^^^^^^^^^^^^^^^^ 
    67096 File
    67097 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67098 packages/numpy/linalg/linalg.py", line 561, in inv 
    67099 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    67100 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67101 File
    67102 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67103 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    67104 raise LinAlgError("Singular matrix") 
    67105 numpy.linalg.LinAlgError: Singular matrix 
    67106  
    67107 numpy.linalg.LinAlgError: Singular matrix 
    67108  
    67109 File
    67110 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67111 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    67112 raise LinAlgError("Singular matrix") 
    67113  
    67114 See log for complete Python traceback. 
    67115  
    67116 Traceback (most recent call last): 
    67117 File
    67118 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67119 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    67120 self.session.ui.mouse_modes.mouse_pause_tracking() 
    67121 File
    67122 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67123 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    67124 mouse_pause_tracking 
    67125 self._mouse_pause() 
    67126 File
    67127 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67128 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    67129 m.pause(self._mouse_pause_position) 
    67130 File
    67131 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67132 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    67133 p = self.view.picked_object(x, y) 
    67134 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67135 File
    67136 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67137 packages/chimerax/graphics/view.py", line 838, in picked_object 
    67138 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    67139 beyond, 
    67140 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67141 File
    67142 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67143 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    67144 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    67145 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67146 File
    67147 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67148 packages/chimerax/core/models.py", line 143, in first_intercept 
    67149 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    67150 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67151 File
    67152 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67153 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    67154 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    67155 exclude=exclude) 
    67156 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67157 File
    67158 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67159 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    67160 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    67161 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67162 File
    67163 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67164 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    67165 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    67166 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67167 File
    67168 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67169 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    67170 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    67171 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67172 File
    67173 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67174 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    67175 p = super().first_intercept(mxyz1, mxyz2) 
    67176 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67177 File
    67178 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67179 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    67180 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    67181 exclude=exclude) 
    67182 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67183 File
    67184 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67185 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    67186 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    67187 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67188 File
    67189 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67190 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    67191 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    67192 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67193 File
    67194 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67195 packages/chimerax/graphics/drawing.py", line 1108, in
    67196 _first_intercept_excluding_children 
    67197 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    67198 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67199 File
    67200 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67201 packages/chimerax/geometry/place.py", line 201, in inverse 
    67202 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    67203 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67204 File
    67205 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67206 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    67207 rinv[:, :] = matrix_inverse(r) 
    67208 ^^^^^^^^^^^^^^^^^ 
    67209 File
    67210 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67211 packages/numpy/linalg/linalg.py", line 561, in inv 
    67212 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    67213 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67214 File
    67215 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67216 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    67217 raise LinAlgError("Singular matrix") 
    67218 numpy.linalg.LinAlgError: Singular matrix 
    67219  
    67220 numpy.linalg.LinAlgError: Singular matrix 
    67221  
    67222 File
    67223 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67224 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    67225 raise LinAlgError("Singular matrix") 
    67226  
    67227 See log for complete Python traceback. 
    67228  
    67229 Traceback (most recent call last): 
    67230 File
    67231 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67232 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    67233 self.session.ui.mouse_modes.mouse_pause_tracking() 
    67234 File
    67235 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67236 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    67237 mouse_pause_tracking 
    67238 self._mouse_pause() 
    67239 File
    67240 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67241 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    67242 m.pause(self._mouse_pause_position) 
    67243 File
    67244 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67245 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    67246 p = self.view.picked_object(x, y) 
    67247 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67248 File
    67249 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67250 packages/chimerax/graphics/view.py", line 838, in picked_object 
    67251 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    67252 beyond, 
    67253 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67254 File
    67255 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67256 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    67257 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    67258 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67259 File
    67260 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67261 packages/chimerax/core/models.py", line 143, in first_intercept 
    67262 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    67263 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67264 File
    67265 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67266 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    67267 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    67268 exclude=exclude) 
    67269 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67270 File
    67271 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67272 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    67273 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    67274 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67275 File
    67276 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67277 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    67278 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    67279 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67280 File
    67281 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67282 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    67283 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    67284 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67285 File
    67286 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67287 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    67288 p = super().first_intercept(mxyz1, mxyz2) 
    67289 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67290 File
    67291 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67292 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    67293 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    67294 exclude=exclude) 
    67295 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67296 File
    67297 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67298 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    67299 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    67300 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67301 File
    67302 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67303 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    67304 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    67305 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67306 File
    67307 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67308 packages/chimerax/graphics/drawing.py", line 1108, in
    67309 _first_intercept_excluding_children 
    67310 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    67311 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67312 File
    67313 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67314 packages/chimerax/geometry/place.py", line 201, in inverse 
    67315 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    67316 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67317 File
    67318 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67319 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    67320 rinv[:, :] = matrix_inverse(r) 
    67321 ^^^^^^^^^^^^^^^^^ 
    67322 File
    67323 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67324 packages/numpy/linalg/linalg.py", line 561, in inv 
    67325 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    67326 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67327 File
    67328 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67329 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    67330 raise LinAlgError("Singular matrix") 
    67331 numpy.linalg.LinAlgError: Singular matrix 
    67332  
    67333 numpy.linalg.LinAlgError: Singular matrix 
    67334  
    67335 File
    67336 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67337 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    67338 raise LinAlgError("Singular matrix") 
    67339  
    67340 See log for complete Python traceback. 
    67341  
    67342 Traceback (most recent call last): 
    67343 File
    67344 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67345 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    67346 self.session.ui.mouse_modes.mouse_pause_tracking() 
    67347 File
    67348 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67349 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    67350 mouse_pause_tracking 
    67351 self._mouse_pause() 
    67352 File
    67353 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67354 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    67355 m.pause(self._mouse_pause_position) 
    67356 File
    67357 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67358 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    67359 p = self.view.picked_object(x, y) 
    67360 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67361 File
    67362 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67363 packages/chimerax/graphics/view.py", line 838, in picked_object 
    67364 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    67365 beyond, 
    67366 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67367 File
    67368 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67369 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    67370 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    67371 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67372 File
    67373 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67374 packages/chimerax/core/models.py", line 143, in first_intercept 
    67375 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    67376 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67377 File
    67378 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67379 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    67380 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    67381 exclude=exclude) 
    67382 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67383 File
    67384 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67385 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    67386 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    67387 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67388 File
    67389 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67390 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    67391 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    67392 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67393 File
    67394 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67395 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    67396 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    67397 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67398 File
    67399 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67400 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    67401 p = super().first_intercept(mxyz1, mxyz2) 
    67402 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67403 File
    67404 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67405 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    67406 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    67407 exclude=exclude) 
    67408 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67409 File
    67410 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67411 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    67412 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    67413 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67414 File
    67415 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67416 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    67417 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    67418 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67419 File
    67420 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67421 packages/chimerax/graphics/drawing.py", line 1108, in
    67422 _first_intercept_excluding_children 
    67423 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    67424 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67425 File
    67426 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67427 packages/chimerax/geometry/place.py", line 201, in inverse 
    67428 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    67429 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67430 File
    67431 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67432 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    67433 rinv[:, :] = matrix_inverse(r) 
    67434 ^^^^^^^^^^^^^^^^^ 
    67435 File
    67436 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67437 packages/numpy/linalg/linalg.py", line 561, in inv 
    67438 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    67439 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67440 File
    67441 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67442 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    67443 raise LinAlgError("Singular matrix") 
    67444 numpy.linalg.LinAlgError: Singular matrix 
    67445  
    67446 numpy.linalg.LinAlgError: Singular matrix 
    67447  
    67448 File
    67449 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67450 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    67451 raise LinAlgError("Singular matrix") 
    67452  
    67453 See log for complete Python traceback. 
    67454  
    67455 Traceback (most recent call last): 
    67456 File
    67457 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67458 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    67459 self.session.ui.mouse_modes.mouse_pause_tracking() 
    67460 File
    67461 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67462 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    67463 mouse_pause_tracking 
    67464 self._mouse_pause() 
    67465 File
    67466 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67467 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    67468 m.pause(self._mouse_pause_position) 
    67469 File
    67470 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67471 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    67472 p = self.view.picked_object(x, y) 
    67473 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67474 File
    67475 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67476 packages/chimerax/graphics/view.py", line 838, in picked_object 
    67477 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    67478 beyond, 
    67479 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67480 File
    67481 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67482 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    67483 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    67484 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67485 File
    67486 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67487 packages/chimerax/core/models.py", line 143, in first_intercept 
    67488 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    67489 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67490 File
    67491 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67492 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    67493 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    67494 exclude=exclude) 
    67495 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67496 File
    67497 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67498 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    67499 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    67500 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67501 File
    67502 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67503 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    67504 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    67505 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67506 File
    67507 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67508 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    67509 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    67510 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67511 File
    67512 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67513 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    67514 p = super().first_intercept(mxyz1, mxyz2) 
    67515 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67516 File
    67517 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67518 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    67519 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    67520 exclude=exclude) 
    67521 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67522 File
    67523 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67524 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    67525 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    67526 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67527 File
    67528 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67529 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    67530 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    67531 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67532 File
    67533 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67534 packages/chimerax/graphics/drawing.py", line 1108, in
    67535 _first_intercept_excluding_children 
    67536 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    67537 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67538 File
    67539 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67540 packages/chimerax/geometry/place.py", line 201, in inverse 
    67541 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    67542 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67543 File
    67544 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67545 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    67546 rinv[:, :] = matrix_inverse(r) 
    67547 ^^^^^^^^^^^^^^^^^ 
    67548 File
    67549 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67550 packages/numpy/linalg/linalg.py", line 561, in inv 
    67551 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    67552 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67553 File
    67554 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67555 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    67556 raise LinAlgError("Singular matrix") 
    67557 numpy.linalg.LinAlgError: Singular matrix 
    67558  
    67559 numpy.linalg.LinAlgError: Singular matrix 
    67560  
    67561 File
    67562 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67563 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    67564 raise LinAlgError("Singular matrix") 
    67565  
    67566 See log for complete Python traceback. 
    67567  
    67568 Traceback (most recent call last): 
    67569 File
    67570 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67571 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    67572 self.session.ui.mouse_modes.mouse_pause_tracking() 
    67573 File
    67574 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67575 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    67576 mouse_pause_tracking 
    67577 self._mouse_pause() 
    67578 File
    67579 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67580 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    67581 m.pause(self._mouse_pause_position) 
    67582 File
    67583 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67584 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    67585 p = self.view.picked_object(x, y) 
    67586 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67587 File
    67588 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67589 packages/chimerax/graphics/view.py", line 838, in picked_object 
    67590 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    67591 beyond, 
    67592 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67593 File
    67594 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67595 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    67596 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    67597 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67598 File
    67599 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67600 packages/chimerax/core/models.py", line 143, in first_intercept 
    67601 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    67602 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67603 File
    67604 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67605 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    67606 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    67607 exclude=exclude) 
    67608 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67609 File
    67610 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67611 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    67612 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    67613 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67614 File
    67615 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67616 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    67617 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    67618 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67619 File
    67620 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67621 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    67622 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    67623 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67624 File
    67625 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67626 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    67627 p = super().first_intercept(mxyz1, mxyz2) 
    67628 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67629 File
    67630 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67631 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    67632 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    67633 exclude=exclude) 
    67634 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67635 File
    67636 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67637 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    67638 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    67639 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67640 File
    67641 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67642 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    67643 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    67644 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67645 File
    67646 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67647 packages/chimerax/graphics/drawing.py", line 1108, in
    67648 _first_intercept_excluding_children 
    67649 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    67650 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67651 File
    67652 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67653 packages/chimerax/geometry/place.py", line 201, in inverse 
    67654 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    67655 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67656 File
    67657 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67658 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    67659 rinv[:, :] = matrix_inverse(r) 
    67660 ^^^^^^^^^^^^^^^^^ 
    67661 File
    67662 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67663 packages/numpy/linalg/linalg.py", line 561, in inv 
    67664 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    67665 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67666 File
    67667 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67668 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    67669 raise LinAlgError("Singular matrix") 
    67670 numpy.linalg.LinAlgError: Singular matrix 
    67671  
    67672 numpy.linalg.LinAlgError: Singular matrix 
    67673  
    67674 File
    67675 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67676 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    67677 raise LinAlgError("Singular matrix") 
    67678  
    67679 See log for complete Python traceback. 
    67680  
    67681 Traceback (most recent call last): 
    67682 File
    67683 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67684 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    67685 self.session.ui.mouse_modes.mouse_pause_tracking() 
    67686 File
    67687 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67688 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    67689 mouse_pause_tracking 
    67690 self._mouse_pause() 
    67691 File
    67692 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67693 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    67694 m.pause(self._mouse_pause_position) 
    67695 File
    67696 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67697 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    67698 p = self.view.picked_object(x, y) 
    67699 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67700 File
    67701 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67702 packages/chimerax/graphics/view.py", line 838, in picked_object 
    67703 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    67704 beyond, 
    67705 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67706 File
    67707 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67708 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    67709 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    67710 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67711 File
    67712 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67713 packages/chimerax/core/models.py", line 143, in first_intercept 
    67714 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    67715 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67716 File
    67717 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67718 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    67719 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    67720 exclude=exclude) 
    67721 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67722 File
    67723 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67724 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    67725 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    67726 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67727 File
    67728 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67729 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    67730 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    67731 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67732 File
    67733 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67734 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    67735 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    67736 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67737 File
    67738 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67739 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    67740 p = super().first_intercept(mxyz1, mxyz2) 
    67741 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67742 File
    67743 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67744 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    67745 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    67746 exclude=exclude) 
    67747 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67748 File
    67749 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67750 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    67751 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    67752 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67753 File
    67754 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67755 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    67756 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    67757 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67758 File
    67759 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67760 packages/chimerax/graphics/drawing.py", line 1108, in
    67761 _first_intercept_excluding_children 
    67762 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    67763 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67764 File
    67765 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67766 packages/chimerax/geometry/place.py", line 201, in inverse 
    67767 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    67768 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67769 File
    67770 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67771 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    67772 rinv[:, :] = matrix_inverse(r) 
    67773 ^^^^^^^^^^^^^^^^^ 
    67774 File
    67775 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67776 packages/numpy/linalg/linalg.py", line 561, in inv 
    67777 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    67778 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67779 File
    67780 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67781 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    67782 raise LinAlgError("Singular matrix") 
    67783 numpy.linalg.LinAlgError: Singular matrix 
    67784  
    67785 numpy.linalg.LinAlgError: Singular matrix 
    67786  
    67787 File
    67788 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67789 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    67790 raise LinAlgError("Singular matrix") 
    67791  
    67792 See log for complete Python traceback. 
    67793  
    67794 Traceback (most recent call last): 
    67795 File
    67796 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67797 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    67798 self.session.ui.mouse_modes.mouse_pause_tracking() 
    67799 File
    67800 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67801 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    67802 mouse_pause_tracking 
    67803 self._mouse_pause() 
    67804 File
    67805 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67806 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    67807 m.pause(self._mouse_pause_position) 
    67808 File
    67809 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67810 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    67811 p = self.view.picked_object(x, y) 
    67812 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67813 File
    67814 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67815 packages/chimerax/graphics/view.py", line 838, in picked_object 
    67816 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    67817 beyond, 
    67818 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67819 File
    67820 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67821 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    67822 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    67823 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67824 File
    67825 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67826 packages/chimerax/core/models.py", line 143, in first_intercept 
    67827 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    67828 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67829 File
    67830 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67831 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    67832 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    67833 exclude=exclude) 
    67834 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67835 File
    67836 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67837 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    67838 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    67839 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67840 File
    67841 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67842 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    67843 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    67844 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67845 File
    67846 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67847 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    67848 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    67849 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67850 File
    67851 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67852 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    67853 p = super().first_intercept(mxyz1, mxyz2) 
    67854 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67855 File
    67856 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67857 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    67858 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    67859 exclude=exclude) 
    67860 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67861 File
    67862 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67863 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    67864 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    67865 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67866 File
    67867 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67868 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    67869 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    67870 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67871 File
    67872 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67873 packages/chimerax/graphics/drawing.py", line 1108, in
    67874 _first_intercept_excluding_children 
    67875 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    67876 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67877 File
    67878 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67879 packages/chimerax/geometry/place.py", line 201, in inverse 
    67880 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    67881 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67882 File
    67883 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67884 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    67885 rinv[:, :] = matrix_inverse(r) 
    67886 ^^^^^^^^^^^^^^^^^ 
    67887 File
    67888 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67889 packages/numpy/linalg/linalg.py", line 561, in inv 
    67890 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    67891 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67892 File
    67893 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67894 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    67895 raise LinAlgError("Singular matrix") 
    67896 numpy.linalg.LinAlgError: Singular matrix 
    67897  
    67898 numpy.linalg.LinAlgError: Singular matrix 
    67899  
    67900 File
    67901 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67902 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    67903 raise LinAlgError("Singular matrix") 
    67904  
    67905 See log for complete Python traceback. 
    67906  
    67907 Traceback (most recent call last): 
    67908 File
    67909 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67910 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    67911 self.session.ui.mouse_modes.mouse_pause_tracking() 
    67912 File
    67913 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67914 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    67915 mouse_pause_tracking 
    67916 self._mouse_pause() 
    67917 File
    67918 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67919 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    67920 m.pause(self._mouse_pause_position) 
    67921 File
    67922 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67923 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    67924 p = self.view.picked_object(x, y) 
    67925 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67926 File
    67927 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67928 packages/chimerax/graphics/view.py", line 838, in picked_object 
    67929 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    67930 beyond, 
    67931 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67932 File
    67933 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67934 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    67935 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    67936 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67937 File
    67938 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67939 packages/chimerax/core/models.py", line 143, in first_intercept 
    67940 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    67941 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67942 File
    67943 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67944 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    67945 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    67946 exclude=exclude) 
    67947 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67948 File
    67949 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67950 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    67951 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    67952 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67953 File
    67954 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67955 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    67956 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    67957 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67958 File
    67959 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67960 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    67961 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    67962 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67963 File
    67964 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67965 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    67966 p = super().first_intercept(mxyz1, mxyz2) 
    67967 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67968 File
    67969 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67970 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    67971 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    67972 exclude=exclude) 
    67973 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67974 File
    67975 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67976 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    67977 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    67978 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67979 File
    67980 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67981 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    67982 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    67983 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67984 File
    67985 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67986 packages/chimerax/graphics/drawing.py", line 1108, in
    67987 _first_intercept_excluding_children 
    67988 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    67989 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67990 File
    67991 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67992 packages/chimerax/geometry/place.py", line 201, in inverse 
    67993 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    67994 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    67995 File
    67996 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    67997 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    67998 rinv[:, :] = matrix_inverse(r) 
    67999 ^^^^^^^^^^^^^^^^^ 
    68000 File
    68001 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68002 packages/numpy/linalg/linalg.py", line 561, in inv 
    68003 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    68004 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68005 File
    68006 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68007 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    68008 raise LinAlgError("Singular matrix") 
    68009 numpy.linalg.LinAlgError: Singular matrix 
    68010  
    68011 numpy.linalg.LinAlgError: Singular matrix 
    68012  
    68013 File
    68014 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68015 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    68016 raise LinAlgError("Singular matrix") 
    68017  
    68018 See log for complete Python traceback. 
    68019  
    68020 Traceback (most recent call last): 
    68021 File
    68022 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68023 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    68024 self.session.ui.mouse_modes.mouse_pause_tracking() 
    68025 File
    68026 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68027 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    68028 mouse_pause_tracking 
    68029 self._mouse_pause() 
    68030 File
    68031 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68032 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    68033 m.pause(self._mouse_pause_position) 
    68034 File
    68035 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68036 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    68037 p = self.view.picked_object(x, y) 
    68038 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68039 File
    68040 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68041 packages/chimerax/graphics/view.py", line 838, in picked_object 
    68042 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    68043 beyond, 
    68044 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68045 File
    68046 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68047 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    68048 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    68049 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68050 File
    68051 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68052 packages/chimerax/core/models.py", line 143, in first_intercept 
    68053 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    68054 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68055 File
    68056 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68057 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    68058 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    68059 exclude=exclude) 
    68060 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68061 File
    68062 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68063 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    68064 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    68065 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68066 File
    68067 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68068 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    68069 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    68070 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68071 File
    68072 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68073 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    68074 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    68075 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68076 File
    68077 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68078 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    68079 p = super().first_intercept(mxyz1, mxyz2) 
    68080 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68081 File
    68082 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68083 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    68084 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    68085 exclude=exclude) 
    68086 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68087 File
    68088 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68089 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    68090 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    68091 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68092 File
    68093 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68094 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    68095 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    68096 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68097 File
    68098 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68099 packages/chimerax/graphics/drawing.py", line 1108, in
    68100 _first_intercept_excluding_children 
    68101 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    68102 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68103 File
    68104 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68105 packages/chimerax/geometry/place.py", line 201, in inverse 
    68106 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    68107 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68108 File
    68109 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68110 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    68111 rinv[:, :] = matrix_inverse(r) 
    68112 ^^^^^^^^^^^^^^^^^ 
    68113 File
    68114 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68115 packages/numpy/linalg/linalg.py", line 561, in inv 
    68116 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    68117 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68118 File
    68119 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68120 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    68121 raise LinAlgError("Singular matrix") 
    68122 numpy.linalg.LinAlgError: Singular matrix 
    68123  
    68124 numpy.linalg.LinAlgError: Singular matrix 
    68125  
    68126 File
    68127 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68128 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    68129 raise LinAlgError("Singular matrix") 
    68130  
    68131 See log for complete Python traceback. 
    68132  
    68133 Traceback (most recent call last): 
    68134 File
    68135 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68136 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    68137 self.session.ui.mouse_modes.mouse_pause_tracking() 
    68138 File
    68139 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68140 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    68141 mouse_pause_tracking 
    68142 self._mouse_pause() 
    68143 File
    68144 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68145 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    68146 m.pause(self._mouse_pause_position) 
    68147 File
    68148 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68149 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    68150 p = self.view.picked_object(x, y) 
    68151 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68152 File
    68153 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68154 packages/chimerax/graphics/view.py", line 838, in picked_object 
    68155 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    68156 beyond, 
    68157 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68158 File
    68159 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68160 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    68161 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    68162 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68163 File
    68164 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68165 packages/chimerax/core/models.py", line 143, in first_intercept 
    68166 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    68167 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68168 File
    68169 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68170 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    68171 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    68172 exclude=exclude) 
    68173 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68174 File
    68175 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68176 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    68177 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    68178 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68179 File
    68180 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68181 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    68182 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    68183 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68184 File
    68185 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68186 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    68187 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    68188 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68189 File
    68190 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68191 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    68192 p = super().first_intercept(mxyz1, mxyz2) 
    68193 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68194 File
    68195 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68196 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    68197 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    68198 exclude=exclude) 
    68199 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68200 File
    68201 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68202 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    68203 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    68204 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68205 File
    68206 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68207 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    68208 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    68209 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68210 File
    68211 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68212 packages/chimerax/graphics/drawing.py", line 1108, in
    68213 _first_intercept_excluding_children 
    68214 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    68215 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68216 File
    68217 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68218 packages/chimerax/geometry/place.py", line 201, in inverse 
    68219 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    68220 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68221 File
    68222 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68223 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    68224 rinv[:, :] = matrix_inverse(r) 
    68225 ^^^^^^^^^^^^^^^^^ 
    68226 File
    68227 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68228 packages/numpy/linalg/linalg.py", line 561, in inv 
    68229 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    68230 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68231 File
    68232 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68233 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    68234 raise LinAlgError("Singular matrix") 
    68235 numpy.linalg.LinAlgError: Singular matrix 
    68236  
    68237 numpy.linalg.LinAlgError: Singular matrix 
    68238  
    68239 File
    68240 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68241 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    68242 raise LinAlgError("Singular matrix") 
    68243  
    68244 See log for complete Python traceback. 
    68245  
    68246 Traceback (most recent call last): 
    68247 File
    68248 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68249 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    68250 self.session.ui.mouse_modes.mouse_pause_tracking() 
    68251 File
    68252 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68253 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    68254 mouse_pause_tracking 
    68255 self._mouse_pause() 
    68256 File
    68257 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68258 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    68259 m.pause(self._mouse_pause_position) 
    68260 File
    68261 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68262 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    68263 p = self.view.picked_object(x, y) 
    68264 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68265 File
    68266 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68267 packages/chimerax/graphics/view.py", line 838, in picked_object 
    68268 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    68269 beyond, 
    68270 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68271 File
    68272 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68273 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    68274 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    68275 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68276 File
    68277 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68278 packages/chimerax/core/models.py", line 143, in first_intercept 
    68279 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    68280 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68281 File
    68282 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68283 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    68284 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    68285 exclude=exclude) 
    68286 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68287 File
    68288 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68289 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    68290 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    68291 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68292 File
    68293 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68294 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    68295 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    68296 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68297 File
    68298 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68299 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    68300 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    68301 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68302 File
    68303 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68304 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    68305 p = super().first_intercept(mxyz1, mxyz2) 
    68306 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68307 File
    68308 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68309 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    68310 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    68311 exclude=exclude) 
    68312 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68313 File
    68314 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68315 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    68316 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    68317 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68318 File
    68319 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68320 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    68321 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    68322 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68323 File
    68324 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68325 packages/chimerax/graphics/drawing.py", line 1108, in
    68326 _first_intercept_excluding_children 
    68327 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    68328 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68329 File
    68330 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68331 packages/chimerax/geometry/place.py", line 201, in inverse 
    68332 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    68333 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68334 File
    68335 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68336 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    68337 rinv[:, :] = matrix_inverse(r) 
    68338 ^^^^^^^^^^^^^^^^^ 
    68339 File
    68340 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68341 packages/numpy/linalg/linalg.py", line 561, in inv 
    68342 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    68343 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68344 File
    68345 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68346 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    68347 raise LinAlgError("Singular matrix") 
    68348 numpy.linalg.LinAlgError: Singular matrix 
    68349  
    68350 numpy.linalg.LinAlgError: Singular matrix 
    68351  
    68352 File
    68353 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68354 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    68355 raise LinAlgError("Singular matrix") 
    68356  
    68357 See log for complete Python traceback. 
    68358  
    68359 Traceback (most recent call last): 
    68360 File
    68361 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68362 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    68363 self.session.ui.mouse_modes.mouse_pause_tracking() 
    68364 File
    68365 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68366 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    68367 mouse_pause_tracking 
    68368 self._mouse_pause() 
    68369 File
    68370 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68371 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    68372 m.pause(self._mouse_pause_position) 
    68373 File
    68374 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68375 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    68376 p = self.view.picked_object(x, y) 
    68377 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68378 File
    68379 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68380 packages/chimerax/graphics/view.py", line 838, in picked_object 
    68381 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    68382 beyond, 
    68383 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68384 File
    68385 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68386 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    68387 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    68388 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68389 File
    68390 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68391 packages/chimerax/core/models.py", line 143, in first_intercept 
    68392 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    68393 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68394 File
    68395 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68396 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    68397 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    68398 exclude=exclude) 
    68399 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68400 File
    68401 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68402 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    68403 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    68404 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68405 File
    68406 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68407 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    68408 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    68409 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68410 File
    68411 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68412 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    68413 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    68414 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68415 File
    68416 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68417 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    68418 p = super().first_intercept(mxyz1, mxyz2) 
    68419 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68420 File
    68421 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68422 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    68423 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    68424 exclude=exclude) 
    68425 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68426 File
    68427 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68428 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    68429 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    68430 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68431 File
    68432 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68433 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    68434 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    68435 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68436 File
    68437 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68438 packages/chimerax/graphics/drawing.py", line 1108, in
    68439 _first_intercept_excluding_children 
    68440 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    68441 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68442 File
    68443 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68444 packages/chimerax/geometry/place.py", line 201, in inverse 
    68445 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    68446 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68447 File
    68448 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68449 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    68450 rinv[:, :] = matrix_inverse(r) 
    68451 ^^^^^^^^^^^^^^^^^ 
    68452 File
    68453 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68454 packages/numpy/linalg/linalg.py", line 561, in inv 
    68455 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    68456 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68457 File
    68458 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68459 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    68460 raise LinAlgError("Singular matrix") 
    68461 numpy.linalg.LinAlgError: Singular matrix 
    68462  
    68463 numpy.linalg.LinAlgError: Singular matrix 
    68464  
    68465 File
    68466 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68467 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    68468 raise LinAlgError("Singular matrix") 
    68469  
    68470 See log for complete Python traceback. 
    68471  
    68472 Traceback (most recent call last): 
    68473 File
    68474 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68475 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    68476 self.session.ui.mouse_modes.mouse_pause_tracking() 
    68477 File
    68478 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68479 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    68480 mouse_pause_tracking 
    68481 self._mouse_pause() 
    68482 File
    68483 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68484 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    68485 m.pause(self._mouse_pause_position) 
    68486 File
    68487 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68488 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    68489 p = self.view.picked_object(x, y) 
    68490 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68491 File
    68492 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68493 packages/chimerax/graphics/view.py", line 838, in picked_object 
    68494 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    68495 beyond, 
    68496 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68497 File
    68498 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68499 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    68500 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    68501 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68502 File
    68503 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68504 packages/chimerax/core/models.py", line 143, in first_intercept 
    68505 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    68506 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68507 File
    68508 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68509 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    68510 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    68511 exclude=exclude) 
    68512 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68513 File
    68514 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68515 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    68516 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    68517 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68518 File
    68519 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68520 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    68521 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    68522 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68523 File
    68524 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68525 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    68526 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    68527 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68528 File
    68529 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68530 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    68531 p = super().first_intercept(mxyz1, mxyz2) 
    68532 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68533 File
    68534 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68535 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    68536 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    68537 exclude=exclude) 
    68538 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68539 File
    68540 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68541 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    68542 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    68543 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68544 File
    68545 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68546 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    68547 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    68548 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68549 File
    68550 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68551 packages/chimerax/graphics/drawing.py", line 1108, in
    68552 _first_intercept_excluding_children 
    68553 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    68554 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68555 File
    68556 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68557 packages/chimerax/geometry/place.py", line 201, in inverse 
    68558 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    68559 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68560 File
    68561 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68562 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    68563 rinv[:, :] = matrix_inverse(r) 
    68564 ^^^^^^^^^^^^^^^^^ 
    68565 File
    68566 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68567 packages/numpy/linalg/linalg.py", line 561, in inv 
    68568 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    68569 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68570 File
    68571 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68572 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    68573 raise LinAlgError("Singular matrix") 
    68574 numpy.linalg.LinAlgError: Singular matrix 
    68575  
    68576 numpy.linalg.LinAlgError: Singular matrix 
    68577  
    68578 File
    68579 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68580 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    68581 raise LinAlgError("Singular matrix") 
    68582  
    68583 See log for complete Python traceback. 
    68584  
    68585 Traceback (most recent call last): 
    68586 File
    68587 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68588 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    68589 self.session.ui.mouse_modes.mouse_pause_tracking() 
    68590 File
    68591 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68592 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    68593 mouse_pause_tracking 
    68594 self._mouse_pause() 
    68595 File
    68596 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68597 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    68598 m.pause(self._mouse_pause_position) 
    68599 File
    68600 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68601 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    68602 p = self.view.picked_object(x, y) 
    68603 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68604 File
    68605 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68606 packages/chimerax/graphics/view.py", line 838, in picked_object 
    68607 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    68608 beyond, 
    68609 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68610 File
    68611 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68612 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    68613 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    68614 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68615 File
    68616 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68617 packages/chimerax/core/models.py", line 143, in first_intercept 
    68618 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    68619 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68620 File
    68621 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68622 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    68623 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    68624 exclude=exclude) 
    68625 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68626 File
    68627 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68628 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    68629 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    68630 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68631 File
    68632 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68633 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    68634 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    68635 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68636 File
    68637 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68638 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    68639 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    68640 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68641 File
    68642 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68643 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    68644 p = super().first_intercept(mxyz1, mxyz2) 
    68645 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68646 File
    68647 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68648 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    68649 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    68650 exclude=exclude) 
    68651 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68652 File
    68653 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68654 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    68655 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    68656 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68657 File
    68658 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68659 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    68660 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    68661 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68662 File
    68663 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68664 packages/chimerax/graphics/drawing.py", line 1108, in
    68665 _first_intercept_excluding_children 
    68666 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    68667 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68668 File
    68669 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68670 packages/chimerax/geometry/place.py", line 201, in inverse 
    68671 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    68672 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68673 File
    68674 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68675 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    68676 rinv[:, :] = matrix_inverse(r) 
    68677 ^^^^^^^^^^^^^^^^^ 
    68678 File
    68679 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68680 packages/numpy/linalg/linalg.py", line 561, in inv 
    68681 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    68682 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68683 File
    68684 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68685 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    68686 raise LinAlgError("Singular matrix") 
    68687 numpy.linalg.LinAlgError: Singular matrix 
    68688  
    68689 numpy.linalg.LinAlgError: Singular matrix 
    68690  
    68691 File
    68692 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68693 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    68694 raise LinAlgError("Singular matrix") 
    68695  
    68696 See log for complete Python traceback. 
    68697  
    68698 Traceback (most recent call last): 
    68699 File
    68700 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68701 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    68702 self.session.ui.mouse_modes.mouse_pause_tracking() 
    68703 File
    68704 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68705 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    68706 mouse_pause_tracking 
    68707 self._mouse_pause() 
    68708 File
    68709 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68710 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    68711 m.pause(self._mouse_pause_position) 
    68712 File
    68713 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68714 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    68715 p = self.view.picked_object(x, y) 
    68716 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68717 File
    68718 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68719 packages/chimerax/graphics/view.py", line 838, in picked_object 
    68720 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    68721 beyond, 
    68722 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68723 File
    68724 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68725 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    68726 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    68727 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68728 File
    68729 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68730 packages/chimerax/core/models.py", line 143, in first_intercept 
    68731 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    68732 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68733 File
    68734 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68735 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    68736 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    68737 exclude=exclude) 
    68738 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68739 File
    68740 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68741 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    68742 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    68743 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68744 File
    68745 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68746 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    68747 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    68748 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68749 File
    68750 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68751 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    68752 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    68753 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68754 File
    68755 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68756 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    68757 p = super().first_intercept(mxyz1, mxyz2) 
    68758 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68759 File
    68760 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68761 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    68762 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    68763 exclude=exclude) 
    68764 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68765 File
    68766 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68767 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    68768 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    68769 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68770 File
    68771 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68772 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    68773 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    68774 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68775 File
    68776 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68777 packages/chimerax/graphics/drawing.py", line 1108, in
    68778 _first_intercept_excluding_children 
    68779 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    68780 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68781 File
    68782 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68783 packages/chimerax/geometry/place.py", line 201, in inverse 
    68784 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    68785 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68786 File
    68787 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68788 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    68789 rinv[:, :] = matrix_inverse(r) 
    68790 ^^^^^^^^^^^^^^^^^ 
    68791 File
    68792 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68793 packages/numpy/linalg/linalg.py", line 561, in inv 
    68794 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    68795 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68796 File
    68797 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68798 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    68799 raise LinAlgError("Singular matrix") 
    68800 numpy.linalg.LinAlgError: Singular matrix 
    68801  
    68802 numpy.linalg.LinAlgError: Singular matrix 
    68803  
    68804 File
    68805 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68806 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    68807 raise LinAlgError("Singular matrix") 
    68808  
    68809 See log for complete Python traceback. 
    68810  
    68811 Traceback (most recent call last): 
    68812 File
    68813 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68814 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    68815 self.session.ui.mouse_modes.mouse_pause_tracking() 
    68816 File
    68817 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68818 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    68819 mouse_pause_tracking 
    68820 self._mouse_pause() 
    68821 File
    68822 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68823 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    68824 m.pause(self._mouse_pause_position) 
    68825 File
    68826 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68827 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    68828 p = self.view.picked_object(x, y) 
    68829 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68830 File
    68831 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68832 packages/chimerax/graphics/view.py", line 838, in picked_object 
    68833 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    68834 beyond, 
    68835 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68836 File
    68837 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68838 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    68839 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    68840 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68841 File
    68842 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68843 packages/chimerax/core/models.py", line 143, in first_intercept 
    68844 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    68845 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68846 File
    68847 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68848 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    68849 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    68850 exclude=exclude) 
    68851 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68852 File
    68853 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68854 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    68855 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    68856 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68857 File
    68858 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68859 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    68860 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    68861 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68862 File
    68863 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68864 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    68865 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    68866 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68867 File
    68868 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68869 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    68870 p = super().first_intercept(mxyz1, mxyz2) 
    68871 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68872 File
    68873 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68874 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    68875 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    68876 exclude=exclude) 
    68877 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68878 File
    68879 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68880 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    68881 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    68882 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68883 File
    68884 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68885 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    68886 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    68887 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68888 File
    68889 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68890 packages/chimerax/graphics/drawing.py", line 1108, in
    68891 _first_intercept_excluding_children 
    68892 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    68893 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68894 File
    68895 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68896 packages/chimerax/geometry/place.py", line 201, in inverse 
    68897 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    68898 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68899 File
    68900 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68901 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    68902 rinv[:, :] = matrix_inverse(r) 
    68903 ^^^^^^^^^^^^^^^^^ 
    68904 File
    68905 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68906 packages/numpy/linalg/linalg.py", line 561, in inv 
    68907 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    68908 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68909 File
    68910 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68911 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    68912 raise LinAlgError("Singular matrix") 
    68913 numpy.linalg.LinAlgError: Singular matrix 
    68914  
    68915 numpy.linalg.LinAlgError: Singular matrix 
    68916  
    68917 File
    68918 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68919 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    68920 raise LinAlgError("Singular matrix") 
    68921  
    68922 See log for complete Python traceback. 
    68923  
    68924 Traceback (most recent call last): 
    68925 File
    68926 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68927 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    68928 self.session.ui.mouse_modes.mouse_pause_tracking() 
    68929 File
    68930 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68931 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    68932 mouse_pause_tracking 
    68933 self._mouse_pause() 
    68934 File
    68935 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68936 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    68937 m.pause(self._mouse_pause_position) 
    68938 File
    68939 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68940 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    68941 p = self.view.picked_object(x, y) 
    68942 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68943 File
    68944 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68945 packages/chimerax/graphics/view.py", line 838, in picked_object 
    68946 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    68947 beyond, 
    68948 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68949 File
    68950 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68951 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    68952 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    68953 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68954 File
    68955 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68956 packages/chimerax/core/models.py", line 143, in first_intercept 
    68957 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    68958 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68959 File
    68960 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68961 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    68962 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    68963 exclude=exclude) 
    68964 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68965 File
    68966 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68967 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    68968 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    68969 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68970 File
    68971 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68972 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    68973 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    68974 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68975 File
    68976 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68977 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    68978 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    68979 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68980 File
    68981 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68982 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    68983 p = super().first_intercept(mxyz1, mxyz2) 
    68984 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68985 File
    68986 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68987 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    68988 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    68989 exclude=exclude) 
    68990 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68991 File
    68992 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68993 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    68994 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    68995 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    68996 File
    68997 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    68998 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    68999 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    69000 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69001 File
    69002 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69003 packages/chimerax/graphics/drawing.py", line 1108, in
    69004 _first_intercept_excluding_children 
    69005 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    69006 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69007 File
    69008 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69009 packages/chimerax/geometry/place.py", line 201, in inverse 
    69010 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    69011 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69012 File
    69013 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69014 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    69015 rinv[:, :] = matrix_inverse(r) 
    69016 ^^^^^^^^^^^^^^^^^ 
    69017 File
    69018 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69019 packages/numpy/linalg/linalg.py", line 561, in inv 
    69020 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    69021 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69022 File
    69023 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69024 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    69025 raise LinAlgError("Singular matrix") 
    69026 numpy.linalg.LinAlgError: Singular matrix 
    69027  
    69028 numpy.linalg.LinAlgError: Singular matrix 
    69029  
    69030 File
    69031 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69032 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    69033 raise LinAlgError("Singular matrix") 
    69034  
    69035 See log for complete Python traceback. 
    69036  
    69037 Traceback (most recent call last): 
    69038 File
    69039 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69040 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    69041 self.session.ui.mouse_modes.mouse_pause_tracking() 
    69042 File
    69043 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69044 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    69045 mouse_pause_tracking 
    69046 self._mouse_pause() 
    69047 File
    69048 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69049 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    69050 m.pause(self._mouse_pause_position) 
    69051 File
    69052 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69053 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    69054 p = self.view.picked_object(x, y) 
    69055 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69056 File
    69057 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69058 packages/chimerax/graphics/view.py", line 838, in picked_object 
    69059 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    69060 beyond, 
    69061 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69062 File
    69063 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69064 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    69065 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    69066 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69067 File
    69068 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69069 packages/chimerax/core/models.py", line 143, in first_intercept 
    69070 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    69071 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69072 File
    69073 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69074 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    69075 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    69076 exclude=exclude) 
    69077 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69078 File
    69079 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69080 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    69081 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    69082 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69083 File
    69084 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69085 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    69086 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    69087 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69088 File
    69089 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69090 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    69091 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    69092 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69093 File
    69094 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69095 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    69096 p = super().first_intercept(mxyz1, mxyz2) 
    69097 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69098 File
    69099 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69100 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    69101 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    69102 exclude=exclude) 
    69103 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69104 File
    69105 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69106 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    69107 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    69108 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69109 File
    69110 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69111 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    69112 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    69113 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69114 File
    69115 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69116 packages/chimerax/graphics/drawing.py", line 1108, in
    69117 _first_intercept_excluding_children 
    69118 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    69119 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69120 File
    69121 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69122 packages/chimerax/geometry/place.py", line 201, in inverse 
    69123 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    69124 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69125 File
    69126 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69127 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    69128 rinv[:, :] = matrix_inverse(r) 
    69129 ^^^^^^^^^^^^^^^^^ 
    69130 File
    69131 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69132 packages/numpy/linalg/linalg.py", line 561, in inv 
    69133 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    69134 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69135 File
    69136 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69137 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    69138 raise LinAlgError("Singular matrix") 
    69139 numpy.linalg.LinAlgError: Singular matrix 
    69140  
    69141 numpy.linalg.LinAlgError: Singular matrix 
    69142  
    69143 File
    69144 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69145 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    69146 raise LinAlgError("Singular matrix") 
    69147  
    69148 See log for complete Python traceback. 
    69149  
    69150 Traceback (most recent call last): 
    69151 File
    69152 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69153 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    69154 self.session.ui.mouse_modes.mouse_pause_tracking() 
    69155 File
    69156 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69157 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    69158 mouse_pause_tracking 
    69159 self._mouse_pause() 
    69160 File
    69161 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69162 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    69163 m.pause(self._mouse_pause_position) 
    69164 File
    69165 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69166 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    69167 p = self.view.picked_object(x, y) 
    69168 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69169 File
    69170 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69171 packages/chimerax/graphics/view.py", line 838, in picked_object 
    69172 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    69173 beyond, 
    69174 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69175 File
    69176 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69177 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    69178 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    69179 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69180 File
    69181 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69182 packages/chimerax/core/models.py", line 143, in first_intercept 
    69183 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    69184 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69185 File
    69186 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69187 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    69188 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    69189 exclude=exclude) 
    69190 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69191 File
    69192 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69193 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    69194 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    69195 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69196 File
    69197 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69198 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    69199 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    69200 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69201 File
    69202 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69203 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    69204 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    69205 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69206 File
    69207 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69208 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    69209 p = super().first_intercept(mxyz1, mxyz2) 
    69210 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69211 File
    69212 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69213 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    69214 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    69215 exclude=exclude) 
    69216 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69217 File
    69218 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69219 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    69220 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    69221 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69222 File
    69223 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69224 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    69225 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    69226 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69227 File
    69228 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69229 packages/chimerax/graphics/drawing.py", line 1108, in
    69230 _first_intercept_excluding_children 
    69231 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    69232 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69233 File
    69234 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69235 packages/chimerax/geometry/place.py", line 201, in inverse 
    69236 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    69237 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69238 File
    69239 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69240 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    69241 rinv[:, :] = matrix_inverse(r) 
    69242 ^^^^^^^^^^^^^^^^^ 
    69243 File
    69244 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69245 packages/numpy/linalg/linalg.py", line 561, in inv 
    69246 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    69247 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69248 File
    69249 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69250 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    69251 raise LinAlgError("Singular matrix") 
    69252 numpy.linalg.LinAlgError: Singular matrix 
    69253  
    69254 numpy.linalg.LinAlgError: Singular matrix 
    69255  
    69256 File
    69257 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69258 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    69259 raise LinAlgError("Singular matrix") 
    69260  
    69261 See log for complete Python traceback. 
    69262  
    69263 Traceback (most recent call last): 
    69264 File
    69265 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69266 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    69267 self.session.ui.mouse_modes.mouse_pause_tracking() 
    69268 File
    69269 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69270 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    69271 mouse_pause_tracking 
    69272 self._mouse_pause() 
    69273 File
    69274 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69275 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    69276 m.pause(self._mouse_pause_position) 
    69277 File
    69278 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69279 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    69280 p = self.view.picked_object(x, y) 
    69281 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69282 File
    69283 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69284 packages/chimerax/graphics/view.py", line 838, in picked_object 
    69285 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    69286 beyond, 
    69287 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69288 File
    69289 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69290 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    69291 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    69292 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69293 File
    69294 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69295 packages/chimerax/core/models.py", line 143, in first_intercept 
    69296 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    69297 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69298 File
    69299 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69300 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    69301 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    69302 exclude=exclude) 
    69303 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69304 File
    69305 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69306 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    69307 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    69308 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69309 File
    69310 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69311 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    69312 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    69313 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69314 File
    69315 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69316 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    69317 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    69318 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69319 File
    69320 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69321 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    69322 p = super().first_intercept(mxyz1, mxyz2) 
    69323 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69324 File
    69325 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69326 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    69327 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    69328 exclude=exclude) 
    69329 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69330 File
    69331 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69332 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    69333 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    69334 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69335 File
    69336 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69337 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    69338 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    69339 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69340 File
    69341 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69342 packages/chimerax/graphics/drawing.py", line 1108, in
    69343 _first_intercept_excluding_children 
    69344 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    69345 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69346 File
    69347 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69348 packages/chimerax/geometry/place.py", line 201, in inverse 
    69349 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    69350 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69351 File
    69352 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69353 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    69354 rinv[:, :] = matrix_inverse(r) 
    69355 ^^^^^^^^^^^^^^^^^ 
    69356 File
    69357 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69358 packages/numpy/linalg/linalg.py", line 561, in inv 
    69359 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    69360 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69361 File
    69362 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69363 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    69364 raise LinAlgError("Singular matrix") 
    69365 numpy.linalg.LinAlgError: Singular matrix 
    69366  
    69367 numpy.linalg.LinAlgError: Singular matrix 
    69368  
    69369 File
    69370 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69371 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    69372 raise LinAlgError("Singular matrix") 
    69373  
    69374 See log for complete Python traceback. 
    69375  
    69376 Traceback (most recent call last): 
    69377 File
    69378 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69379 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    69380 self.session.ui.mouse_modes.mouse_pause_tracking() 
    69381 File
    69382 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69383 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    69384 mouse_pause_tracking 
    69385 self._mouse_pause() 
    69386 File
    69387 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69388 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    69389 m.pause(self._mouse_pause_position) 
    69390 File
    69391 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69392 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    69393 p = self.view.picked_object(x, y) 
    69394 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69395 File
    69396 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69397 packages/chimerax/graphics/view.py", line 838, in picked_object 
    69398 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    69399 beyond, 
    69400 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69401 File
    69402 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69403 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    69404 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    69405 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69406 File
    69407 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69408 packages/chimerax/core/models.py", line 143, in first_intercept 
    69409 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    69410 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69411 File
    69412 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69413 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    69414 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    69415 exclude=exclude) 
    69416 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69417 File
    69418 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69419 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    69420 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    69421 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69422 File
    69423 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69424 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    69425 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    69426 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69427 File
    69428 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69429 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    69430 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    69431 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69432 File
    69433 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69434 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    69435 p = super().first_intercept(mxyz1, mxyz2) 
    69436 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69437 File
    69438 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69439 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    69440 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    69441 exclude=exclude) 
    69442 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69443 File
    69444 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69445 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    69446 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    69447 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69448 File
    69449 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69450 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    69451 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    69452 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69453 File
    69454 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69455 packages/chimerax/graphics/drawing.py", line 1108, in
    69456 _first_intercept_excluding_children 
    69457 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    69458 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69459 File
    69460 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69461 packages/chimerax/geometry/place.py", line 201, in inverse 
    69462 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    69463 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69464 File
    69465 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69466 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    69467 rinv[:, :] = matrix_inverse(r) 
    69468 ^^^^^^^^^^^^^^^^^ 
    69469 File
    69470 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69471 packages/numpy/linalg/linalg.py", line 561, in inv 
    69472 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    69473 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69474 File
    69475 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69476 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    69477 raise LinAlgError("Singular matrix") 
    69478 numpy.linalg.LinAlgError: Singular matrix 
    69479  
    69480 numpy.linalg.LinAlgError: Singular matrix 
    69481  
    69482 File
    69483 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69484 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    69485 raise LinAlgError("Singular matrix") 
    69486  
    69487 See log for complete Python traceback. 
    69488  
    69489 
    69490 > select #5:2103
    69491 
    69492 58 atoms, 66 bonds, 2 residues, 1 model selected 
    69493 
    69494 > hide sel atoms
    69495 
    69496 > select #5:2101
    69497 
    69498 116 atoms, 132 bonds, 4 residues, 1 model selected 
    69499 
    69500 > color sel byhetero
    69501 
    69502 > select clear
    69503 
    69504 Traceback (most recent call last): 
    69505 File
    69506 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69507 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    69508 self.session.ui.mouse_modes.mouse_pause_tracking() 
    69509 File
    69510 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69511 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    69512 mouse_pause_tracking 
    69513 self._mouse_pause() 
    69514 File
    69515 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69516 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    69517 m.pause(self._mouse_pause_position) 
    69518 File
    69519 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69520 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    69521 p = self.view.picked_object(x, y) 
    69522 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69523 File
    69524 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69525 packages/chimerax/graphics/view.py", line 838, in picked_object 
    69526 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    69527 beyond, 
    69528 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69529 File
    69530 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69531 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    69532 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    69533 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69534 File
    69535 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69536 packages/chimerax/core/models.py", line 143, in first_intercept 
    69537 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    69538 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69539 File
    69540 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69541 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    69542 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    69543 exclude=exclude) 
    69544 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69545 File
    69546 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69547 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    69548 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    69549 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69550 File
    69551 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69552 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    69553 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    69554 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69555 File
    69556 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69557 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    69558 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    69559 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69560 File
    69561 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69562 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    69563 p = super().first_intercept(mxyz1, mxyz2) 
    69564 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69565 File
    69566 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69567 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    69568 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    69569 exclude=exclude) 
    69570 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69571 File
    69572 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69573 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    69574 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    69575 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69576 File
    69577 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69578 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    69579 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    69580 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69581 File
    69582 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69583 packages/chimerax/graphics/drawing.py", line 1108, in
    69584 _first_intercept_excluding_children 
    69585 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    69586 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69587 File
    69588 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69589 packages/chimerax/geometry/place.py", line 201, in inverse 
    69590 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    69591 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69592 File
    69593 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69594 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    69595 rinv[:, :] = matrix_inverse(r) 
    69596 ^^^^^^^^^^^^^^^^^ 
    69597 File
    69598 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69599 packages/numpy/linalg/linalg.py", line 561, in inv 
    69600 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    69601 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69602 File
    69603 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69604 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    69605 raise LinAlgError("Singular matrix") 
    69606 numpy.linalg.LinAlgError: Singular matrix 
    69607  
    69608 numpy.linalg.LinAlgError: Singular matrix 
    69609  
    69610 File
    69611 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69612 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    69613 raise LinAlgError("Singular matrix") 
    69614  
    69615 See log for complete Python traceback. 
    69616  
    69617 Traceback (most recent call last): 
    69618 File
    69619 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69620 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    69621 self.session.ui.mouse_modes.mouse_pause_tracking() 
    69622 File
    69623 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69624 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    69625 mouse_pause_tracking 
    69626 self._mouse_pause() 
    69627 File
    69628 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69629 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    69630 m.pause(self._mouse_pause_position) 
    69631 File
    69632 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69633 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    69634 p = self.view.picked_object(x, y) 
    69635 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69636 File
    69637 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69638 packages/chimerax/graphics/view.py", line 838, in picked_object 
    69639 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    69640 beyond, 
    69641 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69642 File
    69643 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69644 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    69645 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    69646 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69647 File
    69648 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69649 packages/chimerax/core/models.py", line 143, in first_intercept 
    69650 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    69651 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69652 File
    69653 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69654 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    69655 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    69656 exclude=exclude) 
    69657 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69658 File
    69659 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69660 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    69661 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    69662 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69663 File
    69664 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69665 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    69666 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    69667 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69668 File
    69669 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69670 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    69671 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    69672 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69673 File
    69674 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69675 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    69676 p = super().first_intercept(mxyz1, mxyz2) 
    69677 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69678 File
    69679 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69680 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    69681 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    69682 exclude=exclude) 
    69683 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69684 File
    69685 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69686 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    69687 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    69688 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69689 File
    69690 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69691 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    69692 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    69693 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69694 File
    69695 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69696 packages/chimerax/graphics/drawing.py", line 1108, in
    69697 _first_intercept_excluding_children 
    69698 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    69699 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69700 File
    69701 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69702 packages/chimerax/geometry/place.py", line 201, in inverse 
    69703 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    69704 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69705 File
    69706 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69707 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    69708 rinv[:, :] = matrix_inverse(r) 
    69709 ^^^^^^^^^^^^^^^^^ 
    69710 File
    69711 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69712 packages/numpy/linalg/linalg.py", line 561, in inv 
    69713 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    69714 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69715 File
    69716 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69717 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    69718 raise LinAlgError("Singular matrix") 
    69719 numpy.linalg.LinAlgError: Singular matrix 
    69720  
    69721 numpy.linalg.LinAlgError: Singular matrix 
    69722  
    69723 File
    69724 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69725 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    69726 raise LinAlgError("Singular matrix") 
    69727  
    69728 See log for complete Python traceback. 
    69729  
    69730 Traceback (most recent call last): 
    69731 File
    69732 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69733 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    69734 self.session.ui.mouse_modes.mouse_pause_tracking() 
    69735 File
    69736 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69737 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    69738 mouse_pause_tracking 
    69739 self._mouse_pause() 
    69740 File
    69741 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69742 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    69743 m.pause(self._mouse_pause_position) 
    69744 File
    69745 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69746 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    69747 p = self.view.picked_object(x, y) 
    69748 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69749 File
    69750 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69751 packages/chimerax/graphics/view.py", line 838, in picked_object 
    69752 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    69753 beyond, 
    69754 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69755 File
    69756 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69757 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    69758 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    69759 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69760 File
    69761 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69762 packages/chimerax/core/models.py", line 143, in first_intercept 
    69763 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    69764 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69765 File
    69766 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69767 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    69768 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    69769 exclude=exclude) 
    69770 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69771 File
    69772 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69773 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    69774 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    69775 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69776 File
    69777 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69778 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    69779 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    69780 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69781 File
    69782 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69783 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    69784 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    69785 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69786 File
    69787 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69788 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    69789 p = super().first_intercept(mxyz1, mxyz2) 
    69790 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69791 File
    69792 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69793 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    69794 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    69795 exclude=exclude) 
    69796 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69797 File
    69798 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69799 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    69800 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    69801 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69802 File
    69803 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69804 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    69805 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    69806 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69807 File
    69808 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69809 packages/chimerax/graphics/drawing.py", line 1108, in
    69810 _first_intercept_excluding_children 
    69811 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    69812 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69813 File
    69814 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69815 packages/chimerax/geometry/place.py", line 201, in inverse 
    69816 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    69817 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69818 File
    69819 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69820 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    69821 rinv[:, :] = matrix_inverse(r) 
    69822 ^^^^^^^^^^^^^^^^^ 
    69823 File
    69824 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69825 packages/numpy/linalg/linalg.py", line 561, in inv 
    69826 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    69827 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69828 File
    69829 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69830 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    69831 raise LinAlgError("Singular matrix") 
    69832 numpy.linalg.LinAlgError: Singular matrix 
    69833  
    69834 numpy.linalg.LinAlgError: Singular matrix 
    69835  
    69836 File
    69837 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69838 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    69839 raise LinAlgError("Singular matrix") 
    69840  
    69841 See log for complete Python traceback. 
    69842  
    69843 Traceback (most recent call last): 
    69844 File
    69845 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69846 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    69847 self.session.ui.mouse_modes.mouse_pause_tracking() 
    69848 File
    69849 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69850 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    69851 mouse_pause_tracking 
    69852 self._mouse_pause() 
    69853 File
    69854 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69855 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    69856 m.pause(self._mouse_pause_position) 
    69857 File
    69858 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69859 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    69860 p = self.view.picked_object(x, y) 
    69861 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69862 File
    69863 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69864 packages/chimerax/graphics/view.py", line 838, in picked_object 
    69865 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    69866 beyond, 
    69867 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69868 File
    69869 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69870 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    69871 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    69872 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69873 File
    69874 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69875 packages/chimerax/core/models.py", line 143, in first_intercept 
    69876 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    69877 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69878 File
    69879 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69880 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    69881 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    69882 exclude=exclude) 
    69883 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69884 File
    69885 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69886 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    69887 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    69888 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69889 File
    69890 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69891 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    69892 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    69893 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69894 File
    69895 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69896 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    69897 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    69898 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69899 File
    69900 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69901 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    69902 p = super().first_intercept(mxyz1, mxyz2) 
    69903 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69904 File
    69905 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69906 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    69907 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    69908 exclude=exclude) 
    69909 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69910 File
    69911 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69912 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    69913 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    69914 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69915 File
    69916 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69917 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    69918 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    69919 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69920 File
    69921 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69922 packages/chimerax/graphics/drawing.py", line 1108, in
    69923 _first_intercept_excluding_children 
    69924 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    69925 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69926 File
    69927 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69928 packages/chimerax/geometry/place.py", line 201, in inverse 
    69929 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    69930 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69931 File
    69932 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69933 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    69934 rinv[:, :] = matrix_inverse(r) 
    69935 ^^^^^^^^^^^^^^^^^ 
    69936 File
    69937 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69938 packages/numpy/linalg/linalg.py", line 561, in inv 
    69939 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    69940 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69941 File
    69942 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69943 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    69944 raise LinAlgError("Singular matrix") 
    69945 numpy.linalg.LinAlgError: Singular matrix 
    69946  
    69947 numpy.linalg.LinAlgError: Singular matrix 
    69948  
    69949 File
    69950 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69951 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    69952 raise LinAlgError("Singular matrix") 
    69953  
    69954 See log for complete Python traceback. 
    69955  
    69956 Traceback (most recent call last): 
    69957 File
    69958 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69959 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    69960 self.session.ui.mouse_modes.mouse_pause_tracking() 
    69961 File
    69962 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69963 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    69964 mouse_pause_tracking 
    69965 self._mouse_pause() 
    69966 File
    69967 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69968 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    69969 m.pause(self._mouse_pause_position) 
    69970 File
    69971 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69972 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    69973 p = self.view.picked_object(x, y) 
    69974 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69975 File
    69976 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69977 packages/chimerax/graphics/view.py", line 838, in picked_object 
    69978 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    69979 beyond, 
    69980 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69981 File
    69982 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69983 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    69984 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    69985 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69986 File
    69987 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69988 packages/chimerax/core/models.py", line 143, in first_intercept 
    69989 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    69990 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69991 File
    69992 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69993 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    69994 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    69995 exclude=exclude) 
    69996 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    69997 File
    69998 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    69999 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    70000 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    70001 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70002 File
    70003 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70004 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    70005 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    70006 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70007 File
    70008 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70009 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    70010 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    70011 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70012 File
    70013 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70014 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    70015 p = super().first_intercept(mxyz1, mxyz2) 
    70016 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70017 File
    70018 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70019 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    70020 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    70021 exclude=exclude) 
    70022 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70023 File
    70024 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70025 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    70026 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    70027 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70028 File
    70029 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70030 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    70031 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    70032 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70033 File
    70034 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70035 packages/chimerax/graphics/drawing.py", line 1108, in
    70036 _first_intercept_excluding_children 
    70037 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    70038 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70039 File
    70040 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70041 packages/chimerax/geometry/place.py", line 201, in inverse 
    70042 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    70043 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70044 File
    70045 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70046 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    70047 rinv[:, :] = matrix_inverse(r) 
    70048 ^^^^^^^^^^^^^^^^^ 
    70049 File
    70050 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70051 packages/numpy/linalg/linalg.py", line 561, in inv 
    70052 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    70053 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70054 File
    70055 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70056 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    70057 raise LinAlgError("Singular matrix") 
    70058 numpy.linalg.LinAlgError: Singular matrix 
    70059  
    70060 numpy.linalg.LinAlgError: Singular matrix 
    70061  
    70062 File
    70063 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70064 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    70065 raise LinAlgError("Singular matrix") 
    70066  
    70067 See log for complete Python traceback. 
    70068  
    70069 Traceback (most recent call last): 
    70070 File
    70071 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70072 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    70073 self.session.ui.mouse_modes.mouse_pause_tracking() 
    70074 File
    70075 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70076 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    70077 mouse_pause_tracking 
    70078 self._mouse_pause() 
    70079 File
    70080 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70081 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    70082 m.pause(self._mouse_pause_position) 
    70083 File
    70084 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70085 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    70086 p = self.view.picked_object(x, y) 
    70087 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70088 File
    70089 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70090 packages/chimerax/graphics/view.py", line 838, in picked_object 
    70091 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    70092 beyond, 
    70093 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70094 File
    70095 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70096 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    70097 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    70098 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70099 File
    70100 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70101 packages/chimerax/core/models.py", line 143, in first_intercept 
    70102 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    70103 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70104 File
    70105 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70106 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    70107 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    70108 exclude=exclude) 
    70109 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70110 File
    70111 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70112 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    70113 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    70114 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70115 File
    70116 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70117 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    70118 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    70119 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70120 File
    70121 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70122 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    70123 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    70124 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70125 File
    70126 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70127 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    70128 p = super().first_intercept(mxyz1, mxyz2) 
    70129 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70130 File
    70131 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70132 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    70133 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    70134 exclude=exclude) 
    70135 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70136 File
    70137 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70138 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    70139 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    70140 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70141 File
    70142 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70143 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    70144 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    70145 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70146 File
    70147 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70148 packages/chimerax/graphics/drawing.py", line 1108, in
    70149 _first_intercept_excluding_children 
    70150 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    70151 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70152 File
    70153 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70154 packages/chimerax/geometry/place.py", line 201, in inverse 
    70155 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    70156 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70157 File
    70158 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70159 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    70160 rinv[:, :] = matrix_inverse(r) 
    70161 ^^^^^^^^^^^^^^^^^ 
    70162 File
    70163 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70164 packages/numpy/linalg/linalg.py", line 561, in inv 
    70165 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    70166 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70167 File
    70168 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70169 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    70170 raise LinAlgError("Singular matrix") 
    70171 numpy.linalg.LinAlgError: Singular matrix 
    70172  
    70173 numpy.linalg.LinAlgError: Singular matrix 
    70174  
    70175 File
    70176 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70177 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    70178 raise LinAlgError("Singular matrix") 
    70179  
    70180 See log for complete Python traceback. 
    70181  
    70182 Traceback (most recent call last): 
    70183 File
    70184 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70185 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    70186 self.session.ui.mouse_modes.mouse_pause_tracking() 
    70187 File
    70188 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70189 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    70190 mouse_pause_tracking 
    70191 self._mouse_pause() 
    70192 File
    70193 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70194 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    70195 m.pause(self._mouse_pause_position) 
    70196 File
    70197 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70198 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    70199 p = self.view.picked_object(x, y) 
    70200 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70201 File
    70202 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70203 packages/chimerax/graphics/view.py", line 838, in picked_object 
    70204 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    70205 beyond, 
    70206 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70207 File
    70208 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70209 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    70210 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    70211 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70212 File
    70213 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70214 packages/chimerax/core/models.py", line 143, in first_intercept 
    70215 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    70216 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70217 File
    70218 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70219 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    70220 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    70221 exclude=exclude) 
    70222 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70223 File
    70224 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70225 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    70226 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    70227 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70228 File
    70229 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70230 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    70231 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    70232 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70233 File
    70234 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70235 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    70236 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    70237 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70238 File
    70239 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70240 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    70241 p = super().first_intercept(mxyz1, mxyz2) 
    70242 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70243 File
    70244 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70245 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    70246 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    70247 exclude=exclude) 
    70248 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70249 File
    70250 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70251 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    70252 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    70253 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70254 File
    70255 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70256 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    70257 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    70258 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70259 File
    70260 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70261 packages/chimerax/graphics/drawing.py", line 1108, in
    70262 _first_intercept_excluding_children 
    70263 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    70264 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70265 File
    70266 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70267 packages/chimerax/geometry/place.py", line 201, in inverse 
    70268 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    70269 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70270 File
    70271 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70272 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    70273 rinv[:, :] = matrix_inverse(r) 
    70274 ^^^^^^^^^^^^^^^^^ 
    70275 File
    70276 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70277 packages/numpy/linalg/linalg.py", line 561, in inv 
    70278 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    70279 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70280 File
    70281 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70282 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    70283 raise LinAlgError("Singular matrix") 
    70284 numpy.linalg.LinAlgError: Singular matrix 
    70285  
    70286 numpy.linalg.LinAlgError: Singular matrix 
    70287  
    70288 File
    70289 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70290 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    70291 raise LinAlgError("Singular matrix") 
    70292  
    70293 See log for complete Python traceback. 
    70294  
    70295 Traceback (most recent call last): 
    70296 File
    70297 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70298 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    70299 self.session.ui.mouse_modes.mouse_pause_tracking() 
    70300 File
    70301 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70302 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    70303 mouse_pause_tracking 
    70304 self._mouse_pause() 
    70305 File
    70306 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70307 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    70308 m.pause(self._mouse_pause_position) 
    70309 File
    70310 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70311 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    70312 p = self.view.picked_object(x, y) 
    70313 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70314 File
    70315 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70316 packages/chimerax/graphics/view.py", line 838, in picked_object 
    70317 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    70318 beyond, 
    70319 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70320 File
    70321 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70322 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    70323 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    70324 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70325 File
    70326 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70327 packages/chimerax/core/models.py", line 143, in first_intercept 
    70328 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    70329 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70330 File
    70331 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70332 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    70333 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    70334 exclude=exclude) 
    70335 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70336 File
    70337 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70338 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    70339 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    70340 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70341 File
    70342 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70343 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    70344 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    70345 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70346 File
    70347 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70348 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    70349 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    70350 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70351 File
    70352 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70353 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    70354 p = super().first_intercept(mxyz1, mxyz2) 
    70355 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70356 File
    70357 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70358 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    70359 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    70360 exclude=exclude) 
    70361 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70362 File
    70363 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70364 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    70365 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    70366 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70367 File
    70368 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70369 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    70370 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    70371 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70372 File
    70373 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70374 packages/chimerax/graphics/drawing.py", line 1108, in
    70375 _first_intercept_excluding_children 
    70376 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    70377 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70378 File
    70379 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70380 packages/chimerax/geometry/place.py", line 201, in inverse 
    70381 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    70382 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70383 File
    70384 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70385 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    70386 rinv[:, :] = matrix_inverse(r) 
    70387 ^^^^^^^^^^^^^^^^^ 
    70388 File
    70389 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70390 packages/numpy/linalg/linalg.py", line 561, in inv 
    70391 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    70392 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70393 File
    70394 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70395 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    70396 raise LinAlgError("Singular matrix") 
    70397 numpy.linalg.LinAlgError: Singular matrix 
    70398  
    70399 numpy.linalg.LinAlgError: Singular matrix 
    70400  
    70401 File
    70402 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70403 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    70404 raise LinAlgError("Singular matrix") 
    70405  
    70406 See log for complete Python traceback. 
    70407  
    70408 Traceback (most recent call last): 
    70409 File
    70410 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70411 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    70412 self.session.ui.mouse_modes.mouse_pause_tracking() 
    70413 File
    70414 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70415 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    70416 mouse_pause_tracking 
    70417 self._mouse_pause() 
    70418 File
    70419 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70420 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    70421 m.pause(self._mouse_pause_position) 
    70422 File
    70423 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70424 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    70425 p = self.view.picked_object(x, y) 
    70426 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70427 File
    70428 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70429 packages/chimerax/graphics/view.py", line 838, in picked_object 
    70430 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    70431 beyond, 
    70432 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70433 File
    70434 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70435 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    70436 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    70437 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70438 File
    70439 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70440 packages/chimerax/core/models.py", line 143, in first_intercept 
    70441 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    70442 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70443 File
    70444 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70445 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    70446 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    70447 exclude=exclude) 
    70448 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70449 File
    70450 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70451 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    70452 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    70453 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70454 File
    70455 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70456 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    70457 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    70458 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70459 File
    70460 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70461 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    70462 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    70463 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70464 File
    70465 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70466 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    70467 p = super().first_intercept(mxyz1, mxyz2) 
    70468 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70469 File
    70470 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70471 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    70472 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    70473 exclude=exclude) 
    70474 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70475 File
    70476 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70477 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    70478 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    70479 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70480 File
    70481 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70482 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    70483 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    70484 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70485 File
    70486 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70487 packages/chimerax/graphics/drawing.py", line 1108, in
    70488 _first_intercept_excluding_children 
    70489 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    70490 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70491 File
    70492 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70493 packages/chimerax/geometry/place.py", line 201, in inverse 
    70494 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    70495 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70496 File
    70497 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70498 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    70499 rinv[:, :] = matrix_inverse(r) 
    70500 ^^^^^^^^^^^^^^^^^ 
    70501 File
    70502 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70503 packages/numpy/linalg/linalg.py", line 561, in inv 
    70504 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    70505 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70506 File
    70507 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70508 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    70509 raise LinAlgError("Singular matrix") 
    70510 numpy.linalg.LinAlgError: Singular matrix 
    70511  
    70512 numpy.linalg.LinAlgError: Singular matrix 
    70513  
    70514 File
    70515 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70516 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    70517 raise LinAlgError("Singular matrix") 
    70518  
    70519 See log for complete Python traceback. 
    70520  
    70521 Traceback (most recent call last): 
    70522 File
    70523 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70524 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    70525 self.session.ui.mouse_modes.mouse_pause_tracking() 
    70526 File
    70527 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70528 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    70529 mouse_pause_tracking 
    70530 self._mouse_pause() 
    70531 File
    70532 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70533 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    70534 m.pause(self._mouse_pause_position) 
    70535 File
    70536 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70537 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    70538 p = self.view.picked_object(x, y) 
    70539 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70540 File
    70541 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70542 packages/chimerax/graphics/view.py", line 838, in picked_object 
    70543 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    70544 beyond, 
    70545 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70546 File
    70547 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70548 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    70549 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    70550 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70551 File
    70552 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70553 packages/chimerax/core/models.py", line 143, in first_intercept 
    70554 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    70555 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70556 File
    70557 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70558 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    70559 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    70560 exclude=exclude) 
    70561 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70562 File
    70563 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70564 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    70565 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    70566 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70567 File
    70568 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70569 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    70570 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    70571 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70572 File
    70573 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70574 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    70575 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    70576 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70577 File
    70578 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70579 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    70580 p = super().first_intercept(mxyz1, mxyz2) 
    70581 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70582 File
    70583 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70584 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    70585 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    70586 exclude=exclude) 
    70587 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70588 File
    70589 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70590 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    70591 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    70592 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70593 File
    70594 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70595 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    70596 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    70597 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70598 File
    70599 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70600 packages/chimerax/graphics/drawing.py", line 1108, in
    70601 _first_intercept_excluding_children 
    70602 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    70603 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70604 File
    70605 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70606 packages/chimerax/geometry/place.py", line 201, in inverse 
    70607 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    70608 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70609 File
    70610 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70611 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    70612 rinv[:, :] = matrix_inverse(r) 
    70613 ^^^^^^^^^^^^^^^^^ 
    70614 File
    70615 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70616 packages/numpy/linalg/linalg.py", line 561, in inv 
    70617 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    70618 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70619 File
    70620 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70621 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    70622 raise LinAlgError("Singular matrix") 
    70623 numpy.linalg.LinAlgError: Singular matrix 
    70624  
    70625 numpy.linalg.LinAlgError: Singular matrix 
    70626  
    70627 File
    70628 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70629 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    70630 raise LinAlgError("Singular matrix") 
    70631  
    70632 See log for complete Python traceback. 
    70633  
    70634 Traceback (most recent call last): 
    70635 File
    70636 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70637 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    70638 self.session.ui.mouse_modes.mouse_pause_tracking() 
    70639 File
    70640 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70641 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    70642 mouse_pause_tracking 
    70643 self._mouse_pause() 
    70644 File
    70645 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70646 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    70647 m.pause(self._mouse_pause_position) 
    70648 File
    70649 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70650 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    70651 p = self.view.picked_object(x, y) 
    70652 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70653 File
    70654 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70655 packages/chimerax/graphics/view.py", line 838, in picked_object 
    70656 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    70657 beyond, 
    70658 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70659 File
    70660 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70661 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    70662 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    70663 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70664 File
    70665 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70666 packages/chimerax/core/models.py", line 143, in first_intercept 
    70667 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    70668 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70669 File
    70670 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70671 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    70672 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    70673 exclude=exclude) 
    70674 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70675 File
    70676 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70677 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    70678 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    70679 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70680 File
    70681 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70682 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    70683 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    70684 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70685 File
    70686 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70687 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    70688 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    70689 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70690 File
    70691 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70692 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    70693 p = super().first_intercept(mxyz1, mxyz2) 
    70694 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70695 File
    70696 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70697 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    70698 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    70699 exclude=exclude) 
    70700 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70701 File
    70702 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70703 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    70704 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    70705 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70706 File
    70707 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70708 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    70709 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    70710 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70711 File
    70712 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70713 packages/chimerax/graphics/drawing.py", line 1108, in
    70714 _first_intercept_excluding_children 
    70715 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    70716 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70717 File
    70718 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70719 packages/chimerax/geometry/place.py", line 201, in inverse 
    70720 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    70721 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70722 File
    70723 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70724 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    70725 rinv[:, :] = matrix_inverse(r) 
    70726 ^^^^^^^^^^^^^^^^^ 
    70727 File
    70728 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70729 packages/numpy/linalg/linalg.py", line 561, in inv 
    70730 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    70731 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70732 File
    70733 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70734 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    70735 raise LinAlgError("Singular matrix") 
    70736 numpy.linalg.LinAlgError: Singular matrix 
    70737  
    70738 numpy.linalg.LinAlgError: Singular matrix 
    70739  
    70740 File
    70741 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70742 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    70743 raise LinAlgError("Singular matrix") 
    70744  
    70745 See log for complete Python traceback. 
    70746  
    70747 Traceback (most recent call last): 
    70748 File
    70749 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70750 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    70751 self.session.ui.mouse_modes.mouse_pause_tracking() 
    70752 File
    70753 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70754 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    70755 mouse_pause_tracking 
    70756 self._mouse_pause() 
    70757 File
    70758 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70759 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    70760 m.pause(self._mouse_pause_position) 
    70761 File
    70762 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70763 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    70764 p = self.view.picked_object(x, y) 
    70765 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70766 File
    70767 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70768 packages/chimerax/graphics/view.py", line 838, in picked_object 
    70769 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    70770 beyond, 
    70771 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70772 File
    70773 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70774 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    70775 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    70776 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70777 File
    70778 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70779 packages/chimerax/core/models.py", line 143, in first_intercept 
    70780 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    70781 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70782 File
    70783 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70784 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    70785 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    70786 exclude=exclude) 
    70787 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70788 File
    70789 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70790 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    70791 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    70792 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70793 File
    70794 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70795 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    70796 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    70797 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70798 File
    70799 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70800 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    70801 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    70802 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70803 File
    70804 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70805 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    70806 p = super().first_intercept(mxyz1, mxyz2) 
    70807 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70808 File
    70809 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70810 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    70811 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    70812 exclude=exclude) 
    70813 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70814 File
    70815 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70816 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    70817 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    70818 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70819 File
    70820 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70821 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    70822 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    70823 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70824 File
    70825 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70826 packages/chimerax/graphics/drawing.py", line 1108, in
    70827 _first_intercept_excluding_children 
    70828 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    70829 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70830 File
    70831 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70832 packages/chimerax/geometry/place.py", line 201, in inverse 
    70833 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    70834 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70835 File
    70836 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70837 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    70838 rinv[:, :] = matrix_inverse(r) 
    70839 ^^^^^^^^^^^^^^^^^ 
    70840 File
    70841 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70842 packages/numpy/linalg/linalg.py", line 561, in inv 
    70843 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    70844 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70845 File
    70846 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70847 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    70848 raise LinAlgError("Singular matrix") 
    70849 numpy.linalg.LinAlgError: Singular matrix 
    70850  
    70851 numpy.linalg.LinAlgError: Singular matrix 
    70852  
    70853 File
    70854 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70855 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    70856 raise LinAlgError("Singular matrix") 
    70857  
    70858 See log for complete Python traceback. 
    70859  
    70860 Traceback (most recent call last): 
    70861 File
    70862 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70863 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    70864 self.session.ui.mouse_modes.mouse_pause_tracking() 
    70865 File
    70866 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70867 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    70868 mouse_pause_tracking 
    70869 self._mouse_pause() 
    70870 File
    70871 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70872 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    70873 m.pause(self._mouse_pause_position) 
    70874 File
    70875 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70876 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    70877 p = self.view.picked_object(x, y) 
    70878 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70879 File
    70880 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70881 packages/chimerax/graphics/view.py", line 838, in picked_object 
    70882 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    70883 beyond, 
    70884 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70885 File
    70886 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70887 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    70888 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    70889 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70890 File
    70891 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70892 packages/chimerax/core/models.py", line 143, in first_intercept 
    70893 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    70894 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70895 File
    70896 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70897 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    70898 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    70899 exclude=exclude) 
    70900 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70901 File
    70902 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70903 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    70904 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    70905 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70906 File
    70907 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70908 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    70909 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    70910 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70911 File
    70912 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70913 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    70914 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    70915 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70916 File
    70917 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70918 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    70919 p = super().first_intercept(mxyz1, mxyz2) 
    70920 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70921 File
    70922 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70923 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    70924 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    70925 exclude=exclude) 
    70926 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70927 File
    70928 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70929 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    70930 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    70931 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70932 File
    70933 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70934 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    70935 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    70936 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70937 File
    70938 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70939 packages/chimerax/graphics/drawing.py", line 1108, in
    70940 _first_intercept_excluding_children 
    70941 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    70942 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70943 File
    70944 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70945 packages/chimerax/geometry/place.py", line 201, in inverse 
    70946 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    70947 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70948 File
    70949 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70950 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    70951 rinv[:, :] = matrix_inverse(r) 
    70952 ^^^^^^^^^^^^^^^^^ 
    70953 File
    70954 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70955 packages/numpy/linalg/linalg.py", line 561, in inv 
    70956 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    70957 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70958 File
    70959 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70960 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    70961 raise LinAlgError("Singular matrix") 
    70962 numpy.linalg.LinAlgError: Singular matrix 
    70963  
    70964 numpy.linalg.LinAlgError: Singular matrix 
    70965  
    70966 File
    70967 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70968 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    70969 raise LinAlgError("Singular matrix") 
    70970  
    70971 See log for complete Python traceback. 
    70972  
    70973 Traceback (most recent call last): 
    70974 File
    70975 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70976 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    70977 self.session.ui.mouse_modes.mouse_pause_tracking() 
    70978 File
    70979 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70980 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    70981 mouse_pause_tracking 
    70982 self._mouse_pause() 
    70983 File
    70984 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70985 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    70986 m.pause(self._mouse_pause_position) 
    70987 File
    70988 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70989 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    70990 p = self.view.picked_object(x, y) 
    70991 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70992 File
    70993 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    70994 packages/chimerax/graphics/view.py", line 838, in picked_object 
    70995 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    70996 beyond, 
    70997 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    70998 File
    70999 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71000 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    71001 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    71002 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71003 File
    71004 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71005 packages/chimerax/core/models.py", line 143, in first_intercept 
    71006 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    71007 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71008 File
    71009 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71010 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    71011 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    71012 exclude=exclude) 
    71013 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71014 File
    71015 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71016 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    71017 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    71018 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71019 File
    71020 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71021 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    71022 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    71023 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71024 File
    71025 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71026 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    71027 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    71028 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71029 File
    71030 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71031 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    71032 p = super().first_intercept(mxyz1, mxyz2) 
    71033 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71034 File
    71035 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71036 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    71037 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    71038 exclude=exclude) 
    71039 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71040 File
    71041 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71042 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    71043 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    71044 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71045 File
    71046 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71047 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    71048 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    71049 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71050 File
    71051 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71052 packages/chimerax/graphics/drawing.py", line 1108, in
    71053 _first_intercept_excluding_children 
    71054 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    71055 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71056 File
    71057 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71058 packages/chimerax/geometry/place.py", line 201, in inverse 
    71059 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    71060 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71061 File
    71062 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71063 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    71064 rinv[:, :] = matrix_inverse(r) 
    71065 ^^^^^^^^^^^^^^^^^ 
    71066 File
    71067 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71068 packages/numpy/linalg/linalg.py", line 561, in inv 
    71069 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    71070 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71071 File
    71072 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71073 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    71074 raise LinAlgError("Singular matrix") 
    71075 numpy.linalg.LinAlgError: Singular matrix 
    71076  
    71077 numpy.linalg.LinAlgError: Singular matrix 
    71078  
    71079 File
    71080 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71081 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    71082 raise LinAlgError("Singular matrix") 
    71083  
    71084 See log for complete Python traceback. 
    71085  
    71086 Traceback (most recent call last): 
    71087 File
    71088 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71089 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    71090 self.session.ui.mouse_modes.mouse_pause_tracking() 
    71091 File
    71092 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71093 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    71094 mouse_pause_tracking 
    71095 self._mouse_pause() 
    71096 File
    71097 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71098 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    71099 m.pause(self._mouse_pause_position) 
    71100 File
    71101 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71102 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    71103 p = self.view.picked_object(x, y) 
    71104 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71105 File
    71106 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71107 packages/chimerax/graphics/view.py", line 838, in picked_object 
    71108 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    71109 beyond, 
    71110 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71111 File
    71112 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71113 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    71114 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    71115 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71116 File
    71117 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71118 packages/chimerax/core/models.py", line 143, in first_intercept 
    71119 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    71120 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71121 File
    71122 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71123 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    71124 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    71125 exclude=exclude) 
    71126 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71127 File
    71128 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71129 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    71130 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    71131 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71132 File
    71133 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71134 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    71135 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    71136 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71137 File
    71138 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71139 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    71140 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    71141 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71142 File
    71143 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71144 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    71145 p = super().first_intercept(mxyz1, mxyz2) 
    71146 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71147 File
    71148 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71149 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    71150 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    71151 exclude=exclude) 
    71152 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71153 File
    71154 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71155 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    71156 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    71157 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71158 File
    71159 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71160 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    71161 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    71162 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71163 File
    71164 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71165 packages/chimerax/graphics/drawing.py", line 1108, in
    71166 _first_intercept_excluding_children 
    71167 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    71168 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71169 File
    71170 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71171 packages/chimerax/geometry/place.py", line 201, in inverse 
    71172 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    71173 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71174 File
    71175 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71176 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    71177 rinv[:, :] = matrix_inverse(r) 
    71178 ^^^^^^^^^^^^^^^^^ 
    71179 File
    71180 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71181 packages/numpy/linalg/linalg.py", line 561, in inv 
    71182 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    71183 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71184 File
    71185 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71186 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    71187 raise LinAlgError("Singular matrix") 
    71188 numpy.linalg.LinAlgError: Singular matrix 
    71189  
    71190 numpy.linalg.LinAlgError: Singular matrix 
    71191  
    71192 File
    71193 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71194 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    71195 raise LinAlgError("Singular matrix") 
    71196  
    71197 See log for complete Python traceback. 
    71198  
    71199 Traceback (most recent call last): 
    71200 File
    71201 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71202 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    71203 self.session.ui.mouse_modes.mouse_pause_tracking() 
    71204 File
    71205 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71206 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    71207 mouse_pause_tracking 
    71208 self._mouse_pause() 
    71209 File
    71210 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71211 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    71212 m.pause(self._mouse_pause_position) 
    71213 File
    71214 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71215 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    71216 p = self.view.picked_object(x, y) 
    71217 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71218 File
    71219 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71220 packages/chimerax/graphics/view.py", line 838, in picked_object 
    71221 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    71222 beyond, 
    71223 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71224 File
    71225 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71226 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    71227 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    71228 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71229 File
    71230 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71231 packages/chimerax/core/models.py", line 143, in first_intercept 
    71232 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    71233 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71234 File
    71235 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71236 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    71237 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    71238 exclude=exclude) 
    71239 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71240 File
    71241 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71242 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    71243 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    71244 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71245 File
    71246 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71247 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    71248 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    71249 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71250 File
    71251 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71252 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    71253 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    71254 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71255 File
    71256 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71257 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    71258 p = super().first_intercept(mxyz1, mxyz2) 
    71259 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71260 File
    71261 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71262 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    71263 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    71264 exclude=exclude) 
    71265 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71266 File
    71267 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71268 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    71269 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    71270 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71271 File
    71272 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71273 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    71274 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    71275 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71276 File
    71277 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71278 packages/chimerax/graphics/drawing.py", line 1108, in
    71279 _first_intercept_excluding_children 
    71280 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    71281 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71282 File
    71283 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71284 packages/chimerax/geometry/place.py", line 201, in inverse 
    71285 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    71286 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71287 File
    71288 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71289 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    71290 rinv[:, :] = matrix_inverse(r) 
    71291 ^^^^^^^^^^^^^^^^^ 
    71292 File
    71293 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71294 packages/numpy/linalg/linalg.py", line 561, in inv 
    71295 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    71296 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71297 File
    71298 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71299 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    71300 raise LinAlgError("Singular matrix") 
    71301 numpy.linalg.LinAlgError: Singular matrix 
    71302  
    71303 numpy.linalg.LinAlgError: Singular matrix 
    71304  
    71305 File
    71306 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71307 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    71308 raise LinAlgError("Singular matrix") 
    71309  
    71310 See log for complete Python traceback. 
    71311  
    71312 Traceback (most recent call last): 
    71313 File
    71314 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71315 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    71316 self.session.ui.mouse_modes.mouse_pause_tracking() 
    71317 File
    71318 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71319 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    71320 mouse_pause_tracking 
    71321 self._mouse_pause() 
    71322 File
    71323 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71324 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    71325 m.pause(self._mouse_pause_position) 
    71326 File
    71327 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71328 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    71329 p = self.view.picked_object(x, y) 
    71330 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71331 File
    71332 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71333 packages/chimerax/graphics/view.py", line 838, in picked_object 
    71334 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    71335 beyond, 
    71336 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71337 File
    71338 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71339 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    71340 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    71341 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71342 File
    71343 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71344 packages/chimerax/core/models.py", line 143, in first_intercept 
    71345 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    71346 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71347 File
    71348 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71349 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    71350 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    71351 exclude=exclude) 
    71352 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71353 File
    71354 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71355 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    71356 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    71357 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71358 File
    71359 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71360 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    71361 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    71362 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71363 File
    71364 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71365 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    71366 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    71367 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71368 File
    71369 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71370 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    71371 p = super().first_intercept(mxyz1, mxyz2) 
    71372 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71373 File
    71374 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71375 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    71376 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    71377 exclude=exclude) 
    71378 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71379 File
    71380 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71381 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    71382 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    71383 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71384 File
    71385 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71386 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    71387 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    71388 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71389 File
    71390 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71391 packages/chimerax/graphics/drawing.py", line 1108, in
    71392 _first_intercept_excluding_children 
    71393 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    71394 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71395 File
    71396 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71397 packages/chimerax/geometry/place.py", line 201, in inverse 
    71398 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    71399 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71400 File
    71401 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71402 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    71403 rinv[:, :] = matrix_inverse(r) 
    71404 ^^^^^^^^^^^^^^^^^ 
    71405 File
    71406 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71407 packages/numpy/linalg/linalg.py", line 561, in inv 
    71408 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    71409 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71410 File
    71411 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71412 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    71413 raise LinAlgError("Singular matrix") 
    71414 numpy.linalg.LinAlgError: Singular matrix 
    71415  
    71416 numpy.linalg.LinAlgError: Singular matrix 
    71417  
    71418 File
    71419 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71420 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    71421 raise LinAlgError("Singular matrix") 
    71422  
    71423 See log for complete Python traceback. 
    71424  
    71425 Traceback (most recent call last): 
    71426 File
    71427 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71428 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    71429 self.session.ui.mouse_modes.mouse_pause_tracking() 
    71430 File
    71431 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71432 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    71433 mouse_pause_tracking 
    71434 self._mouse_pause() 
    71435 File
    71436 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71437 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    71438 m.pause(self._mouse_pause_position) 
    71439 File
    71440 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71441 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    71442 p = self.view.picked_object(x, y) 
    71443 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71444 File
    71445 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71446 packages/chimerax/graphics/view.py", line 838, in picked_object 
    71447 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    71448 beyond, 
    71449 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71450 File
    71451 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71452 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    71453 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    71454 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71455 File
    71456 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71457 packages/chimerax/core/models.py", line 143, in first_intercept 
    71458 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    71459 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71460 File
    71461 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71462 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    71463 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    71464 exclude=exclude) 
    71465 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71466 File
    71467 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71468 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    71469 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    71470 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71471 File
    71472 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71473 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    71474 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    71475 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71476 File
    71477 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71478 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    71479 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    71480 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71481 File
    71482 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71483 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    71484 p = super().first_intercept(mxyz1, mxyz2) 
    71485 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71486 File
    71487 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71488 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    71489 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    71490 exclude=exclude) 
    71491 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71492 File
    71493 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71494 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    71495 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    71496 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71497 File
    71498 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71499 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    71500 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    71501 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71502 File
    71503 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71504 packages/chimerax/graphics/drawing.py", line 1108, in
    71505 _first_intercept_excluding_children 
    71506 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    71507 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71508 File
    71509 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71510 packages/chimerax/geometry/place.py", line 201, in inverse 
    71511 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    71512 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71513 File
    71514 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71515 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    71516 rinv[:, :] = matrix_inverse(r) 
    71517 ^^^^^^^^^^^^^^^^^ 
    71518 File
    71519 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71520 packages/numpy/linalg/linalg.py", line 561, in inv 
    71521 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    71522 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71523 File
    71524 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71525 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    71526 raise LinAlgError("Singular matrix") 
    71527 numpy.linalg.LinAlgError: Singular matrix 
    71528  
    71529 numpy.linalg.LinAlgError: Singular matrix 
    71530  
    71531 File
    71532 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71533 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    71534 raise LinAlgError("Singular matrix") 
    71535  
    71536 See log for complete Python traceback. 
    71537  
    71538 Traceback (most recent call last): 
    71539 File
    71540 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71541 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    71542 self.session.ui.mouse_modes.mouse_pause_tracking() 
    71543 File
    71544 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71545 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    71546 mouse_pause_tracking 
    71547 self._mouse_pause() 
    71548 File
    71549 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71550 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    71551 m.pause(self._mouse_pause_position) 
    71552 File
    71553 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71554 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    71555 p = self.view.picked_object(x, y) 
    71556 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71557 File
    71558 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71559 packages/chimerax/graphics/view.py", line 838, in picked_object 
    71560 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    71561 beyond, 
    71562 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71563 File
    71564 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71565 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    71566 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    71567 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71568 File
    71569 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71570 packages/chimerax/core/models.py", line 143, in first_intercept 
    71571 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    71572 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71573 File
    71574 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71575 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    71576 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    71577 exclude=exclude) 
    71578 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71579 File
    71580 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71581 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    71582 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    71583 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71584 File
    71585 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71586 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    71587 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    71588 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71589 File
    71590 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71591 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    71592 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    71593 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71594 File
    71595 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71596 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    71597 p = super().first_intercept(mxyz1, mxyz2) 
    71598 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71599 File
    71600 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71601 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    71602 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    71603 exclude=exclude) 
    71604 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71605 File
    71606 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71607 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    71608 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    71609 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71610 File
    71611 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71612 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    71613 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    71614 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71615 File
    71616 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71617 packages/chimerax/graphics/drawing.py", line 1108, in
    71618 _first_intercept_excluding_children 
    71619 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    71620 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71621 File
    71622 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71623 packages/chimerax/geometry/place.py", line 201, in inverse 
    71624 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    71625 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71626 File
    71627 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71628 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    71629 rinv[:, :] = matrix_inverse(r) 
    71630 ^^^^^^^^^^^^^^^^^ 
    71631 File
    71632 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71633 packages/numpy/linalg/linalg.py", line 561, in inv 
    71634 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    71635 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71636 File
    71637 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71638 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    71639 raise LinAlgError("Singular matrix") 
    71640 numpy.linalg.LinAlgError: Singular matrix 
    71641  
    71642 numpy.linalg.LinAlgError: Singular matrix 
    71643  
    71644 File
    71645 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71646 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    71647 raise LinAlgError("Singular matrix") 
    71648  
    71649 See log for complete Python traceback. 
    71650  
    71651 Traceback (most recent call last): 
    71652 File
    71653 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71654 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    71655 self.session.ui.mouse_modes.mouse_pause_tracking() 
    71656 File
    71657 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71658 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    71659 mouse_pause_tracking 
    71660 self._mouse_pause() 
    71661 File
    71662 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71663 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    71664 m.pause(self._mouse_pause_position) 
    71665 File
    71666 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71667 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    71668 p = self.view.picked_object(x, y) 
    71669 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71670 File
    71671 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71672 packages/chimerax/graphics/view.py", line 838, in picked_object 
    71673 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    71674 beyond, 
    71675 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71676 File
    71677 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71678 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    71679 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    71680 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71681 File
    71682 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71683 packages/chimerax/core/models.py", line 143, in first_intercept 
    71684 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    71685 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71686 File
    71687 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71688 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    71689 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    71690 exclude=exclude) 
    71691 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71692 File
    71693 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71694 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    71695 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    71696 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71697 File
    71698 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71699 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    71700 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    71701 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71702 File
    71703 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71704 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    71705 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    71706 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71707 File
    71708 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71709 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    71710 p = super().first_intercept(mxyz1, mxyz2) 
    71711 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71712 File
    71713 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71714 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    71715 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    71716 exclude=exclude) 
    71717 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71718 File
    71719 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71720 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    71721 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    71722 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71723 File
    71724 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71725 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    71726 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    71727 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71728 File
    71729 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71730 packages/chimerax/graphics/drawing.py", line 1108, in
    71731 _first_intercept_excluding_children 
    71732 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    71733 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71734 File
    71735 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71736 packages/chimerax/geometry/place.py", line 201, in inverse 
    71737 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    71738 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71739 File
    71740 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71741 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    71742 rinv[:, :] = matrix_inverse(r) 
    71743 ^^^^^^^^^^^^^^^^^ 
    71744 File
    71745 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71746 packages/numpy/linalg/linalg.py", line 561, in inv 
    71747 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    71748 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71749 File
    71750 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71751 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    71752 raise LinAlgError("Singular matrix") 
    71753 numpy.linalg.LinAlgError: Singular matrix 
    71754  
    71755 numpy.linalg.LinAlgError: Singular matrix 
    71756  
    71757 File
    71758 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71759 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    71760 raise LinAlgError("Singular matrix") 
    71761  
    71762 See log for complete Python traceback. 
    71763  
    71764 Traceback (most recent call last): 
    71765 File
    71766 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71767 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    71768 self.session.ui.mouse_modes.mouse_pause_tracking() 
    71769 File
    71770 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71771 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    71772 mouse_pause_tracking 
    71773 self._mouse_pause() 
    71774 File
    71775 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71776 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    71777 m.pause(self._mouse_pause_position) 
    71778 File
    71779 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71780 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    71781 p = self.view.picked_object(x, y) 
    71782 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71783 File
    71784 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71785 packages/chimerax/graphics/view.py", line 838, in picked_object 
    71786 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    71787 beyond, 
    71788 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71789 File
    71790 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71791 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    71792 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    71793 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71794 File
    71795 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71796 packages/chimerax/core/models.py", line 143, in first_intercept 
    71797 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    71798 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71799 File
    71800 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71801 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    71802 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    71803 exclude=exclude) 
    71804 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71805 File
    71806 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71807 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    71808 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    71809 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71810 File
    71811 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71812 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    71813 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    71814 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71815 File
    71816 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71817 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    71818 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    71819 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71820 File
    71821 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71822 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    71823 p = super().first_intercept(mxyz1, mxyz2) 
    71824 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71825 File
    71826 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71827 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    71828 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    71829 exclude=exclude) 
    71830 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71831 File
    71832 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71833 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    71834 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    71835 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71836 File
    71837 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71838 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    71839 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    71840 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71841 File
    71842 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71843 packages/chimerax/graphics/drawing.py", line 1108, in
    71844 _first_intercept_excluding_children 
    71845 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    71846 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71847 File
    71848 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71849 packages/chimerax/geometry/place.py", line 201, in inverse 
    71850 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    71851 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71852 File
    71853 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71854 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    71855 rinv[:, :] = matrix_inverse(r) 
    71856 ^^^^^^^^^^^^^^^^^ 
    71857 File
    71858 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71859 packages/numpy/linalg/linalg.py", line 561, in inv 
    71860 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    71861 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71862 File
    71863 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71864 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    71865 raise LinAlgError("Singular matrix") 
    71866 numpy.linalg.LinAlgError: Singular matrix 
    71867  
    71868 numpy.linalg.LinAlgError: Singular matrix 
    71869  
    71870 File
    71871 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71872 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    71873 raise LinAlgError("Singular matrix") 
    71874  
    71875 See log for complete Python traceback. 
    71876  
    71877 Traceback (most recent call last): 
    71878 File
    71879 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71880 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    71881 self.session.ui.mouse_modes.mouse_pause_tracking() 
    71882 File
    71883 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71884 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    71885 mouse_pause_tracking 
    71886 self._mouse_pause() 
    71887 File
    71888 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71889 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    71890 m.pause(self._mouse_pause_position) 
    71891 File
    71892 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71893 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    71894 p = self.view.picked_object(x, y) 
    71895 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71896 File
    71897 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71898 packages/chimerax/graphics/view.py", line 838, in picked_object 
    71899 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    71900 beyond, 
    71901 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71902 File
    71903 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71904 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    71905 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    71906 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71907 File
    71908 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71909 packages/chimerax/core/models.py", line 143, in first_intercept 
    71910 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    71911 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71912 File
    71913 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71914 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    71915 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    71916 exclude=exclude) 
    71917 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71918 File
    71919 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71920 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    71921 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    71922 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71923 File
    71924 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71925 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    71926 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    71927 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71928 File
    71929 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71930 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    71931 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    71932 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71933 File
    71934 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71935 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    71936 p = super().first_intercept(mxyz1, mxyz2) 
    71937 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71938 File
    71939 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71940 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    71941 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    71942 exclude=exclude) 
    71943 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71944 File
    71945 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71946 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    71947 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    71948 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71949 File
    71950 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71951 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    71952 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    71953 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71954 File
    71955 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71956 packages/chimerax/graphics/drawing.py", line 1108, in
    71957 _first_intercept_excluding_children 
    71958 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    71959 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71960 File
    71961 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71962 packages/chimerax/geometry/place.py", line 201, in inverse 
    71963 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    71964 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71965 File
    71966 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71967 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    71968 rinv[:, :] = matrix_inverse(r) 
    71969 ^^^^^^^^^^^^^^^^^ 
    71970 File
    71971 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71972 packages/numpy/linalg/linalg.py", line 561, in inv 
    71973 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    71974 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    71975 File
    71976 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71977 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    71978 raise LinAlgError("Singular matrix") 
    71979 numpy.linalg.LinAlgError: Singular matrix 
    71980  
    71981 numpy.linalg.LinAlgError: Singular matrix 
    71982  
    71983 File
    71984 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71985 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    71986 raise LinAlgError("Singular matrix") 
    71987  
    71988 See log for complete Python traceback. 
    71989  
    71990 Traceback (most recent call last): 
    71991 File
    71992 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71993 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    71994 self.session.ui.mouse_modes.mouse_pause_tracking() 
    71995 File
    71996 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    71997 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    71998 mouse_pause_tracking 
    71999 self._mouse_pause() 
    72000 File
    72001 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72002 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    72003 m.pause(self._mouse_pause_position) 
    72004 File
    72005 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72006 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    72007 p = self.view.picked_object(x, y) 
    72008 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72009 File
    72010 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72011 packages/chimerax/graphics/view.py", line 838, in picked_object 
    72012 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    72013 beyond, 
    72014 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72015 File
    72016 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72017 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    72018 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    72019 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72020 File
    72021 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72022 packages/chimerax/core/models.py", line 143, in first_intercept 
    72023 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    72024 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72025 File
    72026 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72027 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    72028 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    72029 exclude=exclude) 
    72030 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72031 File
    72032 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72033 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    72034 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    72035 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72036 File
    72037 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72038 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    72039 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    72040 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72041 File
    72042 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72043 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    72044 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    72045 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72046 File
    72047 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72048 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    72049 p = super().first_intercept(mxyz1, mxyz2) 
    72050 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72051 File
    72052 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72053 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    72054 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    72055 exclude=exclude) 
    72056 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72057 File
    72058 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72059 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    72060 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    72061 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72062 File
    72063 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72064 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    72065 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    72066 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72067 File
    72068 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72069 packages/chimerax/graphics/drawing.py", line 1108, in
    72070 _first_intercept_excluding_children 
    72071 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    72072 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72073 File
    72074 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72075 packages/chimerax/geometry/place.py", line 201, in inverse 
    72076 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    72077 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72078 File
    72079 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72080 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    72081 rinv[:, :] = matrix_inverse(r) 
    72082 ^^^^^^^^^^^^^^^^^ 
    72083 File
    72084 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72085 packages/numpy/linalg/linalg.py", line 561, in inv 
    72086 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    72087 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72088 File
    72089 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72090 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    72091 raise LinAlgError("Singular matrix") 
    72092 numpy.linalg.LinAlgError: Singular matrix 
    72093  
    72094 numpy.linalg.LinAlgError: Singular matrix 
    72095  
    72096 File
    72097 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72098 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    72099 raise LinAlgError("Singular matrix") 
    72100  
    72101 See log for complete Python traceback. 
    72102  
    72103 Traceback (most recent call last): 
    72104 File
    72105 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72106 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    72107 self.session.ui.mouse_modes.mouse_pause_tracking() 
    72108 File
    72109 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72110 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    72111 mouse_pause_tracking 
    72112 self._mouse_pause() 
    72113 File
    72114 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72115 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    72116 m.pause(self._mouse_pause_position) 
    72117 File
    72118 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72119 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    72120 p = self.view.picked_object(x, y) 
    72121 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72122 File
    72123 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72124 packages/chimerax/graphics/view.py", line 838, in picked_object 
    72125 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    72126 beyond, 
    72127 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72128 File
    72129 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72130 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    72131 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    72132 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72133 File
    72134 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72135 packages/chimerax/core/models.py", line 143, in first_intercept 
    72136 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    72137 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72138 File
    72139 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72140 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    72141 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    72142 exclude=exclude) 
    72143 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72144 File
    72145 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72146 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    72147 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    72148 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72149 File
    72150 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72151 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    72152 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    72153 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72154 File
    72155 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72156 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    72157 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    72158 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72159 File
    72160 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72161 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    72162 p = super().first_intercept(mxyz1, mxyz2) 
    72163 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72164 File
    72165 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72166 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    72167 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    72168 exclude=exclude) 
    72169 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72170 File
    72171 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72172 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    72173 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    72174 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72175 File
    72176 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72177 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    72178 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    72179 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72180 File
    72181 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72182 packages/chimerax/graphics/drawing.py", line 1108, in
    72183 _first_intercept_excluding_children 
    72184 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    72185 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72186 File
    72187 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72188 packages/chimerax/geometry/place.py", line 201, in inverse 
    72189 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    72190 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72191 File
    72192 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72193 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    72194 rinv[:, :] = matrix_inverse(r) 
    72195 ^^^^^^^^^^^^^^^^^ 
    72196 File
    72197 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72198 packages/numpy/linalg/linalg.py", line 561, in inv 
    72199 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    72200 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72201 File
    72202 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72203 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    72204 raise LinAlgError("Singular matrix") 
    72205 numpy.linalg.LinAlgError: Singular matrix 
    72206  
    72207 numpy.linalg.LinAlgError: Singular matrix 
    72208  
    72209 File
    72210 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72211 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    72212 raise LinAlgError("Singular matrix") 
    72213  
    72214 See log for complete Python traceback. 
    72215  
    72216 Traceback (most recent call last): 
    72217 File
    72218 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72219 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    72220 self.session.ui.mouse_modes.mouse_pause_tracking() 
    72221 File
    72222 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72223 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    72224 mouse_pause_tracking 
    72225 self._mouse_pause() 
    72226 File
    72227 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72228 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    72229 m.pause(self._mouse_pause_position) 
    72230 File
    72231 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72232 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    72233 p = self.view.picked_object(x, y) 
    72234 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72235 File
    72236 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72237 packages/chimerax/graphics/view.py", line 838, in picked_object 
    72238 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    72239 beyond, 
    72240 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72241 File
    72242 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72243 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    72244 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    72245 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72246 File
    72247 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72248 packages/chimerax/core/models.py", line 143, in first_intercept 
    72249 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    72250 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72251 File
    72252 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72253 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    72254 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    72255 exclude=exclude) 
    72256 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72257 File
    72258 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72259 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    72260 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    72261 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72262 File
    72263 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72264 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    72265 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    72266 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72267 File
    72268 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72269 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    72270 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    72271 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72272 File
    72273 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72274 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    72275 p = super().first_intercept(mxyz1, mxyz2) 
    72276 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72277 File
    72278 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72279 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    72280 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    72281 exclude=exclude) 
    72282 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72283 File
    72284 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72285 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    72286 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    72287 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72288 File
    72289 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72290 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    72291 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    72292 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72293 File
    72294 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72295 packages/chimerax/graphics/drawing.py", line 1108, in
    72296 _first_intercept_excluding_children 
    72297 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    72298 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72299 File
    72300 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72301 packages/chimerax/geometry/place.py", line 201, in inverse 
    72302 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    72303 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72304 File
    72305 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72306 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    72307 rinv[:, :] = matrix_inverse(r) 
    72308 ^^^^^^^^^^^^^^^^^ 
    72309 File
    72310 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72311 packages/numpy/linalg/linalg.py", line 561, in inv 
    72312 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    72313 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72314 File
    72315 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72316 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    72317 raise LinAlgError("Singular matrix") 
    72318 numpy.linalg.LinAlgError: Singular matrix 
    72319  
    72320 numpy.linalg.LinAlgError: Singular matrix 
    72321  
    72322 File
    72323 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72324 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    72325 raise LinAlgError("Singular matrix") 
    72326  
    72327 See log for complete Python traceback. 
    72328  
    72329 Traceback (most recent call last): 
    72330 File
    72331 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72332 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    72333 self.session.ui.mouse_modes.mouse_pause_tracking() 
    72334 File
    72335 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72336 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    72337 mouse_pause_tracking 
    72338 self._mouse_pause() 
    72339 File
    72340 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72341 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    72342 m.pause(self._mouse_pause_position) 
    72343 File
    72344 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72345 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    72346 p = self.view.picked_object(x, y) 
    72347 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72348 File
    72349 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72350 packages/chimerax/graphics/view.py", line 838, in picked_object 
    72351 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    72352 beyond, 
    72353 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72354 File
    72355 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72356 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    72357 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    72358 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72359 File
    72360 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72361 packages/chimerax/core/models.py", line 143, in first_intercept 
    72362 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    72363 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72364 File
    72365 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72366 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    72367 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    72368 exclude=exclude) 
    72369 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72370 File
    72371 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72372 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    72373 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    72374 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72375 File
    72376 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72377 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    72378 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    72379 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72380 File
    72381 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72382 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    72383 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    72384 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72385 File
    72386 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72387 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    72388 p = super().first_intercept(mxyz1, mxyz2) 
    72389 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72390 File
    72391 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72392 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    72393 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    72394 exclude=exclude) 
    72395 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72396 File
    72397 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72398 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    72399 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    72400 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72401 File
    72402 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72403 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    72404 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    72405 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72406 File
    72407 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72408 packages/chimerax/graphics/drawing.py", line 1108, in
    72409 _first_intercept_excluding_children 
    72410 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    72411 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72412 File
    72413 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72414 packages/chimerax/geometry/place.py", line 201, in inverse 
    72415 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    72416 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72417 File
    72418 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72419 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    72420 rinv[:, :] = matrix_inverse(r) 
    72421 ^^^^^^^^^^^^^^^^^ 
    72422 File
    72423 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72424 packages/numpy/linalg/linalg.py", line 561, in inv 
    72425 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    72426 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72427 File
    72428 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72429 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    72430 raise LinAlgError("Singular matrix") 
    72431 numpy.linalg.LinAlgError: Singular matrix 
    72432  
    72433 numpy.linalg.LinAlgError: Singular matrix 
    72434  
    72435 File
    72436 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72437 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    72438 raise LinAlgError("Singular matrix") 
    72439  
    72440 See log for complete Python traceback. 
    72441  
    72442 Traceback (most recent call last): 
    72443 File
    72444 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72445 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    72446 self.session.ui.mouse_modes.mouse_pause_tracking() 
    72447 File
    72448 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72449 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    72450 mouse_pause_tracking 
    72451 self._mouse_pause() 
    72452 File
    72453 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72454 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    72455 m.pause(self._mouse_pause_position) 
    72456 File
    72457 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72458 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    72459 p = self.view.picked_object(x, y) 
    72460 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72461 File
    72462 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72463 packages/chimerax/graphics/view.py", line 838, in picked_object 
    72464 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    72465 beyond, 
    72466 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72467 File
    72468 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72469 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    72470 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    72471 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72472 File
    72473 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72474 packages/chimerax/core/models.py", line 143, in first_intercept 
    72475 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    72476 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72477 File
    72478 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72479 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    72480 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    72481 exclude=exclude) 
    72482 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72483 File
    72484 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72485 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    72486 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    72487 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72488 File
    72489 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72490 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    72491 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    72492 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72493 File
    72494 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72495 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    72496 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    72497 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72498 File
    72499 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72500 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    72501 p = super().first_intercept(mxyz1, mxyz2) 
    72502 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72503 File
    72504 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72505 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    72506 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    72507 exclude=exclude) 
    72508 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72509 File
    72510 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72511 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    72512 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    72513 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72514 File
    72515 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72516 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    72517 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    72518 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72519 File
    72520 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72521 packages/chimerax/graphics/drawing.py", line 1108, in
    72522 _first_intercept_excluding_children 
    72523 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    72524 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72525 File
    72526 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72527 packages/chimerax/geometry/place.py", line 201, in inverse 
    72528 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    72529 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72530 File
    72531 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72532 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    72533 rinv[:, :] = matrix_inverse(r) 
    72534 ^^^^^^^^^^^^^^^^^ 
    72535 File
    72536 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72537 packages/numpy/linalg/linalg.py", line 561, in inv 
    72538 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    72539 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72540 File
    72541 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72542 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    72543 raise LinAlgError("Singular matrix") 
    72544 numpy.linalg.LinAlgError: Singular matrix 
    72545  
    72546 numpy.linalg.LinAlgError: Singular matrix 
    72547  
    72548 File
    72549 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72550 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    72551 raise LinAlgError("Singular matrix") 
    72552  
    72553 See log for complete Python traceback. 
    72554  
    72555 Traceback (most recent call last): 
    72556 File
    72557 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72558 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    72559 self.session.ui.mouse_modes.mouse_pause_tracking() 
    72560 File
    72561 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72562 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    72563 mouse_pause_tracking 
    72564 self._mouse_pause() 
    72565 File
    72566 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72567 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    72568 m.pause(self._mouse_pause_position) 
    72569 File
    72570 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72571 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    72572 p = self.view.picked_object(x, y) 
    72573 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72574 File
    72575 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72576 packages/chimerax/graphics/view.py", line 838, in picked_object 
    72577 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    72578 beyond, 
    72579 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72580 File
    72581 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72582 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    72583 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    72584 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72585 File
    72586 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72587 packages/chimerax/core/models.py", line 143, in first_intercept 
    72588 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    72589 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72590 File
    72591 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72592 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    72593 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    72594 exclude=exclude) 
    72595 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72596 File
    72597 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72598 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    72599 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    72600 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72601 File
    72602 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72603 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    72604 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    72605 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72606 File
    72607 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72608 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    72609 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    72610 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72611 File
    72612 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72613 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    72614 p = super().first_intercept(mxyz1, mxyz2) 
    72615 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72616 File
    72617 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72618 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    72619 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    72620 exclude=exclude) 
    72621 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72622 File
    72623 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72624 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    72625 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    72626 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72627 File
    72628 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72629 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    72630 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    72631 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72632 File
    72633 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72634 packages/chimerax/graphics/drawing.py", line 1108, in
    72635 _first_intercept_excluding_children 
    72636 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    72637 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72638 File
    72639 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72640 packages/chimerax/geometry/place.py", line 201, in inverse 
    72641 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    72642 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72643 File
    72644 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72645 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    72646 rinv[:, :] = matrix_inverse(r) 
    72647 ^^^^^^^^^^^^^^^^^ 
    72648 File
    72649 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72650 packages/numpy/linalg/linalg.py", line 561, in inv 
    72651 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    72652 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72653 File
    72654 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72655 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    72656 raise LinAlgError("Singular matrix") 
    72657 numpy.linalg.LinAlgError: Singular matrix 
    72658  
    72659 numpy.linalg.LinAlgError: Singular matrix 
    72660  
    72661 File
    72662 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72663 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    72664 raise LinAlgError("Singular matrix") 
    72665  
    72666 See log for complete Python traceback. 
    72667  
    72668 Traceback (most recent call last): 
    72669 File
    72670 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72671 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    72672 self.session.ui.mouse_modes.mouse_pause_tracking() 
    72673 File
    72674 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72675 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    72676 mouse_pause_tracking 
    72677 self._mouse_pause() 
    72678 File
    72679 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72680 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    72681 m.pause(self._mouse_pause_position) 
    72682 File
    72683 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72684 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    72685 p = self.view.picked_object(x, y) 
    72686 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72687 File
    72688 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72689 packages/chimerax/graphics/view.py", line 838, in picked_object 
    72690 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    72691 beyond, 
    72692 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72693 File
    72694 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72695 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    72696 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    72697 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72698 File
    72699 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72700 packages/chimerax/core/models.py", line 143, in first_intercept 
    72701 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    72702 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72703 File
    72704 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72705 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    72706 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    72707 exclude=exclude) 
    72708 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72709 File
    72710 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72711 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    72712 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    72713 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72714 File
    72715 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72716 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    72717 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    72718 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72719 File
    72720 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72721 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    72722 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    72723 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72724 File
    72725 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72726 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    72727 p = super().first_intercept(mxyz1, mxyz2) 
    72728 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72729 File
    72730 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72731 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    72732 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    72733 exclude=exclude) 
    72734 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72735 File
    72736 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72737 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    72738 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    72739 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72740 File
    72741 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72742 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    72743 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    72744 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72745 File
    72746 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72747 packages/chimerax/graphics/drawing.py", line 1108, in
    72748 _first_intercept_excluding_children 
    72749 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    72750 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72751 File
    72752 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72753 packages/chimerax/geometry/place.py", line 201, in inverse 
    72754 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    72755 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72756 File
    72757 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72758 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    72759 rinv[:, :] = matrix_inverse(r) 
    72760 ^^^^^^^^^^^^^^^^^ 
    72761 File
    72762 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72763 packages/numpy/linalg/linalg.py", line 561, in inv 
    72764 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    72765 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72766 File
    72767 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72768 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    72769 raise LinAlgError("Singular matrix") 
    72770 numpy.linalg.LinAlgError: Singular matrix 
    72771  
    72772 numpy.linalg.LinAlgError: Singular matrix 
    72773  
    72774 File
    72775 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72776 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    72777 raise LinAlgError("Singular matrix") 
    72778  
    72779 See log for complete Python traceback. 
    72780  
    72781 Traceback (most recent call last): 
    72782 File
    72783 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72784 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    72785 self.session.ui.mouse_modes.mouse_pause_tracking() 
    72786 File
    72787 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72788 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    72789 mouse_pause_tracking 
    72790 self._mouse_pause() 
    72791 File
    72792 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72793 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    72794 m.pause(self._mouse_pause_position) 
    72795 File
    72796 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72797 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    72798 p = self.view.picked_object(x, y) 
    72799 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72800 File
    72801 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72802 packages/chimerax/graphics/view.py", line 838, in picked_object 
    72803 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    72804 beyond, 
    72805 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72806 File
    72807 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72808 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    72809 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    72810 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72811 File
    72812 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72813 packages/chimerax/core/models.py", line 143, in first_intercept 
    72814 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    72815 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72816 File
    72817 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72818 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    72819 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    72820 exclude=exclude) 
    72821 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72822 File
    72823 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72824 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    72825 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    72826 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72827 File
    72828 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72829 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    72830 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    72831 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72832 File
    72833 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72834 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    72835 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    72836 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72837 File
    72838 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72839 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    72840 p = super().first_intercept(mxyz1, mxyz2) 
    72841 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72842 File
    72843 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72844 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    72845 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    72846 exclude=exclude) 
    72847 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72848 File
    72849 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72850 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    72851 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    72852 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72853 File
    72854 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72855 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    72856 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    72857 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72858 File
    72859 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72860 packages/chimerax/graphics/drawing.py", line 1108, in
    72861 _first_intercept_excluding_children 
    72862 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    72863 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72864 File
    72865 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72866 packages/chimerax/geometry/place.py", line 201, in inverse 
    72867 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    72868 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72869 File
    72870 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72871 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    72872 rinv[:, :] = matrix_inverse(r) 
    72873 ^^^^^^^^^^^^^^^^^ 
    72874 File
    72875 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72876 packages/numpy/linalg/linalg.py", line 561, in inv 
    72877 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    72878 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72879 File
    72880 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72881 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    72882 raise LinAlgError("Singular matrix") 
    72883 numpy.linalg.LinAlgError: Singular matrix 
    72884  
    72885 numpy.linalg.LinAlgError: Singular matrix 
    72886  
    72887 File
    72888 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72889 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    72890 raise LinAlgError("Singular matrix") 
    72891  
    72892 See log for complete Python traceback. 
    72893  
    72894 Traceback (most recent call last): 
    72895 File
    72896 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72897 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    72898 self.session.ui.mouse_modes.mouse_pause_tracking() 
    72899 File
    72900 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72901 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    72902 mouse_pause_tracking 
    72903 self._mouse_pause() 
    72904 File
    72905 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72906 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    72907 m.pause(self._mouse_pause_position) 
    72908 File
    72909 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72910 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    72911 p = self.view.picked_object(x, y) 
    72912 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72913 File
    72914 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72915 packages/chimerax/graphics/view.py", line 838, in picked_object 
    72916 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    72917 beyond, 
    72918 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72919 File
    72920 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72921 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    72922 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    72923 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72924 File
    72925 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72926 packages/chimerax/core/models.py", line 143, in first_intercept 
    72927 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    72928 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72929 File
    72930 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72931 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    72932 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    72933 exclude=exclude) 
    72934 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72935 File
    72936 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72937 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    72938 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    72939 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72940 File
    72941 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72942 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    72943 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    72944 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72945 File
    72946 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72947 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    72948 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    72949 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72950 File
    72951 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72952 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    72953 p = super().first_intercept(mxyz1, mxyz2) 
    72954 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72955 File
    72956 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72957 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    72958 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    72959 exclude=exclude) 
    72960 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72961 File
    72962 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72963 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    72964 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    72965 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72966 File
    72967 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72968 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    72969 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    72970 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72971 File
    72972 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72973 packages/chimerax/graphics/drawing.py", line 1108, in
    72974 _first_intercept_excluding_children 
    72975 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    72976 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72977 File
    72978 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72979 packages/chimerax/geometry/place.py", line 201, in inverse 
    72980 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    72981 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72982 File
    72983 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72984 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    72985 rinv[:, :] = matrix_inverse(r) 
    72986 ^^^^^^^^^^^^^^^^^ 
    72987 File
    72988 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72989 packages/numpy/linalg/linalg.py", line 561, in inv 
    72990 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    72991 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    72992 File
    72993 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    72994 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    72995 raise LinAlgError("Singular matrix") 
    72996 numpy.linalg.LinAlgError: Singular matrix 
    72997  
    72998 numpy.linalg.LinAlgError: Singular matrix 
    72999  
    73000 File
    73001 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73002 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    73003 raise LinAlgError("Singular matrix") 
    73004  
    73005 See log for complete Python traceback. 
    73006  
    73007 Traceback (most recent call last): 
    73008 File
    73009 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73010 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    73011 self.session.ui.mouse_modes.mouse_pause_tracking() 
    73012 File
    73013 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73014 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    73015 mouse_pause_tracking 
    73016 self._mouse_pause() 
    73017 File
    73018 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73019 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    73020 m.pause(self._mouse_pause_position) 
    73021 File
    73022 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73023 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    73024 p = self.view.picked_object(x, y) 
    73025 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73026 File
    73027 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73028 packages/chimerax/graphics/view.py", line 838, in picked_object 
    73029 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    73030 beyond, 
    73031 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73032 File
    73033 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73034 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    73035 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    73036 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73037 File
    73038 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73039 packages/chimerax/core/models.py", line 143, in first_intercept 
    73040 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    73041 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73042 File
    73043 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73044 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    73045 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    73046 exclude=exclude) 
    73047 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73048 File
    73049 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73050 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    73051 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    73052 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73053 File
    73054 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73055 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    73056 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    73057 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73058 File
    73059 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73060 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    73061 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    73062 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73063 File
    73064 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73065 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    73066 p = super().first_intercept(mxyz1, mxyz2) 
    73067 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73068 File
    73069 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73070 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    73071 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    73072 exclude=exclude) 
    73073 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73074 File
    73075 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73076 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    73077 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    73078 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73079 File
    73080 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73081 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    73082 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    73083 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73084 File
    73085 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73086 packages/chimerax/graphics/drawing.py", line 1108, in
    73087 _first_intercept_excluding_children 
    73088 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    73089 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73090 File
    73091 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73092 packages/chimerax/geometry/place.py", line 201, in inverse 
    73093 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    73094 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73095 File
    73096 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73097 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    73098 rinv[:, :] = matrix_inverse(r) 
    73099 ^^^^^^^^^^^^^^^^^ 
    73100 File
    73101 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73102 packages/numpy/linalg/linalg.py", line 561, in inv 
    73103 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    73104 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73105 File
    73106 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73107 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    73108 raise LinAlgError("Singular matrix") 
    73109 numpy.linalg.LinAlgError: Singular matrix 
    73110  
    73111 numpy.linalg.LinAlgError: Singular matrix 
    73112  
    73113 File
    73114 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73115 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    73116 raise LinAlgError("Singular matrix") 
    73117  
    73118 See log for complete Python traceback. 
    73119  
    73120 Traceback (most recent call last): 
    73121 File
    73122 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73123 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    73124 self.session.ui.mouse_modes.mouse_pause_tracking() 
    73125 File
    73126 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73127 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    73128 mouse_pause_tracking 
    73129 self._mouse_pause() 
    73130 File
    73131 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73132 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    73133 m.pause(self._mouse_pause_position) 
    73134 File
    73135 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73136 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    73137 p = self.view.picked_object(x, y) 
    73138 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73139 File
    73140 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73141 packages/chimerax/graphics/view.py", line 838, in picked_object 
    73142 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    73143 beyond, 
    73144 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73145 File
    73146 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73147 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    73148 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    73149 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73150 File
    73151 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73152 packages/chimerax/core/models.py", line 143, in first_intercept 
    73153 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    73154 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73155 File
    73156 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73157 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    73158 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    73159 exclude=exclude) 
    73160 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73161 File
    73162 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73163 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    73164 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    73165 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73166 File
    73167 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73168 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    73169 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    73170 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73171 File
    73172 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73173 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    73174 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    73175 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73176 File
    73177 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73178 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    73179 p = super().first_intercept(mxyz1, mxyz2) 
    73180 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73181 File
    73182 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73183 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    73184 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    73185 exclude=exclude) 
    73186 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73187 File
    73188 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73189 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    73190 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    73191 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73192 File
    73193 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73194 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    73195 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    73196 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73197 File
    73198 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73199 packages/chimerax/graphics/drawing.py", line 1108, in
    73200 _first_intercept_excluding_children 
    73201 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    73202 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73203 File
    73204 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73205 packages/chimerax/geometry/place.py", line 201, in inverse 
    73206 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    73207 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73208 File
    73209 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73210 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    73211 rinv[:, :] = matrix_inverse(r) 
    73212 ^^^^^^^^^^^^^^^^^ 
    73213 File
    73214 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73215 packages/numpy/linalg/linalg.py", line 561, in inv 
    73216 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    73217 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73218 File
    73219 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73220 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    73221 raise LinAlgError("Singular matrix") 
    73222 numpy.linalg.LinAlgError: Singular matrix 
    73223  
    73224 numpy.linalg.LinAlgError: Singular matrix 
    73225  
    73226 File
    73227 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73228 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    73229 raise LinAlgError("Singular matrix") 
    73230  
    73231 See log for complete Python traceback. 
    73232  
    73233 Traceback (most recent call last): 
    73234 File
    73235 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73236 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    73237 self.session.ui.mouse_modes.mouse_pause_tracking() 
    73238 File
    73239 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73240 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    73241 mouse_pause_tracking 
    73242 self._mouse_pause() 
    73243 File
    73244 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73245 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    73246 m.pause(self._mouse_pause_position) 
    73247 File
    73248 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73249 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    73250 p = self.view.picked_object(x, y) 
    73251 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73252 File
    73253 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73254 packages/chimerax/graphics/view.py", line 838, in picked_object 
    73255 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    73256 beyond, 
    73257 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73258 File
    73259 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73260 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    73261 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    73262 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73263 File
    73264 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73265 packages/chimerax/core/models.py", line 143, in first_intercept 
    73266 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    73267 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73268 File
    73269 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73270 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    73271 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    73272 exclude=exclude) 
    73273 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73274 File
    73275 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73276 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    73277 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    73278 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73279 File
    73280 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73281 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    73282 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    73283 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73284 File
    73285 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73286 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    73287 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    73288 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73289 File
    73290 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73291 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    73292 p = super().first_intercept(mxyz1, mxyz2) 
    73293 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73294 File
    73295 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73296 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    73297 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    73298 exclude=exclude) 
    73299 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73300 File
    73301 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73302 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    73303 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    73304 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73305 File
    73306 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73307 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    73308 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    73309 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73310 File
    73311 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73312 packages/chimerax/graphics/drawing.py", line 1108, in
    73313 _first_intercept_excluding_children 
    73314 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    73315 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73316 File
    73317 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73318 packages/chimerax/geometry/place.py", line 201, in inverse 
    73319 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    73320 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73321 File
    73322 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73323 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    73324 rinv[:, :] = matrix_inverse(r) 
    73325 ^^^^^^^^^^^^^^^^^ 
    73326 File
    73327 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73328 packages/numpy/linalg/linalg.py", line 561, in inv 
    73329 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    73330 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73331 File
    73332 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73333 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    73334 raise LinAlgError("Singular matrix") 
    73335 numpy.linalg.LinAlgError: Singular matrix 
    73336  
    73337 numpy.linalg.LinAlgError: Singular matrix 
    73338  
    73339 File
    73340 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73341 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    73342 raise LinAlgError("Singular matrix") 
    73343  
    73344 See log for complete Python traceback. 
    73345  
    73346 Traceback (most recent call last): 
    73347 File
    73348 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73349 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    73350 self.session.ui.mouse_modes.mouse_pause_tracking() 
    73351 File
    73352 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73353 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    73354 mouse_pause_tracking 
    73355 self._mouse_pause() 
    73356 File
    73357 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73358 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    73359 m.pause(self._mouse_pause_position) 
    73360 File
    73361 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73362 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    73363 p = self.view.picked_object(x, y) 
    73364 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73365 File
    73366 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73367 packages/chimerax/graphics/view.py", line 838, in picked_object 
    73368 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    73369 beyond, 
    73370 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73371 File
    73372 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73373 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    73374 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    73375 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73376 File
    73377 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73378 packages/chimerax/core/models.py", line 143, in first_intercept 
    73379 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    73380 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73381 File
    73382 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73383 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    73384 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    73385 exclude=exclude) 
    73386 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73387 File
    73388 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73389 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    73390 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    73391 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73392 File
    73393 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73394 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    73395 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    73396 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73397 File
    73398 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73399 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    73400 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    73401 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73402 File
    73403 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73404 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    73405 p = super().first_intercept(mxyz1, mxyz2) 
    73406 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73407 File
    73408 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73409 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    73410 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    73411 exclude=exclude) 
    73412 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73413 File
    73414 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73415 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    73416 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    73417 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73418 File
    73419 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73420 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    73421 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    73422 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73423 File
    73424 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73425 packages/chimerax/graphics/drawing.py", line 1108, in
    73426 _first_intercept_excluding_children 
    73427 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    73428 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73429 File
    73430 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73431 packages/chimerax/geometry/place.py", line 201, in inverse 
    73432 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    73433 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73434 File
    73435 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73436 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    73437 rinv[:, :] = matrix_inverse(r) 
    73438 ^^^^^^^^^^^^^^^^^ 
    73439 File
    73440 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73441 packages/numpy/linalg/linalg.py", line 561, in inv 
    73442 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    73443 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73444 File
    73445 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73446 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    73447 raise LinAlgError("Singular matrix") 
    73448 numpy.linalg.LinAlgError: Singular matrix 
    73449  
    73450 numpy.linalg.LinAlgError: Singular matrix 
    73451  
    73452 File
    73453 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73454 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    73455 raise LinAlgError("Singular matrix") 
    73456  
    73457 See log for complete Python traceback. 
    73458  
    73459 Traceback (most recent call last): 
    73460 File
    73461 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73462 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    73463 self.session.ui.mouse_modes.mouse_pause_tracking() 
    73464 File
    73465 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73466 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    73467 mouse_pause_tracking 
    73468 self._mouse_pause() 
    73469 File
    73470 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73471 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    73472 m.pause(self._mouse_pause_position) 
    73473 File
    73474 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73475 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    73476 p = self.view.picked_object(x, y) 
    73477 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73478 File
    73479 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73480 packages/chimerax/graphics/view.py", line 838, in picked_object 
    73481 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    73482 beyond, 
    73483 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73484 File
    73485 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73486 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    73487 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    73488 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73489 File
    73490 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73491 packages/chimerax/core/models.py", line 143, in first_intercept 
    73492 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    73493 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73494 File
    73495 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73496 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    73497 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    73498 exclude=exclude) 
    73499 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73500 File
    73501 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73502 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    73503 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    73504 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73505 File
    73506 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73507 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    73508 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    73509 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73510 File
    73511 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73512 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    73513 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    73514 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73515 File
    73516 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73517 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    73518 p = super().first_intercept(mxyz1, mxyz2) 
    73519 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73520 File
    73521 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73522 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    73523 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    73524 exclude=exclude) 
    73525 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73526 File
    73527 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73528 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    73529 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    73530 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73531 File
    73532 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73533 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    73534 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    73535 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73536 File
    73537 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73538 packages/chimerax/graphics/drawing.py", line 1108, in
    73539 _first_intercept_excluding_children 
    73540 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    73541 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73542 File
    73543 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73544 packages/chimerax/geometry/place.py", line 201, in inverse 
    73545 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    73546 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73547 File
    73548 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73549 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    73550 rinv[:, :] = matrix_inverse(r) 
    73551 ^^^^^^^^^^^^^^^^^ 
    73552 File
    73553 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73554 packages/numpy/linalg/linalg.py", line 561, in inv 
    73555 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    73556 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73557 File
    73558 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73559 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    73560 raise LinAlgError("Singular matrix") 
    73561 numpy.linalg.LinAlgError: Singular matrix 
    73562  
    73563 numpy.linalg.LinAlgError: Singular matrix 
    73564  
    73565 File
    73566 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73567 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    73568 raise LinAlgError("Singular matrix") 
    73569  
    73570 See log for complete Python traceback. 
    73571  
    73572 Traceback (most recent call last): 
    73573 File
    73574 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73575 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    73576 self.session.ui.mouse_modes.mouse_pause_tracking() 
    73577 File
    73578 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73579 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    73580 mouse_pause_tracking 
    73581 self._mouse_pause() 
    73582 File
    73583 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73584 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    73585 m.pause(self._mouse_pause_position) 
    73586 File
    73587 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73588 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    73589 p = self.view.picked_object(x, y) 
    73590 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73591 File
    73592 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73593 packages/chimerax/graphics/view.py", line 838, in picked_object 
    73594 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    73595 beyond, 
    73596 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73597 File
    73598 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73599 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    73600 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    73601 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73602 File
    73603 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73604 packages/chimerax/core/models.py", line 143, in first_intercept 
    73605 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    73606 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73607 File
    73608 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73609 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    73610 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    73611 exclude=exclude) 
    73612 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73613 File
    73614 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73615 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    73616 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    73617 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73618 File
    73619 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73620 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    73621 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    73622 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73623 File
    73624 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73625 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    73626 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    73627 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73628 File
    73629 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73630 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    73631 p = super().first_intercept(mxyz1, mxyz2) 
    73632 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73633 File
    73634 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73635 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    73636 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    73637 exclude=exclude) 
    73638 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73639 File
    73640 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73641 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    73642 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    73643 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73644 File
    73645 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73646 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    73647 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    73648 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73649 File
    73650 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73651 packages/chimerax/graphics/drawing.py", line 1108, in
    73652 _first_intercept_excluding_children 
    73653 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    73654 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73655 File
    73656 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73657 packages/chimerax/geometry/place.py", line 201, in inverse 
    73658 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    73659 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73660 File
    73661 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73662 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    73663 rinv[:, :] = matrix_inverse(r) 
    73664 ^^^^^^^^^^^^^^^^^ 
    73665 File
    73666 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73667 packages/numpy/linalg/linalg.py", line 561, in inv 
    73668 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    73669 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73670 File
    73671 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73672 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    73673 raise LinAlgError("Singular matrix") 
    73674 numpy.linalg.LinAlgError: Singular matrix 
    73675  
    73676 numpy.linalg.LinAlgError: Singular matrix 
    73677  
    73678 File
    73679 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73680 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    73681 raise LinAlgError("Singular matrix") 
    73682  
    73683 See log for complete Python traceback. 
    73684  
    73685 Traceback (most recent call last): 
    73686 File
    73687 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73688 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    73689 self.session.ui.mouse_modes.mouse_pause_tracking() 
    73690 File
    73691 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73692 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    73693 mouse_pause_tracking 
    73694 self._mouse_pause() 
    73695 File
    73696 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73697 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    73698 m.pause(self._mouse_pause_position) 
    73699 File
    73700 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73701 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    73702 p = self.view.picked_object(x, y) 
    73703 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73704 File
    73705 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73706 packages/chimerax/graphics/view.py", line 838, in picked_object 
    73707 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    73708 beyond, 
    73709 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73710 File
    73711 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73712 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    73713 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    73714 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73715 File
    73716 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73717 packages/chimerax/core/models.py", line 143, in first_intercept 
    73718 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    73719 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73720 File
    73721 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73722 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    73723 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    73724 exclude=exclude) 
    73725 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73726 File
    73727 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73728 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    73729 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    73730 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73731 File
    73732 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73733 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    73734 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    73735 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73736 File
    73737 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73738 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    73739 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    73740 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73741 File
    73742 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73743 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    73744 p = super().first_intercept(mxyz1, mxyz2) 
    73745 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73746 File
    73747 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73748 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    73749 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    73750 exclude=exclude) 
    73751 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73752 File
    73753 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73754 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    73755 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    73756 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73757 File
    73758 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73759 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    73760 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    73761 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73762 File
    73763 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73764 packages/chimerax/graphics/drawing.py", line 1108, in
    73765 _first_intercept_excluding_children 
    73766 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    73767 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73768 File
    73769 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73770 packages/chimerax/geometry/place.py", line 201, in inverse 
    73771 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    73772 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73773 File
    73774 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73775 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    73776 rinv[:, :] = matrix_inverse(r) 
    73777 ^^^^^^^^^^^^^^^^^ 
    73778 File
    73779 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73780 packages/numpy/linalg/linalg.py", line 561, in inv 
    73781 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    73782 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73783 File
    73784 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73785 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    73786 raise LinAlgError("Singular matrix") 
    73787 numpy.linalg.LinAlgError: Singular matrix 
    73788  
    73789 numpy.linalg.LinAlgError: Singular matrix 
    73790  
    73791 File
    73792 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73793 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    73794 raise LinAlgError("Singular matrix") 
    73795  
    73796 See log for complete Python traceback. 
    73797  
    73798 Traceback (most recent call last): 
    73799 File
    73800 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73801 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    73802 self.session.ui.mouse_modes.mouse_pause_tracking() 
    73803 File
    73804 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73805 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    73806 mouse_pause_tracking 
    73807 self._mouse_pause() 
    73808 File
    73809 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73810 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    73811 m.pause(self._mouse_pause_position) 
    73812 File
    73813 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73814 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    73815 p = self.view.picked_object(x, y) 
    73816 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73817 File
    73818 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73819 packages/chimerax/graphics/view.py", line 838, in picked_object 
    73820 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    73821 beyond, 
    73822 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73823 File
    73824 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73825 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    73826 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    73827 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73828 File
    73829 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73830 packages/chimerax/core/models.py", line 143, in first_intercept 
    73831 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    73832 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73833 File
    73834 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73835 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    73836 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    73837 exclude=exclude) 
    73838 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73839 File
    73840 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73841 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    73842 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    73843 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73844 File
    73845 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73846 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    73847 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    73848 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73849 File
    73850 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73851 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    73852 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    73853 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73854 File
    73855 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73856 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    73857 p = super().first_intercept(mxyz1, mxyz2) 
    73858 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73859 File
    73860 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73861 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    73862 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    73863 exclude=exclude) 
    73864 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73865 File
    73866 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73867 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    73868 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    73869 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73870 File
    73871 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73872 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    73873 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    73874 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73875 File
    73876 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73877 packages/chimerax/graphics/drawing.py", line 1108, in
    73878 _first_intercept_excluding_children 
    73879 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    73880 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73881 File
    73882 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73883 packages/chimerax/geometry/place.py", line 201, in inverse 
    73884 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    73885 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73886 File
    73887 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73888 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    73889 rinv[:, :] = matrix_inverse(r) 
    73890 ^^^^^^^^^^^^^^^^^ 
    73891 File
    73892 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73893 packages/numpy/linalg/linalg.py", line 561, in inv 
    73894 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    73895 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73896 File
    73897 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73898 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    73899 raise LinAlgError("Singular matrix") 
    73900 numpy.linalg.LinAlgError: Singular matrix 
    73901  
    73902 numpy.linalg.LinAlgError: Singular matrix 
    73903  
    73904 File
    73905 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73906 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    73907 raise LinAlgError("Singular matrix") 
    73908  
    73909 See log for complete Python traceback. 
    73910  
    73911 Traceback (most recent call last): 
    73912 File
    73913 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73914 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    73915 self.session.ui.mouse_modes.mouse_pause_tracking() 
    73916 File
    73917 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73918 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    73919 mouse_pause_tracking 
    73920 self._mouse_pause() 
    73921 File
    73922 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73923 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    73924 m.pause(self._mouse_pause_position) 
    73925 File
    73926 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73927 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    73928 p = self.view.picked_object(x, y) 
    73929 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73930 File
    73931 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73932 packages/chimerax/graphics/view.py", line 838, in picked_object 
    73933 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    73934 beyond, 
    73935 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73936 File
    73937 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73938 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    73939 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    73940 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73941 File
    73942 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73943 packages/chimerax/core/models.py", line 143, in first_intercept 
    73944 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    73945 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73946 File
    73947 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73948 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    73949 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    73950 exclude=exclude) 
    73951 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73952 File
    73953 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73954 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    73955 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    73956 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73957 File
    73958 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73959 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    73960 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    73961 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73962 File
    73963 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73964 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    73965 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    73966 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73967 File
    73968 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73969 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    73970 p = super().first_intercept(mxyz1, mxyz2) 
    73971 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73972 File
    73973 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73974 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    73975 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    73976 exclude=exclude) 
    73977 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73978 File
    73979 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73980 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    73981 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    73982 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73983 File
    73984 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73985 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    73986 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    73987 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73988 File
    73989 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73990 packages/chimerax/graphics/drawing.py", line 1108, in
    73991 _first_intercept_excluding_children 
    73992 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    73993 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73994 File
    73995 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    73996 packages/chimerax/geometry/place.py", line 201, in inverse 
    73997 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    73998 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    73999 File
    74000 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74001 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    74002 rinv[:, :] = matrix_inverse(r) 
    74003 ^^^^^^^^^^^^^^^^^ 
    74004 File
    74005 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74006 packages/numpy/linalg/linalg.py", line 561, in inv 
    74007 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    74008 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74009 File
    74010 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74011 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    74012 raise LinAlgError("Singular matrix") 
    74013 numpy.linalg.LinAlgError: Singular matrix 
    74014  
    74015 numpy.linalg.LinAlgError: Singular matrix 
    74016  
    74017 File
    74018 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74019 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    74020 raise LinAlgError("Singular matrix") 
    74021  
    74022 See log for complete Python traceback. 
    74023  
    74024 Traceback (most recent call last): 
    74025 File
    74026 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74027 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    74028 self.session.ui.mouse_modes.mouse_pause_tracking() 
    74029 File
    74030 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74031 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    74032 mouse_pause_tracking 
    74033 self._mouse_pause() 
    74034 File
    74035 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74036 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    74037 m.pause(self._mouse_pause_position) 
    74038 File
    74039 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74040 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    74041 p = self.view.picked_object(x, y) 
    74042 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74043 File
    74044 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74045 packages/chimerax/graphics/view.py", line 838, in picked_object 
    74046 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    74047 beyond, 
    74048 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74049 File
    74050 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74051 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    74052 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    74053 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74054 File
    74055 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74056 packages/chimerax/core/models.py", line 143, in first_intercept 
    74057 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    74058 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74059 File
    74060 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74061 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    74062 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    74063 exclude=exclude) 
    74064 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74065 File
    74066 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74067 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    74068 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    74069 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74070 File
    74071 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74072 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    74073 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    74074 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74075 File
    74076 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74077 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    74078 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    74079 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74080 File
    74081 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74082 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    74083 p = super().first_intercept(mxyz1, mxyz2) 
    74084 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74085 File
    74086 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74087 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    74088 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    74089 exclude=exclude) 
    74090 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74091 File
    74092 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74093 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    74094 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    74095 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74096 File
    74097 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74098 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    74099 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    74100 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74101 File
    74102 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74103 packages/chimerax/graphics/drawing.py", line 1108, in
    74104 _first_intercept_excluding_children 
    74105 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    74106 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74107 File
    74108 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74109 packages/chimerax/geometry/place.py", line 201, in inverse 
    74110 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    74111 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74112 File
    74113 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74114 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    74115 rinv[:, :] = matrix_inverse(r) 
    74116 ^^^^^^^^^^^^^^^^^ 
    74117 File
    74118 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74119 packages/numpy/linalg/linalg.py", line 561, in inv 
    74120 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    74121 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74122 File
    74123 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74124 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    74125 raise LinAlgError("Singular matrix") 
    74126 numpy.linalg.LinAlgError: Singular matrix 
    74127  
    74128 numpy.linalg.LinAlgError: Singular matrix 
    74129  
    74130 File
    74131 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74132 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    74133 raise LinAlgError("Singular matrix") 
    74134  
    74135 See log for complete Python traceback. 
    74136  
    74137 Traceback (most recent call last): 
    74138 File
    74139 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74140 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    74141 self.session.ui.mouse_modes.mouse_pause_tracking() 
    74142 File
    74143 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74144 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    74145 mouse_pause_tracking 
    74146 self._mouse_pause() 
    74147 File
    74148 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74149 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    74150 m.pause(self._mouse_pause_position) 
    74151 File
    74152 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74153 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    74154 p = self.view.picked_object(x, y) 
    74155 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74156 File
    74157 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74158 packages/chimerax/graphics/view.py", line 838, in picked_object 
    74159 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    74160 beyond, 
    74161 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74162 File
    74163 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74164 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    74165 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    74166 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74167 File
    74168 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74169 packages/chimerax/core/models.py", line 143, in first_intercept 
    74170 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    74171 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74172 File
    74173 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74174 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    74175 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    74176 exclude=exclude) 
    74177 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74178 File
    74179 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74180 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    74181 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    74182 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74183 File
    74184 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74185 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    74186 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    74187 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74188 File
    74189 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74190 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    74191 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    74192 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74193 File
    74194 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74195 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    74196 p = super().first_intercept(mxyz1, mxyz2) 
    74197 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74198 File
    74199 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74200 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    74201 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    74202 exclude=exclude) 
    74203 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74204 File
    74205 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74206 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    74207 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    74208 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74209 File
    74210 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74211 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    74212 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    74213 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74214 File
    74215 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74216 packages/chimerax/graphics/drawing.py", line 1108, in
    74217 _first_intercept_excluding_children 
    74218 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    74219 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74220 File
    74221 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74222 packages/chimerax/geometry/place.py", line 201, in inverse 
    74223 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    74224 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74225 File
    74226 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74227 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    74228 rinv[:, :] = matrix_inverse(r) 
    74229 ^^^^^^^^^^^^^^^^^ 
    74230 File
    74231 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74232 packages/numpy/linalg/linalg.py", line 561, in inv 
    74233 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    74234 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74235 File
    74236 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74237 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    74238 raise LinAlgError("Singular matrix") 
    74239 numpy.linalg.LinAlgError: Singular matrix 
    74240  
    74241 numpy.linalg.LinAlgError: Singular matrix 
    74242  
    74243 File
    74244 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74245 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    74246 raise LinAlgError("Singular matrix") 
    74247  
    74248 See log for complete Python traceback. 
    74249  
    74250 Traceback (most recent call last): 
    74251 File
    74252 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74253 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    74254 self.session.ui.mouse_modes.mouse_pause_tracking() 
    74255 File
    74256 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74257 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    74258 mouse_pause_tracking 
    74259 self._mouse_pause() 
    74260 File
    74261 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74262 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    74263 m.pause(self._mouse_pause_position) 
    74264 File
    74265 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74266 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    74267 p = self.view.picked_object(x, y) 
    74268 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74269 File
    74270 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74271 packages/chimerax/graphics/view.py", line 838, in picked_object 
    74272 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    74273 beyond, 
    74274 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74275 File
    74276 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74277 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    74278 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    74279 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74280 File
    74281 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74282 packages/chimerax/core/models.py", line 143, in first_intercept 
    74283 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    74284 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74285 File
    74286 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74287 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    74288 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    74289 exclude=exclude) 
    74290 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74291 File
    74292 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74293 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    74294 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    74295 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74296 File
    74297 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74298 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    74299 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    74300 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74301 File
    74302 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74303 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    74304 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    74305 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74306 File
    74307 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74308 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    74309 p = super().first_intercept(mxyz1, mxyz2) 
    74310 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74311 File
    74312 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74313 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    74314 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    74315 exclude=exclude) 
    74316 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74317 File
    74318 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74319 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    74320 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    74321 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74322 File
    74323 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74324 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    74325 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    74326 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74327 File
    74328 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74329 packages/chimerax/graphics/drawing.py", line 1108, in
    74330 _first_intercept_excluding_children 
    74331 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    74332 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74333 File
    74334 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74335 packages/chimerax/geometry/place.py", line 201, in inverse 
    74336 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    74337 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74338 File
    74339 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74340 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    74341 rinv[:, :] = matrix_inverse(r) 
    74342 ^^^^^^^^^^^^^^^^^ 
    74343 File
    74344 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74345 packages/numpy/linalg/linalg.py", line 561, in inv 
    74346 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    74347 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74348 File
    74349 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74350 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    74351 raise LinAlgError("Singular matrix") 
    74352 numpy.linalg.LinAlgError: Singular matrix 
    74353  
    74354 numpy.linalg.LinAlgError: Singular matrix 
    74355  
    74356 File
    74357 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74358 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    74359 raise LinAlgError("Singular matrix") 
    74360  
    74361 See log for complete Python traceback. 
    74362  
    74363 Traceback (most recent call last): 
    74364 File
    74365 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74366 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    74367 self.session.ui.mouse_modes.mouse_pause_tracking() 
    74368 File
    74369 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74370 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    74371 mouse_pause_tracking 
    74372 self._mouse_pause() 
    74373 File
    74374 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74375 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    74376 m.pause(self._mouse_pause_position) 
    74377 File
    74378 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74379 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    74380 p = self.view.picked_object(x, y) 
    74381 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74382 File
    74383 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74384 packages/chimerax/graphics/view.py", line 838, in picked_object 
    74385 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    74386 beyond, 
    74387 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74388 File
    74389 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74390 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    74391 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    74392 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74393 File
    74394 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74395 packages/chimerax/core/models.py", line 143, in first_intercept 
    74396 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    74397 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74398 File
    74399 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74400 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    74401 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    74402 exclude=exclude) 
    74403 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74404 File
    74405 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74406 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    74407 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    74408 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74409 File
    74410 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74411 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    74412 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    74413 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74414 File
    74415 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74416 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    74417 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    74418 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74419 File
    74420 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74421 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    74422 p = super().first_intercept(mxyz1, mxyz2) 
    74423 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74424 File
    74425 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74426 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    74427 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    74428 exclude=exclude) 
    74429 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74430 File
    74431 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74432 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    74433 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    74434 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74435 File
    74436 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74437 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    74438 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    74439 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74440 File
    74441 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74442 packages/chimerax/graphics/drawing.py", line 1108, in
    74443 _first_intercept_excluding_children 
    74444 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    74445 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74446 File
    74447 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74448 packages/chimerax/geometry/place.py", line 201, in inverse 
    74449 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    74450 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74451 File
    74452 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74453 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    74454 rinv[:, :] = matrix_inverse(r) 
    74455 ^^^^^^^^^^^^^^^^^ 
    74456 File
    74457 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74458 packages/numpy/linalg/linalg.py", line 561, in inv 
    74459 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    74460 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74461 File
    74462 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74463 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    74464 raise LinAlgError("Singular matrix") 
    74465 numpy.linalg.LinAlgError: Singular matrix 
    74466  
    74467 numpy.linalg.LinAlgError: Singular matrix 
    74468  
    74469 File
    74470 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74471 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    74472 raise LinAlgError("Singular matrix") 
    74473  
    74474 See log for complete Python traceback. 
    74475  
    74476 Traceback (most recent call last): 
    74477 File
    74478 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74479 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    74480 self.session.ui.mouse_modes.mouse_pause_tracking() 
    74481 File
    74482 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74483 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    74484 mouse_pause_tracking 
    74485 self._mouse_pause() 
    74486 File
    74487 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74488 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    74489 m.pause(self._mouse_pause_position) 
    74490 File
    74491 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74492 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    74493 p = self.view.picked_object(x, y) 
    74494 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74495 File
    74496 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74497 packages/chimerax/graphics/view.py", line 838, in picked_object 
    74498 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    74499 beyond, 
    74500 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74501 File
    74502 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74503 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    74504 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    74505 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74506 File
    74507 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74508 packages/chimerax/core/models.py", line 143, in first_intercept 
    74509 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    74510 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74511 File
    74512 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74513 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    74514 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    74515 exclude=exclude) 
    74516 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74517 File
    74518 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74519 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    74520 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    74521 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74522 File
    74523 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74524 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    74525 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    74526 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74527 File
    74528 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74529 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    74530 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    74531 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74532 File
    74533 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74534 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    74535 p = super().first_intercept(mxyz1, mxyz2) 
    74536 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74537 File
    74538 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74539 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    74540 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    74541 exclude=exclude) 
    74542 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74543 File
    74544 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74545 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    74546 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    74547 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74548 File
    74549 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74550 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    74551 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    74552 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74553 File
    74554 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74555 packages/chimerax/graphics/drawing.py", line 1108, in
    74556 _first_intercept_excluding_children 
    74557 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    74558 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74559 File
    74560 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74561 packages/chimerax/geometry/place.py", line 201, in inverse 
    74562 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    74563 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74564 File
    74565 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74566 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    74567 rinv[:, :] = matrix_inverse(r) 
    74568 ^^^^^^^^^^^^^^^^^ 
    74569 File
    74570 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74571 packages/numpy/linalg/linalg.py", line 561, in inv 
    74572 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    74573 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74574 File
    74575 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74576 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    74577 raise LinAlgError("Singular matrix") 
    74578 numpy.linalg.LinAlgError: Singular matrix 
    74579  
    74580 numpy.linalg.LinAlgError: Singular matrix 
    74581  
    74582 File
    74583 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74584 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    74585 raise LinAlgError("Singular matrix") 
    74586  
    74587 See log for complete Python traceback. 
    74588  
    74589 Traceback (most recent call last): 
    74590 File
    74591 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74592 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    74593 self.session.ui.mouse_modes.mouse_pause_tracking() 
    74594 File
    74595 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74596 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    74597 mouse_pause_tracking 
    74598 self._mouse_pause() 
    74599 File
    74600 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74601 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    74602 m.pause(self._mouse_pause_position) 
    74603 File
    74604 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74605 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    74606 p = self.view.picked_object(x, y) 
    74607 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74608 File
    74609 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74610 packages/chimerax/graphics/view.py", line 838, in picked_object 
    74611 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    74612 beyond, 
    74613 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74614 File
    74615 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74616 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    74617 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    74618 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74619 File
    74620 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74621 packages/chimerax/core/models.py", line 143, in first_intercept 
    74622 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    74623 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74624 File
    74625 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74626 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    74627 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    74628 exclude=exclude) 
    74629 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74630 File
    74631 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74632 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    74633 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    74634 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74635 File
    74636 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74637 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    74638 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    74639 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74640 File
    74641 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74642 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    74643 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    74644 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74645 File
    74646 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74647 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    74648 p = super().first_intercept(mxyz1, mxyz2) 
    74649 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74650 File
    74651 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74652 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    74653 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    74654 exclude=exclude) 
    74655 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74656 File
    74657 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74658 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    74659 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    74660 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74661 File
    74662 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74663 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    74664 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    74665 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74666 File
    74667 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74668 packages/chimerax/graphics/drawing.py", line 1108, in
    74669 _first_intercept_excluding_children 
    74670 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    74671 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74672 File
    74673 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74674 packages/chimerax/geometry/place.py", line 201, in inverse 
    74675 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    74676 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74677 File
    74678 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74679 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    74680 rinv[:, :] = matrix_inverse(r) 
    74681 ^^^^^^^^^^^^^^^^^ 
    74682 File
    74683 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74684 packages/numpy/linalg/linalg.py", line 561, in inv 
    74685 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    74686 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74687 File
    74688 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74689 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    74690 raise LinAlgError("Singular matrix") 
    74691 numpy.linalg.LinAlgError: Singular matrix 
    74692  
    74693 numpy.linalg.LinAlgError: Singular matrix 
    74694  
    74695 File
    74696 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74697 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    74698 raise LinAlgError("Singular matrix") 
    74699  
    74700 See log for complete Python traceback. 
    74701  
    74702 Traceback (most recent call last): 
    74703 File
    74704 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74705 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    74706 self.session.ui.mouse_modes.mouse_pause_tracking() 
    74707 File
    74708 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74709 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    74710 mouse_pause_tracking 
    74711 self._mouse_pause() 
    74712 File
    74713 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74714 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    74715 m.pause(self._mouse_pause_position) 
    74716 File
    74717 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74718 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    74719 p = self.view.picked_object(x, y) 
    74720 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74721 File
    74722 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74723 packages/chimerax/graphics/view.py", line 838, in picked_object 
    74724 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    74725 beyond, 
    74726 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74727 File
    74728 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74729 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    74730 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    74731 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74732 File
    74733 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74734 packages/chimerax/core/models.py", line 143, in first_intercept 
    74735 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    74736 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74737 File
    74738 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74739 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    74740 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    74741 exclude=exclude) 
    74742 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74743 File
    74744 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74745 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    74746 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    74747 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74748 File
    74749 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74750 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    74751 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    74752 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74753 File
    74754 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74755 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    74756 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    74757 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74758 File
    74759 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74760 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    74761 p = super().first_intercept(mxyz1, mxyz2) 
    74762 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74763 File
    74764 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74765 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    74766 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    74767 exclude=exclude) 
    74768 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74769 File
    74770 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74771 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    74772 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    74773 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74774 File
    74775 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74776 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    74777 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    74778 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74779 File
    74780 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74781 packages/chimerax/graphics/drawing.py", line 1108, in
    74782 _first_intercept_excluding_children 
    74783 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    74784 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74785 File
    74786 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74787 packages/chimerax/geometry/place.py", line 201, in inverse 
    74788 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    74789 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74790 File
    74791 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74792 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    74793 rinv[:, :] = matrix_inverse(r) 
    74794 ^^^^^^^^^^^^^^^^^ 
    74795 File
    74796 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74797 packages/numpy/linalg/linalg.py", line 561, in inv 
    74798 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    74799 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74800 File
    74801 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74802 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    74803 raise LinAlgError("Singular matrix") 
    74804 numpy.linalg.LinAlgError: Singular matrix 
    74805  
    74806 numpy.linalg.LinAlgError: Singular matrix 
    74807  
    74808 File
    74809 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74810 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    74811 raise LinAlgError("Singular matrix") 
    74812  
    74813 See log for complete Python traceback. 
    74814  
    74815 Traceback (most recent call last): 
    74816 File
    74817 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74818 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    74819 self.session.ui.mouse_modes.mouse_pause_tracking() 
    74820 File
    74821 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74822 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    74823 mouse_pause_tracking 
    74824 self._mouse_pause() 
    74825 File
    74826 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74827 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    74828 m.pause(self._mouse_pause_position) 
    74829 File
    74830 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74831 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    74832 p = self.view.picked_object(x, y) 
    74833 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74834 File
    74835 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74836 packages/chimerax/graphics/view.py", line 838, in picked_object 
    74837 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    74838 beyond, 
    74839 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74840 File
    74841 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74842 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    74843 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    74844 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74845 File
    74846 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74847 packages/chimerax/core/models.py", line 143, in first_intercept 
    74848 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    74849 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74850 File
    74851 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74852 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    74853 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    74854 exclude=exclude) 
    74855 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74856 File
    74857 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74858 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    74859 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    74860 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74861 File
    74862 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74863 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    74864 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    74865 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74866 File
    74867 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74868 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    74869 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    74870 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74871 File
    74872 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74873 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    74874 p = super().first_intercept(mxyz1, mxyz2) 
    74875 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74876 File
    74877 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74878 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    74879 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    74880 exclude=exclude) 
    74881 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74882 File
    74883 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74884 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    74885 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    74886 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74887 File
    74888 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74889 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    74890 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    74891 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74892 File
    74893 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74894 packages/chimerax/graphics/drawing.py", line 1108, in
    74895 _first_intercept_excluding_children 
    74896 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    74897 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74898 File
    74899 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74900 packages/chimerax/geometry/place.py", line 201, in inverse 
    74901 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    74902 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74903 File
    74904 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74905 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    74906 rinv[:, :] = matrix_inverse(r) 
    74907 ^^^^^^^^^^^^^^^^^ 
    74908 File
    74909 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74910 packages/numpy/linalg/linalg.py", line 561, in inv 
    74911 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    74912 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74913 File
    74914 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74915 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    74916 raise LinAlgError("Singular matrix") 
    74917 numpy.linalg.LinAlgError: Singular matrix 
    74918  
    74919 numpy.linalg.LinAlgError: Singular matrix 
    74920  
    74921 File
    74922 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74923 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    74924 raise LinAlgError("Singular matrix") 
    74925  
    74926 See log for complete Python traceback. 
    74927  
    74928 Traceback (most recent call last): 
    74929 File
    74930 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74931 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    74932 self.session.ui.mouse_modes.mouse_pause_tracking() 
    74933 File
    74934 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74935 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    74936 mouse_pause_tracking 
    74937 self._mouse_pause() 
    74938 File
    74939 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74940 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    74941 m.pause(self._mouse_pause_position) 
    74942 File
    74943 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74944 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    74945 p = self.view.picked_object(x, y) 
    74946 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74947 File
    74948 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74949 packages/chimerax/graphics/view.py", line 838, in picked_object 
    74950 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    74951 beyond, 
    74952 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74953 File
    74954 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74955 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    74956 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    74957 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74958 File
    74959 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74960 packages/chimerax/core/models.py", line 143, in first_intercept 
    74961 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    74962 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74963 File
    74964 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74965 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    74966 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    74967 exclude=exclude) 
    74968 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74969 File
    74970 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74971 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    74972 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    74973 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74974 File
    74975 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74976 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    74977 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    74978 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74979 File
    74980 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74981 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    74982 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    74983 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74984 File
    74985 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74986 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    74987 p = super().first_intercept(mxyz1, mxyz2) 
    74988 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74989 File
    74990 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74991 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    74992 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    74993 exclude=exclude) 
    74994 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    74995 File
    74996 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    74997 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    74998 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    74999 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75000 File
    75001 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75002 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    75003 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    75004 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75005 File
    75006 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75007 packages/chimerax/graphics/drawing.py", line 1108, in
    75008 _first_intercept_excluding_children 
    75009 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    75010 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75011 File
    75012 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75013 packages/chimerax/geometry/place.py", line 201, in inverse 
    75014 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    75015 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75016 File
    75017 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75018 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    75019 rinv[:, :] = matrix_inverse(r) 
    75020 ^^^^^^^^^^^^^^^^^ 
    75021 File
    75022 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75023 packages/numpy/linalg/linalg.py", line 561, in inv 
    75024 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    75025 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75026 File
    75027 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75028 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    75029 raise LinAlgError("Singular matrix") 
    75030 numpy.linalg.LinAlgError: Singular matrix 
    75031  
    75032 numpy.linalg.LinAlgError: Singular matrix 
    75033  
    75034 File
    75035 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75036 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    75037 raise LinAlgError("Singular matrix") 
    75038  
    75039 See log for complete Python traceback. 
    75040  
    75041 Traceback (most recent call last): 
    75042 File
    75043 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75044 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    75045 self.session.ui.mouse_modes.mouse_pause_tracking() 
    75046 File
    75047 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75048 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    75049 mouse_pause_tracking 
    75050 self._mouse_pause() 
    75051 File
    75052 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75053 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    75054 m.pause(self._mouse_pause_position) 
    75055 File
    75056 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75057 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    75058 p = self.view.picked_object(x, y) 
    75059 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75060 File
    75061 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75062 packages/chimerax/graphics/view.py", line 838, in picked_object 
    75063 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    75064 beyond, 
    75065 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75066 File
    75067 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75068 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    75069 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    75070 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75071 File
    75072 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75073 packages/chimerax/core/models.py", line 143, in first_intercept 
    75074 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    75075 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75076 File
    75077 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75078 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    75079 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    75080 exclude=exclude) 
    75081 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75082 File
    75083 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75084 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    75085 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    75086 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75087 File
    75088 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75089 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    75090 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    75091 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75092 File
    75093 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75094 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    75095 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    75096 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75097 File
    75098 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75099 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    75100 p = super().first_intercept(mxyz1, mxyz2) 
    75101 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75102 File
    75103 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75104 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    75105 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    75106 exclude=exclude) 
    75107 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75108 File
    75109 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75110 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    75111 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    75112 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75113 File
    75114 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75115 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    75116 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    75117 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75118 File
    75119 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75120 packages/chimerax/graphics/drawing.py", line 1108, in
    75121 _first_intercept_excluding_children 
    75122 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    75123 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75124 File
    75125 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75126 packages/chimerax/geometry/place.py", line 201, in inverse 
    75127 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    75128 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75129 File
    75130 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75131 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    75132 rinv[:, :] = matrix_inverse(r) 
    75133 ^^^^^^^^^^^^^^^^^ 
    75134 File
    75135 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75136 packages/numpy/linalg/linalg.py", line 561, in inv 
    75137 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    75138 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75139 File
    75140 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75141 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    75142 raise LinAlgError("Singular matrix") 
    75143 numpy.linalg.LinAlgError: Singular matrix 
    75144  
    75145 numpy.linalg.LinAlgError: Singular matrix 
    75146  
    75147 File
    75148 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75149 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    75150 raise LinAlgError("Singular matrix") 
    75151  
    75152 See log for complete Python traceback. 
    75153  
    75154 Traceback (most recent call last): 
    75155 File
    75156 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75157 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    75158 self.session.ui.mouse_modes.mouse_pause_tracking() 
    75159 File
    75160 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75161 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    75162 mouse_pause_tracking 
    75163 self._mouse_pause() 
    75164 File
    75165 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75166 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    75167 m.pause(self._mouse_pause_position) 
    75168 File
    75169 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75170 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    75171 p = self.view.picked_object(x, y) 
    75172 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75173 File
    75174 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75175 packages/chimerax/graphics/view.py", line 838, in picked_object 
    75176 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    75177 beyond, 
    75178 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75179 File
    75180 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75181 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    75182 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    75183 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75184 File
    75185 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75186 packages/chimerax/core/models.py", line 143, in first_intercept 
    75187 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    75188 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75189 File
    75190 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75191 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    75192 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    75193 exclude=exclude) 
    75194 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75195 File
    75196 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75197 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    75198 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    75199 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75200 File
    75201 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75202 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    75203 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    75204 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75205 File
    75206 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75207 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    75208 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    75209 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75210 File
    75211 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75212 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    75213 p = super().first_intercept(mxyz1, mxyz2) 
    75214 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75215 File
    75216 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75217 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    75218 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    75219 exclude=exclude) 
    75220 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75221 File
    75222 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75223 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    75224 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    75225 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75226 File
    75227 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75228 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    75229 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    75230 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75231 File
    75232 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75233 packages/chimerax/graphics/drawing.py", line 1108, in
    75234 _first_intercept_excluding_children 
    75235 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    75236 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75237 File
    75238 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75239 packages/chimerax/geometry/place.py", line 201, in inverse 
    75240 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    75241 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75242 File
    75243 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75244 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    75245 rinv[:, :] = matrix_inverse(r) 
    75246 ^^^^^^^^^^^^^^^^^ 
    75247 File
    75248 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75249 packages/numpy/linalg/linalg.py", line 561, in inv 
    75250 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    75251 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75252 File
    75253 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75254 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    75255 raise LinAlgError("Singular matrix") 
    75256 numpy.linalg.LinAlgError: Singular matrix 
    75257  
    75258 numpy.linalg.LinAlgError: Singular matrix 
    75259  
    75260 File
    75261 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75262 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    75263 raise LinAlgError("Singular matrix") 
    75264  
    75265 See log for complete Python traceback. 
    75266  
    75267 Traceback (most recent call last): 
    75268 File
    75269 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75270 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    75271 self.session.ui.mouse_modes.mouse_pause_tracking() 
    75272 File
    75273 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75274 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    75275 mouse_pause_tracking 
    75276 self._mouse_pause() 
    75277 File
    75278 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75279 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    75280 m.pause(self._mouse_pause_position) 
    75281 File
    75282 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75283 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    75284 p = self.view.picked_object(x, y) 
    75285 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75286 File
    75287 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75288 packages/chimerax/graphics/view.py", line 838, in picked_object 
    75289 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    75290 beyond, 
    75291 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75292 File
    75293 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75294 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    75295 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    75296 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75297 File
    75298 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75299 packages/chimerax/core/models.py", line 143, in first_intercept 
    75300 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    75301 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75302 File
    75303 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75304 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    75305 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    75306 exclude=exclude) 
    75307 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75308 File
    75309 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75310 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    75311 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    75312 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75313 File
    75314 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75315 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    75316 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    75317 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75318 File
    75319 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75320 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    75321 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    75322 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75323 File
    75324 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75325 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    75326 p = super().first_intercept(mxyz1, mxyz2) 
    75327 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75328 File
    75329 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75330 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    75331 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    75332 exclude=exclude) 
    75333 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75334 File
    75335 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75336 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    75337 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    75338 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75339 File
    75340 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75341 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    75342 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    75343 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75344 File
    75345 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75346 packages/chimerax/graphics/drawing.py", line 1108, in
    75347 _first_intercept_excluding_children 
    75348 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    75349 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75350 File
    75351 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75352 packages/chimerax/geometry/place.py", line 201, in inverse 
    75353 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    75354 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75355 File
    75356 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75357 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    75358 rinv[:, :] = matrix_inverse(r) 
    75359 ^^^^^^^^^^^^^^^^^ 
    75360 File
    75361 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75362 packages/numpy/linalg/linalg.py", line 561, in inv 
    75363 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    75364 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75365 File
    75366 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75367 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    75368 raise LinAlgError("Singular matrix") 
    75369 numpy.linalg.LinAlgError: Singular matrix 
    75370  
    75371 numpy.linalg.LinAlgError: Singular matrix 
    75372  
    75373 File
    75374 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75375 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    75376 raise LinAlgError("Singular matrix") 
    75377  
    75378 See log for complete Python traceback. 
    75379  
    75380 Traceback (most recent call last): 
    75381 File
    75382 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75383 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    75384 self.session.ui.mouse_modes.mouse_pause_tracking() 
    75385 File
    75386 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75387 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    75388 mouse_pause_tracking 
    75389 self._mouse_pause() 
    75390 File
    75391 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75392 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    75393 m.pause(self._mouse_pause_position) 
    75394 File
    75395 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75396 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    75397 p = self.view.picked_object(x, y) 
    75398 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75399 File
    75400 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75401 packages/chimerax/graphics/view.py", line 838, in picked_object 
    75402 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    75403 beyond, 
    75404 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75405 File
    75406 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75407 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    75408 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    75409 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75410 File
    75411 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75412 packages/chimerax/core/models.py", line 143, in first_intercept 
    75413 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    75414 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75415 File
    75416 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75417 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    75418 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    75419 exclude=exclude) 
    75420 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75421 File
    75422 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75423 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    75424 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    75425 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75426 File
    75427 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75428 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    75429 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    75430 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75431 File
    75432 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75433 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    75434 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    75435 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75436 File
    75437 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75438 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    75439 p = super().first_intercept(mxyz1, mxyz2) 
    75440 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75441 File
    75442 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75443 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    75444 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    75445 exclude=exclude) 
    75446 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75447 File
    75448 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75449 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    75450 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    75451 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75452 File
    75453 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75454 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    75455 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    75456 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75457 File
    75458 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75459 packages/chimerax/graphics/drawing.py", line 1108, in
    75460 _first_intercept_excluding_children 
    75461 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    75462 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75463 File
    75464 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75465 packages/chimerax/geometry/place.py", line 201, in inverse 
    75466 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    75467 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75468 File
    75469 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75470 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    75471 rinv[:, :] = matrix_inverse(r) 
    75472 ^^^^^^^^^^^^^^^^^ 
    75473 File
    75474 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75475 packages/numpy/linalg/linalg.py", line 561, in inv 
    75476 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    75477 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75478 File
    75479 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75480 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    75481 raise LinAlgError("Singular matrix") 
    75482 numpy.linalg.LinAlgError: Singular matrix 
    75483  
    75484 numpy.linalg.LinAlgError: Singular matrix 
    75485  
    75486 File
    75487 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75488 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    75489 raise LinAlgError("Singular matrix") 
    75490  
    75491 See log for complete Python traceback. 
    75492  
    75493 Traceback (most recent call last): 
    75494 File
    75495 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75496 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    75497 self.session.ui.mouse_modes.mouse_pause_tracking() 
    75498 File
    75499 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75500 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    75501 mouse_pause_tracking 
    75502 self._mouse_pause() 
    75503 File
    75504 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75505 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    75506 m.pause(self._mouse_pause_position) 
    75507 File
    75508 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75509 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    75510 p = self.view.picked_object(x, y) 
    75511 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75512 File
    75513 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75514 packages/chimerax/graphics/view.py", line 838, in picked_object 
    75515 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    75516 beyond, 
    75517 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75518 File
    75519 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75520 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    75521 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    75522 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75523 File
    75524 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75525 packages/chimerax/core/models.py", line 143, in first_intercept 
    75526 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    75527 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75528 File
    75529 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75530 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    75531 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    75532 exclude=exclude) 
    75533 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75534 File
    75535 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75536 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    75537 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    75538 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75539 File
    75540 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75541 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    75542 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    75543 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75544 File
    75545 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75546 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    75547 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    75548 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75549 File
    75550 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75551 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    75552 p = super().first_intercept(mxyz1, mxyz2) 
    75553 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75554 File
    75555 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75556 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    75557 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    75558 exclude=exclude) 
    75559 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75560 File
    75561 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75562 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    75563 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    75564 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75565 File
    75566 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75567 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    75568 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    75569 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75570 File
    75571 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75572 packages/chimerax/graphics/drawing.py", line 1108, in
    75573 _first_intercept_excluding_children 
    75574 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    75575 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75576 File
    75577 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75578 packages/chimerax/geometry/place.py", line 201, in inverse 
    75579 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    75580 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75581 File
    75582 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75583 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    75584 rinv[:, :] = matrix_inverse(r) 
    75585 ^^^^^^^^^^^^^^^^^ 
    75586 File
    75587 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75588 packages/numpy/linalg/linalg.py", line 561, in inv 
    75589 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    75590 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75591 File
    75592 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75593 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    75594 raise LinAlgError("Singular matrix") 
    75595 numpy.linalg.LinAlgError: Singular matrix 
    75596  
    75597 numpy.linalg.LinAlgError: Singular matrix 
    75598  
    75599 File
    75600 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75601 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    75602 raise LinAlgError("Singular matrix") 
    75603  
    75604 See log for complete Python traceback. 
    75605  
    75606 Traceback (most recent call last): 
    75607 File
    75608 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75609 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    75610 self.session.ui.mouse_modes.mouse_pause_tracking() 
    75611 File
    75612 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75613 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    75614 mouse_pause_tracking 
    75615 self._mouse_pause() 
    75616 File
    75617 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75618 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    75619 m.pause(self._mouse_pause_position) 
    75620 File
    75621 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75622 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    75623 p = self.view.picked_object(x, y) 
    75624 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75625 File
    75626 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75627 packages/chimerax/graphics/view.py", line 838, in picked_object 
    75628 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    75629 beyond, 
    75630 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75631 File
    75632 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75633 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    75634 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    75635 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75636 File
    75637 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75638 packages/chimerax/core/models.py", line 143, in first_intercept 
    75639 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    75640 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75641 File
    75642 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75643 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    75644 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    75645 exclude=exclude) 
    75646 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75647 File
    75648 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75649 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    75650 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    75651 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75652 File
    75653 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75654 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    75655 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    75656 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75657 File
    75658 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75659 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    75660 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    75661 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75662 File
    75663 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75664 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    75665 p = super().first_intercept(mxyz1, mxyz2) 
    75666 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75667 File
    75668 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75669 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    75670 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    75671 exclude=exclude) 
    75672 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75673 File
    75674 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75675 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    75676 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    75677 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75678 File
    75679 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75680 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    75681 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    75682 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75683 File
    75684 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75685 packages/chimerax/graphics/drawing.py", line 1108, in
    75686 _first_intercept_excluding_children 
    75687 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    75688 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75689 File
    75690 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75691 packages/chimerax/geometry/place.py", line 201, in inverse 
    75692 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    75693 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75694 File
    75695 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75696 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    75697 rinv[:, :] = matrix_inverse(r) 
    75698 ^^^^^^^^^^^^^^^^^ 
    75699 File
    75700 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75701 packages/numpy/linalg/linalg.py", line 561, in inv 
    75702 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    75703 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75704 File
    75705 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75706 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    75707 raise LinAlgError("Singular matrix") 
    75708 numpy.linalg.LinAlgError: Singular matrix 
    75709  
    75710 numpy.linalg.LinAlgError: Singular matrix 
    75711  
    75712 File
    75713 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75714 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    75715 raise LinAlgError("Singular matrix") 
    75716  
    75717 See log for complete Python traceback. 
    75718  
    75719 Traceback (most recent call last): 
    75720 File
    75721 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75722 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    75723 self.session.ui.mouse_modes.mouse_pause_tracking() 
    75724 File
    75725 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75726 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    75727 mouse_pause_tracking 
    75728 self._mouse_pause() 
    75729 File
    75730 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75731 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    75732 m.pause(self._mouse_pause_position) 
    75733 File
    75734 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75735 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    75736 p = self.view.picked_object(x, y) 
    75737 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75738 File
    75739 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75740 packages/chimerax/graphics/view.py", line 838, in picked_object 
    75741 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    75742 beyond, 
    75743 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75744 File
    75745 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75746 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    75747 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    75748 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75749 File
    75750 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75751 packages/chimerax/core/models.py", line 143, in first_intercept 
    75752 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    75753 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75754 File
    75755 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75756 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    75757 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    75758 exclude=exclude) 
    75759 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75760 File
    75761 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75762 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    75763 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    75764 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75765 File
    75766 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75767 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    75768 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    75769 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75770 File
    75771 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75772 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    75773 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    75774 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75775 File
    75776 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75777 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    75778 p = super().first_intercept(mxyz1, mxyz2) 
    75779 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75780 File
    75781 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75782 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    75783 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    75784 exclude=exclude) 
    75785 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75786 File
    75787 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75788 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    75789 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    75790 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75791 File
    75792 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75793 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    75794 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    75795 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75796 File
    75797 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75798 packages/chimerax/graphics/drawing.py", line 1108, in
    75799 _first_intercept_excluding_children 
    75800 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    75801 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75802 File
    75803 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75804 packages/chimerax/geometry/place.py", line 201, in inverse 
    75805 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    75806 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75807 File
    75808 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75809 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    75810 rinv[:, :] = matrix_inverse(r) 
    75811 ^^^^^^^^^^^^^^^^^ 
    75812 File
    75813 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75814 packages/numpy/linalg/linalg.py", line 561, in inv 
    75815 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    75816 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75817 File
    75818 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75819 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    75820 raise LinAlgError("Singular matrix") 
    75821 numpy.linalg.LinAlgError: Singular matrix 
    75822  
    75823 numpy.linalg.LinAlgError: Singular matrix 
    75824  
    75825 File
    75826 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75827 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    75828 raise LinAlgError("Singular matrix") 
    75829  
    75830 See log for complete Python traceback. 
    75831  
    75832 Traceback (most recent call last): 
    75833 File
    75834 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75835 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    75836 self.session.ui.mouse_modes.mouse_pause_tracking() 
    75837 File
    75838 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75839 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    75840 mouse_pause_tracking 
    75841 self._mouse_pause() 
    75842 File
    75843 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75844 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    75845 m.pause(self._mouse_pause_position) 
    75846 File
    75847 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75848 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    75849 p = self.view.picked_object(x, y) 
    75850 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75851 File
    75852 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75853 packages/chimerax/graphics/view.py", line 838, in picked_object 
    75854 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    75855 beyond, 
    75856 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75857 File
    75858 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75859 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    75860 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    75861 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75862 File
    75863 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75864 packages/chimerax/core/models.py", line 143, in first_intercept 
    75865 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    75866 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75867 File
    75868 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75869 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    75870 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    75871 exclude=exclude) 
    75872 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75873 File
    75874 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75875 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    75876 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    75877 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75878 File
    75879 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75880 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    75881 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    75882 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75883 File
    75884 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75885 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    75886 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    75887 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75888 File
    75889 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75890 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    75891 p = super().first_intercept(mxyz1, mxyz2) 
    75892 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75893 File
    75894 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75895 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    75896 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    75897 exclude=exclude) 
    75898 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75899 File
    75900 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75901 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    75902 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    75903 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75904 File
    75905 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75906 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    75907 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    75908 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75909 File
    75910 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75911 packages/chimerax/graphics/drawing.py", line 1108, in
    75912 _first_intercept_excluding_children 
    75913 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    75914 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75915 File
    75916 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75917 packages/chimerax/geometry/place.py", line 201, in inverse 
    75918 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    75919 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75920 File
    75921 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75922 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    75923 rinv[:, :] = matrix_inverse(r) 
    75924 ^^^^^^^^^^^^^^^^^ 
    75925 File
    75926 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75927 packages/numpy/linalg/linalg.py", line 561, in inv 
    75928 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    75929 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75930 File
    75931 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75932 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    75933 raise LinAlgError("Singular matrix") 
    75934 numpy.linalg.LinAlgError: Singular matrix 
    75935  
    75936 numpy.linalg.LinAlgError: Singular matrix 
    75937  
    75938 File
    75939 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75940 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    75941 raise LinAlgError("Singular matrix") 
    75942  
    75943 See log for complete Python traceback. 
    75944  
    75945 Traceback (most recent call last): 
    75946 File
    75947 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75948 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    75949 self.session.ui.mouse_modes.mouse_pause_tracking() 
    75950 File
    75951 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75952 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    75953 mouse_pause_tracking 
    75954 self._mouse_pause() 
    75955 File
    75956 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75957 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    75958 m.pause(self._mouse_pause_position) 
    75959 File
    75960 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75961 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    75962 p = self.view.picked_object(x, y) 
    75963 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75964 File
    75965 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75966 packages/chimerax/graphics/view.py", line 838, in picked_object 
    75967 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    75968 beyond, 
    75969 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75970 File
    75971 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75972 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    75973 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    75974 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75975 File
    75976 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75977 packages/chimerax/core/models.py", line 143, in first_intercept 
    75978 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    75979 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75980 File
    75981 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75982 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    75983 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    75984 exclude=exclude) 
    75985 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75986 File
    75987 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75988 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    75989 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    75990 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75991 File
    75992 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75993 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    75994 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    75995 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    75996 File
    75997 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    75998 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    75999 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    76000 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76001 File
    76002 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76003 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    76004 p = super().first_intercept(mxyz1, mxyz2) 
    76005 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76006 File
    76007 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76008 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    76009 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    76010 exclude=exclude) 
    76011 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76012 File
    76013 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76014 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    76015 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    76016 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76017 File
    76018 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76019 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    76020 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    76021 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76022 File
    76023 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76024 packages/chimerax/graphics/drawing.py", line 1108, in
    76025 _first_intercept_excluding_children 
    76026 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    76027 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76028 File
    76029 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76030 packages/chimerax/geometry/place.py", line 201, in inverse 
    76031 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    76032 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76033 File
    76034 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76035 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    76036 rinv[:, :] = matrix_inverse(r) 
    76037 ^^^^^^^^^^^^^^^^^ 
    76038 File
    76039 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76040 packages/numpy/linalg/linalg.py", line 561, in inv 
    76041 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    76042 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76043 File
    76044 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76045 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    76046 raise LinAlgError("Singular matrix") 
    76047 numpy.linalg.LinAlgError: Singular matrix 
    76048  
    76049 numpy.linalg.LinAlgError: Singular matrix 
    76050  
    76051 File
    76052 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76053 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    76054 raise LinAlgError("Singular matrix") 
    76055  
    76056 See log for complete Python traceback. 
    76057  
    76058 Traceback (most recent call last): 
    76059 File
    76060 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76061 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    76062 self.session.ui.mouse_modes.mouse_pause_tracking() 
    76063 File
    76064 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76065 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    76066 mouse_pause_tracking 
    76067 self._mouse_pause() 
    76068 File
    76069 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76070 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    76071 m.pause(self._mouse_pause_position) 
    76072 File
    76073 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76074 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    76075 p = self.view.picked_object(x, y) 
    76076 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76077 File
    76078 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76079 packages/chimerax/graphics/view.py", line 838, in picked_object 
    76080 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    76081 beyond, 
    76082 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76083 File
    76084 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76085 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    76086 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    76087 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76088 File
    76089 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76090 packages/chimerax/core/models.py", line 143, in first_intercept 
    76091 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    76092 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76093 File
    76094 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76095 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    76096 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    76097 exclude=exclude) 
    76098 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76099 File
    76100 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76101 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    76102 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    76103 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76104 File
    76105 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76106 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    76107 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    76108 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76109 File
    76110 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76111 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    76112 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    76113 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76114 File
    76115 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76116 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    76117 p = super().first_intercept(mxyz1, mxyz2) 
    76118 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76119 File
    76120 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76121 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    76122 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    76123 exclude=exclude) 
    76124 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76125 File
    76126 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76127 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    76128 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    76129 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76130 File
    76131 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76132 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    76133 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    76134 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76135 File
    76136 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76137 packages/chimerax/graphics/drawing.py", line 1108, in
    76138 _first_intercept_excluding_children 
    76139 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    76140 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76141 File
    76142 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76143 packages/chimerax/geometry/place.py", line 201, in inverse 
    76144 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    76145 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76146 File
    76147 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76148 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    76149 rinv[:, :] = matrix_inverse(r) 
    76150 ^^^^^^^^^^^^^^^^^ 
    76151 File
    76152 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76153 packages/numpy/linalg/linalg.py", line 561, in inv 
    76154 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    76155 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76156 File
    76157 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76158 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    76159 raise LinAlgError("Singular matrix") 
    76160 numpy.linalg.LinAlgError: Singular matrix 
    76161  
    76162 numpy.linalg.LinAlgError: Singular matrix 
    76163  
    76164 File
    76165 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76166 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    76167 raise LinAlgError("Singular matrix") 
    76168  
    76169 See log for complete Python traceback. 
    76170  
    76171 Traceback (most recent call last): 
    76172 File
    76173 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76174 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    76175 self.session.ui.mouse_modes.mouse_pause_tracking() 
    76176 File
    76177 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76178 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    76179 mouse_pause_tracking 
    76180 self._mouse_pause() 
    76181 File
    76182 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76183 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    76184 m.pause(self._mouse_pause_position) 
    76185 File
    76186 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76187 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    76188 p = self.view.picked_object(x, y) 
    76189 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76190 File
    76191 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76192 packages/chimerax/graphics/view.py", line 838, in picked_object 
    76193 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    76194 beyond, 
    76195 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76196 File
    76197 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76198 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    76199 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    76200 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76201 File
    76202 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76203 packages/chimerax/core/models.py", line 143, in first_intercept 
    76204 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    76205 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76206 File
    76207 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76208 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    76209 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    76210 exclude=exclude) 
    76211 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76212 File
    76213 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76214 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    76215 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    76216 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76217 File
    76218 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76219 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    76220 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    76221 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76222 File
    76223 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76224 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    76225 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    76226 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76227 File
    76228 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76229 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    76230 p = super().first_intercept(mxyz1, mxyz2) 
    76231 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76232 File
    76233 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76234 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    76235 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    76236 exclude=exclude) 
    76237 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76238 File
    76239 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76240 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    76241 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    76242 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76243 File
    76244 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76245 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    76246 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    76247 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76248 File
    76249 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76250 packages/chimerax/graphics/drawing.py", line 1108, in
    76251 _first_intercept_excluding_children 
    76252 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    76253 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76254 File
    76255 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76256 packages/chimerax/geometry/place.py", line 201, in inverse 
    76257 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    76258 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76259 File
    76260 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76261 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    76262 rinv[:, :] = matrix_inverse(r) 
    76263 ^^^^^^^^^^^^^^^^^ 
    76264 File
    76265 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76266 packages/numpy/linalg/linalg.py", line 561, in inv 
    76267 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    76268 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76269 File
    76270 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76271 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    76272 raise LinAlgError("Singular matrix") 
    76273 numpy.linalg.LinAlgError: Singular matrix 
    76274  
    76275 numpy.linalg.LinAlgError: Singular matrix 
    76276  
    76277 File
    76278 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76279 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    76280 raise LinAlgError("Singular matrix") 
    76281  
    76282 See log for complete Python traceback. 
    76283  
    76284 Traceback (most recent call last): 
    76285 File
    76286 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76287 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    76288 self.session.ui.mouse_modes.mouse_pause_tracking() 
    76289 File
    76290 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76291 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    76292 mouse_pause_tracking 
    76293 self._mouse_pause() 
    76294 File
    76295 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76296 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    76297 m.pause(self._mouse_pause_position) 
    76298 File
    76299 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76300 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    76301 p = self.view.picked_object(x, y) 
    76302 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76303 File
    76304 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76305 packages/chimerax/graphics/view.py", line 838, in picked_object 
    76306 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    76307 beyond, 
    76308 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76309 File
    76310 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76311 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    76312 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    76313 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76314 File
    76315 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76316 packages/chimerax/core/models.py", line 143, in first_intercept 
    76317 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    76318 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76319 File
    76320 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76321 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    76322 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    76323 exclude=exclude) 
    76324 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76325 File
    76326 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76327 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    76328 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    76329 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76330 File
    76331 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76332 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    76333 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    76334 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76335 File
    76336 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76337 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    76338 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    76339 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76340 File
    76341 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76342 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    76343 p = super().first_intercept(mxyz1, mxyz2) 
    76344 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76345 File
    76346 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76347 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    76348 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    76349 exclude=exclude) 
    76350 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76351 File
    76352 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76353 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    76354 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    76355 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76356 File
    76357 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76358 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    76359 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    76360 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76361 File
    76362 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76363 packages/chimerax/graphics/drawing.py", line 1108, in
    76364 _first_intercept_excluding_children 
    76365 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    76366 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76367 File
    76368 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76369 packages/chimerax/geometry/place.py", line 201, in inverse 
    76370 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    76371 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76372 File
    76373 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76374 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    76375 rinv[:, :] = matrix_inverse(r) 
    76376 ^^^^^^^^^^^^^^^^^ 
    76377 File
    76378 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76379 packages/numpy/linalg/linalg.py", line 561, in inv 
    76380 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    76381 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76382 File
    76383 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76384 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    76385 raise LinAlgError("Singular matrix") 
    76386 numpy.linalg.LinAlgError: Singular matrix 
    76387  
    76388 numpy.linalg.LinAlgError: Singular matrix 
    76389  
    76390 File
    76391 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76392 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    76393 raise LinAlgError("Singular matrix") 
    76394  
    76395 See log for complete Python traceback. 
    76396  
    76397 Traceback (most recent call last): 
    76398 File
    76399 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76400 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    76401 self.session.ui.mouse_modes.mouse_pause_tracking() 
    76402 File
    76403 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76404 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    76405 mouse_pause_tracking 
    76406 self._mouse_pause() 
    76407 File
    76408 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76409 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    76410 m.pause(self._mouse_pause_position) 
    76411 File
    76412 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76413 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    76414 p = self.view.picked_object(x, y) 
    76415 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76416 File
    76417 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76418 packages/chimerax/graphics/view.py", line 838, in picked_object 
    76419 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    76420 beyond, 
    76421 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76422 File
    76423 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76424 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    76425 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    76426 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76427 File
    76428 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76429 packages/chimerax/core/models.py", line 143, in first_intercept 
    76430 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    76431 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76432 File
    76433 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76434 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    76435 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    76436 exclude=exclude) 
    76437 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76438 File
    76439 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76440 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    76441 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    76442 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76443 File
    76444 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76445 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    76446 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    76447 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76448 File
    76449 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76450 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    76451 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    76452 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76453 File
    76454 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76455 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    76456 p = super().first_intercept(mxyz1, mxyz2) 
    76457 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76458 File
    76459 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76460 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    76461 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    76462 exclude=exclude) 
    76463 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76464 File
    76465 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76466 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    76467 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    76468 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76469 File
    76470 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76471 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    76472 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    76473 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76474 File
    76475 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76476 packages/chimerax/graphics/drawing.py", line 1108, in
    76477 _first_intercept_excluding_children 
    76478 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    76479 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76480 File
    76481 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76482 packages/chimerax/geometry/place.py", line 201, in inverse 
    76483 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    76484 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76485 File
    76486 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76487 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    76488 rinv[:, :] = matrix_inverse(r) 
    76489 ^^^^^^^^^^^^^^^^^ 
    76490 File
    76491 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76492 packages/numpy/linalg/linalg.py", line 561, in inv 
    76493 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    76494 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76495 File
    76496 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76497 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    76498 raise LinAlgError("Singular matrix") 
    76499 numpy.linalg.LinAlgError: Singular matrix 
    76500  
    76501 numpy.linalg.LinAlgError: Singular matrix 
    76502  
    76503 File
    76504 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76505 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    76506 raise LinAlgError("Singular matrix") 
    76507  
    76508 See log for complete Python traceback. 
    76509  
    76510 Traceback (most recent call last): 
    76511 File
    76512 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76513 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    76514 self.session.ui.mouse_modes.mouse_pause_tracking() 
    76515 File
    76516 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76517 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    76518 mouse_pause_tracking 
    76519 self._mouse_pause() 
    76520 File
    76521 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76522 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    76523 m.pause(self._mouse_pause_position) 
    76524 File
    76525 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76526 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    76527 p = self.view.picked_object(x, y) 
    76528 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76529 File
    76530 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76531 packages/chimerax/graphics/view.py", line 838, in picked_object 
    76532 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    76533 beyond, 
    76534 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76535 File
    76536 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76537 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    76538 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    76539 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76540 File
    76541 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76542 packages/chimerax/core/models.py", line 143, in first_intercept 
    76543 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    76544 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76545 File
    76546 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76547 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    76548 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    76549 exclude=exclude) 
    76550 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76551 File
    76552 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76553 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    76554 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    76555 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76556 File
    76557 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76558 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    76559 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    76560 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76561 File
    76562 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76563 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    76564 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    76565 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76566 File
    76567 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76568 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    76569 p = super().first_intercept(mxyz1, mxyz2) 
    76570 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76571 File
    76572 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76573 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    76574 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    76575 exclude=exclude) 
    76576 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76577 File
    76578 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76579 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    76580 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    76581 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76582 File
    76583 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76584 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    76585 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    76586 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76587 File
    76588 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76589 packages/chimerax/graphics/drawing.py", line 1108, in
    76590 _first_intercept_excluding_children 
    76591 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    76592 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76593 File
    76594 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76595 packages/chimerax/geometry/place.py", line 201, in inverse 
    76596 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    76597 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76598 File
    76599 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76600 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    76601 rinv[:, :] = matrix_inverse(r) 
    76602 ^^^^^^^^^^^^^^^^^ 
    76603 File
    76604 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76605 packages/numpy/linalg/linalg.py", line 561, in inv 
    76606 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    76607 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76608 File
    76609 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76610 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    76611 raise LinAlgError("Singular matrix") 
    76612 numpy.linalg.LinAlgError: Singular matrix 
    76613  
    76614 numpy.linalg.LinAlgError: Singular matrix 
    76615  
    76616 File
    76617 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76618 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    76619 raise LinAlgError("Singular matrix") 
    76620  
    76621 See log for complete Python traceback. 
    76622  
    76623 Traceback (most recent call last): 
    76624 File
    76625 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76626 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    76627 self.session.ui.mouse_modes.mouse_pause_tracking() 
    76628 File
    76629 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76630 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    76631 mouse_pause_tracking 
    76632 self._mouse_pause() 
    76633 File
    76634 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76635 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    76636 m.pause(self._mouse_pause_position) 
    76637 File
    76638 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76639 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    76640 p = self.view.picked_object(x, y) 
    76641 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76642 File
    76643 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76644 packages/chimerax/graphics/view.py", line 838, in picked_object 
    76645 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    76646 beyond, 
    76647 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76648 File
    76649 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76650 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    76651 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    76652 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76653 File
    76654 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76655 packages/chimerax/core/models.py", line 143, in first_intercept 
    76656 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    76657 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76658 File
    76659 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76660 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    76661 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    76662 exclude=exclude) 
    76663 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76664 File
    76665 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76666 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    76667 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    76668 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76669 File
    76670 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76671 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    76672 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    76673 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76674 File
    76675 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76676 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    76677 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    76678 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76679 File
    76680 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76681 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    76682 p = super().first_intercept(mxyz1, mxyz2) 
    76683 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76684 File
    76685 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76686 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    76687 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    76688 exclude=exclude) 
    76689 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76690 File
    76691 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76692 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    76693 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    76694 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76695 File
    76696 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76697 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    76698 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    76699 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76700 File
    76701 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76702 packages/chimerax/graphics/drawing.py", line 1108, in
    76703 _first_intercept_excluding_children 
    76704 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    76705 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76706 File
    76707 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76708 packages/chimerax/geometry/place.py", line 201, in inverse 
    76709 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    76710 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76711 File
    76712 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76713 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    76714 rinv[:, :] = matrix_inverse(r) 
    76715 ^^^^^^^^^^^^^^^^^ 
    76716 File
    76717 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76718 packages/numpy/linalg/linalg.py", line 561, in inv 
    76719 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    76720 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76721 File
    76722 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76723 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    76724 raise LinAlgError("Singular matrix") 
    76725 numpy.linalg.LinAlgError: Singular matrix 
    76726  
    76727 numpy.linalg.LinAlgError: Singular matrix 
    76728  
    76729 File
    76730 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76731 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    76732 raise LinAlgError("Singular matrix") 
    76733  
    76734 See log for complete Python traceback. 
    76735  
    76736 Traceback (most recent call last): 
    76737 File
    76738 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76739 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    76740 self.session.ui.mouse_modes.mouse_pause_tracking() 
    76741 File
    76742 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76743 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    76744 mouse_pause_tracking 
    76745 self._mouse_pause() 
    76746 File
    76747 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76748 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    76749 m.pause(self._mouse_pause_position) 
    76750 File
    76751 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76752 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    76753 p = self.view.picked_object(x, y) 
    76754 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76755 File
    76756 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76757 packages/chimerax/graphics/view.py", line 838, in picked_object 
    76758 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    76759 beyond, 
    76760 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76761 File
    76762 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76763 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    76764 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    76765 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76766 File
    76767 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76768 packages/chimerax/core/models.py", line 143, in first_intercept 
    76769 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    76770 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76771 File
    76772 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76773 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    76774 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    76775 exclude=exclude) 
    76776 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76777 File
    76778 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76779 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    76780 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    76781 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76782 File
    76783 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76784 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    76785 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    76786 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76787 File
    76788 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76789 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    76790 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    76791 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76792 File
    76793 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76794 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    76795 p = super().first_intercept(mxyz1, mxyz2) 
    76796 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76797 File
    76798 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76799 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    76800 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    76801 exclude=exclude) 
    76802 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76803 File
    76804 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76805 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    76806 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    76807 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76808 File
    76809 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76810 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    76811 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    76812 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76813 File
    76814 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76815 packages/chimerax/graphics/drawing.py", line 1108, in
    76816 _first_intercept_excluding_children 
    76817 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    76818 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76819 File
    76820 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76821 packages/chimerax/geometry/place.py", line 201, in inverse 
    76822 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    76823 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76824 File
    76825 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76826 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    76827 rinv[:, :] = matrix_inverse(r) 
    76828 ^^^^^^^^^^^^^^^^^ 
    76829 File
    76830 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76831 packages/numpy/linalg/linalg.py", line 561, in inv 
    76832 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    76833 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76834 File
    76835 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76836 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    76837 raise LinAlgError("Singular matrix") 
    76838 numpy.linalg.LinAlgError: Singular matrix 
    76839  
    76840 numpy.linalg.LinAlgError: Singular matrix 
    76841  
    76842 File
    76843 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76844 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    76845 raise LinAlgError("Singular matrix") 
    76846  
    76847 See log for complete Python traceback. 
    76848  
    76849 Traceback (most recent call last): 
    76850 File
    76851 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76852 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    76853 self.session.ui.mouse_modes.mouse_pause_tracking() 
    76854 File
    76855 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76856 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    76857 mouse_pause_tracking 
    76858 self._mouse_pause() 
    76859 File
    76860 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76861 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    76862 m.pause(self._mouse_pause_position) 
    76863 File
    76864 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76865 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    76866 p = self.view.picked_object(x, y) 
    76867 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76868 File
    76869 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76870 packages/chimerax/graphics/view.py", line 838, in picked_object 
    76871 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    76872 beyond, 
    76873 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76874 File
    76875 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76876 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    76877 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    76878 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76879 File
    76880 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76881 packages/chimerax/core/models.py", line 143, in first_intercept 
    76882 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    76883 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76884 File
    76885 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76886 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    76887 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    76888 exclude=exclude) 
    76889 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76890 File
    76891 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76892 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    76893 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    76894 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76895 File
    76896 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76897 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    76898 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    76899 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76900 File
    76901 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76902 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    76903 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    76904 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76905 File
    76906 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76907 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    76908 p = super().first_intercept(mxyz1, mxyz2) 
    76909 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76910 File
    76911 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76912 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    76913 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    76914 exclude=exclude) 
    76915 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76916 File
    76917 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76918 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    76919 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    76920 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76921 File
    76922 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76923 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    76924 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    76925 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76926 File
    76927 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76928 packages/chimerax/graphics/drawing.py", line 1108, in
    76929 _first_intercept_excluding_children 
    76930 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    76931 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76932 File
    76933 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76934 packages/chimerax/geometry/place.py", line 201, in inverse 
    76935 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    76936 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76937 File
    76938 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76939 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    76940 rinv[:, :] = matrix_inverse(r) 
    76941 ^^^^^^^^^^^^^^^^^ 
    76942 File
    76943 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76944 packages/numpy/linalg/linalg.py", line 561, in inv 
    76945 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    76946 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76947 File
    76948 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76949 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    76950 raise LinAlgError("Singular matrix") 
    76951 numpy.linalg.LinAlgError: Singular matrix 
    76952  
    76953 numpy.linalg.LinAlgError: Singular matrix 
    76954  
    76955 File
    76956 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76957 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    76958 raise LinAlgError("Singular matrix") 
    76959  
    76960 See log for complete Python traceback. 
    76961  
    76962 Traceback (most recent call last): 
    76963 File
    76964 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76965 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    76966 self.session.ui.mouse_modes.mouse_pause_tracking() 
    76967 File
    76968 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76969 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    76970 mouse_pause_tracking 
    76971 self._mouse_pause() 
    76972 File
    76973 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76974 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    76975 m.pause(self._mouse_pause_position) 
    76976 File
    76977 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76978 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    76979 p = self.view.picked_object(x, y) 
    76980 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76981 File
    76982 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76983 packages/chimerax/graphics/view.py", line 838, in picked_object 
    76984 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    76985 beyond, 
    76986 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76987 File
    76988 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76989 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    76990 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    76991 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76992 File
    76993 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76994 packages/chimerax/core/models.py", line 143, in first_intercept 
    76995 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    76996 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    76997 File
    76998 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    76999 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    77000 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    77001 exclude=exclude) 
    77002 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77003 File
    77004 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77005 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    77006 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    77007 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77008 File
    77009 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77010 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    77011 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    77012 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77013 File
    77014 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77015 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    77016 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    77017 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77018 File
    77019 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77020 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    77021 p = super().first_intercept(mxyz1, mxyz2) 
    77022 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77023 File
    77024 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77025 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    77026 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    77027 exclude=exclude) 
    77028 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77029 File
    77030 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77031 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    77032 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    77033 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77034 File
    77035 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77036 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    77037 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    77038 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77039 File
    77040 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77041 packages/chimerax/graphics/drawing.py", line 1108, in
    77042 _first_intercept_excluding_children 
    77043 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    77044 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77045 File
    77046 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77047 packages/chimerax/geometry/place.py", line 201, in inverse 
    77048 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    77049 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77050 File
    77051 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77052 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    77053 rinv[:, :] = matrix_inverse(r) 
    77054 ^^^^^^^^^^^^^^^^^ 
    77055 File
    77056 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77057 packages/numpy/linalg/linalg.py", line 561, in inv 
    77058 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    77059 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77060 File
    77061 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77062 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    77063 raise LinAlgError("Singular matrix") 
    77064 numpy.linalg.LinAlgError: Singular matrix 
    77065  
    77066 numpy.linalg.LinAlgError: Singular matrix 
    77067  
    77068 File
    77069 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77070 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    77071 raise LinAlgError("Singular matrix") 
    77072  
    77073 See log for complete Python traceback. 
    77074  
    77075 Traceback (most recent call last): 
    77076 File
    77077 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77078 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    77079 self.session.ui.mouse_modes.mouse_pause_tracking() 
    77080 File
    77081 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77082 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    77083 mouse_pause_tracking 
    77084 self._mouse_pause() 
    77085 File
    77086 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77087 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    77088 m.pause(self._mouse_pause_position) 
    77089 File
    77090 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77091 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    77092 p = self.view.picked_object(x, y) 
    77093 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77094 File
    77095 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77096 packages/chimerax/graphics/view.py", line 838, in picked_object 
    77097 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    77098 beyond, 
    77099 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77100 File
    77101 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77102 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    77103 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    77104 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77105 File
    77106 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77107 packages/chimerax/core/models.py", line 143, in first_intercept 
    77108 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    77109 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77110 File
    77111 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77112 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    77113 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    77114 exclude=exclude) 
    77115 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77116 File
    77117 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77118 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    77119 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    77120 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77121 File
    77122 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77123 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    77124 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    77125 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77126 File
    77127 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77128 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    77129 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    77130 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77131 File
    77132 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77133 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    77134 p = super().first_intercept(mxyz1, mxyz2) 
    77135 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77136 File
    77137 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77138 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    77139 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    77140 exclude=exclude) 
    77141 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77142 File
    77143 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77144 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    77145 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    77146 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77147 File
    77148 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77149 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    77150 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    77151 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77152 File
    77153 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77154 packages/chimerax/graphics/drawing.py", line 1108, in
    77155 _first_intercept_excluding_children 
    77156 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    77157 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77158 File
    77159 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77160 packages/chimerax/geometry/place.py", line 201, in inverse 
    77161 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    77162 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77163 File
    77164 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77165 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    77166 rinv[:, :] = matrix_inverse(r) 
    77167 ^^^^^^^^^^^^^^^^^ 
    77168 File
    77169 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77170 packages/numpy/linalg/linalg.py", line 561, in inv 
    77171 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    77172 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77173 File
    77174 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77175 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    77176 raise LinAlgError("Singular matrix") 
    77177 numpy.linalg.LinAlgError: Singular matrix 
    77178  
    77179 numpy.linalg.LinAlgError: Singular matrix 
    77180  
    77181 File
    77182 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77183 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    77184 raise LinAlgError("Singular matrix") 
    77185  
    77186 See log for complete Python traceback. 
    77187  
    77188 Traceback (most recent call last): 
    77189 File
    77190 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77191 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    77192 self.session.ui.mouse_modes.mouse_pause_tracking() 
    77193 File
    77194 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77195 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    77196 mouse_pause_tracking 
    77197 self._mouse_pause() 
    77198 File
    77199 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77200 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    77201 m.pause(self._mouse_pause_position) 
    77202 File
    77203 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77204 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    77205 p = self.view.picked_object(x, y) 
    77206 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77207 File
    77208 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77209 packages/chimerax/graphics/view.py", line 838, in picked_object 
    77210 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    77211 beyond, 
    77212 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77213 File
    77214 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77215 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    77216 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    77217 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77218 File
    77219 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77220 packages/chimerax/core/models.py", line 143, in first_intercept 
    77221 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    77222 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77223 File
    77224 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77225 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    77226 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    77227 exclude=exclude) 
    77228 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77229 File
    77230 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77231 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    77232 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    77233 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77234 File
    77235 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77236 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    77237 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    77238 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77239 File
    77240 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77241 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    77242 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    77243 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77244 File
    77245 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77246 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    77247 p = super().first_intercept(mxyz1, mxyz2) 
    77248 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77249 File
    77250 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77251 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    77252 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    77253 exclude=exclude) 
    77254 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77255 File
    77256 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77257 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    77258 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    77259 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77260 File
    77261 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77262 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    77263 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    77264 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77265 File
    77266 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77267 packages/chimerax/graphics/drawing.py", line 1108, in
    77268 _first_intercept_excluding_children 
    77269 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    77270 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77271 File
    77272 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77273 packages/chimerax/geometry/place.py", line 201, in inverse 
    77274 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    77275 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77276 File
    77277 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77278 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    77279 rinv[:, :] = matrix_inverse(r) 
    77280 ^^^^^^^^^^^^^^^^^ 
    77281 File
    77282 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77283 packages/numpy/linalg/linalg.py", line 561, in inv 
    77284 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    77285 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77286 File
    77287 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77288 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    77289 raise LinAlgError("Singular matrix") 
    77290 numpy.linalg.LinAlgError: Singular matrix 
    77291  
    77292 numpy.linalg.LinAlgError: Singular matrix 
    77293  
    77294 File
    77295 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77296 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    77297 raise LinAlgError("Singular matrix") 
    77298  
    77299 See log for complete Python traceback. 
    77300  
    77301 Traceback (most recent call last): 
    77302 File
    77303 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77304 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    77305 self.session.ui.mouse_modes.mouse_pause_tracking() 
    77306 File
    77307 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77308 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    77309 mouse_pause_tracking 
    77310 self._mouse_pause() 
    77311 File
    77312 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77313 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    77314 m.pause(self._mouse_pause_position) 
    77315 File
    77316 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77317 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    77318 p = self.view.picked_object(x, y) 
    77319 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77320 File
    77321 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77322 packages/chimerax/graphics/view.py", line 838, in picked_object 
    77323 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    77324 beyond, 
    77325 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77326 File
    77327 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77328 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    77329 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    77330 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77331 File
    77332 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77333 packages/chimerax/core/models.py", line 143, in first_intercept 
    77334 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    77335 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77336 File
    77337 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77338 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    77339 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    77340 exclude=exclude) 
    77341 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77342 File
    77343 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77344 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    77345 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    77346 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77347 File
    77348 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77349 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    77350 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    77351 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77352 File
    77353 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77354 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    77355 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    77356 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77357 File
    77358 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77359 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    77360 p = super().first_intercept(mxyz1, mxyz2) 
    77361 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77362 File
    77363 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77364 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    77365 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    77366 exclude=exclude) 
    77367 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77368 File
    77369 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77370 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    77371 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    77372 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77373 File
    77374 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77375 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    77376 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    77377 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77378 File
    77379 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77380 packages/chimerax/graphics/drawing.py", line 1108, in
    77381 _first_intercept_excluding_children 
    77382 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    77383 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77384 File
    77385 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77386 packages/chimerax/geometry/place.py", line 201, in inverse 
    77387 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    77388 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77389 File
    77390 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77391 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    77392 rinv[:, :] = matrix_inverse(r) 
    77393 ^^^^^^^^^^^^^^^^^ 
    77394 File
    77395 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77396 packages/numpy/linalg/linalg.py", line 561, in inv 
    77397 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    77398 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77399 File
    77400 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77401 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    77402 raise LinAlgError("Singular matrix") 
    77403 numpy.linalg.LinAlgError: Singular matrix 
    77404  
    77405 numpy.linalg.LinAlgError: Singular matrix 
    77406  
    77407 File
    77408 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77409 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    77410 raise LinAlgError("Singular matrix") 
    77411  
    77412 See log for complete Python traceback. 
    77413  
    77414 Traceback (most recent call last): 
    77415 File
    77416 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77417 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    77418 self.session.ui.mouse_modes.mouse_pause_tracking() 
    77419 File
    77420 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77421 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    77422 mouse_pause_tracking 
    77423 self._mouse_pause() 
    77424 File
    77425 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77426 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    77427 m.pause(self._mouse_pause_position) 
    77428 File
    77429 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77430 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    77431 p = self.view.picked_object(x, y) 
    77432 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77433 File
    77434 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77435 packages/chimerax/graphics/view.py", line 838, in picked_object 
    77436 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    77437 beyond, 
    77438 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77439 File
    77440 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77441 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    77442 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    77443 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77444 File
    77445 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77446 packages/chimerax/core/models.py", line 143, in first_intercept 
    77447 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    77448 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77449 File
    77450 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77451 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    77452 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    77453 exclude=exclude) 
    77454 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77455 File
    77456 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77457 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    77458 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    77459 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77460 File
    77461 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77462 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    77463 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    77464 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77465 File
    77466 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77467 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    77468 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    77469 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77470 File
    77471 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77472 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    77473 p = super().first_intercept(mxyz1, mxyz2) 
    77474 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77475 File
    77476 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77477 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    77478 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    77479 exclude=exclude) 
    77480 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77481 File
    77482 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77483 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    77484 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    77485 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77486 File
    77487 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77488 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    77489 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    77490 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77491 File
    77492 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77493 packages/chimerax/graphics/drawing.py", line 1108, in
    77494 _first_intercept_excluding_children 
    77495 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    77496 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77497 File
    77498 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77499 packages/chimerax/geometry/place.py", line 201, in inverse 
    77500 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    77501 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77502 File
    77503 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77504 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    77505 rinv[:, :] = matrix_inverse(r) 
    77506 ^^^^^^^^^^^^^^^^^ 
    77507 File
    77508 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77509 packages/numpy/linalg/linalg.py", line 561, in inv 
    77510 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    77511 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77512 File
    77513 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77514 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    77515 raise LinAlgError("Singular matrix") 
    77516 numpy.linalg.LinAlgError: Singular matrix 
    77517  
    77518 numpy.linalg.LinAlgError: Singular matrix 
    77519  
    77520 File
    77521 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77522 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    77523 raise LinAlgError("Singular matrix") 
    77524  
    77525 See log for complete Python traceback. 
    77526  
    77527 Traceback (most recent call last): 
    77528 File
    77529 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77530 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    77531 self.session.ui.mouse_modes.mouse_pause_tracking() 
    77532 File
    77533 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77534 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    77535 mouse_pause_tracking 
    77536 self._mouse_pause() 
    77537 File
    77538 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77539 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    77540 m.pause(self._mouse_pause_position) 
    77541 File
    77542 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77543 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    77544 p = self.view.picked_object(x, y) 
    77545 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77546 File
    77547 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77548 packages/chimerax/graphics/view.py", line 838, in picked_object 
    77549 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    77550 beyond, 
    77551 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77552 File
    77553 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77554 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    77555 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    77556 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77557 File
    77558 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77559 packages/chimerax/core/models.py", line 143, in first_intercept 
    77560 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    77561 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77562 File
    77563 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77564 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    77565 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    77566 exclude=exclude) 
    77567 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77568 File
    77569 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77570 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    77571 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    77572 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77573 File
    77574 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77575 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    77576 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    77577 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77578 File
    77579 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77580 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    77581 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    77582 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77583 File
    77584 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77585 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    77586 p = super().first_intercept(mxyz1, mxyz2) 
    77587 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77588 File
    77589 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77590 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    77591 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    77592 exclude=exclude) 
    77593 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77594 File
    77595 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77596 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    77597 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    77598 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77599 File
    77600 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77601 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    77602 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    77603 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77604 File
    77605 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77606 packages/chimerax/graphics/drawing.py", line 1108, in
    77607 _first_intercept_excluding_children 
    77608 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    77609 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77610 File
    77611 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77612 packages/chimerax/geometry/place.py", line 201, in inverse 
    77613 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    77614 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77615 File
    77616 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77617 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    77618 rinv[:, :] = matrix_inverse(r) 
    77619 ^^^^^^^^^^^^^^^^^ 
    77620 File
    77621 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77622 packages/numpy/linalg/linalg.py", line 561, in inv 
    77623 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    77624 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77625 File
    77626 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77627 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    77628 raise LinAlgError("Singular matrix") 
    77629 numpy.linalg.LinAlgError: Singular matrix 
    77630  
    77631 numpy.linalg.LinAlgError: Singular matrix 
    77632  
    77633 File
    77634 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77635 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    77636 raise LinAlgError("Singular matrix") 
    77637  
    77638 See log for complete Python traceback. 
    77639  
    77640 Traceback (most recent call last): 
    77641 File
    77642 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77643 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    77644 self.session.ui.mouse_modes.mouse_pause_tracking() 
    77645 File
    77646 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77647 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    77648 mouse_pause_tracking 
    77649 self._mouse_pause() 
    77650 File
    77651 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77652 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    77653 m.pause(self._mouse_pause_position) 
    77654 File
    77655 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77656 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    77657 p = self.view.picked_object(x, y) 
    77658 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77659 File
    77660 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77661 packages/chimerax/graphics/view.py", line 838, in picked_object 
    77662 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    77663 beyond, 
    77664 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77665 File
    77666 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77667 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    77668 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    77669 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77670 File
    77671 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77672 packages/chimerax/core/models.py", line 143, in first_intercept 
    77673 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    77674 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77675 File
    77676 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77677 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    77678 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    77679 exclude=exclude) 
    77680 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77681 File
    77682 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77683 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    77684 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    77685 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77686 File
    77687 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77688 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    77689 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    77690 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77691 File
    77692 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77693 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    77694 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    77695 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77696 File
    77697 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77698 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    77699 p = super().first_intercept(mxyz1, mxyz2) 
    77700 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77701 File
    77702 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77703 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    77704 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    77705 exclude=exclude) 
    77706 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77707 File
    77708 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77709 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    77710 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    77711 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77712 File
    77713 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77714 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    77715 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    77716 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77717 File
    77718 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77719 packages/chimerax/graphics/drawing.py", line 1108, in
    77720 _first_intercept_excluding_children 
    77721 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    77722 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77723 File
    77724 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77725 packages/chimerax/geometry/place.py", line 201, in inverse 
    77726 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    77727 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77728 File
    77729 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77730 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    77731 rinv[:, :] = matrix_inverse(r) 
    77732 ^^^^^^^^^^^^^^^^^ 
    77733 File
    77734 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77735 packages/numpy/linalg/linalg.py", line 561, in inv 
    77736 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    77737 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77738 File
    77739 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77740 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    77741 raise LinAlgError("Singular matrix") 
    77742 numpy.linalg.LinAlgError: Singular matrix 
    77743  
    77744 numpy.linalg.LinAlgError: Singular matrix 
    77745  
    77746 File
    77747 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77748 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    77749 raise LinAlgError("Singular matrix") 
    77750  
    77751 See log for complete Python traceback. 
    77752  
    77753 Traceback (most recent call last): 
    77754 File
    77755 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77756 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    77757 self.session.ui.mouse_modes.mouse_pause_tracking() 
    77758 File
    77759 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77760 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    77761 mouse_pause_tracking 
    77762 self._mouse_pause() 
    77763 File
    77764 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77765 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    77766 m.pause(self._mouse_pause_position) 
    77767 File
    77768 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77769 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    77770 p = self.view.picked_object(x, y) 
    77771 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77772 File
    77773 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77774 packages/chimerax/graphics/view.py", line 838, in picked_object 
    77775 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    77776 beyond, 
    77777 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77778 File
    77779 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77780 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    77781 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    77782 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77783 File
    77784 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77785 packages/chimerax/core/models.py", line 143, in first_intercept 
    77786 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    77787 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77788 File
    77789 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77790 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    77791 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    77792 exclude=exclude) 
    77793 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77794 File
    77795 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77796 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    77797 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    77798 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77799 File
    77800 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77801 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    77802 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    77803 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77804 File
    77805 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77806 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    77807 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    77808 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77809 File
    77810 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77811 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    77812 p = super().first_intercept(mxyz1, mxyz2) 
    77813 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77814 File
    77815 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77816 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    77817 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    77818 exclude=exclude) 
    77819 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77820 File
    77821 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77822 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    77823 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    77824 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77825 File
    77826 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77827 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    77828 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    77829 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77830 File
    77831 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77832 packages/chimerax/graphics/drawing.py", line 1108, in
    77833 _first_intercept_excluding_children 
    77834 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    77835 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77836 File
    77837 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77838 packages/chimerax/geometry/place.py", line 201, in inverse 
    77839 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    77840 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77841 File
    77842 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77843 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    77844 rinv[:, :] = matrix_inverse(r) 
    77845 ^^^^^^^^^^^^^^^^^ 
    77846 File
    77847 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77848 packages/numpy/linalg/linalg.py", line 561, in inv 
    77849 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    77850 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77851 File
    77852 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77853 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    77854 raise LinAlgError("Singular matrix") 
    77855 numpy.linalg.LinAlgError: Singular matrix 
    77856  
    77857 numpy.linalg.LinAlgError: Singular matrix 
    77858  
    77859 File
    77860 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77861 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    77862 raise LinAlgError("Singular matrix") 
    77863  
    77864 See log for complete Python traceback. 
    77865  
    77866 Traceback (most recent call last): 
    77867 File
    77868 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77869 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    77870 self.session.ui.mouse_modes.mouse_pause_tracking() 
    77871 File
    77872 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77873 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    77874 mouse_pause_tracking 
    77875 self._mouse_pause() 
    77876 File
    77877 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77878 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    77879 m.pause(self._mouse_pause_position) 
    77880 File
    77881 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77882 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    77883 p = self.view.picked_object(x, y) 
    77884 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77885 File
    77886 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77887 packages/chimerax/graphics/view.py", line 838, in picked_object 
    77888 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    77889 beyond, 
    77890 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77891 File
    77892 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77893 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    77894 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    77895 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77896 File
    77897 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77898 packages/chimerax/core/models.py", line 143, in first_intercept 
    77899 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    77900 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77901 File
    77902 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77903 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    77904 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    77905 exclude=exclude) 
    77906 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77907 File
    77908 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77909 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    77910 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    77911 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77912 File
    77913 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77914 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    77915 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    77916 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77917 File
    77918 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77919 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    77920 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    77921 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77922 File
    77923 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77924 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    77925 p = super().first_intercept(mxyz1, mxyz2) 
    77926 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77927 File
    77928 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77929 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    77930 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    77931 exclude=exclude) 
    77932 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77933 File
    77934 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77935 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    77936 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    77937 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77938 File
    77939 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77940 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    77941 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    77942 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77943 File
    77944 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77945 packages/chimerax/graphics/drawing.py", line 1108, in
    77946 _first_intercept_excluding_children 
    77947 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    77948 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77949 File
    77950 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77951 packages/chimerax/geometry/place.py", line 201, in inverse 
    77952 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    77953 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77954 File
    77955 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77956 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    77957 rinv[:, :] = matrix_inverse(r) 
    77958 ^^^^^^^^^^^^^^^^^ 
    77959 File
    77960 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77961 packages/numpy/linalg/linalg.py", line 561, in inv 
    77962 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    77963 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77964 File
    77965 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77966 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    77967 raise LinAlgError("Singular matrix") 
    77968 numpy.linalg.LinAlgError: Singular matrix 
    77969  
    77970 numpy.linalg.LinAlgError: Singular matrix 
    77971  
    77972 File
    77973 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77974 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    77975 raise LinAlgError("Singular matrix") 
    77976  
    77977 See log for complete Python traceback. 
    77978  
    77979 Traceback (most recent call last): 
    77980 File
    77981 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77982 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    77983 self.session.ui.mouse_modes.mouse_pause_tracking() 
    77984 File
    77985 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77986 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    77987 mouse_pause_tracking 
    77988 self._mouse_pause() 
    77989 File
    77990 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77991 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    77992 m.pause(self._mouse_pause_position) 
    77993 File
    77994 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    77995 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    77996 p = self.view.picked_object(x, y) 
    77997 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    77998 File
    77999 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78000 packages/chimerax/graphics/view.py", line 838, in picked_object 
    78001 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    78002 beyond, 
    78003 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78004 File
    78005 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78006 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    78007 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    78008 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78009 File
    78010 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78011 packages/chimerax/core/models.py", line 143, in first_intercept 
    78012 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    78013 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78014 File
    78015 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78016 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    78017 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    78018 exclude=exclude) 
    78019 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78020 File
    78021 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78022 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    78023 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    78024 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78025 File
    78026 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78027 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    78028 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    78029 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78030 File
    78031 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78032 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    78033 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    78034 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78035 File
    78036 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78037 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    78038 p = super().first_intercept(mxyz1, mxyz2) 
    78039 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78040 File
    78041 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78042 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    78043 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    78044 exclude=exclude) 
    78045 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78046 File
    78047 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78048 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    78049 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    78050 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78051 File
    78052 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78053 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    78054 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    78055 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78056 File
    78057 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78058 packages/chimerax/graphics/drawing.py", line 1108, in
    78059 _first_intercept_excluding_children 
    78060 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    78061 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78062 File
    78063 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78064 packages/chimerax/geometry/place.py", line 201, in inverse 
    78065 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    78066 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78067 File
    78068 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78069 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    78070 rinv[:, :] = matrix_inverse(r) 
    78071 ^^^^^^^^^^^^^^^^^ 
    78072 File
    78073 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78074 packages/numpy/linalg/linalg.py", line 561, in inv 
    78075 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    78076 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78077 File
    78078 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78079 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    78080 raise LinAlgError("Singular matrix") 
    78081 numpy.linalg.LinAlgError: Singular matrix 
    78082  
    78083 numpy.linalg.LinAlgError: Singular matrix 
    78084  
    78085 File
    78086 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78087 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    78088 raise LinAlgError("Singular matrix") 
    78089  
    78090 See log for complete Python traceback. 
    78091  
    78092 Traceback (most recent call last): 
    78093 File
    78094 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78095 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    78096 self.session.ui.mouse_modes.mouse_pause_tracking() 
    78097 File
    78098 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78099 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    78100 mouse_pause_tracking 
    78101 self._mouse_pause() 
    78102 File
    78103 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78104 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    78105 m.pause(self._mouse_pause_position) 
    78106 File
    78107 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78108 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    78109 p = self.view.picked_object(x, y) 
    78110 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78111 File
    78112 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78113 packages/chimerax/graphics/view.py", line 838, in picked_object 
    78114 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    78115 beyond, 
    78116 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78117 File
    78118 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78119 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    78120 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    78121 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78122 File
    78123 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78124 packages/chimerax/core/models.py", line 143, in first_intercept 
    78125 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    78126 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78127 File
    78128 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78129 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    78130 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    78131 exclude=exclude) 
    78132 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78133 File
    78134 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78135 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    78136 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    78137 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78138 File
    78139 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78140 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    78141 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    78142 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78143 File
    78144 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78145 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    78146 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    78147 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78148 File
    78149 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78150 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    78151 p = super().first_intercept(mxyz1, mxyz2) 
    78152 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78153 File
    78154 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78155 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    78156 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    78157 exclude=exclude) 
    78158 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78159 File
    78160 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78161 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    78162 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    78163 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78164 File
    78165 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78166 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    78167 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    78168 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78169 File
    78170 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78171 packages/chimerax/graphics/drawing.py", line 1108, in
    78172 _first_intercept_excluding_children 
    78173 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    78174 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78175 File
    78176 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78177 packages/chimerax/geometry/place.py", line 201, in inverse 
    78178 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    78179 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78180 File
    78181 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78182 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    78183 rinv[:, :] = matrix_inverse(r) 
    78184 ^^^^^^^^^^^^^^^^^ 
    78185 File
    78186 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78187 packages/numpy/linalg/linalg.py", line 561, in inv 
    78188 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    78189 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78190 File
    78191 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78192 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    78193 raise LinAlgError("Singular matrix") 
    78194 numpy.linalg.LinAlgError: Singular matrix 
    78195  
    78196 numpy.linalg.LinAlgError: Singular matrix 
    78197  
    78198 File
    78199 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78200 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    78201 raise LinAlgError("Singular matrix") 
    78202  
    78203 See log for complete Python traceback. 
    78204  
    78205 Traceback (most recent call last): 
    78206 File
    78207 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78208 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    78209 self.session.ui.mouse_modes.mouse_pause_tracking() 
    78210 File
    78211 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78212 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    78213 mouse_pause_tracking 
    78214 self._mouse_pause() 
    78215 File
    78216 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78217 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    78218 m.pause(self._mouse_pause_position) 
    78219 File
    78220 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78221 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    78222 p = self.view.picked_object(x, y) 
    78223 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78224 File
    78225 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78226 packages/chimerax/graphics/view.py", line 838, in picked_object 
    78227 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    78228 beyond, 
    78229 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78230 File
    78231 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78232 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    78233 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    78234 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78235 File
    78236 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78237 packages/chimerax/core/models.py", line 143, in first_intercept 
    78238 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    78239 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78240 File
    78241 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78242 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    78243 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    78244 exclude=exclude) 
    78245 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78246 File
    78247 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78248 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    78249 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    78250 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78251 File
    78252 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78253 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    78254 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    78255 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78256 File
    78257 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78258 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    78259 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    78260 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78261 File
    78262 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78263 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    78264 p = super().first_intercept(mxyz1, mxyz2) 
    78265 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78266 File
    78267 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78268 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    78269 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    78270 exclude=exclude) 
    78271 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78272 File
    78273 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78274 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    78275 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    78276 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78277 File
    78278 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78279 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    78280 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    78281 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78282 File
    78283 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78284 packages/chimerax/graphics/drawing.py", line 1108, in
    78285 _first_intercept_excluding_children 
    78286 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    78287 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78288 File
    78289 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78290 packages/chimerax/geometry/place.py", line 201, in inverse 
    78291 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    78292 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78293 File
    78294 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78295 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    78296 rinv[:, :] = matrix_inverse(r) 
    78297 ^^^^^^^^^^^^^^^^^ 
    78298 File
    78299 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78300 packages/numpy/linalg/linalg.py", line 561, in inv 
    78301 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    78302 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78303 File
    78304 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78305 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    78306 raise LinAlgError("Singular matrix") 
    78307 numpy.linalg.LinAlgError: Singular matrix 
    78308  
    78309 numpy.linalg.LinAlgError: Singular matrix 
    78310  
    78311 File
    78312 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78313 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    78314 raise LinAlgError("Singular matrix") 
    78315  
    78316 See log for complete Python traceback. 
    78317  
    78318 Traceback (most recent call last): 
    78319 File
    78320 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78321 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    78322 self.session.ui.mouse_modes.mouse_pause_tracking() 
    78323 File
    78324 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78325 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    78326 mouse_pause_tracking 
    78327 self._mouse_pause() 
    78328 File
    78329 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78330 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    78331 m.pause(self._mouse_pause_position) 
    78332 File
    78333 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78334 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    78335 p = self.view.picked_object(x, y) 
    78336 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78337 File
    78338 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78339 packages/chimerax/graphics/view.py", line 838, in picked_object 
    78340 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    78341 beyond, 
    78342 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78343 File
    78344 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78345 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    78346 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    78347 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78348 File
    78349 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78350 packages/chimerax/core/models.py", line 143, in first_intercept 
    78351 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    78352 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78353 File
    78354 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78355 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    78356 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    78357 exclude=exclude) 
    78358 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78359 File
    78360 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78361 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    78362 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    78363 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78364 File
    78365 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78366 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    78367 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    78368 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78369 File
    78370 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78371 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    78372 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    78373 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78374 File
    78375 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78376 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    78377 p = super().first_intercept(mxyz1, mxyz2) 
    78378 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78379 File
    78380 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78381 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    78382 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    78383 exclude=exclude) 
    78384 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78385 File
    78386 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78387 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    78388 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    78389 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78390 File
    78391 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78392 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    78393 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    78394 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78395 File
    78396 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78397 packages/chimerax/graphics/drawing.py", line 1108, in
    78398 _first_intercept_excluding_children 
    78399 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    78400 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78401 File
    78402 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78403 packages/chimerax/geometry/place.py", line 201, in inverse 
    78404 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    78405 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78406 File
    78407 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78408 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    78409 rinv[:, :] = matrix_inverse(r) 
    78410 ^^^^^^^^^^^^^^^^^ 
    78411 File
    78412 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78413 packages/numpy/linalg/linalg.py", line 561, in inv 
    78414 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    78415 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78416 File
    78417 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78418 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    78419 raise LinAlgError("Singular matrix") 
    78420 numpy.linalg.LinAlgError: Singular matrix 
    78421  
    78422 numpy.linalg.LinAlgError: Singular matrix 
    78423  
    78424 File
    78425 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78426 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    78427 raise LinAlgError("Singular matrix") 
    78428  
    78429 See log for complete Python traceback. 
    78430  
    78431 Traceback (most recent call last): 
    78432 File
    78433 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78434 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    78435 self.session.ui.mouse_modes.mouse_pause_tracking() 
    78436 File
    78437 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78438 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    78439 mouse_pause_tracking 
    78440 self._mouse_pause() 
    78441 File
    78442 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78443 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    78444 m.pause(self._mouse_pause_position) 
    78445 File
    78446 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78447 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    78448 p = self.view.picked_object(x, y) 
    78449 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78450 File
    78451 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78452 packages/chimerax/graphics/view.py", line 838, in picked_object 
    78453 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    78454 beyond, 
    78455 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78456 File
    78457 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78458 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    78459 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    78460 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78461 File
    78462 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78463 packages/chimerax/core/models.py", line 143, in first_intercept 
    78464 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    78465 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78466 File
    78467 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78468 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    78469 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    78470 exclude=exclude) 
    78471 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78472 File
    78473 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78474 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    78475 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    78476 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78477 File
    78478 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78479 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    78480 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    78481 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78482 File
    78483 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78484 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    78485 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    78486 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78487 File
    78488 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78489 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    78490 p = super().first_intercept(mxyz1, mxyz2) 
    78491 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78492 File
    78493 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78494 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    78495 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    78496 exclude=exclude) 
    78497 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78498 File
    78499 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78500 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    78501 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    78502 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78503 File
    78504 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78505 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    78506 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    78507 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78508 File
    78509 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78510 packages/chimerax/graphics/drawing.py", line 1108, in
    78511 _first_intercept_excluding_children 
    78512 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    78513 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78514 File
    78515 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78516 packages/chimerax/geometry/place.py", line 201, in inverse 
    78517 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    78518 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78519 File
    78520 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78521 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    78522 rinv[:, :] = matrix_inverse(r) 
    78523 ^^^^^^^^^^^^^^^^^ 
    78524 File
    78525 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78526 packages/numpy/linalg/linalg.py", line 561, in inv 
    78527 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    78528 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78529 File
    78530 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78531 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    78532 raise LinAlgError("Singular matrix") 
    78533 numpy.linalg.LinAlgError: Singular matrix 
    78534  
    78535 numpy.linalg.LinAlgError: Singular matrix 
    78536  
    78537 File
    78538 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78539 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    78540 raise LinAlgError("Singular matrix") 
    78541  
    78542 See log for complete Python traceback. 
    78543  
    78544 Traceback (most recent call last): 
    78545 File
    78546 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78547 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    78548 self.session.ui.mouse_modes.mouse_pause_tracking() 
    78549 File
    78550 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78551 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    78552 mouse_pause_tracking 
    78553 self._mouse_pause() 
    78554 File
    78555 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78556 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    78557 m.pause(self._mouse_pause_position) 
    78558 File
    78559 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78560 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    78561 p = self.view.picked_object(x, y) 
    78562 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78563 File
    78564 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78565 packages/chimerax/graphics/view.py", line 838, in picked_object 
    78566 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    78567 beyond, 
    78568 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78569 File
    78570 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78571 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    78572 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    78573 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78574 File
    78575 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78576 packages/chimerax/core/models.py", line 143, in first_intercept 
    78577 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    78578 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78579 File
    78580 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78581 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    78582 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    78583 exclude=exclude) 
    78584 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78585 File
    78586 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78587 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    78588 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    78589 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78590 File
    78591 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78592 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    78593 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    78594 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78595 File
    78596 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78597 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    78598 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    78599 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78600 File
    78601 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78602 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    78603 p = super().first_intercept(mxyz1, mxyz2) 
    78604 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78605 File
    78606 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78607 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    78608 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    78609 exclude=exclude) 
    78610 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78611 File
    78612 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78613 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    78614 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    78615 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78616 File
    78617 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78618 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    78619 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    78620 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78621 File
    78622 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78623 packages/chimerax/graphics/drawing.py", line 1108, in
    78624 _first_intercept_excluding_children 
    78625 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    78626 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78627 File
    78628 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78629 packages/chimerax/geometry/place.py", line 201, in inverse 
    78630 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    78631 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78632 File
    78633 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78634 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    78635 rinv[:, :] = matrix_inverse(r) 
    78636 ^^^^^^^^^^^^^^^^^ 
    78637 File
    78638 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78639 packages/numpy/linalg/linalg.py", line 561, in inv 
    78640 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    78641 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78642 File
    78643 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78644 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    78645 raise LinAlgError("Singular matrix") 
    78646 numpy.linalg.LinAlgError: Singular matrix 
    78647  
    78648 numpy.linalg.LinAlgError: Singular matrix 
    78649  
    78650 File
    78651 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78652 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    78653 raise LinAlgError("Singular matrix") 
    78654  
    78655 See log for complete Python traceback. 
    78656  
    78657 Traceback (most recent call last): 
    78658 File
    78659 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78660 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    78661 self.session.ui.mouse_modes.mouse_pause_tracking() 
    78662 File
    78663 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78664 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    78665 mouse_pause_tracking 
    78666 self._mouse_pause() 
    78667 File
    78668 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78669 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    78670 m.pause(self._mouse_pause_position) 
    78671 File
    78672 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78673 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    78674 p = self.view.picked_object(x, y) 
    78675 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78676 File
    78677 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78678 packages/chimerax/graphics/view.py", line 838, in picked_object 
    78679 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    78680 beyond, 
    78681 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78682 File
    78683 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78684 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    78685 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    78686 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78687 File
    78688 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78689 packages/chimerax/core/models.py", line 143, in first_intercept 
    78690 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    78691 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78692 File
    78693 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78694 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    78695 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    78696 exclude=exclude) 
    78697 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78698 File
    78699 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78700 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    78701 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    78702 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78703 File
    78704 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78705 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    78706 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    78707 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78708 File
    78709 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78710 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    78711 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    78712 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78713 File
    78714 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78715 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    78716 p = super().first_intercept(mxyz1, mxyz2) 
    78717 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78718 File
    78719 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78720 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    78721 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    78722 exclude=exclude) 
    78723 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78724 File
    78725 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78726 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    78727 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    78728 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78729 File
    78730 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78731 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    78732 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    78733 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78734 File
    78735 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78736 packages/chimerax/graphics/drawing.py", line 1108, in
    78737 _first_intercept_excluding_children 
    78738 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    78739 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78740 File
    78741 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78742 packages/chimerax/geometry/place.py", line 201, in inverse 
    78743 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    78744 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78745 File
    78746 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78747 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    78748 rinv[:, :] = matrix_inverse(r) 
    78749 ^^^^^^^^^^^^^^^^^ 
    78750 File
    78751 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78752 packages/numpy/linalg/linalg.py", line 561, in inv 
    78753 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    78754 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78755 File
    78756 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78757 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    78758 raise LinAlgError("Singular matrix") 
    78759 numpy.linalg.LinAlgError: Singular matrix 
    78760  
    78761 numpy.linalg.LinAlgError: Singular matrix 
    78762  
    78763 File
    78764 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78765 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    78766 raise LinAlgError("Singular matrix") 
    78767  
    78768 See log for complete Python traceback. 
    78769  
    78770 Traceback (most recent call last): 
    78771 File
    78772 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78773 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    78774 self.session.ui.mouse_modes.mouse_pause_tracking() 
    78775 File
    78776 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78777 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    78778 mouse_pause_tracking 
    78779 self._mouse_pause() 
    78780 File
    78781 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78782 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    78783 m.pause(self._mouse_pause_position) 
    78784 File
    78785 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78786 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    78787 p = self.view.picked_object(x, y) 
    78788 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78789 File
    78790 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78791 packages/chimerax/graphics/view.py", line 838, in picked_object 
    78792 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    78793 beyond, 
    78794 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78795 File
    78796 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78797 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    78798 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    78799 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78800 File
    78801 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78802 packages/chimerax/core/models.py", line 143, in first_intercept 
    78803 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    78804 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78805 File
    78806 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78807 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    78808 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    78809 exclude=exclude) 
    78810 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78811 File
    78812 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78813 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    78814 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    78815 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78816 File
    78817 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78818 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    78819 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    78820 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78821 File
    78822 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78823 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    78824 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    78825 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78826 File
    78827 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78828 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    78829 p = super().first_intercept(mxyz1, mxyz2) 
    78830 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78831 File
    78832 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78833 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    78834 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    78835 exclude=exclude) 
    78836 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78837 File
    78838 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78839 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    78840 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    78841 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78842 File
    78843 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78844 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    78845 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    78846 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78847 File
    78848 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78849 packages/chimerax/graphics/drawing.py", line 1108, in
    78850 _first_intercept_excluding_children 
    78851 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    78852 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78853 File
    78854 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78855 packages/chimerax/geometry/place.py", line 201, in inverse 
    78856 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    78857 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78858 File
    78859 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78860 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    78861 rinv[:, :] = matrix_inverse(r) 
    78862 ^^^^^^^^^^^^^^^^^ 
    78863 File
    78864 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78865 packages/numpy/linalg/linalg.py", line 561, in inv 
    78866 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    78867 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78868 File
    78869 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78870 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    78871 raise LinAlgError("Singular matrix") 
    78872 numpy.linalg.LinAlgError: Singular matrix 
    78873  
    78874 numpy.linalg.LinAlgError: Singular matrix 
    78875  
    78876 File
    78877 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78878 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    78879 raise LinAlgError("Singular matrix") 
    78880  
    78881 See log for complete Python traceback. 
    78882  
    78883 Traceback (most recent call last): 
    78884 File
    78885 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78886 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    78887 self.session.ui.mouse_modes.mouse_pause_tracking() 
    78888 File
    78889 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78890 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    78891 mouse_pause_tracking 
    78892 self._mouse_pause() 
    78893 File
    78894 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78895 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    78896 m.pause(self._mouse_pause_position) 
    78897 File
    78898 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78899 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    78900 p = self.view.picked_object(x, y) 
    78901 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78902 File
    78903 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78904 packages/chimerax/graphics/view.py", line 838, in picked_object 
    78905 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    78906 beyond, 
    78907 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78908 File
    78909 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78910 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    78911 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    78912 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78913 File
    78914 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78915 packages/chimerax/core/models.py", line 143, in first_intercept 
    78916 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    78917 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78918 File
    78919 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78920 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    78921 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    78922 exclude=exclude) 
    78923 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78924 File
    78925 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78926 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    78927 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    78928 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78929 File
    78930 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78931 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    78932 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    78933 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78934 File
    78935 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78936 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    78937 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    78938 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78939 File
    78940 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78941 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    78942 p = super().first_intercept(mxyz1, mxyz2) 
    78943 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78944 File
    78945 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78946 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    78947 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    78948 exclude=exclude) 
    78949 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78950 File
    78951 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78952 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    78953 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    78954 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78955 File
    78956 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78957 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    78958 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    78959 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78960 File
    78961 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78962 packages/chimerax/graphics/drawing.py", line 1108, in
    78963 _first_intercept_excluding_children 
    78964 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    78965 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78966 File
    78967 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78968 packages/chimerax/geometry/place.py", line 201, in inverse 
    78969 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    78970 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78971 File
    78972 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78973 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    78974 rinv[:, :] = matrix_inverse(r) 
    78975 ^^^^^^^^^^^^^^^^^ 
    78976 File
    78977 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78978 packages/numpy/linalg/linalg.py", line 561, in inv 
    78979 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    78980 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    78981 File
    78982 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78983 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    78984 raise LinAlgError("Singular matrix") 
    78985 numpy.linalg.LinAlgError: Singular matrix 
    78986  
    78987 numpy.linalg.LinAlgError: Singular matrix 
    78988  
    78989 File
    78990 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78991 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    78992 raise LinAlgError("Singular matrix") 
    78993  
    78994 See log for complete Python traceback. 
    78995  
    78996 Traceback (most recent call last): 
    78997 File
    78998 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    78999 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    79000 self.session.ui.mouse_modes.mouse_pause_tracking() 
    79001 File
    79002 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79003 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    79004 mouse_pause_tracking 
    79005 self._mouse_pause() 
    79006 File
    79007 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79008 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    79009 m.pause(self._mouse_pause_position) 
    79010 File
    79011 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79012 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    79013 p = self.view.picked_object(x, y) 
    79014 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79015 File
    79016 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79017 packages/chimerax/graphics/view.py", line 838, in picked_object 
    79018 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    79019 beyond, 
    79020 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79021 File
    79022 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79023 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    79024 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    79025 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79026 File
    79027 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79028 packages/chimerax/core/models.py", line 143, in first_intercept 
    79029 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    79030 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79031 File
    79032 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79033 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    79034 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    79035 exclude=exclude) 
    79036 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79037 File
    79038 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79039 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    79040 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    79041 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79042 File
    79043 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79044 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    79045 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    79046 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79047 File
    79048 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79049 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    79050 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    79051 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79052 File
    79053 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79054 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    79055 p = super().first_intercept(mxyz1, mxyz2) 
    79056 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79057 File
    79058 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79059 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    79060 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    79061 exclude=exclude) 
    79062 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79063 File
    79064 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79065 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    79066 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    79067 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79068 File
    79069 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79070 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    79071 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    79072 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79073 File
    79074 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79075 packages/chimerax/graphics/drawing.py", line 1108, in
    79076 _first_intercept_excluding_children 
    79077 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    79078 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79079 File
    79080 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79081 packages/chimerax/geometry/place.py", line 201, in inverse 
    79082 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    79083 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79084 File
    79085 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79086 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    79087 rinv[:, :] = matrix_inverse(r) 
    79088 ^^^^^^^^^^^^^^^^^ 
    79089 File
    79090 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79091 packages/numpy/linalg/linalg.py", line 561, in inv 
    79092 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    79093 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79094 File
    79095 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79096 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    79097 raise LinAlgError("Singular matrix") 
    79098 numpy.linalg.LinAlgError: Singular matrix 
    79099  
    79100 numpy.linalg.LinAlgError: Singular matrix 
    79101  
    79102 File
    79103 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79104 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    79105 raise LinAlgError("Singular matrix") 
    79106  
    79107 See log for complete Python traceback. 
    79108  
    79109 Traceback (most recent call last): 
    79110 File
    79111 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79112 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    79113 self.session.ui.mouse_modes.mouse_pause_tracking() 
    79114 File
    79115 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79116 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    79117 mouse_pause_tracking 
    79118 self._mouse_pause() 
    79119 File
    79120 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79121 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    79122 m.pause(self._mouse_pause_position) 
    79123 File
    79124 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79125 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    79126 p = self.view.picked_object(x, y) 
    79127 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79128 File
    79129 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79130 packages/chimerax/graphics/view.py", line 838, in picked_object 
    79131 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    79132 beyond, 
    79133 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79134 File
    79135 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79136 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    79137 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    79138 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79139 File
    79140 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79141 packages/chimerax/core/models.py", line 143, in first_intercept 
    79142 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    79143 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79144 File
    79145 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79146 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    79147 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    79148 exclude=exclude) 
    79149 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79150 File
    79151 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79152 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    79153 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    79154 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79155 File
    79156 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79157 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    79158 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    79159 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79160 File
    79161 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79162 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    79163 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    79164 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79165 File
    79166 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79167 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    79168 p = super().first_intercept(mxyz1, mxyz2) 
    79169 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79170 File
    79171 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79172 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    79173 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    79174 exclude=exclude) 
    79175 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79176 File
    79177 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79178 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    79179 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    79180 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79181 File
    79182 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79183 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    79184 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    79185 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79186 File
    79187 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79188 packages/chimerax/graphics/drawing.py", line 1108, in
    79189 _first_intercept_excluding_children 
    79190 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    79191 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79192 File
    79193 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79194 packages/chimerax/geometry/place.py", line 201, in inverse 
    79195 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    79196 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79197 File
    79198 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79199 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    79200 rinv[:, :] = matrix_inverse(r) 
    79201 ^^^^^^^^^^^^^^^^^ 
    79202 File
    79203 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79204 packages/numpy/linalg/linalg.py", line 561, in inv 
    79205 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    79206 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79207 File
    79208 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79209 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    79210 raise LinAlgError("Singular matrix") 
    79211 numpy.linalg.LinAlgError: Singular matrix 
    79212  
    79213 numpy.linalg.LinAlgError: Singular matrix 
    79214  
    79215 File
    79216 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79217 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    79218 raise LinAlgError("Singular matrix") 
    79219  
    79220 See log for complete Python traceback. 
    79221  
    79222 Traceback (most recent call last): 
    79223 File
    79224 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79225 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    79226 self.session.ui.mouse_modes.mouse_pause_tracking() 
    79227 File
    79228 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79229 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    79230 mouse_pause_tracking 
    79231 self._mouse_pause() 
    79232 File
    79233 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79234 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    79235 m.pause(self._mouse_pause_position) 
    79236 File
    79237 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79238 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    79239 p = self.view.picked_object(x, y) 
    79240 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79241 File
    79242 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79243 packages/chimerax/graphics/view.py", line 838, in picked_object 
    79244 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    79245 beyond, 
    79246 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79247 File
    79248 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79249 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    79250 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    79251 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79252 File
    79253 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79254 packages/chimerax/core/models.py", line 143, in first_intercept 
    79255 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    79256 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79257 File
    79258 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79259 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    79260 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    79261 exclude=exclude) 
    79262 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79263 File
    79264 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79265 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    79266 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    79267 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79268 File
    79269 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79270 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    79271 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    79272 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79273 File
    79274 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79275 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    79276 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    79277 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79278 File
    79279 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79280 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    79281 p = super().first_intercept(mxyz1, mxyz2) 
    79282 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79283 File
    79284 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79285 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    79286 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    79287 exclude=exclude) 
    79288 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79289 File
    79290 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79291 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    79292 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    79293 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79294 File
    79295 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79296 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    79297 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    79298 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79299 File
    79300 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79301 packages/chimerax/graphics/drawing.py", line 1108, in
    79302 _first_intercept_excluding_children 
    79303 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    79304 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79305 File
    79306 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79307 packages/chimerax/geometry/place.py", line 201, in inverse 
    79308 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    79309 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79310 File
    79311 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79312 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    79313 rinv[:, :] = matrix_inverse(r) 
    79314 ^^^^^^^^^^^^^^^^^ 
    79315 File
    79316 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79317 packages/numpy/linalg/linalg.py", line 561, in inv 
    79318 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    79319 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79320 File
    79321 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79322 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    79323 raise LinAlgError("Singular matrix") 
    79324 numpy.linalg.LinAlgError: Singular matrix 
    79325  
    79326 numpy.linalg.LinAlgError: Singular matrix 
    79327  
    79328 File
    79329 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79330 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    79331 raise LinAlgError("Singular matrix") 
    79332  
    79333 See log for complete Python traceback. 
    79334  
    79335 Traceback (most recent call last): 
    79336 File
    79337 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79338 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    79339 self.session.ui.mouse_modes.mouse_pause_tracking() 
    79340 File
    79341 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79342 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    79343 mouse_pause_tracking 
    79344 self._mouse_pause() 
    79345 File
    79346 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79347 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    79348 m.pause(self._mouse_pause_position) 
    79349 File
    79350 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79351 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    79352 p = self.view.picked_object(x, y) 
    79353 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79354 File
    79355 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79356 packages/chimerax/graphics/view.py", line 838, in picked_object 
    79357 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    79358 beyond, 
    79359 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79360 File
    79361 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79362 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    79363 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    79364 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79365 File
    79366 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79367 packages/chimerax/core/models.py", line 143, in first_intercept 
    79368 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    79369 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79370 File
    79371 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79372 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    79373 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    79374 exclude=exclude) 
    79375 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79376 File
    79377 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79378 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    79379 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    79380 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79381 File
    79382 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79383 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    79384 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    79385 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79386 File
    79387 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79388 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    79389 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    79390 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79391 File
    79392 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79393 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    79394 p = super().first_intercept(mxyz1, mxyz2) 
    79395 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79396 File
    79397 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79398 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    79399 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    79400 exclude=exclude) 
    79401 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79402 File
    79403 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79404 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    79405 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    79406 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79407 File
    79408 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79409 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    79410 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    79411 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79412 File
    79413 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79414 packages/chimerax/graphics/drawing.py", line 1108, in
    79415 _first_intercept_excluding_children 
    79416 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    79417 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79418 File
    79419 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79420 packages/chimerax/geometry/place.py", line 201, in inverse 
    79421 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    79422 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79423 File
    79424 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79425 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    79426 rinv[:, :] = matrix_inverse(r) 
    79427 ^^^^^^^^^^^^^^^^^ 
    79428 File
    79429 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79430 packages/numpy/linalg/linalg.py", line 561, in inv 
    79431 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    79432 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79433 File
    79434 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79435 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    79436 raise LinAlgError("Singular matrix") 
    79437 numpy.linalg.LinAlgError: Singular matrix 
    79438  
    79439 numpy.linalg.LinAlgError: Singular matrix 
    79440  
    79441 File
    79442 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79443 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    79444 raise LinAlgError("Singular matrix") 
    79445  
    79446 See log for complete Python traceback. 
    79447  
    79448 Traceback (most recent call last): 
    79449 File
    79450 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79451 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    79452 self.session.ui.mouse_modes.mouse_pause_tracking() 
    79453 File
    79454 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79455 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    79456 mouse_pause_tracking 
    79457 self._mouse_pause() 
    79458 File
    79459 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79460 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    79461 m.pause(self._mouse_pause_position) 
    79462 File
    79463 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79464 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    79465 p = self.view.picked_object(x, y) 
    79466 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79467 File
    79468 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79469 packages/chimerax/graphics/view.py", line 838, in picked_object 
    79470 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    79471 beyond, 
    79472 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79473 File
    79474 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79475 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    79476 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    79477 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79478 File
    79479 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79480 packages/chimerax/core/models.py", line 143, in first_intercept 
    79481 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    79482 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79483 File
    79484 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79485 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    79486 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    79487 exclude=exclude) 
    79488 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79489 File
    79490 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79491 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    79492 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    79493 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79494 File
    79495 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79496 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    79497 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    79498 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79499 File
    79500 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79501 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    79502 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    79503 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79504 File
    79505 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79506 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    79507 p = super().first_intercept(mxyz1, mxyz2) 
    79508 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79509 File
    79510 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79511 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    79512 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    79513 exclude=exclude) 
    79514 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79515 File
    79516 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79517 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    79518 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    79519 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79520 File
    79521 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79522 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    79523 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    79524 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79525 File
    79526 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79527 packages/chimerax/graphics/drawing.py", line 1108, in
    79528 _first_intercept_excluding_children 
    79529 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    79530 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79531 File
    79532 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79533 packages/chimerax/geometry/place.py", line 201, in inverse 
    79534 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    79535 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79536 File
    79537 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79538 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    79539 rinv[:, :] = matrix_inverse(r) 
    79540 ^^^^^^^^^^^^^^^^^ 
    79541 File
    79542 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79543 packages/numpy/linalg/linalg.py", line 561, in inv 
    79544 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    79545 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79546 File
    79547 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79548 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    79549 raise LinAlgError("Singular matrix") 
    79550 numpy.linalg.LinAlgError: Singular matrix 
    79551  
    79552 numpy.linalg.LinAlgError: Singular matrix 
    79553  
    79554 File
    79555 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79556 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    79557 raise LinAlgError("Singular matrix") 
    79558  
    79559 See log for complete Python traceback. 
    79560  
    79561 Traceback (most recent call last): 
    79562 File
    79563 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79564 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    79565 self.session.ui.mouse_modes.mouse_pause_tracking() 
    79566 File
    79567 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79568 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    79569 mouse_pause_tracking 
    79570 self._mouse_pause() 
    79571 File
    79572 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79573 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    79574 m.pause(self._mouse_pause_position) 
    79575 File
    79576 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79577 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    79578 p = self.view.picked_object(x, y) 
    79579 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79580 File
    79581 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79582 packages/chimerax/graphics/view.py", line 838, in picked_object 
    79583 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    79584 beyond, 
    79585 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79586 File
    79587 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79588 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    79589 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    79590 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79591 File
    79592 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79593 packages/chimerax/core/models.py", line 143, in first_intercept 
    79594 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    79595 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79596 File
    79597 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79598 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    79599 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    79600 exclude=exclude) 
    79601 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79602 File
    79603 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79604 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    79605 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    79606 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79607 File
    79608 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79609 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    79610 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    79611 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79612 File
    79613 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79614 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    79615 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    79616 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79617 File
    79618 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79619 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    79620 p = super().first_intercept(mxyz1, mxyz2) 
    79621 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79622 File
    79623 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79624 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    79625 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    79626 exclude=exclude) 
    79627 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79628 File
    79629 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79630 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    79631 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    79632 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79633 File
    79634 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79635 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    79636 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    79637 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79638 File
    79639 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79640 packages/chimerax/graphics/drawing.py", line 1108, in
    79641 _first_intercept_excluding_children 
    79642 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    79643 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79644 File
    79645 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79646 packages/chimerax/geometry/place.py", line 201, in inverse 
    79647 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    79648 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79649 File
    79650 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79651 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    79652 rinv[:, :] = matrix_inverse(r) 
    79653 ^^^^^^^^^^^^^^^^^ 
    79654 File
    79655 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79656 packages/numpy/linalg/linalg.py", line 561, in inv 
    79657 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    79658 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79659 File
    79660 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79661 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    79662 raise LinAlgError("Singular matrix") 
    79663 numpy.linalg.LinAlgError: Singular matrix 
    79664  
    79665 numpy.linalg.LinAlgError: Singular matrix 
    79666  
    79667 File
    79668 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79669 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    79670 raise LinAlgError("Singular matrix") 
    79671  
    79672 See log for complete Python traceback. 
    79673  
    79674 Traceback (most recent call last): 
    79675 File
    79676 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79677 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    79678 self.session.ui.mouse_modes.mouse_pause_tracking() 
    79679 File
    79680 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79681 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    79682 mouse_pause_tracking 
    79683 self._mouse_pause() 
    79684 File
    79685 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79686 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    79687 m.pause(self._mouse_pause_position) 
    79688 File
    79689 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79690 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    79691 p = self.view.picked_object(x, y) 
    79692 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79693 File
    79694 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79695 packages/chimerax/graphics/view.py", line 838, in picked_object 
    79696 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    79697 beyond, 
    79698 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79699 File
    79700 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79701 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    79702 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    79703 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79704 File
    79705 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79706 packages/chimerax/core/models.py", line 143, in first_intercept 
    79707 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    79708 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79709 File
    79710 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79711 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    79712 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    79713 exclude=exclude) 
    79714 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79715 File
    79716 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79717 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    79718 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    79719 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79720 File
    79721 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79722 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    79723 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    79724 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79725 File
    79726 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79727 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    79728 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    79729 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79730 File
    79731 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79732 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    79733 p = super().first_intercept(mxyz1, mxyz2) 
    79734 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79735 File
    79736 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79737 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    79738 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    79739 exclude=exclude) 
    79740 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79741 File
    79742 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79743 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    79744 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    79745 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79746 File
    79747 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79748 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    79749 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    79750 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79751 File
    79752 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79753 packages/chimerax/graphics/drawing.py", line 1108, in
    79754 _first_intercept_excluding_children 
    79755 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    79756 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79757 File
    79758 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79759 packages/chimerax/geometry/place.py", line 201, in inverse 
    79760 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    79761 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79762 File
    79763 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79764 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    79765 rinv[:, :] = matrix_inverse(r) 
    79766 ^^^^^^^^^^^^^^^^^ 
    79767 File
    79768 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79769 packages/numpy/linalg/linalg.py", line 561, in inv 
    79770 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    79771 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79772 File
    79773 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79774 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    79775 raise LinAlgError("Singular matrix") 
    79776 numpy.linalg.LinAlgError: Singular matrix 
    79777  
    79778 numpy.linalg.LinAlgError: Singular matrix 
    79779  
    79780 File
    79781 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79782 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    79783 raise LinAlgError("Singular matrix") 
    79784  
    79785 See log for complete Python traceback. 
    79786  
    79787 Traceback (most recent call last): 
    79788 File
    79789 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79790 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    79791 self.session.ui.mouse_modes.mouse_pause_tracking() 
    79792 File
    79793 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79794 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    79795 mouse_pause_tracking 
    79796 self._mouse_pause() 
    79797 File
    79798 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79799 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    79800 m.pause(self._mouse_pause_position) 
    79801 File
    79802 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79803 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    79804 p = self.view.picked_object(x, y) 
    79805 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79806 File
    79807 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79808 packages/chimerax/graphics/view.py", line 838, in picked_object 
    79809 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    79810 beyond, 
    79811 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79812 File
    79813 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79814 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    79815 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    79816 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79817 File
    79818 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79819 packages/chimerax/core/models.py", line 143, in first_intercept 
    79820 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    79821 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79822 File
    79823 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79824 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    79825 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    79826 exclude=exclude) 
    79827 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79828 File
    79829 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79830 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    79831 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    79832 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79833 File
    79834 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79835 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    79836 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    79837 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79838 File
    79839 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79840 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    79841 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    79842 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79843 File
    79844 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79845 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    79846 p = super().first_intercept(mxyz1, mxyz2) 
    79847 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79848 File
    79849 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79850 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    79851 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    79852 exclude=exclude) 
    79853 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79854 File
    79855 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79856 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    79857 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    79858 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79859 File
    79860 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79861 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    79862 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    79863 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79864 File
    79865 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79866 packages/chimerax/graphics/drawing.py", line 1108, in
    79867 _first_intercept_excluding_children 
    79868 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    79869 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79870 File
    79871 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79872 packages/chimerax/geometry/place.py", line 201, in inverse 
    79873 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    79874 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79875 File
    79876 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79877 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    79878 rinv[:, :] = matrix_inverse(r) 
    79879 ^^^^^^^^^^^^^^^^^ 
    79880 File
    79881 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79882 packages/numpy/linalg/linalg.py", line 561, in inv 
    79883 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    79884 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79885 File
    79886 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79887 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    79888 raise LinAlgError("Singular matrix") 
    79889 numpy.linalg.LinAlgError: Singular matrix 
    79890  
    79891 numpy.linalg.LinAlgError: Singular matrix 
    79892  
    79893 File
    79894 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79895 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    79896 raise LinAlgError("Singular matrix") 
    79897  
    79898 See log for complete Python traceback. 
    79899  
    79900 Traceback (most recent call last): 
    79901 File
    79902 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79903 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    79904 self.session.ui.mouse_modes.mouse_pause_tracking() 
    79905 File
    79906 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79907 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    79908 mouse_pause_tracking 
    79909 self._mouse_pause() 
    79910 File
    79911 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79912 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    79913 m.pause(self._mouse_pause_position) 
    79914 File
    79915 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79916 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    79917 p = self.view.picked_object(x, y) 
    79918 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79919 File
    79920 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79921 packages/chimerax/graphics/view.py", line 838, in picked_object 
    79922 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    79923 beyond, 
    79924 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79925 File
    79926 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79927 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    79928 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    79929 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79930 File
    79931 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79932 packages/chimerax/core/models.py", line 143, in first_intercept 
    79933 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    79934 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79935 File
    79936 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79937 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    79938 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    79939 exclude=exclude) 
    79940 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79941 File
    79942 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79943 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    79944 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    79945 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79946 File
    79947 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79948 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    79949 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    79950 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79951 File
    79952 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79953 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    79954 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    79955 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79956 File
    79957 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79958 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    79959 p = super().first_intercept(mxyz1, mxyz2) 
    79960 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79961 File
    79962 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79963 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    79964 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    79965 exclude=exclude) 
    79966 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79967 File
    79968 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79969 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    79970 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    79971 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79972 File
    79973 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79974 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    79975 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    79976 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79977 File
    79978 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79979 packages/chimerax/graphics/drawing.py", line 1108, in
    79980 _first_intercept_excluding_children 
    79981 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    79982 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79983 File
    79984 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79985 packages/chimerax/geometry/place.py", line 201, in inverse 
    79986 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    79987 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79988 File
    79989 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79990 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    79991 rinv[:, :] = matrix_inverse(r) 
    79992 ^^^^^^^^^^^^^^^^^ 
    79993 File
    79994 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    79995 packages/numpy/linalg/linalg.py", line 561, in inv 
    79996 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    79997 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    79998 File
    79999 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80000 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    80001 raise LinAlgError("Singular matrix") 
    80002 numpy.linalg.LinAlgError: Singular matrix 
    80003  
    80004 numpy.linalg.LinAlgError: Singular matrix 
    80005  
    80006 File
    80007 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80008 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    80009 raise LinAlgError("Singular matrix") 
    80010  
    80011 See log for complete Python traceback. 
    80012  
    80013 Traceback (most recent call last): 
    80014 File
    80015 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80016 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    80017 self.session.ui.mouse_modes.mouse_pause_tracking() 
    80018 File
    80019 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80020 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    80021 mouse_pause_tracking 
    80022 self._mouse_pause() 
    80023 File
    80024 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80025 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    80026 m.pause(self._mouse_pause_position) 
    80027 File
    80028 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80029 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    80030 p = self.view.picked_object(x, y) 
    80031 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80032 File
    80033 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80034 packages/chimerax/graphics/view.py", line 838, in picked_object 
    80035 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    80036 beyond, 
    80037 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80038 File
    80039 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80040 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    80041 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    80042 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80043 File
    80044 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80045 packages/chimerax/core/models.py", line 143, in first_intercept 
    80046 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    80047 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80048 File
    80049 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80050 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    80051 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    80052 exclude=exclude) 
    80053 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80054 File
    80055 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80056 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    80057 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    80058 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80059 File
    80060 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80061 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    80062 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    80063 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80064 File
    80065 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80066 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    80067 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    80068 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80069 File
    80070 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80071 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    80072 p = super().first_intercept(mxyz1, mxyz2) 
    80073 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80074 File
    80075 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80076 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    80077 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    80078 exclude=exclude) 
    80079 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80080 File
    80081 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80082 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    80083 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    80084 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80085 File
    80086 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80087 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    80088 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    80089 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80090 File
    80091 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80092 packages/chimerax/graphics/drawing.py", line 1108, in
    80093 _first_intercept_excluding_children 
    80094 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    80095 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80096 File
    80097 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80098 packages/chimerax/geometry/place.py", line 201, in inverse 
    80099 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    80100 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80101 File
    80102 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80103 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    80104 rinv[:, :] = matrix_inverse(r) 
    80105 ^^^^^^^^^^^^^^^^^ 
    80106 File
    80107 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80108 packages/numpy/linalg/linalg.py", line 561, in inv 
    80109 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    80110 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80111 File
    80112 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80113 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    80114 raise LinAlgError("Singular matrix") 
    80115 numpy.linalg.LinAlgError: Singular matrix 
    80116  
    80117 numpy.linalg.LinAlgError: Singular matrix 
    80118  
    80119 File
    80120 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80121 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    80122 raise LinAlgError("Singular matrix") 
    80123  
    80124 See log for complete Python traceback. 
    80125  
    80126 Traceback (most recent call last): 
    80127 File
    80128 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80129 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    80130 self.session.ui.mouse_modes.mouse_pause_tracking() 
    80131 File
    80132 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80133 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    80134 mouse_pause_tracking 
    80135 self._mouse_pause() 
    80136 File
    80137 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80138 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    80139 m.pause(self._mouse_pause_position) 
    80140 File
    80141 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80142 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    80143 p = self.view.picked_object(x, y) 
    80144 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80145 File
    80146 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80147 packages/chimerax/graphics/view.py", line 838, in picked_object 
    80148 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    80149 beyond, 
    80150 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80151 File
    80152 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80153 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    80154 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    80155 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80156 File
    80157 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80158 packages/chimerax/core/models.py", line 143, in first_intercept 
    80159 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    80160 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80161 File
    80162 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80163 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    80164 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    80165 exclude=exclude) 
    80166 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80167 File
    80168 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80169 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    80170 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    80171 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80172 File
    80173 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80174 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    80175 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    80176 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80177 File
    80178 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80179 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    80180 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    80181 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80182 File
    80183 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80184 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    80185 p = super().first_intercept(mxyz1, mxyz2) 
    80186 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80187 File
    80188 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80189 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    80190 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    80191 exclude=exclude) 
    80192 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80193 File
    80194 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80195 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    80196 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    80197 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80198 File
    80199 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80200 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    80201 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    80202 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80203 File
    80204 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80205 packages/chimerax/graphics/drawing.py", line 1108, in
    80206 _first_intercept_excluding_children 
    80207 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    80208 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80209 File
    80210 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80211 packages/chimerax/geometry/place.py", line 201, in inverse 
    80212 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    80213 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80214 File
    80215 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80216 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    80217 rinv[:, :] = matrix_inverse(r) 
    80218 ^^^^^^^^^^^^^^^^^ 
    80219 File
    80220 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80221 packages/numpy/linalg/linalg.py", line 561, in inv 
    80222 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    80223 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80224 File
    80225 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80226 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    80227 raise LinAlgError("Singular matrix") 
    80228 numpy.linalg.LinAlgError: Singular matrix 
    80229  
    80230 numpy.linalg.LinAlgError: Singular matrix 
    80231  
    80232 File
    80233 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80234 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    80235 raise LinAlgError("Singular matrix") 
    80236  
    80237 See log for complete Python traceback. 
    80238  
    80239 Traceback (most recent call last): 
    80240 File
    80241 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80242 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    80243 self.session.ui.mouse_modes.mouse_pause_tracking() 
    80244 File
    80245 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80246 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    80247 mouse_pause_tracking 
    80248 self._mouse_pause() 
    80249 File
    80250 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80251 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    80252 m.pause(self._mouse_pause_position) 
    80253 File
    80254 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80255 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    80256 p = self.view.picked_object(x, y) 
    80257 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80258 File
    80259 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80260 packages/chimerax/graphics/view.py", line 838, in picked_object 
    80261 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    80262 beyond, 
    80263 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80264 File
    80265 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80266 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    80267 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    80268 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80269 File
    80270 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80271 packages/chimerax/core/models.py", line 143, in first_intercept 
    80272 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    80273 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80274 File
    80275 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80276 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    80277 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    80278 exclude=exclude) 
    80279 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80280 File
    80281 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80282 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    80283 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    80284 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80285 File
    80286 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80287 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    80288 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    80289 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80290 File
    80291 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80292 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    80293 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    80294 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80295 File
    80296 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80297 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    80298 p = super().first_intercept(mxyz1, mxyz2) 
    80299 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80300 File
    80301 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80302 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    80303 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    80304 exclude=exclude) 
    80305 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80306 File
    80307 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80308 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    80309 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    80310 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80311 File
    80312 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80313 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    80314 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    80315 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80316 File
    80317 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80318 packages/chimerax/graphics/drawing.py", line 1108, in
    80319 _first_intercept_excluding_children 
    80320 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    80321 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80322 File
    80323 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80324 packages/chimerax/geometry/place.py", line 201, in inverse 
    80325 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    80326 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80327 File
    80328 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80329 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    80330 rinv[:, :] = matrix_inverse(r) 
    80331 ^^^^^^^^^^^^^^^^^ 
    80332 File
    80333 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80334 packages/numpy/linalg/linalg.py", line 561, in inv 
    80335 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    80336 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80337 File
    80338 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80339 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    80340 raise LinAlgError("Singular matrix") 
    80341 numpy.linalg.LinAlgError: Singular matrix 
    80342  
    80343 numpy.linalg.LinAlgError: Singular matrix 
    80344  
    80345 File
    80346 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80347 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    80348 raise LinAlgError("Singular matrix") 
    80349  
    80350 See log for complete Python traceback. 
    80351  
    80352 Traceback (most recent call last): 
    80353 File
    80354 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80355 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    80356 self.session.ui.mouse_modes.mouse_pause_tracking() 
    80357 File
    80358 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80359 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    80360 mouse_pause_tracking 
    80361 self._mouse_pause() 
    80362 File
    80363 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80364 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    80365 m.pause(self._mouse_pause_position) 
    80366 File
    80367 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80368 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    80369 p = self.view.picked_object(x, y) 
    80370 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80371 File
    80372 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80373 packages/chimerax/graphics/view.py", line 838, in picked_object 
    80374 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    80375 beyond, 
    80376 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80377 File
    80378 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80379 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    80380 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    80381 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80382 File
    80383 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80384 packages/chimerax/core/models.py", line 143, in first_intercept 
    80385 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    80386 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80387 File
    80388 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80389 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    80390 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    80391 exclude=exclude) 
    80392 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80393 File
    80394 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80395 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    80396 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    80397 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80398 File
    80399 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80400 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    80401 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    80402 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80403 File
    80404 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80405 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    80406 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    80407 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80408 File
    80409 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80410 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    80411 p = super().first_intercept(mxyz1, mxyz2) 
    80412 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80413 File
    80414 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80415 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    80416 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    80417 exclude=exclude) 
    80418 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80419 File
    80420 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80421 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    80422 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    80423 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80424 File
    80425 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80426 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    80427 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    80428 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80429 File
    80430 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80431 packages/chimerax/graphics/drawing.py", line 1108, in
    80432 _first_intercept_excluding_children 
    80433 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    80434 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80435 File
    80436 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80437 packages/chimerax/geometry/place.py", line 201, in inverse 
    80438 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    80439 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80440 File
    80441 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80442 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    80443 rinv[:, :] = matrix_inverse(r) 
    80444 ^^^^^^^^^^^^^^^^^ 
    80445 File
    80446 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80447 packages/numpy/linalg/linalg.py", line 561, in inv 
    80448 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    80449 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80450 File
    80451 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80452 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    80453 raise LinAlgError("Singular matrix") 
    80454 numpy.linalg.LinAlgError: Singular matrix 
    80455  
    80456 numpy.linalg.LinAlgError: Singular matrix 
    80457  
    80458 File
    80459 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80460 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    80461 raise LinAlgError("Singular matrix") 
    80462  
    80463 See log for complete Python traceback. 
    80464  
    80465 Traceback (most recent call last): 
    80466 File
    80467 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80468 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    80469 self.session.ui.mouse_modes.mouse_pause_tracking() 
    80470 File
    80471 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80472 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    80473 mouse_pause_tracking 
    80474 self._mouse_pause() 
    80475 File
    80476 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80477 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    80478 m.pause(self._mouse_pause_position) 
    80479 File
    80480 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80481 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    80482 p = self.view.picked_object(x, y) 
    80483 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80484 File
    80485 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80486 packages/chimerax/graphics/view.py", line 838, in picked_object 
    80487 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    80488 beyond, 
    80489 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80490 File
    80491 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80492 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    80493 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    80494 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80495 File
    80496 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80497 packages/chimerax/core/models.py", line 143, in first_intercept 
    80498 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    80499 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80500 File
    80501 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80502 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    80503 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    80504 exclude=exclude) 
    80505 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80506 File
    80507 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80508 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    80509 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    80510 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80511 File
    80512 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80513 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    80514 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    80515 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80516 File
    80517 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80518 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    80519 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    80520 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80521 File
    80522 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80523 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    80524 p = super().first_intercept(mxyz1, mxyz2) 
    80525 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80526 File
    80527 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80528 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    80529 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    80530 exclude=exclude) 
    80531 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80532 File
    80533 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80534 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    80535 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    80536 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80537 File
    80538 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80539 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    80540 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    80541 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80542 File
    80543 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80544 packages/chimerax/graphics/drawing.py", line 1108, in
    80545 _first_intercept_excluding_children 
    80546 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    80547 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80548 File
    80549 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80550 packages/chimerax/geometry/place.py", line 201, in inverse 
    80551 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    80552 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80553 File
    80554 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80555 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    80556 rinv[:, :] = matrix_inverse(r) 
    80557 ^^^^^^^^^^^^^^^^^ 
    80558 File
    80559 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80560 packages/numpy/linalg/linalg.py", line 561, in inv 
    80561 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    80562 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80563 File
    80564 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80565 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    80566 raise LinAlgError("Singular matrix") 
    80567 numpy.linalg.LinAlgError: Singular matrix 
    80568  
    80569 numpy.linalg.LinAlgError: Singular matrix 
    80570  
    80571 File
    80572 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80573 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    80574 raise LinAlgError("Singular matrix") 
    80575  
    80576 See log for complete Python traceback. 
    80577  
    80578 Traceback (most recent call last): 
    80579 File
    80580 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80581 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    80582 self.session.ui.mouse_modes.mouse_pause_tracking() 
    80583 File
    80584 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80585 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    80586 mouse_pause_tracking 
    80587 self._mouse_pause() 
    80588 File
    80589 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80590 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    80591 m.pause(self._mouse_pause_position) 
    80592 File
    80593 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80594 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    80595 p = self.view.picked_object(x, y) 
    80596 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80597 File
    80598 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80599 packages/chimerax/graphics/view.py", line 838, in picked_object 
    80600 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    80601 beyond, 
    80602 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80603 File
    80604 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80605 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    80606 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    80607 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80608 File
    80609 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80610 packages/chimerax/core/models.py", line 143, in first_intercept 
    80611 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    80612 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80613 File
    80614 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80615 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    80616 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    80617 exclude=exclude) 
    80618 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80619 File
    80620 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80621 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    80622 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    80623 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80624 File
    80625 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80626 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    80627 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    80628 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80629 File
    80630 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80631 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    80632 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    80633 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80634 File
    80635 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80636 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    80637 p = super().first_intercept(mxyz1, mxyz2) 
    80638 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80639 File
    80640 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80641 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    80642 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    80643 exclude=exclude) 
    80644 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80645 File
    80646 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80647 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    80648 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    80649 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80650 File
    80651 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80652 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    80653 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    80654 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80655 File
    80656 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80657 packages/chimerax/graphics/drawing.py", line 1108, in
    80658 _first_intercept_excluding_children 
    80659 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    80660 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80661 File
    80662 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80663 packages/chimerax/geometry/place.py", line 201, in inverse 
    80664 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    80665 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80666 File
    80667 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80668 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    80669 rinv[:, :] = matrix_inverse(r) 
    80670 ^^^^^^^^^^^^^^^^^ 
    80671 File
    80672 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80673 packages/numpy/linalg/linalg.py", line 561, in inv 
    80674 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    80675 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80676 File
    80677 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80678 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    80679 raise LinAlgError("Singular matrix") 
    80680 numpy.linalg.LinAlgError: Singular matrix 
    80681  
    80682 numpy.linalg.LinAlgError: Singular matrix 
    80683  
    80684 File
    80685 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80686 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    80687 raise LinAlgError("Singular matrix") 
    80688  
    80689 See log for complete Python traceback. 
    80690  
    80691 Traceback (most recent call last): 
    80692 File
    80693 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80694 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    80695 self.session.ui.mouse_modes.mouse_pause_tracking() 
    80696 File
    80697 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80698 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    80699 mouse_pause_tracking 
    80700 self._mouse_pause() 
    80701 File
    80702 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80703 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    80704 m.pause(self._mouse_pause_position) 
    80705 File
    80706 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80707 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    80708 p = self.view.picked_object(x, y) 
    80709 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80710 File
    80711 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80712 packages/chimerax/graphics/view.py", line 838, in picked_object 
    80713 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    80714 beyond, 
    80715 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80716 File
    80717 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80718 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    80719 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    80720 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80721 File
    80722 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80723 packages/chimerax/core/models.py", line 143, in first_intercept 
    80724 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    80725 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80726 File
    80727 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80728 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    80729 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    80730 exclude=exclude) 
    80731 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80732 File
    80733 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80734 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    80735 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    80736 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80737 File
    80738 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80739 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    80740 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    80741 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80742 File
    80743 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80744 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    80745 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    80746 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80747 File
    80748 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80749 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    80750 p = super().first_intercept(mxyz1, mxyz2) 
    80751 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80752 File
    80753 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80754 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    80755 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    80756 exclude=exclude) 
    80757 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80758 File
    80759 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80760 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    80761 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    80762 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80763 File
    80764 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80765 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    80766 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    80767 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80768 File
    80769 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80770 packages/chimerax/graphics/drawing.py", line 1108, in
    80771 _first_intercept_excluding_children 
    80772 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    80773 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80774 File
    80775 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80776 packages/chimerax/geometry/place.py", line 201, in inverse 
    80777 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    80778 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80779 File
    80780 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80781 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    80782 rinv[:, :] = matrix_inverse(r) 
    80783 ^^^^^^^^^^^^^^^^^ 
    80784 File
    80785 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80786 packages/numpy/linalg/linalg.py", line 561, in inv 
    80787 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    80788 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80789 File
    80790 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80791 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    80792 raise LinAlgError("Singular matrix") 
    80793 numpy.linalg.LinAlgError: Singular matrix 
    80794  
    80795 numpy.linalg.LinAlgError: Singular matrix 
    80796  
    80797 File
    80798 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80799 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    80800 raise LinAlgError("Singular matrix") 
    80801  
    80802 See log for complete Python traceback. 
    80803  
    80804 Traceback (most recent call last): 
    80805 File
    80806 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80807 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    80808 self.session.ui.mouse_modes.mouse_pause_tracking() 
    80809 File
    80810 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80811 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    80812 mouse_pause_tracking 
    80813 self._mouse_pause() 
    80814 File
    80815 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80816 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    80817 m.pause(self._mouse_pause_position) 
    80818 File
    80819 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80820 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    80821 p = self.view.picked_object(x, y) 
    80822 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80823 File
    80824 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80825 packages/chimerax/graphics/view.py", line 838, in picked_object 
    80826 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    80827 beyond, 
    80828 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80829 File
    80830 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80831 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    80832 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    80833 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80834 File
    80835 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80836 packages/chimerax/core/models.py", line 143, in first_intercept 
    80837 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    80838 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80839 File
    80840 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80841 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    80842 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    80843 exclude=exclude) 
    80844 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80845 File
    80846 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80847 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    80848 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    80849 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80850 File
    80851 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80852 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    80853 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    80854 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80855 File
    80856 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80857 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    80858 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    80859 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80860 File
    80861 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80862 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    80863 p = super().first_intercept(mxyz1, mxyz2) 
    80864 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80865 File
    80866 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80867 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    80868 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    80869 exclude=exclude) 
    80870 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80871 File
    80872 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80873 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    80874 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    80875 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80876 File
    80877 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80878 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    80879 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    80880 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80881 File
    80882 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80883 packages/chimerax/graphics/drawing.py", line 1108, in
    80884 _first_intercept_excluding_children 
    80885 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    80886 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80887 File
    80888 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80889 packages/chimerax/geometry/place.py", line 201, in inverse 
    80890 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    80891 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80892 File
    80893 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80894 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    80895 rinv[:, :] = matrix_inverse(r) 
    80896 ^^^^^^^^^^^^^^^^^ 
    80897 File
    80898 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80899 packages/numpy/linalg/linalg.py", line 561, in inv 
    80900 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    80901 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80902 File
    80903 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80904 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    80905 raise LinAlgError("Singular matrix") 
    80906 numpy.linalg.LinAlgError: Singular matrix 
    80907  
    80908 numpy.linalg.LinAlgError: Singular matrix 
    80909  
    80910 File
    80911 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80912 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    80913 raise LinAlgError("Singular matrix") 
    80914  
    80915 See log for complete Python traceback. 
    80916  
    80917 Traceback (most recent call last): 
    80918 File
    80919 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80920 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    80921 self.session.ui.mouse_modes.mouse_pause_tracking() 
    80922 File
    80923 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80924 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    80925 mouse_pause_tracking 
    80926 self._mouse_pause() 
    80927 File
    80928 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80929 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    80930 m.pause(self._mouse_pause_position) 
    80931 File
    80932 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80933 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    80934 p = self.view.picked_object(x, y) 
    80935 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80936 File
    80937 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80938 packages/chimerax/graphics/view.py", line 838, in picked_object 
    80939 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    80940 beyond, 
    80941 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80942 File
    80943 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80944 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    80945 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    80946 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80947 File
    80948 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80949 packages/chimerax/core/models.py", line 143, in first_intercept 
    80950 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    80951 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80952 File
    80953 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80954 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    80955 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    80956 exclude=exclude) 
    80957 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80958 File
    80959 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80960 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    80961 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    80962 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80963 File
    80964 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80965 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    80966 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    80967 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80968 File
    80969 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80970 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    80971 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    80972 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80973 File
    80974 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80975 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    80976 p = super().first_intercept(mxyz1, mxyz2) 
    80977 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80978 File
    80979 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80980 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    80981 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    80982 exclude=exclude) 
    80983 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80984 File
    80985 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80986 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    80987 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    80988 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80989 File
    80990 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80991 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    80992 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    80993 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    80994 File
    80995 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    80996 packages/chimerax/graphics/drawing.py", line 1108, in
    80997 _first_intercept_excluding_children 
    80998 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    80999 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81000 File
    81001 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81002 packages/chimerax/geometry/place.py", line 201, in inverse 
    81003 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    81004 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81005 File
    81006 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81007 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    81008 rinv[:, :] = matrix_inverse(r) 
    81009 ^^^^^^^^^^^^^^^^^ 
    81010 File
    81011 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81012 packages/numpy/linalg/linalg.py", line 561, in inv 
    81013 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    81014 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81015 File
    81016 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81017 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    81018 raise LinAlgError("Singular matrix") 
    81019 numpy.linalg.LinAlgError: Singular matrix 
    81020  
    81021 numpy.linalg.LinAlgError: Singular matrix 
    81022  
    81023 File
    81024 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81025 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    81026 raise LinAlgError("Singular matrix") 
    81027  
    81028 See log for complete Python traceback. 
    81029  
    81030 Traceback (most recent call last): 
    81031 File
    81032 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81033 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    81034 self.session.ui.mouse_modes.mouse_pause_tracking() 
    81035 File
    81036 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81037 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    81038 mouse_pause_tracking 
    81039 self._mouse_pause() 
    81040 File
    81041 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81042 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    81043 m.pause(self._mouse_pause_position) 
    81044 File
    81045 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81046 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    81047 p = self.view.picked_object(x, y) 
    81048 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81049 File
    81050 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81051 packages/chimerax/graphics/view.py", line 838, in picked_object 
    81052 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    81053 beyond, 
    81054 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81055 File
    81056 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81057 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    81058 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    81059 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81060 File
    81061 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81062 packages/chimerax/core/models.py", line 143, in first_intercept 
    81063 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    81064 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81065 File
    81066 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81067 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    81068 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    81069 exclude=exclude) 
    81070 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81071 File
    81072 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81073 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    81074 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    81075 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81076 File
    81077 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81078 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    81079 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    81080 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81081 File
    81082 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81083 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    81084 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    81085 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81086 File
    81087 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81088 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    81089 p = super().first_intercept(mxyz1, mxyz2) 
    81090 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81091 File
    81092 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81093 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    81094 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    81095 exclude=exclude) 
    81096 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81097 File
    81098 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81099 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    81100 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    81101 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81102 File
    81103 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81104 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    81105 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    81106 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81107 File
    81108 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81109 packages/chimerax/graphics/drawing.py", line 1108, in
    81110 _first_intercept_excluding_children 
    81111 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    81112 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81113 File
    81114 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81115 packages/chimerax/geometry/place.py", line 201, in inverse 
    81116 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    81117 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81118 File
    81119 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81120 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    81121 rinv[:, :] = matrix_inverse(r) 
    81122 ^^^^^^^^^^^^^^^^^ 
    81123 File
    81124 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81125 packages/numpy/linalg/linalg.py", line 561, in inv 
    81126 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    81127 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81128 File
    81129 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81130 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    81131 raise LinAlgError("Singular matrix") 
    81132 numpy.linalg.LinAlgError: Singular matrix 
    81133  
    81134 numpy.linalg.LinAlgError: Singular matrix 
    81135  
    81136 File
    81137 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81138 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    81139 raise LinAlgError("Singular matrix") 
    81140  
    81141 See log for complete Python traceback. 
    81142  
    81143 Traceback (most recent call last): 
    81144 File
    81145 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81146 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    81147 self.session.ui.mouse_modes.mouse_pause_tracking() 
    81148 File
    81149 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81150 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    81151 mouse_pause_tracking 
    81152 self._mouse_pause() 
    81153 File
    81154 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81155 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    81156 m.pause(self._mouse_pause_position) 
    81157 File
    81158 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81159 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    81160 p = self.view.picked_object(x, y) 
    81161 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81162 File
    81163 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81164 packages/chimerax/graphics/view.py", line 838, in picked_object 
    81165 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    81166 beyond, 
    81167 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81168 File
    81169 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81170 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    81171 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    81172 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81173 File
    81174 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81175 packages/chimerax/core/models.py", line 143, in first_intercept 
    81176 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    81177 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81178 File
    81179 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81180 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    81181 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    81182 exclude=exclude) 
    81183 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81184 File
    81185 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81186 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    81187 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    81188 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81189 File
    81190 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81191 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    81192 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    81193 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81194 File
    81195 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81196 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    81197 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    81198 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81199 File
    81200 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81201 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    81202 p = super().first_intercept(mxyz1, mxyz2) 
    81203 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81204 File
    81205 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81206 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    81207 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    81208 exclude=exclude) 
    81209 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81210 File
    81211 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81212 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    81213 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    81214 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81215 File
    81216 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81217 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    81218 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    81219 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81220 File
    81221 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81222 packages/chimerax/graphics/drawing.py", line 1108, in
    81223 _first_intercept_excluding_children 
    81224 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    81225 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81226 File
    81227 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81228 packages/chimerax/geometry/place.py", line 201, in inverse 
    81229 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    81230 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81231 File
    81232 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81233 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    81234 rinv[:, :] = matrix_inverse(r) 
    81235 ^^^^^^^^^^^^^^^^^ 
    81236 File
    81237 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81238 packages/numpy/linalg/linalg.py", line 561, in inv 
    81239 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    81240 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81241 File
    81242 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81243 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    81244 raise LinAlgError("Singular matrix") 
    81245 numpy.linalg.LinAlgError: Singular matrix 
    81246  
    81247 numpy.linalg.LinAlgError: Singular matrix 
    81248  
    81249 File
    81250 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81251 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    81252 raise LinAlgError("Singular matrix") 
    81253  
    81254 See log for complete Python traceback. 
    81255  
    81256 Traceback (most recent call last): 
    81257 File
    81258 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81259 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    81260 self.session.ui.mouse_modes.mouse_pause_tracking() 
    81261 File
    81262 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81263 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    81264 mouse_pause_tracking 
    81265 self._mouse_pause() 
    81266 File
    81267 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81268 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    81269 m.pause(self._mouse_pause_position) 
    81270 File
    81271 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81272 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    81273 p = self.view.picked_object(x, y) 
    81274 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81275 File
    81276 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81277 packages/chimerax/graphics/view.py", line 838, in picked_object 
    81278 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    81279 beyond, 
    81280 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81281 File
    81282 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81283 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    81284 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    81285 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81286 File
    81287 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81288 packages/chimerax/core/models.py", line 143, in first_intercept 
    81289 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    81290 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81291 File
    81292 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81293 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    81294 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    81295 exclude=exclude) 
    81296 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81297 File
    81298 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81299 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    81300 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    81301 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81302 File
    81303 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81304 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    81305 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    81306 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81307 File
    81308 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81309 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    81310 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    81311 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81312 File
    81313 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81314 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    81315 p = super().first_intercept(mxyz1, mxyz2) 
    81316 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81317 File
    81318 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81319 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    81320 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    81321 exclude=exclude) 
    81322 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81323 File
    81324 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81325 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    81326 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    81327 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81328 File
    81329 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81330 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    81331 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    81332 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81333 File
    81334 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81335 packages/chimerax/graphics/drawing.py", line 1108, in
    81336 _first_intercept_excluding_children 
    81337 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    81338 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81339 File
    81340 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81341 packages/chimerax/geometry/place.py", line 201, in inverse 
    81342 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    81343 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81344 File
    81345 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81346 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    81347 rinv[:, :] = matrix_inverse(r) 
    81348 ^^^^^^^^^^^^^^^^^ 
    81349 File
    81350 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81351 packages/numpy/linalg/linalg.py", line 561, in inv 
    81352 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    81353 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81354 File
    81355 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81356 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    81357 raise LinAlgError("Singular matrix") 
    81358 numpy.linalg.LinAlgError: Singular matrix 
    81359  
    81360 numpy.linalg.LinAlgError: Singular matrix 
    81361  
    81362 File
    81363 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81364 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    81365 raise LinAlgError("Singular matrix") 
    81366  
    81367 See log for complete Python traceback. 
    81368  
    81369 Traceback (most recent call last): 
    81370 File
    81371 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81372 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    81373 self.session.ui.mouse_modes.mouse_pause_tracking() 
    81374 File
    81375 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81376 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    81377 mouse_pause_tracking 
    81378 self._mouse_pause() 
    81379 File
    81380 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81381 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    81382 m.pause(self._mouse_pause_position) 
    81383 File
    81384 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81385 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    81386 p = self.view.picked_object(x, y) 
    81387 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81388 File
    81389 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81390 packages/chimerax/graphics/view.py", line 838, in picked_object 
    81391 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    81392 beyond, 
    81393 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81394 File
    81395 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81396 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    81397 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    81398 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81399 File
    81400 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81401 packages/chimerax/core/models.py", line 143, in first_intercept 
    81402 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    81403 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81404 File
    81405 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81406 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    81407 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    81408 exclude=exclude) 
    81409 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81410 File
    81411 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81412 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    81413 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    81414 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81415 File
    81416 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81417 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    81418 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    81419 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81420 File
    81421 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81422 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    81423 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    81424 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81425 File
    81426 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81427 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    81428 p = super().first_intercept(mxyz1, mxyz2) 
    81429 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81430 File
    81431 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81432 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    81433 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    81434 exclude=exclude) 
    81435 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81436 File
    81437 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81438 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    81439 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    81440 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81441 File
    81442 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81443 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    81444 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    81445 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81446 File
    81447 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81448 packages/chimerax/graphics/drawing.py", line 1108, in
    81449 _first_intercept_excluding_children 
    81450 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    81451 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81452 File
    81453 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81454 packages/chimerax/geometry/place.py", line 201, in inverse 
    81455 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    81456 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81457 File
    81458 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81459 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    81460 rinv[:, :] = matrix_inverse(r) 
    81461 ^^^^^^^^^^^^^^^^^ 
    81462 File
    81463 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81464 packages/numpy/linalg/linalg.py", line 561, in inv 
    81465 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    81466 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81467 File
    81468 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81469 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    81470 raise LinAlgError("Singular matrix") 
    81471 numpy.linalg.LinAlgError: Singular matrix 
    81472  
    81473 numpy.linalg.LinAlgError: Singular matrix 
    81474  
    81475 File
    81476 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81477 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    81478 raise LinAlgError("Singular matrix") 
    81479  
    81480 See log for complete Python traceback. 
    81481  
    81482 Traceback (most recent call last): 
    81483 File
    81484 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81485 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    81486 self.session.ui.mouse_modes.mouse_pause_tracking() 
    81487 File
    81488 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81489 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    81490 mouse_pause_tracking 
    81491 self._mouse_pause() 
    81492 File
    81493 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81494 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    81495 m.pause(self._mouse_pause_position) 
    81496 File
    81497 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81498 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    81499 p = self.view.picked_object(x, y) 
    81500 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81501 File
    81502 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81503 packages/chimerax/graphics/view.py", line 838, in picked_object 
    81504 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    81505 beyond, 
    81506 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81507 File
    81508 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81509 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    81510 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    81511 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81512 File
    81513 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81514 packages/chimerax/core/models.py", line 143, in first_intercept 
    81515 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    81516 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81517 File
    81518 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81519 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    81520 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    81521 exclude=exclude) 
    81522 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81523 File
    81524 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81525 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    81526 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    81527 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81528 File
    81529 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81530 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    81531 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    81532 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81533 File
    81534 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81535 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    81536 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    81537 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81538 File
    81539 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81540 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    81541 p = super().first_intercept(mxyz1, mxyz2) 
    81542 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81543 File
    81544 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81545 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    81546 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    81547 exclude=exclude) 
    81548 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81549 File
    81550 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81551 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    81552 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    81553 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81554 File
    81555 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81556 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    81557 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    81558 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81559 File
    81560 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81561 packages/chimerax/graphics/drawing.py", line 1108, in
    81562 _first_intercept_excluding_children 
    81563 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    81564 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81565 File
    81566 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81567 packages/chimerax/geometry/place.py", line 201, in inverse 
    81568 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    81569 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81570 File
    81571 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81572 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    81573 rinv[:, :] = matrix_inverse(r) 
    81574 ^^^^^^^^^^^^^^^^^ 
    81575 File
    81576 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81577 packages/numpy/linalg/linalg.py", line 561, in inv 
    81578 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    81579 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81580 File
    81581 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81582 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    81583 raise LinAlgError("Singular matrix") 
    81584 numpy.linalg.LinAlgError: Singular matrix 
    81585  
    81586 numpy.linalg.LinAlgError: Singular matrix 
    81587  
    81588 File
    81589 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81590 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    81591 raise LinAlgError("Singular matrix") 
    81592  
    81593 See log for complete Python traceback. 
    81594  
    81595 Traceback (most recent call last): 
    81596 File
    81597 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81598 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    81599 self.session.ui.mouse_modes.mouse_pause_tracking() 
    81600 File
    81601 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81602 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    81603 mouse_pause_tracking 
    81604 self._mouse_pause() 
    81605 File
    81606 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81607 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    81608 m.pause(self._mouse_pause_position) 
    81609 File
    81610 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81611 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    81612 p = self.view.picked_object(x, y) 
    81613 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81614 File
    81615 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81616 packages/chimerax/graphics/view.py", line 838, in picked_object 
    81617 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    81618 beyond, 
    81619 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81620 File
    81621 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81622 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    81623 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    81624 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81625 File
    81626 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81627 packages/chimerax/core/models.py", line 143, in first_intercept 
    81628 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    81629 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81630 File
    81631 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81632 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    81633 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    81634 exclude=exclude) 
    81635 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81636 File
    81637 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81638 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    81639 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    81640 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81641 File
    81642 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81643 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    81644 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    81645 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81646 File
    81647 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81648 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    81649 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    81650 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81651 File
    81652 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81653 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    81654 p = super().first_intercept(mxyz1, mxyz2) 
    81655 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81656 File
    81657 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81658 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    81659 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    81660 exclude=exclude) 
    81661 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81662 File
    81663 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81664 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    81665 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    81666 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81667 File
    81668 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81669 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    81670 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    81671 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81672 File
    81673 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81674 packages/chimerax/graphics/drawing.py", line 1108, in
    81675 _first_intercept_excluding_children 
    81676 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    81677 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81678 File
    81679 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81680 packages/chimerax/geometry/place.py", line 201, in inverse 
    81681 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    81682 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81683 File
    81684 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81685 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    81686 rinv[:, :] = matrix_inverse(r) 
    81687 ^^^^^^^^^^^^^^^^^ 
    81688 File
    81689 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81690 packages/numpy/linalg/linalg.py", line 561, in inv 
    81691 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    81692 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81693 File
    81694 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81695 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    81696 raise LinAlgError("Singular matrix") 
    81697 numpy.linalg.LinAlgError: Singular matrix 
    81698  
    81699 numpy.linalg.LinAlgError: Singular matrix 
    81700  
    81701 File
    81702 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81703 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    81704 raise LinAlgError("Singular matrix") 
    81705  
    81706 See log for complete Python traceback. 
    81707  
    81708 Traceback (most recent call last): 
    81709 File
    81710 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81711 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    81712 self.session.ui.mouse_modes.mouse_pause_tracking() 
    81713 File
    81714 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81715 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    81716 mouse_pause_tracking 
    81717 self._mouse_pause() 
    81718 File
    81719 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81720 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    81721 m.pause(self._mouse_pause_position) 
    81722 File
    81723 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81724 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    81725 p = self.view.picked_object(x, y) 
    81726 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81727 File
    81728 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81729 packages/chimerax/graphics/view.py", line 838, in picked_object 
    81730 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    81731 beyond, 
    81732 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81733 File
    81734 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81735 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    81736 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    81737 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81738 File
    81739 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81740 packages/chimerax/core/models.py", line 143, in first_intercept 
    81741 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    81742 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81743 File
    81744 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81745 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    81746 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    81747 exclude=exclude) 
    81748 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81749 File
    81750 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81751 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    81752 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    81753 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81754 File
    81755 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81756 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    81757 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    81758 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81759 File
    81760 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81761 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    81762 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    81763 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81764 File
    81765 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81766 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    81767 p = super().first_intercept(mxyz1, mxyz2) 
    81768 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81769 File
    81770 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81771 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    81772 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    81773 exclude=exclude) 
    81774 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81775 File
    81776 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81777 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    81778 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    81779 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81780 File
    81781 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81782 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    81783 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    81784 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81785 File
    81786 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81787 packages/chimerax/graphics/drawing.py", line 1108, in
    81788 _first_intercept_excluding_children 
    81789 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    81790 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81791 File
    81792 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81793 packages/chimerax/geometry/place.py", line 201, in inverse 
    81794 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    81795 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81796 File
    81797 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81798 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    81799 rinv[:, :] = matrix_inverse(r) 
    81800 ^^^^^^^^^^^^^^^^^ 
    81801 File
    81802 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81803 packages/numpy/linalg/linalg.py", line 561, in inv 
    81804 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    81805 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81806 File
    81807 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81808 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    81809 raise LinAlgError("Singular matrix") 
    81810 numpy.linalg.LinAlgError: Singular matrix 
    81811  
    81812 numpy.linalg.LinAlgError: Singular matrix 
    81813  
    81814 File
    81815 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81816 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    81817 raise LinAlgError("Singular matrix") 
    81818  
    81819 See log for complete Python traceback. 
    81820  
    81821 Traceback (most recent call last): 
    81822 File
    81823 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81824 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    81825 self.session.ui.mouse_modes.mouse_pause_tracking() 
    81826 File
    81827 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81828 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    81829 mouse_pause_tracking 
    81830 self._mouse_pause() 
    81831 File
    81832 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81833 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    81834 m.pause(self._mouse_pause_position) 
    81835 File
    81836 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81837 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    81838 p = self.view.picked_object(x, y) 
    81839 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81840 File
    81841 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81842 packages/chimerax/graphics/view.py", line 838, in picked_object 
    81843 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    81844 beyond, 
    81845 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81846 File
    81847 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81848 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    81849 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    81850 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81851 File
    81852 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81853 packages/chimerax/core/models.py", line 143, in first_intercept 
    81854 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    81855 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81856 File
    81857 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81858 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    81859 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    81860 exclude=exclude) 
    81861 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81862 File
    81863 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81864 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    81865 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    81866 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81867 File
    81868 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81869 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    81870 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    81871 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81872 File
    81873 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81874 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    81875 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    81876 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81877 File
    81878 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81879 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    81880 p = super().first_intercept(mxyz1, mxyz2) 
    81881 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81882 File
    81883 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81884 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    81885 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    81886 exclude=exclude) 
    81887 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81888 File
    81889 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81890 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    81891 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    81892 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81893 File
    81894 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81895 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    81896 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    81897 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81898 File
    81899 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81900 packages/chimerax/graphics/drawing.py", line 1108, in
    81901 _first_intercept_excluding_children 
    81902 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    81903 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81904 File
    81905 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81906 packages/chimerax/geometry/place.py", line 201, in inverse 
    81907 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    81908 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81909 File
    81910 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81911 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    81912 rinv[:, :] = matrix_inverse(r) 
    81913 ^^^^^^^^^^^^^^^^^ 
    81914 File
    81915 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81916 packages/numpy/linalg/linalg.py", line 561, in inv 
    81917 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    81918 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81919 File
    81920 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81921 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    81922 raise LinAlgError("Singular matrix") 
    81923 numpy.linalg.LinAlgError: Singular matrix 
    81924  
    81925 numpy.linalg.LinAlgError: Singular matrix 
    81926  
    81927 File
    81928 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81929 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    81930 raise LinAlgError("Singular matrix") 
    81931  
    81932 See log for complete Python traceback. 
    81933  
    81934 Traceback (most recent call last): 
    81935 File
    81936 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81937 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    81938 self.session.ui.mouse_modes.mouse_pause_tracking() 
    81939 File
    81940 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81941 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    81942 mouse_pause_tracking 
    81943 self._mouse_pause() 
    81944 File
    81945 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81946 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    81947 m.pause(self._mouse_pause_position) 
    81948 File
    81949 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81950 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    81951 p = self.view.picked_object(x, y) 
    81952 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81953 File
    81954 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81955 packages/chimerax/graphics/view.py", line 838, in picked_object 
    81956 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    81957 beyond, 
    81958 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81959 File
    81960 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81961 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    81962 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    81963 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81964 File
    81965 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81966 packages/chimerax/core/models.py", line 143, in first_intercept 
    81967 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    81968 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81969 File
    81970 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81971 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    81972 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    81973 exclude=exclude) 
    81974 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81975 File
    81976 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81977 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    81978 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    81979 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81980 File
    81981 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81982 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    81983 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    81984 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81985 File
    81986 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81987 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    81988 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    81989 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81990 File
    81991 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81992 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    81993 p = super().first_intercept(mxyz1, mxyz2) 
    81994 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    81995 File
    81996 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    81997 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    81998 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    81999 exclude=exclude) 
    82000 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82001 File
    82002 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82003 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    82004 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    82005 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82006 File
    82007 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82008 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    82009 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    82010 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82011 File
    82012 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82013 packages/chimerax/graphics/drawing.py", line 1108, in
    82014 _first_intercept_excluding_children 
    82015 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    82016 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82017 File
    82018 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82019 packages/chimerax/geometry/place.py", line 201, in inverse 
    82020 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    82021 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82022 File
    82023 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82024 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    82025 rinv[:, :] = matrix_inverse(r) 
    82026 ^^^^^^^^^^^^^^^^^ 
    82027 File
    82028 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82029 packages/numpy/linalg/linalg.py", line 561, in inv 
    82030 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    82031 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82032 File
    82033 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82034 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    82035 raise LinAlgError("Singular matrix") 
    82036 numpy.linalg.LinAlgError: Singular matrix 
    82037  
    82038 numpy.linalg.LinAlgError: Singular matrix 
    82039  
    82040 File
    82041 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82042 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    82043 raise LinAlgError("Singular matrix") 
    82044  
    82045 See log for complete Python traceback. 
    82046  
    82047 Traceback (most recent call last): 
    82048 File
    82049 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82050 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    82051 self.session.ui.mouse_modes.mouse_pause_tracking() 
    82052 File
    82053 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82054 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    82055 mouse_pause_tracking 
    82056 self._mouse_pause() 
    82057 File
    82058 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82059 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    82060 m.pause(self._mouse_pause_position) 
    82061 File
    82062 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82063 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    82064 p = self.view.picked_object(x, y) 
    82065 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82066 File
    82067 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82068 packages/chimerax/graphics/view.py", line 838, in picked_object 
    82069 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    82070 beyond, 
    82071 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82072 File
    82073 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82074 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    82075 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    82076 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82077 File
    82078 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82079 packages/chimerax/core/models.py", line 143, in first_intercept 
    82080 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    82081 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82082 File
    82083 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82084 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    82085 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    82086 exclude=exclude) 
    82087 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82088 File
    82089 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82090 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    82091 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    82092 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82093 File
    82094 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82095 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    82096 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    82097 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82098 File
    82099 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82100 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    82101 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    82102 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82103 File
    82104 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82105 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    82106 p = super().first_intercept(mxyz1, mxyz2) 
    82107 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82108 File
    82109 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82110 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    82111 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    82112 exclude=exclude) 
    82113 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82114 File
    82115 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82116 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    82117 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    82118 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82119 File
    82120 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82121 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    82122 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    82123 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82124 File
    82125 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82126 packages/chimerax/graphics/drawing.py", line 1108, in
    82127 _first_intercept_excluding_children 
    82128 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    82129 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82130 File
    82131 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82132 packages/chimerax/geometry/place.py", line 201, in inverse 
    82133 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    82134 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82135 File
    82136 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82137 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    82138 rinv[:, :] = matrix_inverse(r) 
    82139 ^^^^^^^^^^^^^^^^^ 
    82140 File
    82141 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82142 packages/numpy/linalg/linalg.py", line 561, in inv 
    82143 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    82144 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82145 File
    82146 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82147 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    82148 raise LinAlgError("Singular matrix") 
    82149 numpy.linalg.LinAlgError: Singular matrix 
    82150  
    82151 numpy.linalg.LinAlgError: Singular matrix 
    82152  
    82153 File
    82154 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82155 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    82156 raise LinAlgError("Singular matrix") 
    82157  
    82158 See log for complete Python traceback. 
    82159  
    82160 Traceback (most recent call last): 
    82161 File
    82162 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82163 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    82164 self.session.ui.mouse_modes.mouse_pause_tracking() 
    82165 File
    82166 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82167 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    82168 mouse_pause_tracking 
    82169 self._mouse_pause() 
    82170 File
    82171 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82172 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    82173 m.pause(self._mouse_pause_position) 
    82174 File
    82175 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82176 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    82177 p = self.view.picked_object(x, y) 
    82178 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82179 File
    82180 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82181 packages/chimerax/graphics/view.py", line 838, in picked_object 
    82182 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    82183 beyond, 
    82184 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82185 File
    82186 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82187 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    82188 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    82189 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82190 File
    82191 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82192 packages/chimerax/core/models.py", line 143, in first_intercept 
    82193 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    82194 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82195 File
    82196 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82197 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    82198 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    82199 exclude=exclude) 
    82200 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82201 File
    82202 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82203 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    82204 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    82205 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82206 File
    82207 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82208 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    82209 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    82210 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82211 File
    82212 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82213 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    82214 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    82215 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82216 File
    82217 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82218 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    82219 p = super().first_intercept(mxyz1, mxyz2) 
    82220 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82221 File
    82222 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82223 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    82224 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    82225 exclude=exclude) 
    82226 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82227 File
    82228 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82229 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    82230 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    82231 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82232 File
    82233 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82234 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    82235 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    82236 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82237 File
    82238 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82239 packages/chimerax/graphics/drawing.py", line 1108, in
    82240 _first_intercept_excluding_children 
    82241 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    82242 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82243 File
    82244 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82245 packages/chimerax/geometry/place.py", line 201, in inverse 
    82246 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    82247 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82248 File
    82249 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82250 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    82251 rinv[:, :] = matrix_inverse(r) 
    82252 ^^^^^^^^^^^^^^^^^ 
    82253 File
    82254 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82255 packages/numpy/linalg/linalg.py", line 561, in inv 
    82256 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    82257 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82258 File
    82259 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82260 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    82261 raise LinAlgError("Singular matrix") 
    82262 numpy.linalg.LinAlgError: Singular matrix 
    82263  
    82264 numpy.linalg.LinAlgError: Singular matrix 
    82265  
    82266 File
    82267 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82268 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    82269 raise LinAlgError("Singular matrix") 
    82270  
    82271 See log for complete Python traceback. 
    82272  
    82273 Traceback (most recent call last): 
    82274 File
    82275 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82276 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    82277 self.session.ui.mouse_modes.mouse_pause_tracking() 
    82278 File
    82279 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82280 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    82281 mouse_pause_tracking 
    82282 self._mouse_pause() 
    82283 File
    82284 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82285 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    82286 m.pause(self._mouse_pause_position) 
    82287 File
    82288 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82289 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    82290 p = self.view.picked_object(x, y) 
    82291 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82292 File
    82293 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82294 packages/chimerax/graphics/view.py", line 838, in picked_object 
    82295 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    82296 beyond, 
    82297 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82298 File
    82299 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82300 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    82301 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    82302 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82303 File
    82304 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82305 packages/chimerax/core/models.py", line 143, in first_intercept 
    82306 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    82307 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82308 File
    82309 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82310 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    82311 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    82312 exclude=exclude) 
    82313 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82314 File
    82315 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82316 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    82317 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    82318 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82319 File
    82320 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82321 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    82322 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    82323 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82324 File
    82325 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82326 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    82327 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    82328 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82329 File
    82330 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82331 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    82332 p = super().first_intercept(mxyz1, mxyz2) 
    82333 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82334 File
    82335 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82336 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    82337 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    82338 exclude=exclude) 
    82339 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82340 File
    82341 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82342 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    82343 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    82344 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82345 File
    82346 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82347 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    82348 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    82349 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82350 File
    82351 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82352 packages/chimerax/graphics/drawing.py", line 1108, in
    82353 _first_intercept_excluding_children 
    82354 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    82355 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82356 File
    82357 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82358 packages/chimerax/geometry/place.py", line 201, in inverse 
    82359 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    82360 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82361 File
    82362 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82363 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    82364 rinv[:, :] = matrix_inverse(r) 
    82365 ^^^^^^^^^^^^^^^^^ 
    82366 File
    82367 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82368 packages/numpy/linalg/linalg.py", line 561, in inv 
    82369 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    82370 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82371 File
    82372 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82373 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    82374 raise LinAlgError("Singular matrix") 
    82375 numpy.linalg.LinAlgError: Singular matrix 
    82376  
    82377 numpy.linalg.LinAlgError: Singular matrix 
    82378  
    82379 File
    82380 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82381 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    82382 raise LinAlgError("Singular matrix") 
    82383  
    82384 See log for complete Python traceback. 
    82385  
    82386 Traceback (most recent call last): 
    82387 File
    82388 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82389 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    82390 self.session.ui.mouse_modes.mouse_pause_tracking() 
    82391 File
    82392 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82393 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    82394 mouse_pause_tracking 
    82395 self._mouse_pause() 
    82396 File
    82397 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82398 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    82399 m.pause(self._mouse_pause_position) 
    82400 File
    82401 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82402 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    82403 p = self.view.picked_object(x, y) 
    82404 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82405 File
    82406 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82407 packages/chimerax/graphics/view.py", line 838, in picked_object 
    82408 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    82409 beyond, 
    82410 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82411 File
    82412 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82413 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    82414 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    82415 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82416 File
    82417 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82418 packages/chimerax/core/models.py", line 143, in first_intercept 
    82419 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    82420 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82421 File
    82422 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82423 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    82424 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    82425 exclude=exclude) 
    82426 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82427 File
    82428 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82429 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    82430 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    82431 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82432 File
    82433 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82434 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    82435 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    82436 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82437 File
    82438 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82439 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    82440 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    82441 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82442 File
    82443 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82444 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    82445 p = super().first_intercept(mxyz1, mxyz2) 
    82446 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82447 File
    82448 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82449 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    82450 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    82451 exclude=exclude) 
    82452 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82453 File
    82454 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82455 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    82456 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    82457 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82458 File
    82459 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82460 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    82461 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    82462 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82463 File
    82464 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82465 packages/chimerax/graphics/drawing.py", line 1108, in
    82466 _first_intercept_excluding_children 
    82467 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    82468 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82469 File
    82470 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82471 packages/chimerax/geometry/place.py", line 201, in inverse 
    82472 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    82473 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82474 File
    82475 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82476 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    82477 rinv[:, :] = matrix_inverse(r) 
    82478 ^^^^^^^^^^^^^^^^^ 
    82479 File
    82480 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82481 packages/numpy/linalg/linalg.py", line 561, in inv 
    82482 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    82483 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82484 File
    82485 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82486 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    82487 raise LinAlgError("Singular matrix") 
    82488 numpy.linalg.LinAlgError: Singular matrix 
    82489  
    82490 numpy.linalg.LinAlgError: Singular matrix 
    82491  
    82492 File
    82493 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82494 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    82495 raise LinAlgError("Singular matrix") 
    82496  
    82497 See log for complete Python traceback. 
    82498  
    82499 Traceback (most recent call last): 
    82500 File
    82501 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82502 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    82503 self.session.ui.mouse_modes.mouse_pause_tracking() 
    82504 File
    82505 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82506 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    82507 mouse_pause_tracking 
    82508 self._mouse_pause() 
    82509 File
    82510 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82511 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    82512 m.pause(self._mouse_pause_position) 
    82513 File
    82514 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82515 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    82516 p = self.view.picked_object(x, y) 
    82517 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82518 File
    82519 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82520 packages/chimerax/graphics/view.py", line 838, in picked_object 
    82521 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    82522 beyond, 
    82523 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82524 File
    82525 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82526 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    82527 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    82528 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82529 File
    82530 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82531 packages/chimerax/core/models.py", line 143, in first_intercept 
    82532 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    82533 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82534 File
    82535 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82536 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    82537 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    82538 exclude=exclude) 
    82539 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82540 File
    82541 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82542 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    82543 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    82544 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82545 File
    82546 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82547 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    82548 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    82549 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82550 File
    82551 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82552 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    82553 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    82554 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82555 File
    82556 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82557 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    82558 p = super().first_intercept(mxyz1, mxyz2) 
    82559 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82560 File
    82561 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82562 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    82563 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    82564 exclude=exclude) 
    82565 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82566 File
    82567 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82568 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    82569 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    82570 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82571 File
    82572 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82573 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    82574 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    82575 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82576 File
    82577 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82578 packages/chimerax/graphics/drawing.py", line 1108, in
    82579 _first_intercept_excluding_children 
    82580 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    82581 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82582 File
    82583 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82584 packages/chimerax/geometry/place.py", line 201, in inverse 
    82585 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    82586 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82587 File
    82588 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82589 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    82590 rinv[:, :] = matrix_inverse(r) 
    82591 ^^^^^^^^^^^^^^^^^ 
    82592 File
    82593 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82594 packages/numpy/linalg/linalg.py", line 561, in inv 
    82595 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    82596 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82597 File
    82598 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82599 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    82600 raise LinAlgError("Singular matrix") 
    82601 numpy.linalg.LinAlgError: Singular matrix 
    82602  
    82603 numpy.linalg.LinAlgError: Singular matrix 
    82604  
    82605 File
    82606 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82607 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    82608 raise LinAlgError("Singular matrix") 
    82609  
    82610 See log for complete Python traceback. 
    82611  
    82612 Traceback (most recent call last): 
    82613 File
    82614 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82615 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    82616 self.session.ui.mouse_modes.mouse_pause_tracking() 
    82617 File
    82618 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82619 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    82620 mouse_pause_tracking 
    82621 self._mouse_pause() 
    82622 File
    82623 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82624 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    82625 m.pause(self._mouse_pause_position) 
    82626 File
    82627 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82628 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    82629 p = self.view.picked_object(x, y) 
    82630 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82631 File
    82632 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82633 packages/chimerax/graphics/view.py", line 838, in picked_object 
    82634 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    82635 beyond, 
    82636 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82637 File
    82638 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82639 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    82640 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    82641 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82642 File
    82643 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82644 packages/chimerax/core/models.py", line 143, in first_intercept 
    82645 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    82646 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82647 File
    82648 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82649 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    82650 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    82651 exclude=exclude) 
    82652 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82653 File
    82654 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82655 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    82656 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    82657 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82658 File
    82659 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82660 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    82661 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    82662 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82663 File
    82664 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82665 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    82666 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    82667 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82668 File
    82669 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82670 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    82671 p = super().first_intercept(mxyz1, mxyz2) 
    82672 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82673 File
    82674 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82675 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    82676 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    82677 exclude=exclude) 
    82678 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82679 File
    82680 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82681 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    82682 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    82683 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82684 File
    82685 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82686 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    82687 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    82688 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82689 File
    82690 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82691 packages/chimerax/graphics/drawing.py", line 1108, in
    82692 _first_intercept_excluding_children 
    82693 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    82694 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82695 File
    82696 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82697 packages/chimerax/geometry/place.py", line 201, in inverse 
    82698 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    82699 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82700 File
    82701 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82702 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    82703 rinv[:, :] = matrix_inverse(r) 
    82704 ^^^^^^^^^^^^^^^^^ 
    82705 File
    82706 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82707 packages/numpy/linalg/linalg.py", line 561, in inv 
    82708 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    82709 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82710 File
    82711 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82712 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    82713 raise LinAlgError("Singular matrix") 
    82714 numpy.linalg.LinAlgError: Singular matrix 
    82715  
    82716 numpy.linalg.LinAlgError: Singular matrix 
    82717  
    82718 File
    82719 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82720 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    82721 raise LinAlgError("Singular matrix") 
    82722  
    82723 See log for complete Python traceback. 
    82724  
    82725 Traceback (most recent call last): 
    82726 File
    82727 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82728 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    82729 self.session.ui.mouse_modes.mouse_pause_tracking() 
    82730 File
    82731 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82732 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    82733 mouse_pause_tracking 
    82734 self._mouse_pause() 
    82735 File
    82736 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82737 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    82738 m.pause(self._mouse_pause_position) 
    82739 File
    82740 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82741 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    82742 p = self.view.picked_object(x, y) 
    82743 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82744 File
    82745 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82746 packages/chimerax/graphics/view.py", line 838, in picked_object 
    82747 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    82748 beyond, 
    82749 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82750 File
    82751 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82752 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    82753 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    82754 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82755 File
    82756 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82757 packages/chimerax/core/models.py", line 143, in first_intercept 
    82758 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    82759 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82760 File
    82761 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82762 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    82763 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    82764 exclude=exclude) 
    82765 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82766 File
    82767 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82768 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    82769 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    82770 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82771 File
    82772 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82773 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    82774 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    82775 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82776 File
    82777 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82778 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    82779 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    82780 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82781 File
    82782 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82783 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    82784 p = super().first_intercept(mxyz1, mxyz2) 
    82785 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82786 File
    82787 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82788 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    82789 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    82790 exclude=exclude) 
    82791 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82792 File
    82793 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82794 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    82795 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    82796 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82797 File
    82798 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82799 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    82800 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    82801 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82802 File
    82803 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82804 packages/chimerax/graphics/drawing.py", line 1108, in
    82805 _first_intercept_excluding_children 
    82806 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    82807 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82808 File
    82809 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82810 packages/chimerax/geometry/place.py", line 201, in inverse 
    82811 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    82812 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82813 File
    82814 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82815 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    82816 rinv[:, :] = matrix_inverse(r) 
    82817 ^^^^^^^^^^^^^^^^^ 
    82818 File
    82819 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82820 packages/numpy/linalg/linalg.py", line 561, in inv 
    82821 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    82822 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82823 File
    82824 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82825 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    82826 raise LinAlgError("Singular matrix") 
    82827 numpy.linalg.LinAlgError: Singular matrix 
    82828  
    82829 numpy.linalg.LinAlgError: Singular matrix 
    82830  
    82831 File
    82832 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82833 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    82834 raise LinAlgError("Singular matrix") 
    82835  
    82836 See log for complete Python traceback. 
    82837  
    82838 Traceback (most recent call last): 
    82839 File
    82840 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82841 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    82842 self.session.ui.mouse_modes.mouse_pause_tracking() 
    82843 File
    82844 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82845 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    82846 mouse_pause_tracking 
    82847 self._mouse_pause() 
    82848 File
    82849 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82850 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    82851 m.pause(self._mouse_pause_position) 
    82852 File
    82853 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82854 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    82855 p = self.view.picked_object(x, y) 
    82856 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82857 File
    82858 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82859 packages/chimerax/graphics/view.py", line 838, in picked_object 
    82860 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    82861 beyond, 
    82862 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82863 File
    82864 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82865 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    82866 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    82867 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82868 File
    82869 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82870 packages/chimerax/core/models.py", line 143, in first_intercept 
    82871 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    82872 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82873 File
    82874 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82875 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    82876 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    82877 exclude=exclude) 
    82878 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82879 File
    82880 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82881 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    82882 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    82883 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82884 File
    82885 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82886 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    82887 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    82888 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82889 File
    82890 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82891 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    82892 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    82893 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82894 File
    82895 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82896 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    82897 p = super().first_intercept(mxyz1, mxyz2) 
    82898 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82899 File
    82900 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82901 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    82902 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    82903 exclude=exclude) 
    82904 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82905 File
    82906 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82907 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    82908 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    82909 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82910 File
    82911 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82912 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    82913 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    82914 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82915 File
    82916 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82917 packages/chimerax/graphics/drawing.py", line 1108, in
    82918 _first_intercept_excluding_children 
    82919 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    82920 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82921 File
    82922 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82923 packages/chimerax/geometry/place.py", line 201, in inverse 
    82924 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    82925 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82926 File
    82927 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82928 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    82929 rinv[:, :] = matrix_inverse(r) 
    82930 ^^^^^^^^^^^^^^^^^ 
    82931 File
    82932 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82933 packages/numpy/linalg/linalg.py", line 561, in inv 
    82934 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    82935 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82936 File
    82937 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82938 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    82939 raise LinAlgError("Singular matrix") 
    82940 numpy.linalg.LinAlgError: Singular matrix 
    82941  
    82942 numpy.linalg.LinAlgError: Singular matrix 
    82943  
    82944 File
    82945 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82946 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    82947 raise LinAlgError("Singular matrix") 
    82948  
    82949 See log for complete Python traceback. 
    82950  
    82951 Traceback (most recent call last): 
    82952 File
    82953 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82954 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    82955 self.session.ui.mouse_modes.mouse_pause_tracking() 
    82956 File
    82957 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82958 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    82959 mouse_pause_tracking 
    82960 self._mouse_pause() 
    82961 File
    82962 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82963 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    82964 m.pause(self._mouse_pause_position) 
    82965 File
    82966 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82967 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    82968 p = self.view.picked_object(x, y) 
    82969 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82970 File
    82971 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82972 packages/chimerax/graphics/view.py", line 838, in picked_object 
    82973 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    82974 beyond, 
    82975 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82976 File
    82977 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82978 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    82979 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    82980 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82981 File
    82982 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82983 packages/chimerax/core/models.py", line 143, in first_intercept 
    82984 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    82985 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82986 File
    82987 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82988 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    82989 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    82990 exclude=exclude) 
    82991 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82992 File
    82993 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82994 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    82995 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    82996 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    82997 File
    82998 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    82999 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    83000 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    83001 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83002 File
    83003 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83004 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    83005 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    83006 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83007 File
    83008 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83009 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    83010 p = super().first_intercept(mxyz1, mxyz2) 
    83011 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83012 File
    83013 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83014 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    83015 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    83016 exclude=exclude) 
    83017 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83018 File
    83019 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83020 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    83021 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    83022 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83023 File
    83024 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83025 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    83026 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    83027 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83028 File
    83029 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83030 packages/chimerax/graphics/drawing.py", line 1108, in
    83031 _first_intercept_excluding_children 
    83032 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    83033 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83034 File
    83035 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83036 packages/chimerax/geometry/place.py", line 201, in inverse 
    83037 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    83038 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83039 File
    83040 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83041 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    83042 rinv[:, :] = matrix_inverse(r) 
    83043 ^^^^^^^^^^^^^^^^^ 
    83044 File
    83045 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83046 packages/numpy/linalg/linalg.py", line 561, in inv 
    83047 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    83048 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83049 File
    83050 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83051 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    83052 raise LinAlgError("Singular matrix") 
    83053 numpy.linalg.LinAlgError: Singular matrix 
    83054  
    83055 numpy.linalg.LinAlgError: Singular matrix 
    83056  
    83057 File
    83058 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83059 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    83060 raise LinAlgError("Singular matrix") 
    83061  
    83062 See log for complete Python traceback. 
    83063  
    83064 Traceback (most recent call last): 
    83065 File
    83066 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83067 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    83068 self.session.ui.mouse_modes.mouse_pause_tracking() 
    83069 File
    83070 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83071 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    83072 mouse_pause_tracking 
    83073 self._mouse_pause() 
    83074 File
    83075 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83076 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    83077 m.pause(self._mouse_pause_position) 
    83078 File
    83079 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83080 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    83081 p = self.view.picked_object(x, y) 
    83082 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83083 File
    83084 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83085 packages/chimerax/graphics/view.py", line 838, in picked_object 
    83086 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    83087 beyond, 
    83088 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83089 File
    83090 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83091 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    83092 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    83093 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83094 File
    83095 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83096 packages/chimerax/core/models.py", line 143, in first_intercept 
    83097 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    83098 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83099 File
    83100 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83101 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    83102 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    83103 exclude=exclude) 
    83104 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83105 File
    83106 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83107 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    83108 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    83109 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83110 File
    83111 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83112 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    83113 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    83114 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83115 File
    83116 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83117 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    83118 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    83119 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83120 File
    83121 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83122 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    83123 p = super().first_intercept(mxyz1, mxyz2) 
    83124 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83125 File
    83126 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83127 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    83128 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    83129 exclude=exclude) 
    83130 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83131 File
    83132 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83133 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    83134 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    83135 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83136 File
    83137 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83138 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    83139 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    83140 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83141 File
    83142 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83143 packages/chimerax/graphics/drawing.py", line 1108, in
    83144 _first_intercept_excluding_children 
    83145 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    83146 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83147 File
    83148 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83149 packages/chimerax/geometry/place.py", line 201, in inverse 
    83150 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    83151 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83152 File
    83153 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83154 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    83155 rinv[:, :] = matrix_inverse(r) 
    83156 ^^^^^^^^^^^^^^^^^ 
    83157 File
    83158 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83159 packages/numpy/linalg/linalg.py", line 561, in inv 
    83160 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    83161 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83162 File
    83163 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83164 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    83165 raise LinAlgError("Singular matrix") 
    83166 numpy.linalg.LinAlgError: Singular matrix 
    83167  
    83168 numpy.linalg.LinAlgError: Singular matrix 
    83169  
    83170 File
    83171 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83172 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    83173 raise LinAlgError("Singular matrix") 
    83174  
    83175 See log for complete Python traceback. 
    83176  
    83177 Traceback (most recent call last): 
    83178 File
    83179 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83180 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    83181 self.session.ui.mouse_modes.mouse_pause_tracking() 
    83182 File
    83183 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83184 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    83185 mouse_pause_tracking 
    83186 self._mouse_pause() 
    83187 File
    83188 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83189 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    83190 m.pause(self._mouse_pause_position) 
    83191 File
    83192 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83193 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    83194 p = self.view.picked_object(x, y) 
    83195 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83196 File
    83197 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83198 packages/chimerax/graphics/view.py", line 838, in picked_object 
    83199 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    83200 beyond, 
    83201 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83202 File
    83203 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83204 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    83205 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    83206 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83207 File
    83208 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83209 packages/chimerax/core/models.py", line 143, in first_intercept 
    83210 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    83211 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83212 File
    83213 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83214 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    83215 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    83216 exclude=exclude) 
    83217 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83218 File
    83219 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83220 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    83221 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    83222 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83223 File
    83224 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83225 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    83226 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    83227 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83228 File
    83229 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83230 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    83231 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    83232 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83233 File
    83234 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83235 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    83236 p = super().first_intercept(mxyz1, mxyz2) 
    83237 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83238 File
    83239 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83240 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    83241 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    83242 exclude=exclude) 
    83243 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83244 File
    83245 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83246 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    83247 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    83248 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83249 File
    83250 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83251 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    83252 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    83253 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83254 File
    83255 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83256 packages/chimerax/graphics/drawing.py", line 1108, in
    83257 _first_intercept_excluding_children 
    83258 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    83259 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83260 File
    83261 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83262 packages/chimerax/geometry/place.py", line 201, in inverse 
    83263 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    83264 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83265 File
    83266 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83267 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    83268 rinv[:, :] = matrix_inverse(r) 
    83269 ^^^^^^^^^^^^^^^^^ 
    83270 File
    83271 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83272 packages/numpy/linalg/linalg.py", line 561, in inv 
    83273 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    83274 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83275 File
    83276 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83277 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    83278 raise LinAlgError("Singular matrix") 
    83279 numpy.linalg.LinAlgError: Singular matrix 
    83280  
    83281 numpy.linalg.LinAlgError: Singular matrix 
    83282  
    83283 File
    83284 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83285 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    83286 raise LinAlgError("Singular matrix") 
    83287  
    83288 See log for complete Python traceback. 
    83289  
    83290 Traceback (most recent call last): 
    83291 File
    83292 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83293 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    83294 self.session.ui.mouse_modes.mouse_pause_tracking() 
    83295 File
    83296 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83297 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    83298 mouse_pause_tracking 
    83299 self._mouse_pause() 
    83300 File
    83301 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83302 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    83303 m.pause(self._mouse_pause_position) 
    83304 File
    83305 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83306 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    83307 p = self.view.picked_object(x, y) 
    83308 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83309 File
    83310 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83311 packages/chimerax/graphics/view.py", line 838, in picked_object 
    83312 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    83313 beyond, 
    83314 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83315 File
    83316 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83317 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    83318 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    83319 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83320 File
    83321 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83322 packages/chimerax/core/models.py", line 143, in first_intercept 
    83323 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    83324 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83325 File
    83326 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83327 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    83328 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    83329 exclude=exclude) 
    83330 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83331 File
    83332 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83333 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    83334 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    83335 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83336 File
    83337 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83338 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    83339 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    83340 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83341 File
    83342 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83343 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    83344 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    83345 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83346 File
    83347 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83348 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    83349 p = super().first_intercept(mxyz1, mxyz2) 
    83350 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83351 File
    83352 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83353 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    83354 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    83355 exclude=exclude) 
    83356 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83357 File
    83358 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83359 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    83360 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    83361 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83362 File
    83363 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83364 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    83365 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    83366 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83367 File
    83368 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83369 packages/chimerax/graphics/drawing.py", line 1108, in
    83370 _first_intercept_excluding_children 
    83371 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    83372 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83373 File
    83374 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83375 packages/chimerax/geometry/place.py", line 201, in inverse 
    83376 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    83377 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83378 File
    83379 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83380 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    83381 rinv[:, :] = matrix_inverse(r) 
    83382 ^^^^^^^^^^^^^^^^^ 
    83383 File
    83384 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83385 packages/numpy/linalg/linalg.py", line 561, in inv 
    83386 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    83387 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83388 File
    83389 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83390 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    83391 raise LinAlgError("Singular matrix") 
    83392 numpy.linalg.LinAlgError: Singular matrix 
    83393  
    83394 numpy.linalg.LinAlgError: Singular matrix 
    83395  
    83396 File
    83397 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83398 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    83399 raise LinAlgError("Singular matrix") 
    83400  
    83401 See log for complete Python traceback. 
    83402  
    83403 Traceback (most recent call last): 
    83404 File
    83405 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83406 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    83407 self.session.ui.mouse_modes.mouse_pause_tracking() 
    83408 File
    83409 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83410 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    83411 mouse_pause_tracking 
    83412 self._mouse_pause() 
    83413 File
    83414 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83415 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    83416 m.pause(self._mouse_pause_position) 
    83417 File
    83418 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83419 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    83420 p = self.view.picked_object(x, y) 
    83421 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83422 File
    83423 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83424 packages/chimerax/graphics/view.py", line 838, in picked_object 
    83425 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    83426 beyond, 
    83427 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83428 File
    83429 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83430 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    83431 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    83432 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83433 File
    83434 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83435 packages/chimerax/core/models.py", line 143, in first_intercept 
    83436 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    83437 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83438 File
    83439 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83440 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    83441 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    83442 exclude=exclude) 
    83443 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83444 File
    83445 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83446 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    83447 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    83448 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83449 File
    83450 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83451 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    83452 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    83453 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83454 File
    83455 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83456 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    83457 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    83458 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83459 File
    83460 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83461 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    83462 p = super().first_intercept(mxyz1, mxyz2) 
    83463 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83464 File
    83465 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83466 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    83467 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    83468 exclude=exclude) 
    83469 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83470 File
    83471 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83472 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    83473 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    83474 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83475 File
    83476 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83477 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    83478 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    83479 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83480 File
    83481 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83482 packages/chimerax/graphics/drawing.py", line 1108, in
    83483 _first_intercept_excluding_children 
    83484 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    83485 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83486 File
    83487 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83488 packages/chimerax/geometry/place.py", line 201, in inverse 
    83489 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    83490 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83491 File
    83492 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83493 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    83494 rinv[:, :] = matrix_inverse(r) 
    83495 ^^^^^^^^^^^^^^^^^ 
    83496 File
    83497 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83498 packages/numpy/linalg/linalg.py", line 561, in inv 
    83499 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    83500 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83501 File
    83502 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83503 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    83504 raise LinAlgError("Singular matrix") 
    83505 numpy.linalg.LinAlgError: Singular matrix 
    83506  
    83507 numpy.linalg.LinAlgError: Singular matrix 
    83508  
    83509 File
    83510 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83511 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    83512 raise LinAlgError("Singular matrix") 
    83513  
    83514 See log for complete Python traceback. 
    83515  
    83516 Traceback (most recent call last): 
    83517 File
    83518 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83519 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    83520 self.session.ui.mouse_modes.mouse_pause_tracking() 
    83521 File
    83522 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83523 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    83524 mouse_pause_tracking 
    83525 self._mouse_pause() 
    83526 File
    83527 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83528 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    83529 m.pause(self._mouse_pause_position) 
    83530 File
    83531 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83532 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    83533 p = self.view.picked_object(x, y) 
    83534 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83535 File
    83536 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83537 packages/chimerax/graphics/view.py", line 838, in picked_object 
    83538 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    83539 beyond, 
    83540 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83541 File
    83542 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83543 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    83544 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    83545 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83546 File
    83547 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83548 packages/chimerax/core/models.py", line 143, in first_intercept 
    83549 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    83550 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83551 File
    83552 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83553 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    83554 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    83555 exclude=exclude) 
    83556 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83557 File
    83558 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83559 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    83560 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    83561 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83562 File
    83563 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83564 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    83565 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    83566 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83567 File
    83568 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83569 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    83570 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    83571 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83572 File
    83573 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83574 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    83575 p = super().first_intercept(mxyz1, mxyz2) 
    83576 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83577 File
    83578 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83579 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    83580 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    83581 exclude=exclude) 
    83582 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83583 File
    83584 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83585 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    83586 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    83587 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83588 File
    83589 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83590 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    83591 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    83592 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83593 File
    83594 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83595 packages/chimerax/graphics/drawing.py", line 1108, in
    83596 _first_intercept_excluding_children 
    83597 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    83598 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83599 File
    83600 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83601 packages/chimerax/geometry/place.py", line 201, in inverse 
    83602 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    83603 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83604 File
    83605 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83606 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    83607 rinv[:, :] = matrix_inverse(r) 
    83608 ^^^^^^^^^^^^^^^^^ 
    83609 File
    83610 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83611 packages/numpy/linalg/linalg.py", line 561, in inv 
    83612 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    83613 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83614 File
    83615 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83616 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    83617 raise LinAlgError("Singular matrix") 
    83618 numpy.linalg.LinAlgError: Singular matrix 
    83619  
    83620 numpy.linalg.LinAlgError: Singular matrix 
    83621  
    83622 File
    83623 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83624 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    83625 raise LinAlgError("Singular matrix") 
    83626  
    83627 See log for complete Python traceback. 
    83628  
    83629 Traceback (most recent call last): 
    83630 File
    83631 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83632 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    83633 self.session.ui.mouse_modes.mouse_pause_tracking() 
    83634 File
    83635 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83636 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    83637 mouse_pause_tracking 
    83638 self._mouse_pause() 
    83639 File
    83640 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83641 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    83642 m.pause(self._mouse_pause_position) 
    83643 File
    83644 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83645 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    83646 p = self.view.picked_object(x, y) 
    83647 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83648 File
    83649 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83650 packages/chimerax/graphics/view.py", line 838, in picked_object 
    83651 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    83652 beyond, 
    83653 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83654 File
    83655 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83656 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    83657 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    83658 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83659 File
    83660 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83661 packages/chimerax/core/models.py", line 143, in first_intercept 
    83662 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    83663 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83664 File
    83665 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83666 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    83667 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    83668 exclude=exclude) 
    83669 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83670 File
    83671 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83672 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    83673 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    83674 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83675 File
    83676 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83677 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    83678 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    83679 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83680 File
    83681 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83682 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    83683 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    83684 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83685 File
    83686 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83687 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    83688 p = super().first_intercept(mxyz1, mxyz2) 
    83689 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83690 File
    83691 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83692 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    83693 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    83694 exclude=exclude) 
    83695 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83696 File
    83697 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83698 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    83699 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    83700 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83701 File
    83702 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83703 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    83704 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    83705 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83706 File
    83707 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83708 packages/chimerax/graphics/drawing.py", line 1108, in
    83709 _first_intercept_excluding_children 
    83710 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    83711 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83712 File
    83713 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83714 packages/chimerax/geometry/place.py", line 201, in inverse 
    83715 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    83716 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83717 File
    83718 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83719 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    83720 rinv[:, :] = matrix_inverse(r) 
    83721 ^^^^^^^^^^^^^^^^^ 
    83722 File
    83723 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83724 packages/numpy/linalg/linalg.py", line 561, in inv 
    83725 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    83726 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83727 File
    83728 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83729 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    83730 raise LinAlgError("Singular matrix") 
    83731 numpy.linalg.LinAlgError: Singular matrix 
    83732  
    83733 numpy.linalg.LinAlgError: Singular matrix 
    83734  
    83735 File
    83736 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83737 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    83738 raise LinAlgError("Singular matrix") 
    83739  
    83740 See log for complete Python traceback. 
    83741  
    83742 Traceback (most recent call last): 
    83743 File
    83744 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83745 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    83746 self.session.ui.mouse_modes.mouse_pause_tracking() 
    83747 File
    83748 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83749 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    83750 mouse_pause_tracking 
    83751 self._mouse_pause() 
    83752 File
    83753 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83754 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    83755 m.pause(self._mouse_pause_position) 
    83756 File
    83757 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83758 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    83759 p = self.view.picked_object(x, y) 
    83760 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83761 File
    83762 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83763 packages/chimerax/graphics/view.py", line 838, in picked_object 
    83764 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    83765 beyond, 
    83766 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83767 File
    83768 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83769 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    83770 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    83771 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83772 File
    83773 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83774 packages/chimerax/core/models.py", line 143, in first_intercept 
    83775 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    83776 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83777 File
    83778 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83779 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    83780 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    83781 exclude=exclude) 
    83782 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83783 File
    83784 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83785 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    83786 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    83787 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83788 File
    83789 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83790 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    83791 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    83792 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83793 File
    83794 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83795 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    83796 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    83797 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83798 File
    83799 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83800 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    83801 p = super().first_intercept(mxyz1, mxyz2) 
    83802 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83803 File
    83804 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83805 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    83806 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    83807 exclude=exclude) 
    83808 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83809 File
    83810 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83811 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    83812 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    83813 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83814 File
    83815 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83816 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    83817 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    83818 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83819 File
    83820 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83821 packages/chimerax/graphics/drawing.py", line 1108, in
    83822 _first_intercept_excluding_children 
    83823 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    83824 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83825 File
    83826 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83827 packages/chimerax/geometry/place.py", line 201, in inverse 
    83828 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    83829 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83830 File
    83831 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83832 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    83833 rinv[:, :] = matrix_inverse(r) 
    83834 ^^^^^^^^^^^^^^^^^ 
    83835 File
    83836 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83837 packages/numpy/linalg/linalg.py", line 561, in inv 
    83838 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    83839 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83840 File
    83841 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83842 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    83843 raise LinAlgError("Singular matrix") 
    83844 numpy.linalg.LinAlgError: Singular matrix 
    83845  
    83846 numpy.linalg.LinAlgError: Singular matrix 
    83847  
    83848 File
    83849 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83850 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    83851 raise LinAlgError("Singular matrix") 
    83852  
    83853 See log for complete Python traceback. 
    83854  
    83855 Traceback (most recent call last): 
    83856 File
    83857 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83858 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    83859 self.session.ui.mouse_modes.mouse_pause_tracking() 
    83860 File
    83861 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83862 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    83863 mouse_pause_tracking 
    83864 self._mouse_pause() 
    83865 File
    83866 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83867 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    83868 m.pause(self._mouse_pause_position) 
    83869 File
    83870 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83871 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    83872 p = self.view.picked_object(x, y) 
    83873 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83874 File
    83875 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83876 packages/chimerax/graphics/view.py", line 838, in picked_object 
    83877 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    83878 beyond, 
    83879 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83880 File
    83881 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83882 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    83883 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    83884 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83885 File
    83886 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83887 packages/chimerax/core/models.py", line 143, in first_intercept 
    83888 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    83889 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83890 File
    83891 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83892 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    83893 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    83894 exclude=exclude) 
    83895 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83896 File
    83897 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83898 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    83899 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    83900 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83901 File
    83902 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83903 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    83904 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    83905 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83906 File
    83907 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83908 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    83909 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    83910 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83911 File
    83912 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83913 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    83914 p = super().first_intercept(mxyz1, mxyz2) 
    83915 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83916 File
    83917 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83918 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    83919 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    83920 exclude=exclude) 
    83921 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83922 File
    83923 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83924 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    83925 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    83926 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83927 File
    83928 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83929 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    83930 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    83931 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83932 File
    83933 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83934 packages/chimerax/graphics/drawing.py", line 1108, in
    83935 _first_intercept_excluding_children 
    83936 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    83937 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83938 File
    83939 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83940 packages/chimerax/geometry/place.py", line 201, in inverse 
    83941 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    83942 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83943 File
    83944 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83945 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    83946 rinv[:, :] = matrix_inverse(r) 
    83947 ^^^^^^^^^^^^^^^^^ 
    83948 File
    83949 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83950 packages/numpy/linalg/linalg.py", line 561, in inv 
    83951 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    83952 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83953 File
    83954 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83955 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    83956 raise LinAlgError("Singular matrix") 
    83957 numpy.linalg.LinAlgError: Singular matrix 
    83958  
    83959 numpy.linalg.LinAlgError: Singular matrix 
    83960  
    83961 File
    83962 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83963 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    83964 raise LinAlgError("Singular matrix") 
    83965  
    83966 See log for complete Python traceback. 
    83967  
    83968 Traceback (most recent call last): 
    83969 File
    83970 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83971 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    83972 self.session.ui.mouse_modes.mouse_pause_tracking() 
    83973 File
    83974 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83975 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    83976 mouse_pause_tracking 
    83977 self._mouse_pause() 
    83978 File
    83979 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83980 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    83981 m.pause(self._mouse_pause_position) 
    83982 File
    83983 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83984 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    83985 p = self.view.picked_object(x, y) 
    83986 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83987 File
    83988 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83989 packages/chimerax/graphics/view.py", line 838, in picked_object 
    83990 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    83991 beyond, 
    83992 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83993 File
    83994 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    83995 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    83996 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    83997 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    83998 File
    83999 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84000 packages/chimerax/core/models.py", line 143, in first_intercept 
    84001 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    84002 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84003 File
    84004 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84005 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    84006 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    84007 exclude=exclude) 
    84008 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84009 File
    84010 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84011 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    84012 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    84013 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84014 File
    84015 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84016 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    84017 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    84018 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84019 File
    84020 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84021 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    84022 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    84023 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84024 File
    84025 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84026 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    84027 p = super().first_intercept(mxyz1, mxyz2) 
    84028 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84029 File
    84030 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84031 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    84032 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    84033 exclude=exclude) 
    84034 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84035 File
    84036 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84037 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    84038 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    84039 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84040 File
    84041 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84042 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    84043 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    84044 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84045 File
    84046 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84047 packages/chimerax/graphics/drawing.py", line 1108, in
    84048 _first_intercept_excluding_children 
    84049 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    84050 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84051 File
    84052 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84053 packages/chimerax/geometry/place.py", line 201, in inverse 
    84054 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    84055 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84056 File
    84057 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84058 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    84059 rinv[:, :] = matrix_inverse(r) 
    84060 ^^^^^^^^^^^^^^^^^ 
    84061 File
    84062 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84063 packages/numpy/linalg/linalg.py", line 561, in inv 
    84064 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    84065 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84066 File
    84067 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84068 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    84069 raise LinAlgError("Singular matrix") 
    84070 numpy.linalg.LinAlgError: Singular matrix 
    84071  
    84072 numpy.linalg.LinAlgError: Singular matrix 
    84073  
    84074 File
    84075 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84076 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    84077 raise LinAlgError("Singular matrix") 
    84078  
    84079 See log for complete Python traceback. 
    84080  
    84081 Traceback (most recent call last): 
    84082 File
    84083 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84084 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    84085 self.session.ui.mouse_modes.mouse_pause_tracking() 
    84086 File
    84087 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84088 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    84089 mouse_pause_tracking 
    84090 self._mouse_pause() 
    84091 File
    84092 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84093 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    84094 m.pause(self._mouse_pause_position) 
    84095 File
    84096 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84097 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    84098 p = self.view.picked_object(x, y) 
    84099 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84100 File
    84101 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84102 packages/chimerax/graphics/view.py", line 838, in picked_object 
    84103 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    84104 beyond, 
    84105 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84106 File
    84107 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84108 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    84109 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    84110 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84111 File
    84112 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84113 packages/chimerax/core/models.py", line 143, in first_intercept 
    84114 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    84115 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84116 File
    84117 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84118 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    84119 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    84120 exclude=exclude) 
    84121 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84122 File
    84123 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84124 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    84125 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    84126 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84127 File
    84128 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84129 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    84130 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    84131 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84132 File
    84133 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84134 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    84135 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    84136 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84137 File
    84138 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84139 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    84140 p = super().first_intercept(mxyz1, mxyz2) 
    84141 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84142 File
    84143 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84144 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    84145 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    84146 exclude=exclude) 
    84147 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84148 File
    84149 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84150 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    84151 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    84152 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84153 File
    84154 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84155 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    84156 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    84157 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84158 File
    84159 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84160 packages/chimerax/graphics/drawing.py", line 1108, in
    84161 _first_intercept_excluding_children 
    84162 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    84163 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84164 File
    84165 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84166 packages/chimerax/geometry/place.py", line 201, in inverse 
    84167 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    84168 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84169 File
    84170 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84171 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    84172 rinv[:, :] = matrix_inverse(r) 
    84173 ^^^^^^^^^^^^^^^^^ 
    84174 File
    84175 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84176 packages/numpy/linalg/linalg.py", line 561, in inv 
    84177 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    84178 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84179 File
    84180 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84181 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    84182 raise LinAlgError("Singular matrix") 
    84183 numpy.linalg.LinAlgError: Singular matrix 
    84184  
    84185 numpy.linalg.LinAlgError: Singular matrix 
    84186  
    84187 File
    84188 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84189 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    84190 raise LinAlgError("Singular matrix") 
    84191  
    84192 See log for complete Python traceback. 
    84193  
    84194 Traceback (most recent call last): 
    84195 File
    84196 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84197 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    84198 self.session.ui.mouse_modes.mouse_pause_tracking() 
    84199 File
    84200 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84201 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    84202 mouse_pause_tracking 
    84203 self._mouse_pause() 
    84204 File
    84205 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84206 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    84207 m.pause(self._mouse_pause_position) 
    84208 File
    84209 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84210 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    84211 p = self.view.picked_object(x, y) 
    84212 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84213 File
    84214 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84215 packages/chimerax/graphics/view.py", line 838, in picked_object 
    84216 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    84217 beyond, 
    84218 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84219 File
    84220 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84221 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    84222 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    84223 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84224 File
    84225 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84226 packages/chimerax/core/models.py", line 143, in first_intercept 
    84227 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    84228 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84229 File
    84230 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84231 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    84232 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    84233 exclude=exclude) 
    84234 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84235 File
    84236 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84237 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    84238 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    84239 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84240 File
    84241 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84242 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    84243 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    84244 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84245 File
    84246 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84247 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    84248 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    84249 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84250 File
    84251 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84252 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    84253 p = super().first_intercept(mxyz1, mxyz2) 
    84254 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84255 File
    84256 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84257 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    84258 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    84259 exclude=exclude) 
    84260 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84261 File
    84262 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84263 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    84264 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    84265 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84266 File
    84267 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84268 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    84269 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    84270 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84271 File
    84272 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84273 packages/chimerax/graphics/drawing.py", line 1108, in
    84274 _first_intercept_excluding_children 
    84275 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    84276 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84277 File
    84278 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84279 packages/chimerax/geometry/place.py", line 201, in inverse 
    84280 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    84281 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84282 File
    84283 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84284 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    84285 rinv[:, :] = matrix_inverse(r) 
    84286 ^^^^^^^^^^^^^^^^^ 
    84287 File
    84288 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84289 packages/numpy/linalg/linalg.py", line 561, in inv 
    84290 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    84291 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84292 File
    84293 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84294 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    84295 raise LinAlgError("Singular matrix") 
    84296 numpy.linalg.LinAlgError: Singular matrix 
    84297  
    84298 numpy.linalg.LinAlgError: Singular matrix 
    84299  
    84300 File
    84301 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84302 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    84303 raise LinAlgError("Singular matrix") 
    84304  
    84305 See log for complete Python traceback. 
    84306  
    84307 Traceback (most recent call last): 
    84308 File
    84309 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84310 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    84311 self.session.ui.mouse_modes.mouse_pause_tracking() 
    84312 File
    84313 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84314 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    84315 mouse_pause_tracking 
    84316 self._mouse_pause() 
    84317 File
    84318 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84319 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    84320 m.pause(self._mouse_pause_position) 
    84321 File
    84322 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84323 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    84324 p = self.view.picked_object(x, y) 
    84325 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84326 File
    84327 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84328 packages/chimerax/graphics/view.py", line 838, in picked_object 
    84329 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    84330 beyond, 
    84331 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84332 File
    84333 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84334 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    84335 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    84336 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84337 File
    84338 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84339 packages/chimerax/core/models.py", line 143, in first_intercept 
    84340 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    84341 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84342 File
    84343 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84344 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    84345 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    84346 exclude=exclude) 
    84347 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84348 File
    84349 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84350 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    84351 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    84352 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84353 File
    84354 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84355 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    84356 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    84357 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84358 File
    84359 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84360 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    84361 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    84362 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84363 File
    84364 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84365 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    84366 p = super().first_intercept(mxyz1, mxyz2) 
    84367 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84368 File
    84369 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84370 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    84371 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    84372 exclude=exclude) 
    84373 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84374 File
    84375 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84376 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    84377 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    84378 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84379 File
    84380 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84381 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    84382 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    84383 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84384 File
    84385 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84386 packages/chimerax/graphics/drawing.py", line 1108, in
    84387 _first_intercept_excluding_children 
    84388 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    84389 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84390 File
    84391 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84392 packages/chimerax/geometry/place.py", line 201, in inverse 
    84393 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    84394 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84395 File
    84396 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84397 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    84398 rinv[:, :] = matrix_inverse(r) 
    84399 ^^^^^^^^^^^^^^^^^ 
    84400 File
    84401 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84402 packages/numpy/linalg/linalg.py", line 561, in inv 
    84403 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    84404 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84405 File
    84406 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84407 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    84408 raise LinAlgError("Singular matrix") 
    84409 numpy.linalg.LinAlgError: Singular matrix 
    84410  
    84411 numpy.linalg.LinAlgError: Singular matrix 
    84412  
    84413 File
    84414 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84415 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    84416 raise LinAlgError("Singular matrix") 
    84417  
    84418 See log for complete Python traceback. 
    84419  
    84420 Traceback (most recent call last): 
    84421 File
    84422 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84423 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    84424 self.session.ui.mouse_modes.mouse_pause_tracking() 
    84425 File
    84426 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84427 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    84428 mouse_pause_tracking 
    84429 self._mouse_pause() 
    84430 File
    84431 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84432 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    84433 m.pause(self._mouse_pause_position) 
    84434 File
    84435 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84436 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    84437 p = self.view.picked_object(x, y) 
    84438 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84439 File
    84440 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84441 packages/chimerax/graphics/view.py", line 838, in picked_object 
    84442 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    84443 beyond, 
    84444 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84445 File
    84446 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84447 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    84448 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    84449 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84450 File
    84451 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84452 packages/chimerax/core/models.py", line 143, in first_intercept 
    84453 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    84454 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84455 File
    84456 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84457 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    84458 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    84459 exclude=exclude) 
    84460 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84461 File
    84462 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84463 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    84464 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    84465 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84466 File
    84467 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84468 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    84469 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    84470 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84471 File
    84472 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84473 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    84474 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    84475 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84476 File
    84477 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84478 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    84479 p = super().first_intercept(mxyz1, mxyz2) 
    84480 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84481 File
    84482 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84483 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    84484 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    84485 exclude=exclude) 
    84486 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84487 File
    84488 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84489 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    84490 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    84491 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84492 File
    84493 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84494 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    84495 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    84496 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84497 File
    84498 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84499 packages/chimerax/graphics/drawing.py", line 1108, in
    84500 _first_intercept_excluding_children 
    84501 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    84502 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84503 File
    84504 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84505 packages/chimerax/geometry/place.py", line 201, in inverse 
    84506 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    84507 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84508 File
    84509 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84510 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    84511 rinv[:, :] = matrix_inverse(r) 
    84512 ^^^^^^^^^^^^^^^^^ 
    84513 File
    84514 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84515 packages/numpy/linalg/linalg.py", line 561, in inv 
    84516 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    84517 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84518 File
    84519 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84520 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    84521 raise LinAlgError("Singular matrix") 
    84522 numpy.linalg.LinAlgError: Singular matrix 
    84523  
    84524 numpy.linalg.LinAlgError: Singular matrix 
    84525  
    84526 File
    84527 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84528 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    84529 raise LinAlgError("Singular matrix") 
    84530  
    84531 See log for complete Python traceback. 
    84532  
    84533 Traceback (most recent call last): 
    84534 File
    84535 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84536 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    84537 self.session.ui.mouse_modes.mouse_pause_tracking() 
    84538 File
    84539 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84540 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    84541 mouse_pause_tracking 
    84542 self._mouse_pause() 
    84543 File
    84544 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84545 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    84546 m.pause(self._mouse_pause_position) 
    84547 File
    84548 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84549 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    84550 p = self.view.picked_object(x, y) 
    84551 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84552 File
    84553 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84554 packages/chimerax/graphics/view.py", line 838, in picked_object 
    84555 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    84556 beyond, 
    84557 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84558 File
    84559 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84560 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    84561 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    84562 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84563 File
    84564 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84565 packages/chimerax/core/models.py", line 143, in first_intercept 
    84566 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    84567 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84568 File
    84569 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84570 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    84571 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    84572 exclude=exclude) 
    84573 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84574 File
    84575 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84576 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    84577 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    84578 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84579 File
    84580 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84581 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    84582 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    84583 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84584 File
    84585 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84586 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    84587 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    84588 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84589 File
    84590 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84591 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    84592 p = super().first_intercept(mxyz1, mxyz2) 
    84593 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84594 File
    84595 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84596 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    84597 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    84598 exclude=exclude) 
    84599 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84600 File
    84601 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84602 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    84603 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    84604 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84605 File
    84606 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84607 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    84608 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    84609 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84610 File
    84611 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84612 packages/chimerax/graphics/drawing.py", line 1108, in
    84613 _first_intercept_excluding_children 
    84614 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    84615 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84616 File
    84617 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84618 packages/chimerax/geometry/place.py", line 201, in inverse 
    84619 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    84620 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84621 File
    84622 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84623 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    84624 rinv[:, :] = matrix_inverse(r) 
    84625 ^^^^^^^^^^^^^^^^^ 
    84626 File
    84627 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84628 packages/numpy/linalg/linalg.py", line 561, in inv 
    84629 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    84630 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84631 File
    84632 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84633 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    84634 raise LinAlgError("Singular matrix") 
    84635 numpy.linalg.LinAlgError: Singular matrix 
    84636  
    84637 numpy.linalg.LinAlgError: Singular matrix 
    84638  
    84639 File
    84640 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84641 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    84642 raise LinAlgError("Singular matrix") 
    84643  
    84644 See log for complete Python traceback. 
    84645  
    84646 Traceback (most recent call last): 
    84647 File
    84648 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84649 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    84650 self.session.ui.mouse_modes.mouse_pause_tracking() 
    84651 File
    84652 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84653 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    84654 mouse_pause_tracking 
    84655 self._mouse_pause() 
    84656 File
    84657 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84658 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    84659 m.pause(self._mouse_pause_position) 
    84660 File
    84661 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84662 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    84663 p = self.view.picked_object(x, y) 
    84664 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84665 File
    84666 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84667 packages/chimerax/graphics/view.py", line 838, in picked_object 
    84668 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    84669 beyond, 
    84670 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84671 File
    84672 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84673 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    84674 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    84675 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84676 File
    84677 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84678 packages/chimerax/core/models.py", line 143, in first_intercept 
    84679 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    84680 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84681 File
    84682 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84683 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    84684 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    84685 exclude=exclude) 
    84686 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84687 File
    84688 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84689 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    84690 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    84691 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84692 File
    84693 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84694 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    84695 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    84696 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84697 File
    84698 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84699 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    84700 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    84701 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84702 File
    84703 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84704 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    84705 p = super().first_intercept(mxyz1, mxyz2) 
    84706 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84707 File
    84708 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84709 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    84710 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    84711 exclude=exclude) 
    84712 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84713 File
    84714 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84715 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    84716 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    84717 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84718 File
    84719 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84720 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    84721 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    84722 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84723 File
    84724 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84725 packages/chimerax/graphics/drawing.py", line 1108, in
    84726 _first_intercept_excluding_children 
    84727 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    84728 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84729 File
    84730 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84731 packages/chimerax/geometry/place.py", line 201, in inverse 
    84732 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    84733 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84734 File
    84735 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84736 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    84737 rinv[:, :] = matrix_inverse(r) 
    84738 ^^^^^^^^^^^^^^^^^ 
    84739 File
    84740 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84741 packages/numpy/linalg/linalg.py", line 561, in inv 
    84742 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    84743 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84744 File
    84745 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84746 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    84747 raise LinAlgError("Singular matrix") 
    84748 numpy.linalg.LinAlgError: Singular matrix 
    84749  
    84750 numpy.linalg.LinAlgError: Singular matrix 
    84751  
    84752 File
    84753 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84754 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    84755 raise LinAlgError("Singular matrix") 
    84756  
    84757 See log for complete Python traceback. 
    84758  
    84759 Traceback (most recent call last): 
    84760 File
    84761 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84762 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    84763 self.session.ui.mouse_modes.mouse_pause_tracking() 
    84764 File
    84765 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84766 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    84767 mouse_pause_tracking 
    84768 self._mouse_pause() 
    84769 File
    84770 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84771 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    84772 m.pause(self._mouse_pause_position) 
    84773 File
    84774 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84775 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    84776 p = self.view.picked_object(x, y) 
    84777 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84778 File
    84779 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84780 packages/chimerax/graphics/view.py", line 838, in picked_object 
    84781 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    84782 beyond, 
    84783 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84784 File
    84785 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84786 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    84787 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    84788 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84789 File
    84790 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84791 packages/chimerax/core/models.py", line 143, in first_intercept 
    84792 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    84793 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84794 File
    84795 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84796 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    84797 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    84798 exclude=exclude) 
    84799 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84800 File
    84801 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84802 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    84803 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    84804 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84805 File
    84806 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84807 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    84808 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    84809 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84810 File
    84811 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84812 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    84813 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    84814 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84815 File
    84816 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84817 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    84818 p = super().first_intercept(mxyz1, mxyz2) 
    84819 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84820 File
    84821 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84822 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    84823 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    84824 exclude=exclude) 
    84825 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84826 File
    84827 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84828 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    84829 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    84830 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84831 File
    84832 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84833 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    84834 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    84835 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84836 File
    84837 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84838 packages/chimerax/graphics/drawing.py", line 1108, in
    84839 _first_intercept_excluding_children 
    84840 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    84841 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84842 File
    84843 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84844 packages/chimerax/geometry/place.py", line 201, in inverse 
    84845 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    84846 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84847 File
    84848 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84849 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    84850 rinv[:, :] = matrix_inverse(r) 
    84851 ^^^^^^^^^^^^^^^^^ 
    84852 File
    84853 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84854 packages/numpy/linalg/linalg.py", line 561, in inv 
    84855 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    84856 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84857 File
    84858 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84859 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    84860 raise LinAlgError("Singular matrix") 
    84861 numpy.linalg.LinAlgError: Singular matrix 
    84862  
    84863 numpy.linalg.LinAlgError: Singular matrix 
    84864  
    84865 File
    84866 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84867 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    84868 raise LinAlgError("Singular matrix") 
    84869  
    84870 See log for complete Python traceback. 
    84871  
    84872 Traceback (most recent call last): 
    84873 File
    84874 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84875 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    84876 self.session.ui.mouse_modes.mouse_pause_tracking() 
    84877 File
    84878 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84879 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    84880 mouse_pause_tracking 
    84881 self._mouse_pause() 
    84882 File
    84883 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84884 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    84885 m.pause(self._mouse_pause_position) 
    84886 File
    84887 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84888 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    84889 p = self.view.picked_object(x, y) 
    84890 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84891 File
    84892 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84893 packages/chimerax/graphics/view.py", line 838, in picked_object 
    84894 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    84895 beyond, 
    84896 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84897 File
    84898 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84899 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    84900 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    84901 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84902 File
    84903 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84904 packages/chimerax/core/models.py", line 143, in first_intercept 
    84905 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    84906 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84907 File
    84908 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84909 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    84910 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    84911 exclude=exclude) 
    84912 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84913 File
    84914 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84915 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    84916 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    84917 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84918 File
    84919 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84920 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    84921 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    84922 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84923 File
    84924 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84925 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    84926 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    84927 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84928 File
    84929 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84930 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    84931 p = super().first_intercept(mxyz1, mxyz2) 
    84932 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84933 File
    84934 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84935 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    84936 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    84937 exclude=exclude) 
    84938 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84939 File
    84940 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84941 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    84942 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    84943 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84944 File
    84945 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84946 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    84947 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    84948 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84949 File
    84950 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84951 packages/chimerax/graphics/drawing.py", line 1108, in
    84952 _first_intercept_excluding_children 
    84953 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    84954 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84955 File
    84956 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84957 packages/chimerax/geometry/place.py", line 201, in inverse 
    84958 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    84959 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84960 File
    84961 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84962 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    84963 rinv[:, :] = matrix_inverse(r) 
    84964 ^^^^^^^^^^^^^^^^^ 
    84965 File
    84966 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84967 packages/numpy/linalg/linalg.py", line 561, in inv 
    84968 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    84969 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    84970 File
    84971 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84972 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    84973 raise LinAlgError("Singular matrix") 
    84974 numpy.linalg.LinAlgError: Singular matrix 
    84975  
    84976 numpy.linalg.LinAlgError: Singular matrix 
    84977  
    84978 File
    84979 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84980 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    84981 raise LinAlgError("Singular matrix") 
    84982  
    84983 See log for complete Python traceback. 
    84984  
    84985 Traceback (most recent call last): 
    84986 File
    84987 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84988 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    84989 self.session.ui.mouse_modes.mouse_pause_tracking() 
    84990 File
    84991 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84992 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    84993 mouse_pause_tracking 
    84994 self._mouse_pause() 
    84995 File
    84996 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    84997 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    84998 m.pause(self._mouse_pause_position) 
    84999 File
    85000 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85001 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    85002 p = self.view.picked_object(x, y) 
    85003 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85004 File
    85005 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85006 packages/chimerax/graphics/view.py", line 838, in picked_object 
    85007 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    85008 beyond, 
    85009 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85010 File
    85011 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85012 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    85013 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    85014 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85015 File
    85016 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85017 packages/chimerax/core/models.py", line 143, in first_intercept 
    85018 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    85019 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85020 File
    85021 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85022 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    85023 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    85024 exclude=exclude) 
    85025 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85026 File
    85027 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85028 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    85029 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    85030 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85031 File
    85032 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85033 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    85034 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    85035 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85036 File
    85037 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85038 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    85039 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    85040 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85041 File
    85042 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85043 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    85044 p = super().first_intercept(mxyz1, mxyz2) 
    85045 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85046 File
    85047 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85048 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    85049 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    85050 exclude=exclude) 
    85051 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85052 File
    85053 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85054 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    85055 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    85056 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85057 File
    85058 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85059 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    85060 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    85061 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85062 File
    85063 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85064 packages/chimerax/graphics/drawing.py", line 1108, in
    85065 _first_intercept_excluding_children 
    85066 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    85067 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85068 File
    85069 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85070 packages/chimerax/geometry/place.py", line 201, in inverse 
    85071 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    85072 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85073 File
    85074 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85075 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    85076 rinv[:, :] = matrix_inverse(r) 
    85077 ^^^^^^^^^^^^^^^^^ 
    85078 File
    85079 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85080 packages/numpy/linalg/linalg.py", line 561, in inv 
    85081 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    85082 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85083 File
    85084 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85085 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    85086 raise LinAlgError("Singular matrix") 
    85087 numpy.linalg.LinAlgError: Singular matrix 
    85088  
    85089 numpy.linalg.LinAlgError: Singular matrix 
    85090  
    85091 File
    85092 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85093 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    85094 raise LinAlgError("Singular matrix") 
    85095  
    85096 See log for complete Python traceback. 
    85097  
    85098 Traceback (most recent call last): 
    85099 File
    85100 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85101 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    85102 self.session.ui.mouse_modes.mouse_pause_tracking() 
    85103 File
    85104 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85105 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    85106 mouse_pause_tracking 
    85107 self._mouse_pause() 
    85108 File
    85109 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85110 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    85111 m.pause(self._mouse_pause_position) 
    85112 File
    85113 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85114 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    85115 p = self.view.picked_object(x, y) 
    85116 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85117 File
    85118 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85119 packages/chimerax/graphics/view.py", line 838, in picked_object 
    85120 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    85121 beyond, 
    85122 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85123 File
    85124 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85125 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    85126 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    85127 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85128 File
    85129 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85130 packages/chimerax/core/models.py", line 143, in first_intercept 
    85131 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    85132 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85133 File
    85134 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85135 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    85136 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    85137 exclude=exclude) 
    85138 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85139 File
    85140 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85141 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    85142 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    85143 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85144 File
    85145 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85146 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    85147 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    85148 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85149 File
    85150 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85151 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    85152 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    85153 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85154 File
    85155 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85156 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    85157 p = super().first_intercept(mxyz1, mxyz2) 
    85158 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85159 File
    85160 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85161 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    85162 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    85163 exclude=exclude) 
    85164 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85165 File
    85166 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85167 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    85168 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    85169 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85170 File
    85171 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85172 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    85173 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    85174 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85175 File
    85176 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85177 packages/chimerax/graphics/drawing.py", line 1108, in
    85178 _first_intercept_excluding_children 
    85179 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    85180 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85181 File
    85182 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85183 packages/chimerax/geometry/place.py", line 201, in inverse 
    85184 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    85185 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85186 File
    85187 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85188 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    85189 rinv[:, :] = matrix_inverse(r) 
    85190 ^^^^^^^^^^^^^^^^^ 
    85191 File
    85192 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85193 packages/numpy/linalg/linalg.py", line 561, in inv 
    85194 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    85195 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85196 File
    85197 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85198 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    85199 raise LinAlgError("Singular matrix") 
    85200 numpy.linalg.LinAlgError: Singular matrix 
    85201  
    85202 numpy.linalg.LinAlgError: Singular matrix 
    85203  
    85204 File
    85205 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85206 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    85207 raise LinAlgError("Singular matrix") 
    85208  
    85209 See log for complete Python traceback. 
    85210  
    85211 Traceback (most recent call last): 
    85212 File
    85213 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85214 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    85215 self.session.ui.mouse_modes.mouse_pause_tracking() 
    85216 File
    85217 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85218 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    85219 mouse_pause_tracking 
    85220 self._mouse_pause() 
    85221 File
    85222 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85223 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    85224 m.pause(self._mouse_pause_position) 
    85225 File
    85226 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85227 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    85228 p = self.view.picked_object(x, y) 
    85229 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85230 File
    85231 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85232 packages/chimerax/graphics/view.py", line 838, in picked_object 
    85233 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    85234 beyond, 
    85235 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85236 File
    85237 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85238 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    85239 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    85240 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85241 File
    85242 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85243 packages/chimerax/core/models.py", line 143, in first_intercept 
    85244 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    85245 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85246 File
    85247 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85248 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    85249 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    85250 exclude=exclude) 
    85251 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85252 File
    85253 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85254 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    85255 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    85256 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85257 File
    85258 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85259 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    85260 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    85261 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85262 File
    85263 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85264 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    85265 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    85266 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85267 File
    85268 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85269 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    85270 p = super().first_intercept(mxyz1, mxyz2) 
    85271 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85272 File
    85273 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85274 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    85275 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    85276 exclude=exclude) 
    85277 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85278 File
    85279 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85280 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    85281 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    85282 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85283 File
    85284 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85285 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    85286 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    85287 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85288 File
    85289 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85290 packages/chimerax/graphics/drawing.py", line 1108, in
    85291 _first_intercept_excluding_children 
    85292 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    85293 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85294 File
    85295 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85296 packages/chimerax/geometry/place.py", line 201, in inverse 
    85297 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    85298 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85299 File
    85300 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85301 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    85302 rinv[:, :] = matrix_inverse(r) 
    85303 ^^^^^^^^^^^^^^^^^ 
    85304 File
    85305 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85306 packages/numpy/linalg/linalg.py", line 561, in inv 
    85307 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    85308 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85309 File
    85310 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85311 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    85312 raise LinAlgError("Singular matrix") 
    85313 numpy.linalg.LinAlgError: Singular matrix 
    85314  
    85315 numpy.linalg.LinAlgError: Singular matrix 
    85316  
    85317 File
    85318 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85319 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    85320 raise LinAlgError("Singular matrix") 
    85321  
    85322 See log for complete Python traceback. 
    85323  
    85324 Traceback (most recent call last): 
    85325 File
    85326 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85327 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    85328 self.session.ui.mouse_modes.mouse_pause_tracking() 
    85329 File
    85330 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85331 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    85332 mouse_pause_tracking 
    85333 self._mouse_pause() 
    85334 File
    85335 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85336 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    85337 m.pause(self._mouse_pause_position) 
    85338 File
    85339 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85340 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    85341 p = self.view.picked_object(x, y) 
    85342 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85343 File
    85344 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85345 packages/chimerax/graphics/view.py", line 838, in picked_object 
    85346 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    85347 beyond, 
    85348 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85349 File
    85350 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85351 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    85352 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    85353 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85354 File
    85355 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85356 packages/chimerax/core/models.py", line 143, in first_intercept 
    85357 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    85358 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85359 File
    85360 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85361 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    85362 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    85363 exclude=exclude) 
    85364 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85365 File
    85366 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85367 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    85368 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    85369 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85370 File
    85371 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85372 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    85373 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    85374 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85375 File
    85376 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85377 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    85378 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    85379 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85380 File
    85381 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85382 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    85383 p = super().first_intercept(mxyz1, mxyz2) 
    85384 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85385 File
    85386 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85387 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    85388 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    85389 exclude=exclude) 
    85390 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85391 File
    85392 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85393 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    85394 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    85395 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85396 File
    85397 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85398 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    85399 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    85400 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85401 File
    85402 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85403 packages/chimerax/graphics/drawing.py", line 1108, in
    85404 _first_intercept_excluding_children 
    85405 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    85406 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85407 File
    85408 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85409 packages/chimerax/geometry/place.py", line 201, in inverse 
    85410 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    85411 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85412 File
    85413 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85414 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    85415 rinv[:, :] = matrix_inverse(r) 
    85416 ^^^^^^^^^^^^^^^^^ 
    85417 File
    85418 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85419 packages/numpy/linalg/linalg.py", line 561, in inv 
    85420 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    85421 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85422 File
    85423 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85424 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    85425 raise LinAlgError("Singular matrix") 
    85426 numpy.linalg.LinAlgError: Singular matrix 
    85427  
    85428 numpy.linalg.LinAlgError: Singular matrix 
    85429  
    85430 File
    85431 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85432 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    85433 raise LinAlgError("Singular matrix") 
    85434  
    85435 See log for complete Python traceback. 
    85436  
    85437 Traceback (most recent call last): 
    85438 File
    85439 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85440 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    85441 self.session.ui.mouse_modes.mouse_pause_tracking() 
    85442 File
    85443 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85444 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    85445 mouse_pause_tracking 
    85446 self._mouse_pause() 
    85447 File
    85448 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85449 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    85450 m.pause(self._mouse_pause_position) 
    85451 File
    85452 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85453 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    85454 p = self.view.picked_object(x, y) 
    85455 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85456 File
    85457 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85458 packages/chimerax/graphics/view.py", line 838, in picked_object 
    85459 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    85460 beyond, 
    85461 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85462 File
    85463 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85464 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    85465 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    85466 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85467 File
    85468 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85469 packages/chimerax/core/models.py", line 143, in first_intercept 
    85470 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    85471 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85472 File
    85473 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85474 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    85475 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    85476 exclude=exclude) 
    85477 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85478 File
    85479 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85480 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    85481 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    85482 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85483 File
    85484 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85485 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    85486 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    85487 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85488 File
    85489 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85490 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    85491 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    85492 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85493 File
    85494 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85495 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    85496 p = super().first_intercept(mxyz1, mxyz2) 
    85497 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85498 File
    85499 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85500 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    85501 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    85502 exclude=exclude) 
    85503 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85504 File
    85505 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85506 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    85507 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    85508 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85509 File
    85510 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85511 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    85512 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    85513 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85514 File
    85515 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85516 packages/chimerax/graphics/drawing.py", line 1108, in
    85517 _first_intercept_excluding_children 
    85518 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    85519 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85520 File
    85521 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85522 packages/chimerax/geometry/place.py", line 201, in inverse 
    85523 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    85524 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85525 File
    85526 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85527 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    85528 rinv[:, :] = matrix_inverse(r) 
    85529 ^^^^^^^^^^^^^^^^^ 
    85530 File
    85531 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85532 packages/numpy/linalg/linalg.py", line 561, in inv 
    85533 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    85534 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85535 File
    85536 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85537 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    85538 raise LinAlgError("Singular matrix") 
    85539 numpy.linalg.LinAlgError: Singular matrix 
    85540  
    85541 numpy.linalg.LinAlgError: Singular matrix 
    85542  
    85543 File
    85544 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85545 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    85546 raise LinAlgError("Singular matrix") 
    85547  
    85548 See log for complete Python traceback. 
    85549  
    85550 Traceback (most recent call last): 
    85551 File
    85552 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85553 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    85554 self.session.ui.mouse_modes.mouse_pause_tracking() 
    85555 File
    85556 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85557 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    85558 mouse_pause_tracking 
    85559 self._mouse_pause() 
    85560 File
    85561 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85562 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    85563 m.pause(self._mouse_pause_position) 
    85564 File
    85565 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85566 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    85567 p = self.view.picked_object(x, y) 
    85568 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85569 File
    85570 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85571 packages/chimerax/graphics/view.py", line 838, in picked_object 
    85572 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    85573 beyond, 
    85574 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85575 File
    85576 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85577 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    85578 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    85579 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85580 File
    85581 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85582 packages/chimerax/core/models.py", line 143, in first_intercept 
    85583 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    85584 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85585 File
    85586 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85587 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    85588 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    85589 exclude=exclude) 
    85590 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85591 File
    85592 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85593 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    85594 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    85595 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85596 File
    85597 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85598 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    85599 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    85600 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85601 File
    85602 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85603 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    85604 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    85605 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85606 File
    85607 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85608 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    85609 p = super().first_intercept(mxyz1, mxyz2) 
    85610 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85611 File
    85612 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85613 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    85614 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    85615 exclude=exclude) 
    85616 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85617 File
    85618 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85619 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    85620 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    85621 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85622 File
    85623 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85624 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    85625 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    85626 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85627 File
    85628 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85629 packages/chimerax/graphics/drawing.py", line 1108, in
    85630 _first_intercept_excluding_children 
    85631 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    85632 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85633 File
    85634 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85635 packages/chimerax/geometry/place.py", line 201, in inverse 
    85636 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    85637 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85638 File
    85639 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85640 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    85641 rinv[:, :] = matrix_inverse(r) 
    85642 ^^^^^^^^^^^^^^^^^ 
    85643 File
    85644 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85645 packages/numpy/linalg/linalg.py", line 561, in inv 
    85646 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    85647 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85648 File
    85649 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85650 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    85651 raise LinAlgError("Singular matrix") 
    85652 numpy.linalg.LinAlgError: Singular matrix 
    85653  
    85654 numpy.linalg.LinAlgError: Singular matrix 
    85655  
    85656 File
    85657 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85658 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    85659 raise LinAlgError("Singular matrix") 
    85660  
    85661 See log for complete Python traceback. 
    85662  
    85663 Traceback (most recent call last): 
    85664 File
    85665 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85666 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    85667 self.session.ui.mouse_modes.mouse_pause_tracking() 
    85668 File
    85669 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85670 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    85671 mouse_pause_tracking 
    85672 self._mouse_pause() 
    85673 File
    85674 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85675 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    85676 m.pause(self._mouse_pause_position) 
    85677 File
    85678 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85679 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    85680 p = self.view.picked_object(x, y) 
    85681 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85682 File
    85683 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85684 packages/chimerax/graphics/view.py", line 838, in picked_object 
    85685 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    85686 beyond, 
    85687 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85688 File
    85689 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85690 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    85691 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    85692 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85693 File
    85694 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85695 packages/chimerax/core/models.py", line 143, in first_intercept 
    85696 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    85697 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85698 File
    85699 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85700 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    85701 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    85702 exclude=exclude) 
    85703 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85704 File
    85705 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85706 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    85707 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    85708 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85709 File
    85710 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85711 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    85712 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    85713 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85714 File
    85715 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85716 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    85717 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    85718 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85719 File
    85720 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85721 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    85722 p = super().first_intercept(mxyz1, mxyz2) 
    85723 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85724 File
    85725 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85726 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    85727 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    85728 exclude=exclude) 
    85729 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85730 File
    85731 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85732 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    85733 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    85734 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85735 File
    85736 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85737 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    85738 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    85739 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85740 File
    85741 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85742 packages/chimerax/graphics/drawing.py", line 1108, in
    85743 _first_intercept_excluding_children 
    85744 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    85745 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85746 File
    85747 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85748 packages/chimerax/geometry/place.py", line 201, in inverse 
    85749 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    85750 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85751 File
    85752 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85753 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    85754 rinv[:, :] = matrix_inverse(r) 
    85755 ^^^^^^^^^^^^^^^^^ 
    85756 File
    85757 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85758 packages/numpy/linalg/linalg.py", line 561, in inv 
    85759 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    85760 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85761 File
    85762 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85763 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    85764 raise LinAlgError("Singular matrix") 
    85765 numpy.linalg.LinAlgError: Singular matrix 
    85766  
    85767 numpy.linalg.LinAlgError: Singular matrix 
    85768  
    85769 File
    85770 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85771 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    85772 raise LinAlgError("Singular matrix") 
    85773  
    85774 See log for complete Python traceback. 
    85775  
    85776 Traceback (most recent call last): 
    85777 File
    85778 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85779 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    85780 self.session.ui.mouse_modes.mouse_pause_tracking() 
    85781 File
    85782 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85783 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    85784 mouse_pause_tracking 
    85785 self._mouse_pause() 
    85786 File
    85787 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85788 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    85789 m.pause(self._mouse_pause_position) 
    85790 File
    85791 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85792 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    85793 p = self.view.picked_object(x, y) 
    85794 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85795 File
    85796 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85797 packages/chimerax/graphics/view.py", line 838, in picked_object 
    85798 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    85799 beyond, 
    85800 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85801 File
    85802 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85803 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    85804 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    85805 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85806 File
    85807 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85808 packages/chimerax/core/models.py", line 143, in first_intercept 
    85809 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    85810 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85811 File
    85812 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85813 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    85814 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    85815 exclude=exclude) 
    85816 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85817 File
    85818 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85819 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    85820 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    85821 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85822 File
    85823 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85824 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    85825 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    85826 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85827 File
    85828 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85829 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    85830 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    85831 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85832 File
    85833 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85834 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    85835 p = super().first_intercept(mxyz1, mxyz2) 
    85836 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85837 File
    85838 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85839 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    85840 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    85841 exclude=exclude) 
    85842 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85843 File
    85844 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85845 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    85846 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    85847 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85848 File
    85849 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85850 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    85851 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    85852 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85853 File
    85854 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85855 packages/chimerax/graphics/drawing.py", line 1108, in
    85856 _first_intercept_excluding_children 
    85857 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    85858 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85859 File
    85860 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85861 packages/chimerax/geometry/place.py", line 201, in inverse 
    85862 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    85863 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85864 File
    85865 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85866 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    85867 rinv[:, :] = matrix_inverse(r) 
    85868 ^^^^^^^^^^^^^^^^^ 
    85869 File
    85870 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85871 packages/numpy/linalg/linalg.py", line 561, in inv 
    85872 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    85873 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85874 File
    85875 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85876 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    85877 raise LinAlgError("Singular matrix") 
    85878 numpy.linalg.LinAlgError: Singular matrix 
    85879  
    85880 numpy.linalg.LinAlgError: Singular matrix 
    85881  
    85882 File
    85883 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85884 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    85885 raise LinAlgError("Singular matrix") 
    85886  
    85887 See log for complete Python traceback. 
    85888  
    85889 Traceback (most recent call last): 
    85890 File
    85891 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85892 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    85893 self.session.ui.mouse_modes.mouse_pause_tracking() 
    85894 File
    85895 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85896 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    85897 mouse_pause_tracking 
    85898 self._mouse_pause() 
    85899 File
    85900 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85901 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    85902 m.pause(self._mouse_pause_position) 
    85903 File
    85904 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85905 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    85906 p = self.view.picked_object(x, y) 
    85907 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85908 File
    85909 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85910 packages/chimerax/graphics/view.py", line 838, in picked_object 
    85911 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    85912 beyond, 
    85913 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85914 File
    85915 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85916 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    85917 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    85918 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85919 File
    85920 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85921 packages/chimerax/core/models.py", line 143, in first_intercept 
    85922 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    85923 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85924 File
    85925 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85926 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    85927 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    85928 exclude=exclude) 
    85929 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85930 File
    85931 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85932 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    85933 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    85934 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85935 File
    85936 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85937 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    85938 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    85939 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85940 File
    85941 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85942 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    85943 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    85944 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85945 File
    85946 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85947 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    85948 p = super().first_intercept(mxyz1, mxyz2) 
    85949 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85950 File
    85951 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85952 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    85953 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    85954 exclude=exclude) 
    85955 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85956 File
    85957 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85958 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    85959 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    85960 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85961 File
    85962 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85963 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    85964 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    85965 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85966 File
    85967 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85968 packages/chimerax/graphics/drawing.py", line 1108, in
    85969 _first_intercept_excluding_children 
    85970 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    85971 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85972 File
    85973 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85974 packages/chimerax/geometry/place.py", line 201, in inverse 
    85975 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    85976 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85977 File
    85978 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85979 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    85980 rinv[:, :] = matrix_inverse(r) 
    85981 ^^^^^^^^^^^^^^^^^ 
    85982 File
    85983 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85984 packages/numpy/linalg/linalg.py", line 561, in inv 
    85985 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    85986 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    85987 File
    85988 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85989 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    85990 raise LinAlgError("Singular matrix") 
    85991 numpy.linalg.LinAlgError: Singular matrix 
    85992  
    85993 numpy.linalg.LinAlgError: Singular matrix 
    85994  
    85995 File
    85996 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    85997 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    85998 raise LinAlgError("Singular matrix") 
    85999  
    86000 See log for complete Python traceback. 
    86001  
    86002 Traceback (most recent call last): 
    86003 File
    86004 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86005 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    86006 self.session.ui.mouse_modes.mouse_pause_tracking() 
    86007 File
    86008 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86009 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    86010 mouse_pause_tracking 
    86011 self._mouse_pause() 
    86012 File
    86013 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86014 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    86015 m.pause(self._mouse_pause_position) 
    86016 File
    86017 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86018 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    86019 p = self.view.picked_object(x, y) 
    86020 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86021 File
    86022 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86023 packages/chimerax/graphics/view.py", line 838, in picked_object 
    86024 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    86025 beyond, 
    86026 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86027 File
    86028 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86029 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    86030 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    86031 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86032 File
    86033 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86034 packages/chimerax/core/models.py", line 143, in first_intercept 
    86035 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    86036 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86037 File
    86038 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86039 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    86040 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    86041 exclude=exclude) 
    86042 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86043 File
    86044 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86045 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    86046 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    86047 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86048 File
    86049 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86050 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    86051 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    86052 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86053 File
    86054 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86055 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    86056 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    86057 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86058 File
    86059 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86060 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    86061 p = super().first_intercept(mxyz1, mxyz2) 
    86062 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86063 File
    86064 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86065 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    86066 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    86067 exclude=exclude) 
    86068 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86069 File
    86070 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86071 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    86072 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    86073 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86074 File
    86075 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86076 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    86077 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    86078 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86079 File
    86080 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86081 packages/chimerax/graphics/drawing.py", line 1108, in
    86082 _first_intercept_excluding_children 
    86083 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    86084 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86085 File
    86086 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86087 packages/chimerax/geometry/place.py", line 201, in inverse 
    86088 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    86089 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86090 File
    86091 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86092 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    86093 rinv[:, :] = matrix_inverse(r) 
    86094 ^^^^^^^^^^^^^^^^^ 
    86095 File
    86096 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86097 packages/numpy/linalg/linalg.py", line 561, in inv 
    86098 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    86099 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86100 File
    86101 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86102 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    86103 raise LinAlgError("Singular matrix") 
    86104 numpy.linalg.LinAlgError: Singular matrix 
    86105  
    86106 numpy.linalg.LinAlgError: Singular matrix 
    86107  
    86108 File
    86109 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86110 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    86111 raise LinAlgError("Singular matrix") 
    86112  
    86113 See log for complete Python traceback. 
    86114  
    86115 Traceback (most recent call last): 
    86116 File
    86117 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86118 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    86119 self.session.ui.mouse_modes.mouse_pause_tracking() 
    86120 File
    86121 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86122 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    86123 mouse_pause_tracking 
    86124 self._mouse_pause() 
    86125 File
    86126 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86127 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    86128 m.pause(self._mouse_pause_position) 
    86129 File
    86130 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86131 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    86132 p = self.view.picked_object(x, y) 
    86133 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86134 File
    86135 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86136 packages/chimerax/graphics/view.py", line 838, in picked_object 
    86137 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    86138 beyond, 
    86139 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86140 File
    86141 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86142 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    86143 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    86144 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86145 File
    86146 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86147 packages/chimerax/core/models.py", line 143, in first_intercept 
    86148 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    86149 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86150 File
    86151 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86152 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    86153 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    86154 exclude=exclude) 
    86155 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86156 File
    86157 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86158 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    86159 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    86160 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86161 File
    86162 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86163 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    86164 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    86165 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86166 File
    86167 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86168 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    86169 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    86170 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86171 File
    86172 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86173 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    86174 p = super().first_intercept(mxyz1, mxyz2) 
    86175 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86176 File
    86177 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86178 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    86179 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    86180 exclude=exclude) 
    86181 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86182 File
    86183 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86184 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    86185 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    86186 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86187 File
    86188 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86189 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    86190 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    86191 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86192 File
    86193 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86194 packages/chimerax/graphics/drawing.py", line 1108, in
    86195 _first_intercept_excluding_children 
    86196 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    86197 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86198 File
    86199 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86200 packages/chimerax/geometry/place.py", line 201, in inverse 
    86201 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    86202 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86203 File
    86204 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86205 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    86206 rinv[:, :] = matrix_inverse(r) 
    86207 ^^^^^^^^^^^^^^^^^ 
    86208 File
    86209 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86210 packages/numpy/linalg/linalg.py", line 561, in inv 
    86211 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    86212 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86213 File
    86214 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86215 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    86216 raise LinAlgError("Singular matrix") 
    86217 numpy.linalg.LinAlgError: Singular matrix 
    86218  
    86219 numpy.linalg.LinAlgError: Singular matrix 
    86220  
    86221 File
    86222 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86223 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    86224 raise LinAlgError("Singular matrix") 
    86225  
    86226 See log for complete Python traceback. 
    86227  
    86228 Traceback (most recent call last): 
    86229 File
    86230 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86231 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    86232 self.session.ui.mouse_modes.mouse_pause_tracking() 
    86233 File
    86234 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86235 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    86236 mouse_pause_tracking 
    86237 self._mouse_pause() 
    86238 File
    86239 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86240 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    86241 m.pause(self._mouse_pause_position) 
    86242 File
    86243 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86244 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    86245 p = self.view.picked_object(x, y) 
    86246 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86247 File
    86248 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86249 packages/chimerax/graphics/view.py", line 838, in picked_object 
    86250 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    86251 beyond, 
    86252 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86253 File
    86254 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86255 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    86256 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    86257 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86258 File
    86259 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86260 packages/chimerax/core/models.py", line 143, in first_intercept 
    86261 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    86262 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86263 File
    86264 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86265 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    86266 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    86267 exclude=exclude) 
    86268 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86269 File
    86270 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86271 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    86272 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    86273 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86274 File
    86275 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86276 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    86277 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    86278 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86279 File
    86280 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86281 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    86282 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    86283 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86284 File
    86285 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86286 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    86287 p = super().first_intercept(mxyz1, mxyz2) 
    86288 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86289 File
    86290 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86291 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    86292 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    86293 exclude=exclude) 
    86294 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86295 File
    86296 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86297 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    86298 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    86299 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86300 File
    86301 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86302 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    86303 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    86304 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86305 File
    86306 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86307 packages/chimerax/graphics/drawing.py", line 1108, in
    86308 _first_intercept_excluding_children 
    86309 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    86310 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86311 File
    86312 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86313 packages/chimerax/geometry/place.py", line 201, in inverse 
    86314 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    86315 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86316 File
    86317 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86318 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    86319 rinv[:, :] = matrix_inverse(r) 
    86320 ^^^^^^^^^^^^^^^^^ 
    86321 File
    86322 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86323 packages/numpy/linalg/linalg.py", line 561, in inv 
    86324 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    86325 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86326 File
    86327 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86328 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    86329 raise LinAlgError("Singular matrix") 
    86330 numpy.linalg.LinAlgError: Singular matrix 
    86331  
    86332 numpy.linalg.LinAlgError: Singular matrix 
    86333  
    86334 File
    86335 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86336 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    86337 raise LinAlgError("Singular matrix") 
    86338  
    86339 See log for complete Python traceback. 
    86340  
    86341 Traceback (most recent call last): 
    86342 File
    86343 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86344 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    86345 self.session.ui.mouse_modes.mouse_pause_tracking() 
    86346 File
    86347 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86348 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    86349 mouse_pause_tracking 
    86350 self._mouse_pause() 
    86351 File
    86352 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86353 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    86354 m.pause(self._mouse_pause_position) 
    86355 File
    86356 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86357 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    86358 p = self.view.picked_object(x, y) 
    86359 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86360 File
    86361 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86362 packages/chimerax/graphics/view.py", line 838, in picked_object 
    86363 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    86364 beyond, 
    86365 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86366 File
    86367 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86368 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    86369 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    86370 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86371 File
    86372 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86373 packages/chimerax/core/models.py", line 143, in first_intercept 
    86374 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    86375 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86376 File
    86377 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86378 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    86379 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    86380 exclude=exclude) 
    86381 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86382 File
    86383 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86384 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    86385 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    86386 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86387 File
    86388 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86389 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    86390 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    86391 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86392 File
    86393 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86394 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    86395 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    86396 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86397 File
    86398 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86399 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    86400 p = super().first_intercept(mxyz1, mxyz2) 
    86401 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86402 File
    86403 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86404 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    86405 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    86406 exclude=exclude) 
    86407 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86408 File
    86409 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86410 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    86411 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    86412 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86413 File
    86414 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86415 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    86416 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    86417 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86418 File
    86419 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86420 packages/chimerax/graphics/drawing.py", line 1108, in
    86421 _first_intercept_excluding_children 
    86422 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    86423 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86424 File
    86425 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86426 packages/chimerax/geometry/place.py", line 201, in inverse 
    86427 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    86428 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86429 File
    86430 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86431 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    86432 rinv[:, :] = matrix_inverse(r) 
    86433 ^^^^^^^^^^^^^^^^^ 
    86434 File
    86435 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86436 packages/numpy/linalg/linalg.py", line 561, in inv 
    86437 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    86438 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86439 File
    86440 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86441 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    86442 raise LinAlgError("Singular matrix") 
    86443 numpy.linalg.LinAlgError: Singular matrix 
    86444  
    86445 numpy.linalg.LinAlgError: Singular matrix 
    86446  
    86447 File
    86448 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86449 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    86450 raise LinAlgError("Singular matrix") 
    86451  
    86452 See log for complete Python traceback. 
    86453  
    86454 Traceback (most recent call last): 
    86455 File
    86456 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86457 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    86458 self.session.ui.mouse_modes.mouse_pause_tracking() 
    86459 File
    86460 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86461 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    86462 mouse_pause_tracking 
    86463 self._mouse_pause() 
    86464 File
    86465 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86466 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    86467 m.pause(self._mouse_pause_position) 
    86468 File
    86469 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86470 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    86471 p = self.view.picked_object(x, y) 
    86472 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86473 File
    86474 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86475 packages/chimerax/graphics/view.py", line 838, in picked_object 
    86476 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    86477 beyond, 
    86478 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86479 File
    86480 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86481 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    86482 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    86483 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86484 File
    86485 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86486 packages/chimerax/core/models.py", line 143, in first_intercept 
    86487 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    86488 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86489 File
    86490 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86491 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    86492 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    86493 exclude=exclude) 
    86494 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86495 File
    86496 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86497 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    86498 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    86499 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86500 File
    86501 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86502 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    86503 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    86504 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86505 File
    86506 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86507 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    86508 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    86509 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86510 File
    86511 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86512 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    86513 p = super().first_intercept(mxyz1, mxyz2) 
    86514 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86515 File
    86516 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86517 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    86518 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    86519 exclude=exclude) 
    86520 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86521 File
    86522 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86523 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    86524 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    86525 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86526 File
    86527 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86528 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    86529 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    86530 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86531 File
    86532 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86533 packages/chimerax/graphics/drawing.py", line 1108, in
    86534 _first_intercept_excluding_children 
    86535 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    86536 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86537 File
    86538 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86539 packages/chimerax/geometry/place.py", line 201, in inverse 
    86540 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    86541 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86542 File
    86543 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86544 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    86545 rinv[:, :] = matrix_inverse(r) 
    86546 ^^^^^^^^^^^^^^^^^ 
    86547 File
    86548 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86549 packages/numpy/linalg/linalg.py", line 561, in inv 
    86550 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    86551 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86552 File
    86553 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86554 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    86555 raise LinAlgError("Singular matrix") 
    86556 numpy.linalg.LinAlgError: Singular matrix 
    86557  
    86558 numpy.linalg.LinAlgError: Singular matrix 
    86559  
    86560 File
    86561 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86562 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    86563 raise LinAlgError("Singular matrix") 
    86564  
    86565 See log for complete Python traceback. 
    86566  
    86567 Traceback (most recent call last): 
    86568 File
    86569 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86570 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    86571 self.session.ui.mouse_modes.mouse_pause_tracking() 
    86572 File
    86573 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86574 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    86575 mouse_pause_tracking 
    86576 self._mouse_pause() 
    86577 File
    86578 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86579 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    86580 m.pause(self._mouse_pause_position) 
    86581 File
    86582 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86583 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    86584 p = self.view.picked_object(x, y) 
    86585 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86586 File
    86587 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86588 packages/chimerax/graphics/view.py", line 838, in picked_object 
    86589 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    86590 beyond, 
    86591 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86592 File
    86593 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86594 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    86595 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    86596 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86597 File
    86598 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86599 packages/chimerax/core/models.py", line 143, in first_intercept 
    86600 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    86601 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86602 File
    86603 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86604 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    86605 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    86606 exclude=exclude) 
    86607 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86608 File
    86609 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86610 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    86611 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    86612 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86613 File
    86614 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86615 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    86616 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    86617 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86618 File
    86619 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86620 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    86621 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    86622 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86623 File
    86624 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86625 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    86626 p = super().first_intercept(mxyz1, mxyz2) 
    86627 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86628 File
    86629 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86630 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    86631 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    86632 exclude=exclude) 
    86633 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86634 File
    86635 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86636 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    86637 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    86638 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86639 File
    86640 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86641 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    86642 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    86643 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86644 File
    86645 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86646 packages/chimerax/graphics/drawing.py", line 1108, in
    86647 _first_intercept_excluding_children 
    86648 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    86649 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86650 File
    86651 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86652 packages/chimerax/geometry/place.py", line 201, in inverse 
    86653 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    86654 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86655 File
    86656 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86657 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    86658 rinv[:, :] = matrix_inverse(r) 
    86659 ^^^^^^^^^^^^^^^^^ 
    86660 File
    86661 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86662 packages/numpy/linalg/linalg.py", line 561, in inv 
    86663 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    86664 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86665 File
    86666 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86667 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    86668 raise LinAlgError("Singular matrix") 
    86669 numpy.linalg.LinAlgError: Singular matrix 
    86670  
    86671 numpy.linalg.LinAlgError: Singular matrix 
    86672  
    86673 File
    86674 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86675 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    86676 raise LinAlgError("Singular matrix") 
    86677  
    86678 See log for complete Python traceback. 
    86679  
    86680 Traceback (most recent call last): 
    86681 File
    86682 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86683 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    86684 self.session.ui.mouse_modes.mouse_pause_tracking() 
    86685 File
    86686 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86687 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    86688 mouse_pause_tracking 
    86689 self._mouse_pause() 
    86690 File
    86691 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86692 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    86693 m.pause(self._mouse_pause_position) 
    86694 File
    86695 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86696 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    86697 p = self.view.picked_object(x, y) 
    86698 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86699 File
    86700 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86701 packages/chimerax/graphics/view.py", line 838, in picked_object 
    86702 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    86703 beyond, 
    86704 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86705 File
    86706 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86707 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    86708 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    86709 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86710 File
    86711 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86712 packages/chimerax/core/models.py", line 143, in first_intercept 
    86713 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    86714 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86715 File
    86716 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86717 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    86718 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    86719 exclude=exclude) 
    86720 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86721 File
    86722 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86723 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    86724 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    86725 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86726 File
    86727 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86728 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    86729 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    86730 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86731 File
    86732 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86733 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    86734 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    86735 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86736 File
    86737 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86738 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    86739 p = super().first_intercept(mxyz1, mxyz2) 
    86740 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86741 File
    86742 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86743 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    86744 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    86745 exclude=exclude) 
    86746 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86747 File
    86748 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86749 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    86750 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    86751 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86752 File
    86753 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86754 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    86755 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    86756 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86757 File
    86758 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86759 packages/chimerax/graphics/drawing.py", line 1108, in
    86760 _first_intercept_excluding_children 
    86761 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    86762 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86763 File
    86764 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86765 packages/chimerax/geometry/place.py", line 201, in inverse 
    86766 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    86767 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86768 File
    86769 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86770 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    86771 rinv[:, :] = matrix_inverse(r) 
    86772 ^^^^^^^^^^^^^^^^^ 
    86773 File
    86774 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86775 packages/numpy/linalg/linalg.py", line 561, in inv 
    86776 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    86777 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86778 File
    86779 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86780 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    86781 raise LinAlgError("Singular matrix") 
    86782 numpy.linalg.LinAlgError: Singular matrix 
    86783  
    86784 numpy.linalg.LinAlgError: Singular matrix 
    86785  
    86786 File
    86787 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86788 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    86789 raise LinAlgError("Singular matrix") 
    86790  
    86791 See log for complete Python traceback. 
    86792  
    86793 Traceback (most recent call last): 
    86794 File
    86795 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86796 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    86797 self.session.ui.mouse_modes.mouse_pause_tracking() 
    86798 File
    86799 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86800 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    86801 mouse_pause_tracking 
    86802 self._mouse_pause() 
    86803 File
    86804 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86805 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    86806 m.pause(self._mouse_pause_position) 
    86807 File
    86808 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86809 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    86810 p = self.view.picked_object(x, y) 
    86811 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86812 File
    86813 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86814 packages/chimerax/graphics/view.py", line 838, in picked_object 
    86815 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    86816 beyond, 
    86817 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86818 File
    86819 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86820 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    86821 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    86822 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86823 File
    86824 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86825 packages/chimerax/core/models.py", line 143, in first_intercept 
    86826 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    86827 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86828 File
    86829 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86830 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    86831 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    86832 exclude=exclude) 
    86833 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86834 File
    86835 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86836 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    86837 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    86838 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86839 File
    86840 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86841 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    86842 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    86843 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86844 File
    86845 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86846 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    86847 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    86848 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86849 File
    86850 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86851 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    86852 p = super().first_intercept(mxyz1, mxyz2) 
    86853 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86854 File
    86855 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86856 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    86857 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    86858 exclude=exclude) 
    86859 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86860 File
    86861 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86862 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    86863 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    86864 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86865 File
    86866 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86867 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    86868 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    86869 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86870 File
    86871 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86872 packages/chimerax/graphics/drawing.py", line 1108, in
    86873 _first_intercept_excluding_children 
    86874 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    86875 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86876 File
    86877 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86878 packages/chimerax/geometry/place.py", line 201, in inverse 
    86879 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    86880 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86881 File
    86882 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86883 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    86884 rinv[:, :] = matrix_inverse(r) 
    86885 ^^^^^^^^^^^^^^^^^ 
    86886 File
    86887 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86888 packages/numpy/linalg/linalg.py", line 561, in inv 
    86889 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    86890 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86891 File
    86892 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86893 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    86894 raise LinAlgError("Singular matrix") 
    86895 numpy.linalg.LinAlgError: Singular matrix 
    86896  
    86897 numpy.linalg.LinAlgError: Singular matrix 
    86898  
    86899 File
    86900 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86901 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    86902 raise LinAlgError("Singular matrix") 
    86903  
    86904 See log for complete Python traceback. 
    86905  
    86906 Traceback (most recent call last): 
    86907 File
    86908 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86909 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    86910 self.session.ui.mouse_modes.mouse_pause_tracking() 
    86911 File
    86912 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86913 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    86914 mouse_pause_tracking 
    86915 self._mouse_pause() 
    86916 File
    86917 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86918 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    86919 m.pause(self._mouse_pause_position) 
    86920 File
    86921 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86922 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    86923 p = self.view.picked_object(x, y) 
    86924 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86925 File
    86926 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86927 packages/chimerax/graphics/view.py", line 838, in picked_object 
    86928 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    86929 beyond, 
    86930 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86931 File
    86932 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86933 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    86934 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    86935 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86936 File
    86937 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86938 packages/chimerax/core/models.py", line 143, in first_intercept 
    86939 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    86940 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86941 File
    86942 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86943 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    86944 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    86945 exclude=exclude) 
    86946 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86947 File
    86948 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86949 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    86950 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    86951 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86952 File
    86953 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86954 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    86955 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    86956 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86957 File
    86958 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86959 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    86960 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    86961 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86962 File
    86963 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86964 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    86965 p = super().first_intercept(mxyz1, mxyz2) 
    86966 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86967 File
    86968 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86969 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    86970 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    86971 exclude=exclude) 
    86972 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86973 File
    86974 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86975 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    86976 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    86977 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86978 File
    86979 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86980 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    86981 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    86982 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86983 File
    86984 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86985 packages/chimerax/graphics/drawing.py", line 1108, in
    86986 _first_intercept_excluding_children 
    86987 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    86988 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86989 File
    86990 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86991 packages/chimerax/geometry/place.py", line 201, in inverse 
    86992 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    86993 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    86994 File
    86995 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    86996 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    86997 rinv[:, :] = matrix_inverse(r) 
    86998 ^^^^^^^^^^^^^^^^^ 
    86999 File
    87000 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87001 packages/numpy/linalg/linalg.py", line 561, in inv 
    87002 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    87003 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87004 File
    87005 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87006 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    87007 raise LinAlgError("Singular matrix") 
    87008 numpy.linalg.LinAlgError: Singular matrix 
    87009  
    87010 numpy.linalg.LinAlgError: Singular matrix 
    87011  
    87012 File
    87013 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87014 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    87015 raise LinAlgError("Singular matrix") 
    87016  
    87017 See log for complete Python traceback. 
    87018  
    87019 Traceback (most recent call last): 
    87020 File
    87021 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87022 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    87023 self.session.ui.mouse_modes.mouse_pause_tracking() 
    87024 File
    87025 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87026 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    87027 mouse_pause_tracking 
    87028 self._mouse_pause() 
    87029 File
    87030 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87031 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    87032 m.pause(self._mouse_pause_position) 
    87033 File
    87034 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87035 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    87036 p = self.view.picked_object(x, y) 
    87037 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87038 File
    87039 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87040 packages/chimerax/graphics/view.py", line 838, in picked_object 
    87041 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    87042 beyond, 
    87043 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87044 File
    87045 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87046 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    87047 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    87048 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87049 File
    87050 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87051 packages/chimerax/core/models.py", line 143, in first_intercept 
    87052 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    87053 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87054 File
    87055 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87056 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    87057 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    87058 exclude=exclude) 
    87059 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87060 File
    87061 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87062 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    87063 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    87064 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87065 File
    87066 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87067 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    87068 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    87069 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87070 File
    87071 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87072 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    87073 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    87074 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87075 File
    87076 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87077 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    87078 p = super().first_intercept(mxyz1, mxyz2) 
    87079 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87080 File
    87081 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87082 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    87083 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    87084 exclude=exclude) 
    87085 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87086 File
    87087 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87088 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    87089 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    87090 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87091 File
    87092 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87093 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    87094 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    87095 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87096 File
    87097 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87098 packages/chimerax/graphics/drawing.py", line 1108, in
    87099 _first_intercept_excluding_children 
    87100 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    87101 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87102 File
    87103 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87104 packages/chimerax/geometry/place.py", line 201, in inverse 
    87105 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    87106 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87107 File
    87108 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87109 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    87110 rinv[:, :] = matrix_inverse(r) 
    87111 ^^^^^^^^^^^^^^^^^ 
    87112 File
    87113 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87114 packages/numpy/linalg/linalg.py", line 561, in inv 
    87115 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    87116 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87117 File
    87118 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87119 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    87120 raise LinAlgError("Singular matrix") 
    87121 numpy.linalg.LinAlgError: Singular matrix 
    87122  
    87123 numpy.linalg.LinAlgError: Singular matrix 
    87124  
    87125 File
    87126 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87127 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    87128 raise LinAlgError("Singular matrix") 
    87129  
    87130 See log for complete Python traceback. 
    87131  
    87132 Traceback (most recent call last): 
    87133 File
    87134 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87135 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    87136 self.session.ui.mouse_modes.mouse_pause_tracking() 
    87137 File
    87138 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87139 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    87140 mouse_pause_tracking 
    87141 self._mouse_pause() 
    87142 File
    87143 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87144 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    87145 m.pause(self._mouse_pause_position) 
    87146 File
    87147 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87148 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    87149 p = self.view.picked_object(x, y) 
    87150 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87151 File
    87152 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87153 packages/chimerax/graphics/view.py", line 838, in picked_object 
    87154 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    87155 beyond, 
    87156 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87157 File
    87158 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87159 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    87160 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    87161 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87162 File
    87163 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87164 packages/chimerax/core/models.py", line 143, in first_intercept 
    87165 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    87166 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87167 File
    87168 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87169 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    87170 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    87171 exclude=exclude) 
    87172 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87173 File
    87174 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87175 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    87176 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    87177 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87178 File
    87179 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87180 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    87181 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    87182 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87183 File
    87184 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87185 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    87186 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    87187 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87188 File
    87189 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87190 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    87191 p = super().first_intercept(mxyz1, mxyz2) 
    87192 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87193 File
    87194 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87195 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    87196 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    87197 exclude=exclude) 
    87198 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87199 File
    87200 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87201 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    87202 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    87203 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87204 File
    87205 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87206 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    87207 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    87208 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87209 File
    87210 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87211 packages/chimerax/graphics/drawing.py", line 1108, in
    87212 _first_intercept_excluding_children 
    87213 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    87214 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87215 File
    87216 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87217 packages/chimerax/geometry/place.py", line 201, in inverse 
    87218 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    87219 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87220 File
    87221 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87222 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    87223 rinv[:, :] = matrix_inverse(r) 
    87224 ^^^^^^^^^^^^^^^^^ 
    87225 File
    87226 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87227 packages/numpy/linalg/linalg.py", line 561, in inv 
    87228 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    87229 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87230 File
    87231 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87232 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    87233 raise LinAlgError("Singular matrix") 
    87234 numpy.linalg.LinAlgError: Singular matrix 
    87235  
    87236 numpy.linalg.LinAlgError: Singular matrix 
    87237  
    87238 File
    87239 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87240 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    87241 raise LinAlgError("Singular matrix") 
    87242  
    87243 See log for complete Python traceback. 
    87244  
    87245 Traceback (most recent call last): 
    87246 File
    87247 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87248 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    87249 self.session.ui.mouse_modes.mouse_pause_tracking() 
    87250 File
    87251 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87252 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    87253 mouse_pause_tracking 
    87254 self._mouse_pause() 
    87255 File
    87256 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87257 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    87258 m.pause(self._mouse_pause_position) 
    87259 File
    87260 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87261 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    87262 p = self.view.picked_object(x, y) 
    87263 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87264 File
    87265 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87266 packages/chimerax/graphics/view.py", line 838, in picked_object 
    87267 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    87268 beyond, 
    87269 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87270 File
    87271 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87272 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    87273 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    87274 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87275 File
    87276 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87277 packages/chimerax/core/models.py", line 143, in first_intercept 
    87278 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    87279 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87280 File
    87281 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87282 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    87283 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    87284 exclude=exclude) 
    87285 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87286 File
    87287 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87288 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    87289 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    87290 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87291 File
    87292 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87293 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    87294 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    87295 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87296 File
    87297 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87298 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    87299 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    87300 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87301 File
    87302 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87303 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    87304 p = super().first_intercept(mxyz1, mxyz2) 
    87305 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87306 File
    87307 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87308 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    87309 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    87310 exclude=exclude) 
    87311 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87312 File
    87313 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87314 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    87315 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    87316 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87317 File
    87318 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87319 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    87320 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    87321 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87322 File
    87323 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87324 packages/chimerax/graphics/drawing.py", line 1108, in
    87325 _first_intercept_excluding_children 
    87326 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    87327 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87328 File
    87329 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87330 packages/chimerax/geometry/place.py", line 201, in inverse 
    87331 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    87332 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87333 File
    87334 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87335 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    87336 rinv[:, :] = matrix_inverse(r) 
    87337 ^^^^^^^^^^^^^^^^^ 
    87338 File
    87339 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87340 packages/numpy/linalg/linalg.py", line 561, in inv 
    87341 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    87342 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87343 File
    87344 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87345 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    87346 raise LinAlgError("Singular matrix") 
    87347 numpy.linalg.LinAlgError: Singular matrix 
    87348  
    87349 numpy.linalg.LinAlgError: Singular matrix 
    87350  
    87351 File
    87352 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87353 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    87354 raise LinAlgError("Singular matrix") 
    87355  
    87356 See log for complete Python traceback. 
    87357  
    87358 Traceback (most recent call last): 
    87359 File
    87360 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87361 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    87362 self.session.ui.mouse_modes.mouse_pause_tracking() 
    87363 File
    87364 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87365 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    87366 mouse_pause_tracking 
    87367 self._mouse_pause() 
    87368 File
    87369 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87370 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    87371 m.pause(self._mouse_pause_position) 
    87372 File
    87373 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87374 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    87375 p = self.view.picked_object(x, y) 
    87376 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87377 File
    87378 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87379 packages/chimerax/graphics/view.py", line 838, in picked_object 
    87380 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    87381 beyond, 
    87382 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87383 File
    87384 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87385 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    87386 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    87387 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87388 File
    87389 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87390 packages/chimerax/core/models.py", line 143, in first_intercept 
    87391 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    87392 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87393 File
    87394 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87395 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    87396 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    87397 exclude=exclude) 
    87398 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87399 File
    87400 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87401 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    87402 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    87403 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87404 File
    87405 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87406 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    87407 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    87408 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87409 File
    87410 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87411 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    87412 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    87413 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87414 File
    87415 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87416 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    87417 p = super().first_intercept(mxyz1, mxyz2) 
    87418 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87419 File
    87420 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87421 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    87422 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    87423 exclude=exclude) 
    87424 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87425 File
    87426 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87427 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    87428 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    87429 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87430 File
    87431 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87432 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    87433 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    87434 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87435 File
    87436 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87437 packages/chimerax/graphics/drawing.py", line 1108, in
    87438 _first_intercept_excluding_children 
    87439 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    87440 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87441 File
    87442 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87443 packages/chimerax/geometry/place.py", line 201, in inverse 
    87444 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    87445 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87446 File
    87447 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87448 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    87449 rinv[:, :] = matrix_inverse(r) 
    87450 ^^^^^^^^^^^^^^^^^ 
    87451 File
    87452 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87453 packages/numpy/linalg/linalg.py", line 561, in inv 
    87454 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    87455 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87456 File
    87457 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87458 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    87459 raise LinAlgError("Singular matrix") 
    87460 numpy.linalg.LinAlgError: Singular matrix 
    87461  
    87462 numpy.linalg.LinAlgError: Singular matrix 
    87463  
    87464 File
    87465 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87466 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    87467 raise LinAlgError("Singular matrix") 
    87468  
    87469 See log for complete Python traceback. 
    87470  
    87471 Traceback (most recent call last): 
    87472 File
    87473 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87474 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    87475 self.session.ui.mouse_modes.mouse_pause_tracking() 
    87476 File
    87477 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87478 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    87479 mouse_pause_tracking 
    87480 self._mouse_pause() 
    87481 File
    87482 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87483 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    87484 m.pause(self._mouse_pause_position) 
    87485 File
    87486 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87487 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    87488 p = self.view.picked_object(x, y) 
    87489 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87490 File
    87491 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87492 packages/chimerax/graphics/view.py", line 838, in picked_object 
    87493 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    87494 beyond, 
    87495 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87496 File
    87497 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87498 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    87499 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    87500 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87501 File
    87502 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87503 packages/chimerax/core/models.py", line 143, in first_intercept 
    87504 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    87505 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87506 File
    87507 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87508 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    87509 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    87510 exclude=exclude) 
    87511 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87512 File
    87513 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87514 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    87515 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    87516 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87517 File
    87518 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87519 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    87520 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    87521 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87522 File
    87523 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87524 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    87525 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    87526 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87527 File
    87528 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87529 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    87530 p = super().first_intercept(mxyz1, mxyz2) 
    87531 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87532 File
    87533 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87534 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    87535 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    87536 exclude=exclude) 
    87537 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87538 File
    87539 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87540 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    87541 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    87542 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87543 File
    87544 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87545 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    87546 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    87547 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87548 File
    87549 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87550 packages/chimerax/graphics/drawing.py", line 1108, in
    87551 _first_intercept_excluding_children 
    87552 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    87553 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87554 File
    87555 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87556 packages/chimerax/geometry/place.py", line 201, in inverse 
    87557 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    87558 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87559 File
    87560 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87561 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    87562 rinv[:, :] = matrix_inverse(r) 
    87563 ^^^^^^^^^^^^^^^^^ 
    87564 File
    87565 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87566 packages/numpy/linalg/linalg.py", line 561, in inv 
    87567 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    87568 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87569 File
    87570 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87571 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    87572 raise LinAlgError("Singular matrix") 
    87573 numpy.linalg.LinAlgError: Singular matrix 
    87574  
    87575 numpy.linalg.LinAlgError: Singular matrix 
    87576  
    87577 File
    87578 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87579 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    87580 raise LinAlgError("Singular matrix") 
    87581  
    87582 See log for complete Python traceback. 
    87583  
    87584 Traceback (most recent call last): 
    87585 File
    87586 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87587 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    87588 self.session.ui.mouse_modes.mouse_pause_tracking() 
    87589 File
    87590 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87591 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    87592 mouse_pause_tracking 
    87593 self._mouse_pause() 
    87594 File
    87595 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87596 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    87597 m.pause(self._mouse_pause_position) 
    87598 File
    87599 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87600 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    87601 p = self.view.picked_object(x, y) 
    87602 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87603 File
    87604 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87605 packages/chimerax/graphics/view.py", line 838, in picked_object 
    87606 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    87607 beyond, 
    87608 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87609 File
    87610 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87611 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    87612 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    87613 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87614 File
    87615 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87616 packages/chimerax/core/models.py", line 143, in first_intercept 
    87617 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    87618 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87619 File
    87620 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87621 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    87622 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    87623 exclude=exclude) 
    87624 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87625 File
    87626 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87627 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    87628 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    87629 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87630 File
    87631 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87632 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    87633 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    87634 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87635 File
    87636 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87637 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    87638 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    87639 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87640 File
    87641 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87642 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    87643 p = super().first_intercept(mxyz1, mxyz2) 
    87644 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87645 File
    87646 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87647 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    87648 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    87649 exclude=exclude) 
    87650 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87651 File
    87652 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87653 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    87654 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    87655 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87656 File
    87657 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87658 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    87659 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    87660 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87661 File
    87662 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87663 packages/chimerax/graphics/drawing.py", line 1108, in
    87664 _first_intercept_excluding_children 
    87665 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    87666 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87667 File
    87668 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87669 packages/chimerax/geometry/place.py", line 201, in inverse 
    87670 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    87671 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87672 File
    87673 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87674 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    87675 rinv[:, :] = matrix_inverse(r) 
    87676 ^^^^^^^^^^^^^^^^^ 
    87677 File
    87678 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87679 packages/numpy/linalg/linalg.py", line 561, in inv 
    87680 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    87681 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87682 File
    87683 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87684 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    87685 raise LinAlgError("Singular matrix") 
    87686 numpy.linalg.LinAlgError: Singular matrix 
    87687  
    87688 numpy.linalg.LinAlgError: Singular matrix 
    87689  
    87690 File
    87691 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87692 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    87693 raise LinAlgError("Singular matrix") 
    87694  
    87695 See log for complete Python traceback. 
    87696  
    87697 Traceback (most recent call last): 
    87698 File
    87699 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87700 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    87701 self.session.ui.mouse_modes.mouse_pause_tracking() 
    87702 File
    87703 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87704 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    87705 mouse_pause_tracking 
    87706 self._mouse_pause() 
    87707 File
    87708 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87709 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    87710 m.pause(self._mouse_pause_position) 
    87711 File
    87712 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87713 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    87714 p = self.view.picked_object(x, y) 
    87715 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87716 File
    87717 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87718 packages/chimerax/graphics/view.py", line 838, in picked_object 
    87719 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    87720 beyond, 
    87721 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87722 File
    87723 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87724 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    87725 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    87726 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87727 File
    87728 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87729 packages/chimerax/core/models.py", line 143, in first_intercept 
    87730 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    87731 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87732 File
    87733 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87734 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    87735 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    87736 exclude=exclude) 
    87737 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87738 File
    87739 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87740 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    87741 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    87742 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87743 File
    87744 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87745 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    87746 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    87747 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87748 File
    87749 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87750 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    87751 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    87752 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87753 File
    87754 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87755 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    87756 p = super().first_intercept(mxyz1, mxyz2) 
    87757 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87758 File
    87759 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87760 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    87761 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    87762 exclude=exclude) 
    87763 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87764 File
    87765 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87766 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    87767 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    87768 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87769 File
    87770 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87771 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    87772 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    87773 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87774 File
    87775 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87776 packages/chimerax/graphics/drawing.py", line 1108, in
    87777 _first_intercept_excluding_children 
    87778 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    87779 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87780 File
    87781 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87782 packages/chimerax/geometry/place.py", line 201, in inverse 
    87783 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    87784 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87785 File
    87786 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87787 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    87788 rinv[:, :] = matrix_inverse(r) 
    87789 ^^^^^^^^^^^^^^^^^ 
    87790 File
    87791 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87792 packages/numpy/linalg/linalg.py", line 561, in inv 
    87793 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    87794 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87795 File
    87796 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87797 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    87798 raise LinAlgError("Singular matrix") 
    87799 numpy.linalg.LinAlgError: Singular matrix 
    87800  
    87801 numpy.linalg.LinAlgError: Singular matrix 
    87802  
    87803 File
    87804 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87805 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    87806 raise LinAlgError("Singular matrix") 
    87807  
    87808 See log for complete Python traceback. 
    87809  
    87810 Traceback (most recent call last): 
    87811 File
    87812 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87813 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    87814 self.session.ui.mouse_modes.mouse_pause_tracking() 
    87815 File
    87816 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87817 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    87818 mouse_pause_tracking 
    87819 self._mouse_pause() 
    87820 File
    87821 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87822 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    87823 m.pause(self._mouse_pause_position) 
    87824 File
    87825 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87826 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    87827 p = self.view.picked_object(x, y) 
    87828 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87829 File
    87830 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87831 packages/chimerax/graphics/view.py", line 838, in picked_object 
    87832 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    87833 beyond, 
    87834 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87835 File
    87836 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87837 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    87838 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    87839 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87840 File
    87841 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87842 packages/chimerax/core/models.py", line 143, in first_intercept 
    87843 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    87844 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87845 File
    87846 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87847 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    87848 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    87849 exclude=exclude) 
    87850 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87851 File
    87852 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87853 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    87854 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    87855 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87856 File
    87857 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87858 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    87859 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    87860 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87861 File
    87862 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87863 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    87864 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    87865 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87866 File
    87867 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87868 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    87869 p = super().first_intercept(mxyz1, mxyz2) 
    87870 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87871 File
    87872 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87873 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    87874 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    87875 exclude=exclude) 
    87876 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87877 File
    87878 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87879 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    87880 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    87881 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87882 File
    87883 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87884 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    87885 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    87886 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87887 File
    87888 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87889 packages/chimerax/graphics/drawing.py", line 1108, in
    87890 _first_intercept_excluding_children 
    87891 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    87892 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87893 File
    87894 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87895 packages/chimerax/geometry/place.py", line 201, in inverse 
    87896 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    87897 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87898 File
    87899 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87900 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    87901 rinv[:, :] = matrix_inverse(r) 
    87902 ^^^^^^^^^^^^^^^^^ 
    87903 File
    87904 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87905 packages/numpy/linalg/linalg.py", line 561, in inv 
    87906 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    87907 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87908 File
    87909 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87910 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    87911 raise LinAlgError("Singular matrix") 
    87912 numpy.linalg.LinAlgError: Singular matrix 
    87913  
    87914 numpy.linalg.LinAlgError: Singular matrix 
    87915  
    87916 File
    87917 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87918 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    87919 raise LinAlgError("Singular matrix") 
    87920  
    87921 See log for complete Python traceback. 
    87922  
    87923 Traceback (most recent call last): 
    87924 File
    87925 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87926 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    87927 self.session.ui.mouse_modes.mouse_pause_tracking() 
    87928 File
    87929 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87930 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    87931 mouse_pause_tracking 
    87932 self._mouse_pause() 
    87933 File
    87934 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87935 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    87936 m.pause(self._mouse_pause_position) 
    87937 File
    87938 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87939 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    87940 p = self.view.picked_object(x, y) 
    87941 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87942 File
    87943 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87944 packages/chimerax/graphics/view.py", line 838, in picked_object 
    87945 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    87946 beyond, 
    87947 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87948 File
    87949 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87950 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    87951 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    87952 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87953 File
    87954 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87955 packages/chimerax/core/models.py", line 143, in first_intercept 
    87956 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    87957 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87958 File
    87959 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87960 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    87961 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    87962 exclude=exclude) 
    87963 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87964 File
    87965 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87966 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    87967 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    87968 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87969 File
    87970 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87971 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    87972 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    87973 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87974 File
    87975 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87976 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    87977 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    87978 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87979 File
    87980 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87981 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    87982 p = super().first_intercept(mxyz1, mxyz2) 
    87983 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87984 File
    87985 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87986 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    87987 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    87988 exclude=exclude) 
    87989 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87990 File
    87991 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87992 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    87993 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    87994 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    87995 File
    87996 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    87997 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    87998 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    87999 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88000 File
    88001 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88002 packages/chimerax/graphics/drawing.py", line 1108, in
    88003 _first_intercept_excluding_children 
    88004 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    88005 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88006 File
    88007 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88008 packages/chimerax/geometry/place.py", line 201, in inverse 
    88009 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    88010 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88011 File
    88012 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88013 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    88014 rinv[:, :] = matrix_inverse(r) 
    88015 ^^^^^^^^^^^^^^^^^ 
    88016 File
    88017 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88018 packages/numpy/linalg/linalg.py", line 561, in inv 
    88019 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    88020 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88021 File
    88022 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88023 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    88024 raise LinAlgError("Singular matrix") 
    88025 numpy.linalg.LinAlgError: Singular matrix 
    88026  
    88027 numpy.linalg.LinAlgError: Singular matrix 
    88028  
    88029 File
    88030 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88031 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    88032 raise LinAlgError("Singular matrix") 
    88033  
    88034 See log for complete Python traceback. 
    88035  
    88036 Traceback (most recent call last): 
    88037 File
    88038 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88039 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    88040 self.session.ui.mouse_modes.mouse_pause_tracking() 
    88041 File
    88042 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88043 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    88044 mouse_pause_tracking 
    88045 self._mouse_pause() 
    88046 File
    88047 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88048 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    88049 m.pause(self._mouse_pause_position) 
    88050 File
    88051 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88052 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    88053 p = self.view.picked_object(x, y) 
    88054 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88055 File
    88056 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88057 packages/chimerax/graphics/view.py", line 838, in picked_object 
    88058 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    88059 beyond, 
    88060 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88061 File
    88062 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88063 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    88064 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    88065 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88066 File
    88067 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88068 packages/chimerax/core/models.py", line 143, in first_intercept 
    88069 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    88070 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88071 File
    88072 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88073 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    88074 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    88075 exclude=exclude) 
    88076 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88077 File
    88078 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88079 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    88080 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    88081 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88082 File
    88083 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88084 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    88085 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    88086 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88087 File
    88088 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88089 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    88090 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    88091 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88092 File
    88093 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88094 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    88095 p = super().first_intercept(mxyz1, mxyz2) 
    88096 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88097 File
    88098 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88099 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    88100 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    88101 exclude=exclude) 
    88102 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88103 File
    88104 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88105 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    88106 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    88107 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88108 File
    88109 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88110 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    88111 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    88112 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88113 File
    88114 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88115 packages/chimerax/graphics/drawing.py", line 1108, in
    88116 _first_intercept_excluding_children 
    88117 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    88118 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88119 File
    88120 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88121 packages/chimerax/geometry/place.py", line 201, in inverse 
    88122 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    88123 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88124 File
    88125 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88126 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    88127 rinv[:, :] = matrix_inverse(r) 
    88128 ^^^^^^^^^^^^^^^^^ 
    88129 File
    88130 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88131 packages/numpy/linalg/linalg.py", line 561, in inv 
    88132 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    88133 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88134 File
    88135 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88136 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    88137 raise LinAlgError("Singular matrix") 
    88138 numpy.linalg.LinAlgError: Singular matrix 
    88139  
    88140 numpy.linalg.LinAlgError: Singular matrix 
    88141  
    88142 File
    88143 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88144 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    88145 raise LinAlgError("Singular matrix") 
    88146  
    88147 See log for complete Python traceback. 
    88148  
    88149 Traceback (most recent call last): 
    88150 File
    88151 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88152 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    88153 self.session.ui.mouse_modes.mouse_pause_tracking() 
    88154 File
    88155 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88156 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    88157 mouse_pause_tracking 
    88158 self._mouse_pause() 
    88159 File
    88160 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88161 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    88162 m.pause(self._mouse_pause_position) 
    88163 File
    88164 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88165 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    88166 p = self.view.picked_object(x, y) 
    88167 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88168 File
    88169 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88170 packages/chimerax/graphics/view.py", line 838, in picked_object 
    88171 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    88172 beyond, 
    88173 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88174 File
    88175 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88176 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    88177 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    88178 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88179 File
    88180 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88181 packages/chimerax/core/models.py", line 143, in first_intercept 
    88182 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    88183 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88184 File
    88185 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88186 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    88187 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    88188 exclude=exclude) 
    88189 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88190 File
    88191 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88192 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    88193 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    88194 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88195 File
    88196 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88197 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    88198 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    88199 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88200 File
    88201 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88202 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    88203 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    88204 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88205 File
    88206 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88207 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    88208 p = super().first_intercept(mxyz1, mxyz2) 
    88209 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88210 File
    88211 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88212 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    88213 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    88214 exclude=exclude) 
    88215 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88216 File
    88217 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88218 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    88219 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    88220 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88221 File
    88222 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88223 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    88224 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    88225 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88226 File
    88227 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88228 packages/chimerax/graphics/drawing.py", line 1108, in
    88229 _first_intercept_excluding_children 
    88230 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    88231 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88232 File
    88233 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88234 packages/chimerax/geometry/place.py", line 201, in inverse 
    88235 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    88236 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88237 File
    88238 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88239 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    88240 rinv[:, :] = matrix_inverse(r) 
    88241 ^^^^^^^^^^^^^^^^^ 
    88242 File
    88243 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88244 packages/numpy/linalg/linalg.py", line 561, in inv 
    88245 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    88246 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88247 File
    88248 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88249 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    88250 raise LinAlgError("Singular matrix") 
    88251 numpy.linalg.LinAlgError: Singular matrix 
    88252  
    88253 numpy.linalg.LinAlgError: Singular matrix 
    88254  
    88255 File
    88256 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88257 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    88258 raise LinAlgError("Singular matrix") 
    88259  
    88260 See log for complete Python traceback. 
    88261  
    88262 Traceback (most recent call last): 
    88263 File
    88264 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88265 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    88266 self.session.ui.mouse_modes.mouse_pause_tracking() 
    88267 File
    88268 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88269 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    88270 mouse_pause_tracking 
    88271 self._mouse_pause() 
    88272 File
    88273 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88274 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    88275 m.pause(self._mouse_pause_position) 
    88276 File
    88277 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88278 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    88279 p = self.view.picked_object(x, y) 
    88280 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88281 File
    88282 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88283 packages/chimerax/graphics/view.py", line 838, in picked_object 
    88284 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    88285 beyond, 
    88286 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88287 File
    88288 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88289 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    88290 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    88291 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88292 File
    88293 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88294 packages/chimerax/core/models.py", line 143, in first_intercept 
    88295 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    88296 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88297 File
    88298 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88299 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    88300 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    88301 exclude=exclude) 
    88302 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88303 File
    88304 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88305 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    88306 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    88307 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88308 File
    88309 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88310 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    88311 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    88312 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88313 File
    88314 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88315 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    88316 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    88317 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88318 File
    88319 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88320 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    88321 p = super().first_intercept(mxyz1, mxyz2) 
    88322 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88323 File
    88324 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88325 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    88326 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    88327 exclude=exclude) 
    88328 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88329 File
    88330 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88331 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    88332 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    88333 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88334 File
    88335 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88336 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    88337 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    88338 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88339 File
    88340 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88341 packages/chimerax/graphics/drawing.py", line 1108, in
    88342 _first_intercept_excluding_children 
    88343 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    88344 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88345 File
    88346 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88347 packages/chimerax/geometry/place.py", line 201, in inverse 
    88348 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    88349 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88350 File
    88351 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88352 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    88353 rinv[:, :] = matrix_inverse(r) 
    88354 ^^^^^^^^^^^^^^^^^ 
    88355 File
    88356 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88357 packages/numpy/linalg/linalg.py", line 561, in inv 
    88358 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    88359 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88360 File
    88361 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88362 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    88363 raise LinAlgError("Singular matrix") 
    88364 numpy.linalg.LinAlgError: Singular matrix 
    88365  
    88366 numpy.linalg.LinAlgError: Singular matrix 
    88367  
    88368 File
    88369 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88370 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    88371 raise LinAlgError("Singular matrix") 
    88372  
    88373 See log for complete Python traceback. 
    88374  
    88375 Traceback (most recent call last): 
    88376 File
    88377 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88378 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    88379 self.session.ui.mouse_modes.mouse_pause_tracking() 
    88380 File
    88381 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88382 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    88383 mouse_pause_tracking 
    88384 self._mouse_pause() 
    88385 File
    88386 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88387 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    88388 m.pause(self._mouse_pause_position) 
    88389 File
    88390 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88391 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    88392 p = self.view.picked_object(x, y) 
    88393 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88394 File
    88395 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88396 packages/chimerax/graphics/view.py", line 838, in picked_object 
    88397 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    88398 beyond, 
    88399 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88400 File
    88401 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88402 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    88403 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    88404 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88405 File
    88406 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88407 packages/chimerax/core/models.py", line 143, in first_intercept 
    88408 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    88409 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88410 File
    88411 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88412 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    88413 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    88414 exclude=exclude) 
    88415 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88416 File
    88417 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88418 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    88419 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    88420 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88421 File
    88422 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88423 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    88424 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    88425 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88426 File
    88427 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88428 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    88429 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    88430 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88431 File
    88432 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88433 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    88434 p = super().first_intercept(mxyz1, mxyz2) 
    88435 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88436 File
    88437 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88438 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    88439 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    88440 exclude=exclude) 
    88441 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88442 File
    88443 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88444 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    88445 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    88446 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88447 File
    88448 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88449 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    88450 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    88451 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88452 File
    88453 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88454 packages/chimerax/graphics/drawing.py", line 1108, in
    88455 _first_intercept_excluding_children 
    88456 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    88457 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88458 File
    88459 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88460 packages/chimerax/geometry/place.py", line 201, in inverse 
    88461 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    88462 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88463 File
    88464 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88465 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    88466 rinv[:, :] = matrix_inverse(r) 
    88467 ^^^^^^^^^^^^^^^^^ 
    88468 File
    88469 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88470 packages/numpy/linalg/linalg.py", line 561, in inv 
    88471 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    88472 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88473 File
    88474 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88475 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    88476 raise LinAlgError("Singular matrix") 
    88477 numpy.linalg.LinAlgError: Singular matrix 
    88478  
    88479 numpy.linalg.LinAlgError: Singular matrix 
    88480  
    88481 File
    88482 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88483 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    88484 raise LinAlgError("Singular matrix") 
    88485  
    88486 See log for complete Python traceback. 
    88487  
    88488 Traceback (most recent call last): 
    88489 File
    88490 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88491 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    88492 self.session.ui.mouse_modes.mouse_pause_tracking() 
    88493 File
    88494 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88495 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    88496 mouse_pause_tracking 
    88497 self._mouse_pause() 
    88498 File
    88499 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88500 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    88501 m.pause(self._mouse_pause_position) 
    88502 File
    88503 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88504 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    88505 p = self.view.picked_object(x, y) 
    88506 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88507 File
    88508 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88509 packages/chimerax/graphics/view.py", line 838, in picked_object 
    88510 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    88511 beyond, 
    88512 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88513 File
    88514 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88515 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    88516 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    88517 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88518 File
    88519 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88520 packages/chimerax/core/models.py", line 143, in first_intercept 
    88521 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    88522 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88523 File
    88524 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88525 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    88526 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    88527 exclude=exclude) 
    88528 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88529 File
    88530 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88531 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    88532 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    88533 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88534 File
    88535 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88536 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    88537 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    88538 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88539 File
    88540 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88541 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    88542 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    88543 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88544 File
    88545 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88546 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    88547 p = super().first_intercept(mxyz1, mxyz2) 
    88548 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88549 File
    88550 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88551 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    88552 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    88553 exclude=exclude) 
    88554 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88555 File
    88556 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88557 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    88558 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    88559 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88560 File
    88561 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88562 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    88563 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    88564 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88565 File
    88566 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88567 packages/chimerax/graphics/drawing.py", line 1108, in
    88568 _first_intercept_excluding_children 
    88569 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    88570 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88571 File
    88572 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88573 packages/chimerax/geometry/place.py", line 201, in inverse 
    88574 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    88575 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88576 File
    88577 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88578 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    88579 rinv[:, :] = matrix_inverse(r) 
    88580 ^^^^^^^^^^^^^^^^^ 
    88581 File
    88582 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88583 packages/numpy/linalg/linalg.py", line 561, in inv 
    88584 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    88585 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88586 File
    88587 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88588 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    88589 raise LinAlgError("Singular matrix") 
    88590 numpy.linalg.LinAlgError: Singular matrix 
    88591  
    88592 numpy.linalg.LinAlgError: Singular matrix 
    88593  
    88594 File
    88595 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88596 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    88597 raise LinAlgError("Singular matrix") 
    88598  
    88599 See log for complete Python traceback. 
    88600  
    88601 Traceback (most recent call last): 
    88602 File
    88603 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88604 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    88605 self.session.ui.mouse_modes.mouse_pause_tracking() 
    88606 File
    88607 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88608 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    88609 mouse_pause_tracking 
    88610 self._mouse_pause() 
    88611 File
    88612 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88613 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    88614 m.pause(self._mouse_pause_position) 
    88615 File
    88616 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88617 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    88618 p = self.view.picked_object(x, y) 
    88619 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88620 File
    88621 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88622 packages/chimerax/graphics/view.py", line 838, in picked_object 
    88623 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    88624 beyond, 
    88625 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88626 File
    88627 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88628 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    88629 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    88630 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88631 File
    88632 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88633 packages/chimerax/core/models.py", line 143, in first_intercept 
    88634 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    88635 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88636 File
    88637 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88638 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    88639 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    88640 exclude=exclude) 
    88641 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88642 File
    88643 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88644 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    88645 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    88646 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88647 File
    88648 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88649 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    88650 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    88651 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88652 File
    88653 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88654 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    88655 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    88656 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88657 File
    88658 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88659 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    88660 p = super().first_intercept(mxyz1, mxyz2) 
    88661 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88662 File
    88663 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88664 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    88665 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    88666 exclude=exclude) 
    88667 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88668 File
    88669 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88670 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    88671 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    88672 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88673 File
    88674 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88675 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    88676 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    88677 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88678 File
    88679 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88680 packages/chimerax/graphics/drawing.py", line 1108, in
    88681 _first_intercept_excluding_children 
    88682 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    88683 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88684 File
    88685 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88686 packages/chimerax/geometry/place.py", line 201, in inverse 
    88687 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    88688 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88689 File
    88690 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88691 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    88692 rinv[:, :] = matrix_inverse(r) 
    88693 ^^^^^^^^^^^^^^^^^ 
    88694 File
    88695 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88696 packages/numpy/linalg/linalg.py", line 561, in inv 
    88697 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    88698 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88699 File
    88700 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88701 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    88702 raise LinAlgError("Singular matrix") 
    88703 numpy.linalg.LinAlgError: Singular matrix 
    88704  
    88705 numpy.linalg.LinAlgError: Singular matrix 
    88706  
    88707 File
    88708 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88709 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    88710 raise LinAlgError("Singular matrix") 
    88711  
    88712 See log for complete Python traceback. 
    88713  
    88714 Traceback (most recent call last): 
    88715 File
    88716 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88717 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    88718 self.session.ui.mouse_modes.mouse_pause_tracking() 
    88719 File
    88720 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88721 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    88722 mouse_pause_tracking 
    88723 self._mouse_pause() 
    88724 File
    88725 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88726 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    88727 m.pause(self._mouse_pause_position) 
    88728 File
    88729 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88730 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    88731 p = self.view.picked_object(x, y) 
    88732 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88733 File
    88734 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88735 packages/chimerax/graphics/view.py", line 838, in picked_object 
    88736 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    88737 beyond, 
    88738 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88739 File
    88740 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88741 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    88742 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    88743 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88744 File
    88745 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88746 packages/chimerax/core/models.py", line 143, in first_intercept 
    88747 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    88748 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88749 File
    88750 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88751 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    88752 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    88753 exclude=exclude) 
    88754 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88755 File
    88756 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88757 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    88758 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    88759 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88760 File
    88761 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88762 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    88763 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    88764 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88765 File
    88766 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88767 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    88768 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    88769 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88770 File
    88771 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88772 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    88773 p = super().first_intercept(mxyz1, mxyz2) 
    88774 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88775 File
    88776 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88777 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    88778 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    88779 exclude=exclude) 
    88780 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88781 File
    88782 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88783 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    88784 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    88785 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88786 File
    88787 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88788 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    88789 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    88790 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88791 File
    88792 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88793 packages/chimerax/graphics/drawing.py", line 1108, in
    88794 _first_intercept_excluding_children 
    88795 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    88796 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88797 File
    88798 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88799 packages/chimerax/geometry/place.py", line 201, in inverse 
    88800 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    88801 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88802 File
    88803 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88804 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    88805 rinv[:, :] = matrix_inverse(r) 
    88806 ^^^^^^^^^^^^^^^^^ 
    88807 File
    88808 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88809 packages/numpy/linalg/linalg.py", line 561, in inv 
    88810 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    88811 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88812 File
    88813 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88814 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    88815 raise LinAlgError("Singular matrix") 
    88816 numpy.linalg.LinAlgError: Singular matrix 
    88817  
    88818 numpy.linalg.LinAlgError: Singular matrix 
    88819  
    88820 File
    88821 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88822 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    88823 raise LinAlgError("Singular matrix") 
    88824  
    88825 See log for complete Python traceback. 
    88826  
    88827 Traceback (most recent call last): 
    88828 File
    88829 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88830 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    88831 self.session.ui.mouse_modes.mouse_pause_tracking() 
    88832 File
    88833 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88834 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    88835 mouse_pause_tracking 
    88836 self._mouse_pause() 
    88837 File
    88838 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88839 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    88840 m.pause(self._mouse_pause_position) 
    88841 File
    88842 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88843 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    88844 p = self.view.picked_object(x, y) 
    88845 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88846 File
    88847 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88848 packages/chimerax/graphics/view.py", line 838, in picked_object 
    88849 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    88850 beyond, 
    88851 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88852 File
    88853 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88854 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    88855 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    88856 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88857 File
    88858 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88859 packages/chimerax/core/models.py", line 143, in first_intercept 
    88860 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    88861 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88862 File
    88863 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88864 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    88865 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    88866 exclude=exclude) 
    88867 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88868 File
    88869 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88870 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    88871 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    88872 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88873 File
    88874 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88875 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    88876 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    88877 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88878 File
    88879 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88880 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    88881 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    88882 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88883 File
    88884 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88885 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    88886 p = super().first_intercept(mxyz1, mxyz2) 
    88887 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88888 File
    88889 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88890 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    88891 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    88892 exclude=exclude) 
    88893 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88894 File
    88895 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88896 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    88897 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    88898 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88899 File
    88900 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88901 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    88902 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    88903 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88904 File
    88905 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88906 packages/chimerax/graphics/drawing.py", line 1108, in
    88907 _first_intercept_excluding_children 
    88908 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    88909 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88910 File
    88911 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88912 packages/chimerax/geometry/place.py", line 201, in inverse 
    88913 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    88914 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88915 File
    88916 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88917 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    88918 rinv[:, :] = matrix_inverse(r) 
    88919 ^^^^^^^^^^^^^^^^^ 
    88920 File
    88921 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88922 packages/numpy/linalg/linalg.py", line 561, in inv 
    88923 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    88924 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88925 File
    88926 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88927 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    88928 raise LinAlgError("Singular matrix") 
    88929 numpy.linalg.LinAlgError: Singular matrix 
    88930  
    88931 numpy.linalg.LinAlgError: Singular matrix 
    88932  
    88933 File
    88934 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88935 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    88936 raise LinAlgError("Singular matrix") 
    88937  
    88938 See log for complete Python traceback. 
    88939  
    88940 Traceback (most recent call last): 
    88941 File
    88942 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88943 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    88944 self.session.ui.mouse_modes.mouse_pause_tracking() 
    88945 File
    88946 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88947 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    88948 mouse_pause_tracking 
    88949 self._mouse_pause() 
    88950 File
    88951 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88952 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    88953 m.pause(self._mouse_pause_position) 
    88954 File
    88955 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88956 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    88957 p = self.view.picked_object(x, y) 
    88958 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88959 File
    88960 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88961 packages/chimerax/graphics/view.py", line 838, in picked_object 
    88962 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    88963 beyond, 
    88964 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88965 File
    88966 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88967 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    88968 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    88969 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88970 File
    88971 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88972 packages/chimerax/core/models.py", line 143, in first_intercept 
    88973 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    88974 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88975 File
    88976 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88977 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    88978 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    88979 exclude=exclude) 
    88980 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88981 File
    88982 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88983 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    88984 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    88985 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88986 File
    88987 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88988 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    88989 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    88990 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88991 File
    88992 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88993 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    88994 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    88995 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    88996 File
    88997 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    88998 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    88999 p = super().first_intercept(mxyz1, mxyz2) 
    89000 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89001 File
    89002 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89003 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    89004 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    89005 exclude=exclude) 
    89006 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89007 File
    89008 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89009 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    89010 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    89011 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89012 File
    89013 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89014 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    89015 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    89016 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89017 File
    89018 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89019 packages/chimerax/graphics/drawing.py", line 1108, in
    89020 _first_intercept_excluding_children 
    89021 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    89022 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89023 File
    89024 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89025 packages/chimerax/geometry/place.py", line 201, in inverse 
    89026 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    89027 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89028 File
    89029 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89030 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    89031 rinv[:, :] = matrix_inverse(r) 
    89032 ^^^^^^^^^^^^^^^^^ 
    89033 File
    89034 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89035 packages/numpy/linalg/linalg.py", line 561, in inv 
    89036 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    89037 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89038 File
    89039 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89040 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    89041 raise LinAlgError("Singular matrix") 
    89042 numpy.linalg.LinAlgError: Singular matrix 
    89043  
    89044 numpy.linalg.LinAlgError: Singular matrix 
    89045  
    89046 File
    89047 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89048 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    89049 raise LinAlgError("Singular matrix") 
    89050  
    89051 See log for complete Python traceback. 
    89052  
    89053 Traceback (most recent call last): 
    89054 File
    89055 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89056 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    89057 self.session.ui.mouse_modes.mouse_pause_tracking() 
    89058 File
    89059 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89060 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    89061 mouse_pause_tracking 
    89062 self._mouse_pause() 
    89063 File
    89064 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89065 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    89066 m.pause(self._mouse_pause_position) 
    89067 File
    89068 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89069 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    89070 p = self.view.picked_object(x, y) 
    89071 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89072 File
    89073 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89074 packages/chimerax/graphics/view.py", line 838, in picked_object 
    89075 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    89076 beyond, 
    89077 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89078 File
    89079 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89080 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    89081 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    89082 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89083 File
    89084 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89085 packages/chimerax/core/models.py", line 143, in first_intercept 
    89086 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    89087 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89088 File
    89089 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89090 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    89091 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    89092 exclude=exclude) 
    89093 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89094 File
    89095 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89096 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    89097 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    89098 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89099 File
    89100 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89101 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    89102 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    89103 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89104 File
    89105 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89106 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    89107 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    89108 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89109 File
    89110 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89111 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    89112 p = super().first_intercept(mxyz1, mxyz2) 
    89113 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89114 File
    89115 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89116 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    89117 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    89118 exclude=exclude) 
    89119 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89120 File
    89121 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89122 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    89123 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    89124 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89125 File
    89126 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89127 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    89128 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    89129 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89130 File
    89131 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89132 packages/chimerax/graphics/drawing.py", line 1108, in
    89133 _first_intercept_excluding_children 
    89134 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    89135 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89136 File
    89137 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89138 packages/chimerax/geometry/place.py", line 201, in inverse 
    89139 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    89140 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89141 File
    89142 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89143 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    89144 rinv[:, :] = matrix_inverse(r) 
    89145 ^^^^^^^^^^^^^^^^^ 
    89146 File
    89147 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89148 packages/numpy/linalg/linalg.py", line 561, in inv 
    89149 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    89150 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89151 File
    89152 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89153 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    89154 raise LinAlgError("Singular matrix") 
    89155 numpy.linalg.LinAlgError: Singular matrix 
    89156  
    89157 numpy.linalg.LinAlgError: Singular matrix 
    89158  
    89159 File
    89160 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89161 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    89162 raise LinAlgError("Singular matrix") 
    89163  
    89164 See log for complete Python traceback. 
    89165  
    89166 Traceback (most recent call last): 
    89167 File
    89168 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89169 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    89170 self.session.ui.mouse_modes.mouse_pause_tracking() 
    89171 File
    89172 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89173 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    89174 mouse_pause_tracking 
    89175 self._mouse_pause() 
    89176 File
    89177 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89178 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    89179 m.pause(self._mouse_pause_position) 
    89180 File
    89181 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89182 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    89183 p = self.view.picked_object(x, y) 
    89184 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89185 File
    89186 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89187 packages/chimerax/graphics/view.py", line 838, in picked_object 
    89188 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    89189 beyond, 
    89190 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89191 File
    89192 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89193 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    89194 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    89195 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89196 File
    89197 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89198 packages/chimerax/core/models.py", line 143, in first_intercept 
    89199 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    89200 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89201 File
    89202 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89203 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    89204 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    89205 exclude=exclude) 
    89206 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89207 File
    89208 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89209 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    89210 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    89211 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89212 File
    89213 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89214 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    89215 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    89216 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89217 File
    89218 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89219 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    89220 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    89221 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89222 File
    89223 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89224 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    89225 p = super().first_intercept(mxyz1, mxyz2) 
    89226 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89227 File
    89228 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89229 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    89230 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    89231 exclude=exclude) 
    89232 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89233 File
    89234 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89235 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    89236 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    89237 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89238 File
    89239 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89240 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    89241 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    89242 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89243 File
    89244 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89245 packages/chimerax/graphics/drawing.py", line 1108, in
    89246 _first_intercept_excluding_children 
    89247 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    89248 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89249 File
    89250 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89251 packages/chimerax/geometry/place.py", line 201, in inverse 
    89252 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    89253 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89254 File
    89255 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89256 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    89257 rinv[:, :] = matrix_inverse(r) 
    89258 ^^^^^^^^^^^^^^^^^ 
    89259 File
    89260 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89261 packages/numpy/linalg/linalg.py", line 561, in inv 
    89262 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    89263 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89264 File
    89265 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89266 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    89267 raise LinAlgError("Singular matrix") 
    89268 numpy.linalg.LinAlgError: Singular matrix 
    89269  
    89270 numpy.linalg.LinAlgError: Singular matrix 
    89271  
    89272 File
    89273 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89274 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    89275 raise LinAlgError("Singular matrix") 
    89276  
    89277 See log for complete Python traceback. 
    89278  
    89279 
    89280 > select add #5/F:2210@O
    89281 
    89282 1 atom, 1 residue, 1 model selected 
    89283 
    89284 > select add #1/D:477
    89285 
    89286 7 atoms, 5 bonds, 2 residues, 2 models selected 
    89287 
    89288 > select add #1/D:476
    89289 
    89290 13 atoms, 10 bonds, 3 residues, 2 models selected 
    89291 
    89292 > select add #1/D:475
    89293 
    89294 21 atoms, 17 bonds, 4 residues, 2 models selected 
    89295 
    89296 > hide sel cartoons
    89297 
    89298 > hide sel atoms
    89299 
    89300 > select clear
    89301 
    89302 Traceback (most recent call last): 
    89303 File
    89304 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89305 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    89306 self.session.ui.mouse_modes.mouse_pause_tracking() 
    89307 File
    89308 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89309 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    89310 mouse_pause_tracking 
    89311 self._mouse_pause() 
    89312 File
    89313 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89314 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    89315 m.pause(self._mouse_pause_position) 
    89316 File
    89317 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89318 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    89319 p = self.view.picked_object(x, y) 
    89320 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89321 File
    89322 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89323 packages/chimerax/graphics/view.py", line 838, in picked_object 
    89324 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    89325 beyond, 
    89326 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89327 File
    89328 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89329 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    89330 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    89331 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89332 File
    89333 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89334 packages/chimerax/core/models.py", line 143, in first_intercept 
    89335 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    89336 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89337 File
    89338 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89339 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    89340 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    89341 exclude=exclude) 
    89342 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89343 File
    89344 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89345 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    89346 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    89347 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89348 File
    89349 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89350 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    89351 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    89352 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89353 File
    89354 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89355 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    89356 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    89357 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89358 File
    89359 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89360 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    89361 p = super().first_intercept(mxyz1, mxyz2) 
    89362 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89363 File
    89364 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89365 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    89366 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    89367 exclude=exclude) 
    89368 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89369 File
    89370 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89371 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    89372 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    89373 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89374 File
    89375 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89376 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    89377 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    89378 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89379 File
    89380 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89381 packages/chimerax/graphics/drawing.py", line 1108, in
    89382 _first_intercept_excluding_children 
    89383 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    89384 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89385 File
    89386 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89387 packages/chimerax/geometry/place.py", line 201, in inverse 
    89388 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    89389 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89390 File
    89391 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89392 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    89393 rinv[:, :] = matrix_inverse(r) 
    89394 ^^^^^^^^^^^^^^^^^ 
    89395 File
    89396 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89397 packages/numpy/linalg/linalg.py", line 561, in inv 
    89398 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    89399 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89400 File
    89401 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89402 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    89403 raise LinAlgError("Singular matrix") 
    89404 numpy.linalg.LinAlgError: Singular matrix 
    89405  
    89406 numpy.linalg.LinAlgError: Singular matrix 
    89407  
    89408 File
    89409 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89410 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    89411 raise LinAlgError("Singular matrix") 
    89412  
    89413 See log for complete Python traceback. 
    89414  
    89415 Traceback (most recent call last): 
    89416 File
    89417 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89418 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    89419 self.session.ui.mouse_modes.mouse_pause_tracking() 
    89420 File
    89421 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89422 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    89423 mouse_pause_tracking 
    89424 self._mouse_pause() 
    89425 File
    89426 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89427 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    89428 m.pause(self._mouse_pause_position) 
    89429 File
    89430 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89431 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    89432 p = self.view.picked_object(x, y) 
    89433 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89434 File
    89435 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89436 packages/chimerax/graphics/view.py", line 838, in picked_object 
    89437 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    89438 beyond, 
    89439 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89440 File
    89441 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89442 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    89443 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    89444 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89445 File
    89446 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89447 packages/chimerax/core/models.py", line 143, in first_intercept 
    89448 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    89449 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89450 File
    89451 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89452 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    89453 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    89454 exclude=exclude) 
    89455 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89456 File
    89457 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89458 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    89459 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    89460 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89461 File
    89462 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89463 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    89464 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    89465 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89466 File
    89467 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89468 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    89469 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    89470 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89471 File
    89472 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89473 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    89474 p = super().first_intercept(mxyz1, mxyz2) 
    89475 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89476 File
    89477 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89478 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    89479 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    89480 exclude=exclude) 
    89481 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89482 File
    89483 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89484 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    89485 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    89486 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89487 File
    89488 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89489 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    89490 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    89491 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89492 File
    89493 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89494 packages/chimerax/graphics/drawing.py", line 1108, in
    89495 _first_intercept_excluding_children 
    89496 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    89497 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89498 File
    89499 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89500 packages/chimerax/geometry/place.py", line 201, in inverse 
    89501 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    89502 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89503 File
    89504 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89505 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    89506 rinv[:, :] = matrix_inverse(r) 
    89507 ^^^^^^^^^^^^^^^^^ 
    89508 File
    89509 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89510 packages/numpy/linalg/linalg.py", line 561, in inv 
    89511 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    89512 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89513 File
    89514 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89515 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    89516 raise LinAlgError("Singular matrix") 
    89517 numpy.linalg.LinAlgError: Singular matrix 
    89518  
    89519 numpy.linalg.LinAlgError: Singular matrix 
    89520  
    89521 File
    89522 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89523 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    89524 raise LinAlgError("Singular matrix") 
    89525  
    89526 See log for complete Python traceback. 
    89527  
    89528 Traceback (most recent call last): 
    89529 File
    89530 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89531 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    89532 self.session.ui.mouse_modes.mouse_pause_tracking() 
    89533 File
    89534 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89535 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    89536 mouse_pause_tracking 
    89537 self._mouse_pause() 
    89538 File
    89539 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89540 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    89541 m.pause(self._mouse_pause_position) 
    89542 File
    89543 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89544 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    89545 p = self.view.picked_object(x, y) 
    89546 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89547 File
    89548 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89549 packages/chimerax/graphics/view.py", line 838, in picked_object 
    89550 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    89551 beyond, 
    89552 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89553 File
    89554 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89555 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    89556 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    89557 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89558 File
    89559 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89560 packages/chimerax/core/models.py", line 143, in first_intercept 
    89561 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    89562 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89563 File
    89564 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89565 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    89566 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    89567 exclude=exclude) 
    89568 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89569 File
    89570 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89571 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    89572 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    89573 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89574 File
    89575 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89576 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    89577 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    89578 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89579 File
    89580 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89581 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    89582 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    89583 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89584 File
    89585 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89586 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    89587 p = super().first_intercept(mxyz1, mxyz2) 
    89588 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89589 File
    89590 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89591 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    89592 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    89593 exclude=exclude) 
    89594 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89595 File
    89596 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89597 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    89598 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    89599 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89600 File
    89601 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89602 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    89603 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    89604 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89605 File
    89606 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89607 packages/chimerax/graphics/drawing.py", line 1108, in
    89608 _first_intercept_excluding_children 
    89609 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    89610 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89611 File
    89612 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89613 packages/chimerax/geometry/place.py", line 201, in inverse 
    89614 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    89615 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89616 File
    89617 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89618 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    89619 rinv[:, :] = matrix_inverse(r) 
    89620 ^^^^^^^^^^^^^^^^^ 
    89621 File
    89622 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89623 packages/numpy/linalg/linalg.py", line 561, in inv 
    89624 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    89625 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89626 File
    89627 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89628 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    89629 raise LinAlgError("Singular matrix") 
    89630 numpy.linalg.LinAlgError: Singular matrix 
    89631  
    89632 numpy.linalg.LinAlgError: Singular matrix 
    89633  
    89634 File
    89635 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89636 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    89637 raise LinAlgError("Singular matrix") 
    89638  
    89639 See log for complete Python traceback. 
    89640  
    89641 Traceback (most recent call last): 
    89642 File
    89643 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89644 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    89645 self.session.ui.mouse_modes.mouse_pause_tracking() 
    89646 File
    89647 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89648 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    89649 mouse_pause_tracking 
    89650 self._mouse_pause() 
    89651 File
    89652 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89653 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    89654 m.pause(self._mouse_pause_position) 
    89655 File
    89656 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89657 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    89658 p = self.view.picked_object(x, y) 
    89659 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89660 File
    89661 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89662 packages/chimerax/graphics/view.py", line 838, in picked_object 
    89663 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    89664 beyond, 
    89665 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89666 File
    89667 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89668 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    89669 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    89670 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89671 File
    89672 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89673 packages/chimerax/core/models.py", line 143, in first_intercept 
    89674 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    89675 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89676 File
    89677 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89678 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    89679 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    89680 exclude=exclude) 
    89681 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89682 File
    89683 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89684 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    89685 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    89686 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89687 File
    89688 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89689 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    89690 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    89691 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89692 File
    89693 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89694 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    89695 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    89696 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89697 File
    89698 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89699 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    89700 p = super().first_intercept(mxyz1, mxyz2) 
    89701 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89702 File
    89703 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89704 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    89705 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    89706 exclude=exclude) 
    89707 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89708 File
    89709 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89710 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    89711 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    89712 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89713 File
    89714 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89715 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    89716 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    89717 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89718 File
    89719 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89720 packages/chimerax/graphics/drawing.py", line 1108, in
    89721 _first_intercept_excluding_children 
    89722 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    89723 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89724 File
    89725 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89726 packages/chimerax/geometry/place.py", line 201, in inverse 
    89727 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    89728 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89729 File
    89730 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89731 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    89732 rinv[:, :] = matrix_inverse(r) 
    89733 ^^^^^^^^^^^^^^^^^ 
    89734 File
    89735 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89736 packages/numpy/linalg/linalg.py", line 561, in inv 
    89737 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    89738 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89739 File
    89740 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89741 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    89742 raise LinAlgError("Singular matrix") 
    89743 numpy.linalg.LinAlgError: Singular matrix 
    89744  
    89745 numpy.linalg.LinAlgError: Singular matrix 
    89746  
    89747 File
    89748 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89749 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    89750 raise LinAlgError("Singular matrix") 
    89751  
    89752 See log for complete Python traceback. 
    89753  
    89754 Traceback (most recent call last): 
    89755 File
    89756 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89757 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    89758 self.session.ui.mouse_modes.mouse_pause_tracking() 
    89759 File
    89760 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89761 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    89762 mouse_pause_tracking 
    89763 self._mouse_pause() 
    89764 File
    89765 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89766 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    89767 m.pause(self._mouse_pause_position) 
    89768 File
    89769 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89770 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    89771 p = self.view.picked_object(x, y) 
    89772 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89773 File
    89774 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89775 packages/chimerax/graphics/view.py", line 838, in picked_object 
    89776 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    89777 beyond, 
    89778 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89779 File
    89780 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89781 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    89782 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    89783 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89784 File
    89785 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89786 packages/chimerax/core/models.py", line 143, in first_intercept 
    89787 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    89788 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89789 File
    89790 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89791 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    89792 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    89793 exclude=exclude) 
    89794 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89795 File
    89796 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89797 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    89798 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    89799 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89800 File
    89801 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89802 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    89803 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    89804 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89805 File
    89806 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89807 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    89808 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    89809 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89810 File
    89811 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89812 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    89813 p = super().first_intercept(mxyz1, mxyz2) 
    89814 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89815 File
    89816 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89817 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    89818 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    89819 exclude=exclude) 
    89820 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89821 File
    89822 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89823 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    89824 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    89825 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89826 File
    89827 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89828 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    89829 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    89830 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89831 File
    89832 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89833 packages/chimerax/graphics/drawing.py", line 1108, in
    89834 _first_intercept_excluding_children 
    89835 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    89836 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89837 File
    89838 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89839 packages/chimerax/geometry/place.py", line 201, in inverse 
    89840 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    89841 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89842 File
    89843 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89844 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    89845 rinv[:, :] = matrix_inverse(r) 
    89846 ^^^^^^^^^^^^^^^^^ 
    89847 File
    89848 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89849 packages/numpy/linalg/linalg.py", line 561, in inv 
    89850 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    89851 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89852 File
    89853 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89854 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    89855 raise LinAlgError("Singular matrix") 
    89856 numpy.linalg.LinAlgError: Singular matrix 
    89857  
    89858 numpy.linalg.LinAlgError: Singular matrix 
    89859  
    89860 File
    89861 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89862 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    89863 raise LinAlgError("Singular matrix") 
    89864  
    89865 See log for complete Python traceback. 
    89866  
    89867 Traceback (most recent call last): 
    89868 File
    89869 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89870 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    89871 self.session.ui.mouse_modes.mouse_pause_tracking() 
    89872 File
    89873 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89874 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    89875 mouse_pause_tracking 
    89876 self._mouse_pause() 
    89877 File
    89878 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89879 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    89880 m.pause(self._mouse_pause_position) 
    89881 File
    89882 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89883 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    89884 p = self.view.picked_object(x, y) 
    89885 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89886 File
    89887 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89888 packages/chimerax/graphics/view.py", line 838, in picked_object 
    89889 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    89890 beyond, 
    89891 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89892 File
    89893 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89894 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    89895 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    89896 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89897 File
    89898 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89899 packages/chimerax/core/models.py", line 143, in first_intercept 
    89900 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    89901 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89902 File
    89903 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89904 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    89905 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    89906 exclude=exclude) 
    89907 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89908 File
    89909 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89910 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    89911 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    89912 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89913 File
    89914 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89915 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    89916 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    89917 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89918 File
    89919 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89920 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    89921 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    89922 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89923 File
    89924 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89925 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    89926 p = super().first_intercept(mxyz1, mxyz2) 
    89927 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89928 File
    89929 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89930 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    89931 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    89932 exclude=exclude) 
    89933 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89934 File
    89935 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89936 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    89937 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    89938 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89939 File
    89940 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89941 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    89942 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    89943 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89944 File
    89945 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89946 packages/chimerax/graphics/drawing.py", line 1108, in
    89947 _first_intercept_excluding_children 
    89948 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    89949 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89950 File
    89951 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89952 packages/chimerax/geometry/place.py", line 201, in inverse 
    89953 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    89954 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89955 File
    89956 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89957 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    89958 rinv[:, :] = matrix_inverse(r) 
    89959 ^^^^^^^^^^^^^^^^^ 
    89960 File
    89961 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89962 packages/numpy/linalg/linalg.py", line 561, in inv 
    89963 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    89964 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89965 File
    89966 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89967 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    89968 raise LinAlgError("Singular matrix") 
    89969 numpy.linalg.LinAlgError: Singular matrix 
    89970  
    89971 numpy.linalg.LinAlgError: Singular matrix 
    89972  
    89973 File
    89974 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89975 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    89976 raise LinAlgError("Singular matrix") 
    89977  
    89978 See log for complete Python traceback. 
    89979  
    89980 Traceback (most recent call last): 
    89981 File
    89982 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89983 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    89984 self.session.ui.mouse_modes.mouse_pause_tracking() 
    89985 File
    89986 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89987 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    89988 mouse_pause_tracking 
    89989 self._mouse_pause() 
    89990 File
    89991 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89992 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    89993 m.pause(self._mouse_pause_position) 
    89994 File
    89995 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    89996 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    89997 p = self.view.picked_object(x, y) 
    89998 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    89999 File
    90000 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90001 packages/chimerax/graphics/view.py", line 838, in picked_object 
    90002 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    90003 beyond, 
    90004 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90005 File
    90006 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90007 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    90008 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    90009 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90010 File
    90011 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90012 packages/chimerax/core/models.py", line 143, in first_intercept 
    90013 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    90014 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90015 File
    90016 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90017 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    90018 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    90019 exclude=exclude) 
    90020 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90021 File
    90022 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90023 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    90024 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    90025 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90026 File
    90027 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90028 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    90029 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    90030 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90031 File
    90032 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90033 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    90034 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    90035 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90036 File
    90037 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90038 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    90039 p = super().first_intercept(mxyz1, mxyz2) 
    90040 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90041 File
    90042 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90043 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    90044 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    90045 exclude=exclude) 
    90046 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90047 File
    90048 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90049 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    90050 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    90051 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90052 File
    90053 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90054 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    90055 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    90056 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90057 File
    90058 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90059 packages/chimerax/graphics/drawing.py", line 1108, in
    90060 _first_intercept_excluding_children 
    90061 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    90062 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90063 File
    90064 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90065 packages/chimerax/geometry/place.py", line 201, in inverse 
    90066 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    90067 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90068 File
    90069 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90070 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    90071 rinv[:, :] = matrix_inverse(r) 
    90072 ^^^^^^^^^^^^^^^^^ 
    90073 File
    90074 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90075 packages/numpy/linalg/linalg.py", line 561, in inv 
    90076 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    90077 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90078 File
    90079 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90080 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    90081 raise LinAlgError("Singular matrix") 
    90082 numpy.linalg.LinAlgError: Singular matrix 
    90083  
    90084 numpy.linalg.LinAlgError: Singular matrix 
    90085  
    90086 File
    90087 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90088 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    90089 raise LinAlgError("Singular matrix") 
    90090  
    90091 See log for complete Python traceback. 
    90092  
    90093 Traceback (most recent call last): 
    90094 File
    90095 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90096 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    90097 self.session.ui.mouse_modes.mouse_pause_tracking() 
    90098 File
    90099 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90100 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    90101 mouse_pause_tracking 
    90102 self._mouse_pause() 
    90103 File
    90104 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90105 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    90106 m.pause(self._mouse_pause_position) 
    90107 File
    90108 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90109 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    90110 p = self.view.picked_object(x, y) 
    90111 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90112 File
    90113 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90114 packages/chimerax/graphics/view.py", line 838, in picked_object 
    90115 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    90116 beyond, 
    90117 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90118 File
    90119 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90120 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    90121 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    90122 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90123 File
    90124 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90125 packages/chimerax/core/models.py", line 143, in first_intercept 
    90126 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    90127 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90128 File
    90129 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90130 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    90131 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    90132 exclude=exclude) 
    90133 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90134 File
    90135 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90136 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    90137 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    90138 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90139 File
    90140 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90141 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    90142 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    90143 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90144 File
    90145 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90146 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    90147 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    90148 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90149 File
    90150 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90151 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    90152 p = super().first_intercept(mxyz1, mxyz2) 
    90153 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90154 File
    90155 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90156 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    90157 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    90158 exclude=exclude) 
    90159 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90160 File
    90161 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90162 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    90163 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    90164 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90165 File
    90166 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90167 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    90168 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    90169 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90170 File
    90171 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90172 packages/chimerax/graphics/drawing.py", line 1108, in
    90173 _first_intercept_excluding_children 
    90174 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    90175 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90176 File
    90177 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90178 packages/chimerax/geometry/place.py", line 201, in inverse 
    90179 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    90180 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90181 File
    90182 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90183 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    90184 rinv[:, :] = matrix_inverse(r) 
    90185 ^^^^^^^^^^^^^^^^^ 
    90186 File
    90187 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90188 packages/numpy/linalg/linalg.py", line 561, in inv 
    90189 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    90190 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90191 File
    90192 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90193 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    90194 raise LinAlgError("Singular matrix") 
    90195 numpy.linalg.LinAlgError: Singular matrix 
    90196  
    90197 numpy.linalg.LinAlgError: Singular matrix 
    90198  
    90199 File
    90200 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90201 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    90202 raise LinAlgError("Singular matrix") 
    90203  
    90204 See log for complete Python traceback. 
    90205  
    90206 Traceback (most recent call last): 
    90207 File
    90208 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90209 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    90210 self.session.ui.mouse_modes.mouse_pause_tracking() 
    90211 File
    90212 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90213 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    90214 mouse_pause_tracking 
    90215 self._mouse_pause() 
    90216 File
    90217 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90218 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    90219 m.pause(self._mouse_pause_position) 
    90220 File
    90221 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90222 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    90223 p = self.view.picked_object(x, y) 
    90224 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90225 File
    90226 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90227 packages/chimerax/graphics/view.py", line 838, in picked_object 
    90228 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    90229 beyond, 
    90230 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90231 File
    90232 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90233 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    90234 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    90235 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90236 File
    90237 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90238 packages/chimerax/core/models.py", line 143, in first_intercept 
    90239 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    90240 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90241 File
    90242 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90243 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    90244 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    90245 exclude=exclude) 
    90246 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90247 File
    90248 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90249 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    90250 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    90251 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90252 File
    90253 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90254 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    90255 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    90256 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90257 File
    90258 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90259 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    90260 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    90261 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90262 File
    90263 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90264 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    90265 p = super().first_intercept(mxyz1, mxyz2) 
    90266 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90267 File
    90268 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90269 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    90270 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    90271 exclude=exclude) 
    90272 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90273 File
    90274 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90275 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    90276 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    90277 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90278 File
    90279 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90280 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    90281 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    90282 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90283 File
    90284 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90285 packages/chimerax/graphics/drawing.py", line 1108, in
    90286 _first_intercept_excluding_children 
    90287 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    90288 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90289 File
    90290 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90291 packages/chimerax/geometry/place.py", line 201, in inverse 
    90292 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    90293 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90294 File
    90295 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90296 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    90297 rinv[:, :] = matrix_inverse(r) 
    90298 ^^^^^^^^^^^^^^^^^ 
    90299 File
    90300 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90301 packages/numpy/linalg/linalg.py", line 561, in inv 
    90302 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    90303 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90304 File
    90305 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90306 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    90307 raise LinAlgError("Singular matrix") 
    90308 numpy.linalg.LinAlgError: Singular matrix 
    90309  
    90310 numpy.linalg.LinAlgError: Singular matrix 
    90311  
    90312 File
    90313 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90314 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    90315 raise LinAlgError("Singular matrix") 
    90316  
    90317 See log for complete Python traceback. 
    90318  
    90319 Traceback (most recent call last): 
    90320 File
    90321 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90322 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    90323 self.session.ui.mouse_modes.mouse_pause_tracking() 
    90324 File
    90325 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90326 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    90327 mouse_pause_tracking 
    90328 self._mouse_pause() 
    90329 File
    90330 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90331 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    90332 m.pause(self._mouse_pause_position) 
    90333 File
    90334 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90335 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    90336 p = self.view.picked_object(x, y) 
    90337 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90338 File
    90339 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90340 packages/chimerax/graphics/view.py", line 838, in picked_object 
    90341 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    90342 beyond, 
    90343 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90344 File
    90345 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90346 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    90347 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    90348 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90349 File
    90350 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90351 packages/chimerax/core/models.py", line 143, in first_intercept 
    90352 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    90353 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90354 File
    90355 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90356 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    90357 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    90358 exclude=exclude) 
    90359 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90360 File
    90361 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90362 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    90363 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    90364 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90365 File
    90366 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90367 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    90368 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    90369 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90370 File
    90371 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90372 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    90373 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    90374 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90375 File
    90376 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90377 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    90378 p = super().first_intercept(mxyz1, mxyz2) 
    90379 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90380 File
    90381 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90382 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    90383 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    90384 exclude=exclude) 
    90385 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90386 File
    90387 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90388 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    90389 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    90390 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90391 File
    90392 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90393 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    90394 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    90395 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90396 File
    90397 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90398 packages/chimerax/graphics/drawing.py", line 1108, in
    90399 _first_intercept_excluding_children 
    90400 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    90401 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90402 File
    90403 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90404 packages/chimerax/geometry/place.py", line 201, in inverse 
    90405 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    90406 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90407 File
    90408 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90409 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    90410 rinv[:, :] = matrix_inverse(r) 
    90411 ^^^^^^^^^^^^^^^^^ 
    90412 File
    90413 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90414 packages/numpy/linalg/linalg.py", line 561, in inv 
    90415 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    90416 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90417 File
    90418 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90419 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    90420 raise LinAlgError("Singular matrix") 
    90421 numpy.linalg.LinAlgError: Singular matrix 
    90422  
    90423 numpy.linalg.LinAlgError: Singular matrix 
    90424  
    90425 File
    90426 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90427 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    90428 raise LinAlgError("Singular matrix") 
    90429  
    90430 See log for complete Python traceback. 
    90431  
    90432 Traceback (most recent call last): 
    90433 File
    90434 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90435 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    90436 self.session.ui.mouse_modes.mouse_pause_tracking() 
    90437 File
    90438 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90439 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    90440 mouse_pause_tracking 
    90441 self._mouse_pause() 
    90442 File
    90443 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90444 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    90445 m.pause(self._mouse_pause_position) 
    90446 File
    90447 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90448 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    90449 p = self.view.picked_object(x, y) 
    90450 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90451 File
    90452 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90453 packages/chimerax/graphics/view.py", line 838, in picked_object 
    90454 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    90455 beyond, 
    90456 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90457 File
    90458 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90459 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    90460 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    90461 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90462 File
    90463 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90464 packages/chimerax/core/models.py", line 143, in first_intercept 
    90465 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    90466 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90467 File
    90468 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90469 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    90470 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    90471 exclude=exclude) 
    90472 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90473 File
    90474 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90475 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    90476 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    90477 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90478 File
    90479 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90480 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    90481 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    90482 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90483 File
    90484 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90485 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    90486 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    90487 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90488 File
    90489 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90490 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    90491 p = super().first_intercept(mxyz1, mxyz2) 
    90492 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90493 File
    90494 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90495 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    90496 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    90497 exclude=exclude) 
    90498 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90499 File
    90500 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90501 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    90502 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    90503 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90504 File
    90505 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90506 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    90507 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    90508 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90509 File
    90510 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90511 packages/chimerax/graphics/drawing.py", line 1108, in
    90512 _first_intercept_excluding_children 
    90513 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    90514 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90515 File
    90516 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90517 packages/chimerax/geometry/place.py", line 201, in inverse 
    90518 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    90519 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90520 File
    90521 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90522 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    90523 rinv[:, :] = matrix_inverse(r) 
    90524 ^^^^^^^^^^^^^^^^^ 
    90525 File
    90526 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90527 packages/numpy/linalg/linalg.py", line 561, in inv 
    90528 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    90529 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90530 File
    90531 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90532 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    90533 raise LinAlgError("Singular matrix") 
    90534 numpy.linalg.LinAlgError: Singular matrix 
    90535  
    90536 numpy.linalg.LinAlgError: Singular matrix 
    90537  
    90538 File
    90539 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90540 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    90541 raise LinAlgError("Singular matrix") 
    90542  
    90543 See log for complete Python traceback. 
    90544  
    90545 Traceback (most recent call last): 
    90546 File
    90547 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90548 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    90549 self.session.ui.mouse_modes.mouse_pause_tracking() 
    90550 File
    90551 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90552 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    90553 mouse_pause_tracking 
    90554 self._mouse_pause() 
    90555 File
    90556 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90557 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    90558 m.pause(self._mouse_pause_position) 
    90559 File
    90560 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90561 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    90562 p = self.view.picked_object(x, y) 
    90563 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90564 File
    90565 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90566 packages/chimerax/graphics/view.py", line 838, in picked_object 
    90567 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    90568 beyond, 
    90569 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90570 File
    90571 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90572 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    90573 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    90574 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90575 File
    90576 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90577 packages/chimerax/core/models.py", line 143, in first_intercept 
    90578 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    90579 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90580 File
    90581 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90582 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    90583 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    90584 exclude=exclude) 
    90585 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90586 File
    90587 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90588 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    90589 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    90590 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90591 File
    90592 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90593 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    90594 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    90595 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90596 File
    90597 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90598 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    90599 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    90600 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90601 File
    90602 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90603 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    90604 p = super().first_intercept(mxyz1, mxyz2) 
    90605 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90606 File
    90607 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90608 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    90609 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    90610 exclude=exclude) 
    90611 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90612 File
    90613 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90614 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    90615 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    90616 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90617 File
    90618 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90619 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    90620 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    90621 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90622 File
    90623 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90624 packages/chimerax/graphics/drawing.py", line 1108, in
    90625 _first_intercept_excluding_children 
    90626 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    90627 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90628 File
    90629 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90630 packages/chimerax/geometry/place.py", line 201, in inverse 
    90631 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    90632 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90633 File
    90634 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90635 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    90636 rinv[:, :] = matrix_inverse(r) 
    90637 ^^^^^^^^^^^^^^^^^ 
    90638 File
    90639 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90640 packages/numpy/linalg/linalg.py", line 561, in inv 
    90641 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    90642 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90643 File
    90644 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90645 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    90646 raise LinAlgError("Singular matrix") 
    90647 numpy.linalg.LinAlgError: Singular matrix 
    90648  
    90649 numpy.linalg.LinAlgError: Singular matrix 
    90650  
    90651 File
    90652 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90653 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    90654 raise LinAlgError("Singular matrix") 
    90655  
    90656 See log for complete Python traceback. 
    90657  
    90658 Traceback (most recent call last): 
    90659 File
    90660 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90661 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    90662 self.session.ui.mouse_modes.mouse_pause_tracking() 
    90663 File
    90664 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90665 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    90666 mouse_pause_tracking 
    90667 self._mouse_pause() 
    90668 File
    90669 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90670 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    90671 m.pause(self._mouse_pause_position) 
    90672 File
    90673 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90674 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    90675 p = self.view.picked_object(x, y) 
    90676 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90677 File
    90678 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90679 packages/chimerax/graphics/view.py", line 838, in picked_object 
    90680 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    90681 beyond, 
    90682 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90683 File
    90684 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90685 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    90686 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    90687 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90688 File
    90689 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90690 packages/chimerax/core/models.py", line 143, in first_intercept 
    90691 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    90692 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90693 File
    90694 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90695 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    90696 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    90697 exclude=exclude) 
    90698 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90699 File
    90700 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90701 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    90702 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    90703 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90704 File
    90705 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90706 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    90707 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    90708 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90709 File
    90710 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90711 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    90712 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    90713 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90714 File
    90715 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90716 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    90717 p = super().first_intercept(mxyz1, mxyz2) 
    90718 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90719 File
    90720 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90721 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    90722 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    90723 exclude=exclude) 
    90724 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90725 File
    90726 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90727 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    90728 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    90729 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90730 File
    90731 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90732 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    90733 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    90734 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90735 File
    90736 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90737 packages/chimerax/graphics/drawing.py", line 1108, in
    90738 _first_intercept_excluding_children 
    90739 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    90740 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90741 File
    90742 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90743 packages/chimerax/geometry/place.py", line 201, in inverse 
    90744 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    90745 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90746 File
    90747 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90748 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    90749 rinv[:, :] = matrix_inverse(r) 
    90750 ^^^^^^^^^^^^^^^^^ 
    90751 File
    90752 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90753 packages/numpy/linalg/linalg.py", line 561, in inv 
    90754 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    90755 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90756 File
    90757 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90758 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    90759 raise LinAlgError("Singular matrix") 
    90760 numpy.linalg.LinAlgError: Singular matrix 
    90761  
    90762 numpy.linalg.LinAlgError: Singular matrix 
    90763  
    90764 File
    90765 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90766 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    90767 raise LinAlgError("Singular matrix") 
    90768  
    90769 See log for complete Python traceback. 
    90770  
    90771 Traceback (most recent call last): 
    90772 File
    90773 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90774 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    90775 self.session.ui.mouse_modes.mouse_pause_tracking() 
    90776 File
    90777 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90778 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    90779 mouse_pause_tracking 
    90780 self._mouse_pause() 
    90781 File
    90782 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90783 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    90784 m.pause(self._mouse_pause_position) 
    90785 File
    90786 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90787 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    90788 p = self.view.picked_object(x, y) 
    90789 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90790 File
    90791 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90792 packages/chimerax/graphics/view.py", line 838, in picked_object 
    90793 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    90794 beyond, 
    90795 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90796 File
    90797 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90798 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    90799 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    90800 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90801 File
    90802 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90803 packages/chimerax/core/models.py", line 143, in first_intercept 
    90804 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    90805 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90806 File
    90807 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90808 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    90809 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    90810 exclude=exclude) 
    90811 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90812 File
    90813 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90814 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    90815 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    90816 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90817 File
    90818 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90819 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    90820 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    90821 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90822 File
    90823 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90824 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    90825 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    90826 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90827 File
    90828 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90829 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    90830 p = super().first_intercept(mxyz1, mxyz2) 
    90831 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90832 File
    90833 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90834 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    90835 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    90836 exclude=exclude) 
    90837 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90838 File
    90839 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90840 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    90841 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    90842 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90843 File
    90844 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90845 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    90846 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    90847 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90848 File
    90849 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90850 packages/chimerax/graphics/drawing.py", line 1108, in
    90851 _first_intercept_excluding_children 
    90852 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    90853 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90854 File
    90855 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90856 packages/chimerax/geometry/place.py", line 201, in inverse 
    90857 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    90858 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90859 File
    90860 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90861 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    90862 rinv[:, :] = matrix_inverse(r) 
    90863 ^^^^^^^^^^^^^^^^^ 
    90864 File
    90865 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90866 packages/numpy/linalg/linalg.py", line 561, in inv 
    90867 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    90868 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90869 File
    90870 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90871 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    90872 raise LinAlgError("Singular matrix") 
    90873 numpy.linalg.LinAlgError: Singular matrix 
    90874  
    90875 numpy.linalg.LinAlgError: Singular matrix 
    90876  
    90877 File
    90878 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90879 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    90880 raise LinAlgError("Singular matrix") 
    90881  
    90882 See log for complete Python traceback. 
    90883  
    90884 Traceback (most recent call last): 
    90885 File
    90886 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90887 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    90888 self.session.ui.mouse_modes.mouse_pause_tracking() 
    90889 File
    90890 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90891 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    90892 mouse_pause_tracking 
    90893 self._mouse_pause() 
    90894 File
    90895 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90896 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    90897 m.pause(self._mouse_pause_position) 
    90898 File
    90899 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90900 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    90901 p = self.view.picked_object(x, y) 
    90902 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90903 File
    90904 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90905 packages/chimerax/graphics/view.py", line 838, in picked_object 
    90906 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    90907 beyond, 
    90908 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90909 File
    90910 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90911 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    90912 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    90913 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90914 File
    90915 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90916 packages/chimerax/core/models.py", line 143, in first_intercept 
    90917 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    90918 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90919 File
    90920 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90921 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    90922 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    90923 exclude=exclude) 
    90924 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90925 File
    90926 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90927 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    90928 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    90929 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90930 File
    90931 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90932 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    90933 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    90934 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90935 File
    90936 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90937 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    90938 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    90939 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90940 File
    90941 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90942 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    90943 p = super().first_intercept(mxyz1, mxyz2) 
    90944 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90945 File
    90946 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90947 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    90948 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    90949 exclude=exclude) 
    90950 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90951 File
    90952 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90953 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    90954 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    90955 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90956 File
    90957 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90958 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    90959 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    90960 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90961 File
    90962 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90963 packages/chimerax/graphics/drawing.py", line 1108, in
    90964 _first_intercept_excluding_children 
    90965 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    90966 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90967 File
    90968 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90969 packages/chimerax/geometry/place.py", line 201, in inverse 
    90970 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    90971 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90972 File
    90973 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90974 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    90975 rinv[:, :] = matrix_inverse(r) 
    90976 ^^^^^^^^^^^^^^^^^ 
    90977 File
    90978 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90979 packages/numpy/linalg/linalg.py", line 561, in inv 
    90980 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    90981 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    90982 File
    90983 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90984 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    90985 raise LinAlgError("Singular matrix") 
    90986 numpy.linalg.LinAlgError: Singular matrix 
    90987  
    90988 numpy.linalg.LinAlgError: Singular matrix 
    90989  
    90990 File
    90991 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    90992 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    90993 raise LinAlgError("Singular matrix") 
    90994  
    90995 See log for complete Python traceback. 
    90996  
    90997 Traceback (most recent call last): 
    90998 File
    90999 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91000 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    91001 self.session.ui.mouse_modes.mouse_pause_tracking() 
    91002 File
    91003 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91004 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    91005 mouse_pause_tracking 
    91006 self._mouse_pause() 
    91007 File
    91008 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91009 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    91010 m.pause(self._mouse_pause_position) 
    91011 File
    91012 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91013 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    91014 p = self.view.picked_object(x, y) 
    91015 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91016 File
    91017 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91018 packages/chimerax/graphics/view.py", line 838, in picked_object 
    91019 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    91020 beyond, 
    91021 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91022 File
    91023 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91024 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    91025 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    91026 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91027 File
    91028 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91029 packages/chimerax/core/models.py", line 143, in first_intercept 
    91030 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    91031 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91032 File
    91033 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91034 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    91035 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    91036 exclude=exclude) 
    91037 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91038 File
    91039 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91040 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    91041 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    91042 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91043 File
    91044 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91045 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    91046 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    91047 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91048 File
    91049 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91050 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    91051 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    91052 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91053 File
    91054 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91055 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    91056 p = super().first_intercept(mxyz1, mxyz2) 
    91057 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91058 File
    91059 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91060 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    91061 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    91062 exclude=exclude) 
    91063 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91064 File
    91065 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91066 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    91067 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    91068 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91069 File
    91070 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91071 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    91072 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    91073 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91074 File
    91075 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91076 packages/chimerax/graphics/drawing.py", line 1108, in
    91077 _first_intercept_excluding_children 
    91078 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    91079 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91080 File
    91081 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91082 packages/chimerax/geometry/place.py", line 201, in inverse 
    91083 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    91084 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91085 File
    91086 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91087 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    91088 rinv[:, :] = matrix_inverse(r) 
    91089 ^^^^^^^^^^^^^^^^^ 
    91090 File
    91091 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91092 packages/numpy/linalg/linalg.py", line 561, in inv 
    91093 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    91094 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91095 File
    91096 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91097 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    91098 raise LinAlgError("Singular matrix") 
    91099 numpy.linalg.LinAlgError: Singular matrix 
    91100  
    91101 numpy.linalg.LinAlgError: Singular matrix 
    91102  
    91103 File
    91104 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91105 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    91106 raise LinAlgError("Singular matrix") 
    91107  
    91108 See log for complete Python traceback. 
    91109  
    91110 Traceback (most recent call last): 
    91111 File
    91112 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91113 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    91114 self.session.ui.mouse_modes.mouse_pause_tracking() 
    91115 File
    91116 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91117 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    91118 mouse_pause_tracking 
    91119 self._mouse_pause() 
    91120 File
    91121 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91122 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    91123 m.pause(self._mouse_pause_position) 
    91124 File
    91125 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91126 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    91127 p = self.view.picked_object(x, y) 
    91128 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91129 File
    91130 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91131 packages/chimerax/graphics/view.py", line 838, in picked_object 
    91132 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    91133 beyond, 
    91134 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91135 File
    91136 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91137 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    91138 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    91139 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91140 File
    91141 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91142 packages/chimerax/core/models.py", line 143, in first_intercept 
    91143 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    91144 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91145 File
    91146 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91147 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    91148 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    91149 exclude=exclude) 
    91150 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91151 File
    91152 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91153 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    91154 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    91155 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91156 File
    91157 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91158 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    91159 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    91160 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91161 File
    91162 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91163 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    91164 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    91165 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91166 File
    91167 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91168 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    91169 p = super().first_intercept(mxyz1, mxyz2) 
    91170 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91171 File
    91172 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91173 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    91174 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    91175 exclude=exclude) 
    91176 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91177 File
    91178 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91179 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    91180 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    91181 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91182 File
    91183 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91184 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    91185 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    91186 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91187 File
    91188 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91189 packages/chimerax/graphics/drawing.py", line 1108, in
    91190 _first_intercept_excluding_children 
    91191 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    91192 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91193 File
    91194 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91195 packages/chimerax/geometry/place.py", line 201, in inverse 
    91196 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    91197 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91198 File
    91199 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91200 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    91201 rinv[:, :] = matrix_inverse(r) 
    91202 ^^^^^^^^^^^^^^^^^ 
    91203 File
    91204 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91205 packages/numpy/linalg/linalg.py", line 561, in inv 
    91206 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    91207 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91208 File
    91209 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91210 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    91211 raise LinAlgError("Singular matrix") 
    91212 numpy.linalg.LinAlgError: Singular matrix 
    91213  
    91214 numpy.linalg.LinAlgError: Singular matrix 
    91215  
    91216 File
    91217 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91218 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    91219 raise LinAlgError("Singular matrix") 
    91220  
    91221 See log for complete Python traceback. 
    91222  
    91223 Traceback (most recent call last): 
    91224 File
    91225 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91226 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    91227 self.session.ui.mouse_modes.mouse_pause_tracking() 
    91228 File
    91229 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91230 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    91231 mouse_pause_tracking 
    91232 self._mouse_pause() 
    91233 File
    91234 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91235 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    91236 m.pause(self._mouse_pause_position) 
    91237 File
    91238 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91239 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    91240 p = self.view.picked_object(x, y) 
    91241 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91242 File
    91243 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91244 packages/chimerax/graphics/view.py", line 838, in picked_object 
    91245 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    91246 beyond, 
    91247 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91248 File
    91249 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91250 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    91251 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    91252 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91253 File
    91254 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91255 packages/chimerax/core/models.py", line 143, in first_intercept 
    91256 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    91257 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91258 File
    91259 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91260 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    91261 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    91262 exclude=exclude) 
    91263 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91264 File
    91265 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91266 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    91267 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    91268 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91269 File
    91270 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91271 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    91272 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    91273 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91274 File
    91275 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91276 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    91277 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    91278 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91279 File
    91280 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91281 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    91282 p = super().first_intercept(mxyz1, mxyz2) 
    91283 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91284 File
    91285 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91286 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    91287 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    91288 exclude=exclude) 
    91289 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91290 File
    91291 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91292 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    91293 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    91294 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91295 File
    91296 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91297 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    91298 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    91299 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91300 File
    91301 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91302 packages/chimerax/graphics/drawing.py", line 1108, in
    91303 _first_intercept_excluding_children 
    91304 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    91305 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91306 File
    91307 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91308 packages/chimerax/geometry/place.py", line 201, in inverse 
    91309 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    91310 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91311 File
    91312 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91313 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    91314 rinv[:, :] = matrix_inverse(r) 
    91315 ^^^^^^^^^^^^^^^^^ 
    91316 File
    91317 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91318 packages/numpy/linalg/linalg.py", line 561, in inv 
    91319 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    91320 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91321 File
    91322 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91323 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    91324 raise LinAlgError("Singular matrix") 
    91325 numpy.linalg.LinAlgError: Singular matrix 
    91326  
    91327 numpy.linalg.LinAlgError: Singular matrix 
    91328  
    91329 File
    91330 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91331 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    91332 raise LinAlgError("Singular matrix") 
    91333  
    91334 See log for complete Python traceback. 
    91335  
    91336 Traceback (most recent call last): 
    91337 File
    91338 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91339 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    91340 self.session.ui.mouse_modes.mouse_pause_tracking() 
    91341 File
    91342 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91343 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    91344 mouse_pause_tracking 
    91345 self._mouse_pause() 
    91346 File
    91347 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91348 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    91349 m.pause(self._mouse_pause_position) 
    91350 File
    91351 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91352 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    91353 p = self.view.picked_object(x, y) 
    91354 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91355 File
    91356 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91357 packages/chimerax/graphics/view.py", line 838, in picked_object 
    91358 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    91359 beyond, 
    91360 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91361 File
    91362 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91363 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    91364 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    91365 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91366 File
    91367 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91368 packages/chimerax/core/models.py", line 143, in first_intercept 
    91369 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    91370 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91371 File
    91372 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91373 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    91374 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    91375 exclude=exclude) 
    91376 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91377 File
    91378 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91379 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    91380 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    91381 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91382 File
    91383 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91384 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    91385 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    91386 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91387 File
    91388 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91389 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    91390 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    91391 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91392 File
    91393 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91394 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    91395 p = super().first_intercept(mxyz1, mxyz2) 
    91396 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91397 File
    91398 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91399 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    91400 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    91401 exclude=exclude) 
    91402 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91403 File
    91404 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91405 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    91406 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    91407 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91408 File
    91409 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91410 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    91411 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    91412 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91413 File
    91414 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91415 packages/chimerax/graphics/drawing.py", line 1108, in
    91416 _first_intercept_excluding_children 
    91417 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    91418 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91419 File
    91420 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91421 packages/chimerax/geometry/place.py", line 201, in inverse 
    91422 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    91423 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91424 File
    91425 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91426 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    91427 rinv[:, :] = matrix_inverse(r) 
    91428 ^^^^^^^^^^^^^^^^^ 
    91429 File
    91430 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91431 packages/numpy/linalg/linalg.py", line 561, in inv 
    91432 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    91433 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91434 File
    91435 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91436 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    91437 raise LinAlgError("Singular matrix") 
    91438 numpy.linalg.LinAlgError: Singular matrix 
    91439  
    91440 numpy.linalg.LinAlgError: Singular matrix 
    91441  
    91442 File
    91443 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91444 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    91445 raise LinAlgError("Singular matrix") 
    91446  
    91447 See log for complete Python traceback. 
    91448  
    91449 Traceback (most recent call last): 
    91450 File
    91451 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91452 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    91453 self.session.ui.mouse_modes.mouse_pause_tracking() 
    91454 File
    91455 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91456 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    91457 mouse_pause_tracking 
    91458 self._mouse_pause() 
    91459 File
    91460 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91461 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    91462 m.pause(self._mouse_pause_position) 
    91463 File
    91464 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91465 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    91466 p = self.view.picked_object(x, y) 
    91467 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91468 File
    91469 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91470 packages/chimerax/graphics/view.py", line 838, in picked_object 
    91471 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    91472 beyond, 
    91473 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91474 File
    91475 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91476 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    91477 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    91478 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91479 File
    91480 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91481 packages/chimerax/core/models.py", line 143, in first_intercept 
    91482 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    91483 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91484 File
    91485 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91486 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    91487 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    91488 exclude=exclude) 
    91489 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91490 File
    91491 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91492 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    91493 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    91494 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91495 File
    91496 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91497 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    91498 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    91499 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91500 File
    91501 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91502 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    91503 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    91504 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91505 File
    91506 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91507 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    91508 p = super().first_intercept(mxyz1, mxyz2) 
    91509 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91510 File
    91511 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91512 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    91513 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    91514 exclude=exclude) 
    91515 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91516 File
    91517 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91518 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    91519 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    91520 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91521 File
    91522 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91523 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    91524 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    91525 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91526 File
    91527 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91528 packages/chimerax/graphics/drawing.py", line 1108, in
    91529 _first_intercept_excluding_children 
    91530 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    91531 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91532 File
    91533 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91534 packages/chimerax/geometry/place.py", line 201, in inverse 
    91535 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    91536 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91537 File
    91538 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91539 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    91540 rinv[:, :] = matrix_inverse(r) 
    91541 ^^^^^^^^^^^^^^^^^ 
    91542 File
    91543 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91544 packages/numpy/linalg/linalg.py", line 561, in inv 
    91545 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    91546 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91547 File
    91548 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91549 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    91550 raise LinAlgError("Singular matrix") 
    91551 numpy.linalg.LinAlgError: Singular matrix 
    91552  
    91553 numpy.linalg.LinAlgError: Singular matrix 
    91554  
    91555 File
    91556 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91557 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    91558 raise LinAlgError("Singular matrix") 
    91559  
    91560 See log for complete Python traceback. 
    91561  
    91562 Traceback (most recent call last): 
    91563 File
    91564 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91565 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    91566 self.session.ui.mouse_modes.mouse_pause_tracking() 
    91567 File
    91568 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91569 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    91570 mouse_pause_tracking 
    91571 self._mouse_pause() 
    91572 File
    91573 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91574 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    91575 m.pause(self._mouse_pause_position) 
    91576 File
    91577 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91578 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    91579 p = self.view.picked_object(x, y) 
    91580 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91581 File
    91582 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91583 packages/chimerax/graphics/view.py", line 838, in picked_object 
    91584 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    91585 beyond, 
    91586 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91587 File
    91588 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91589 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    91590 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    91591 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91592 File
    91593 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91594 packages/chimerax/core/models.py", line 143, in first_intercept 
    91595 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    91596 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91597 File
    91598 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91599 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    91600 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    91601 exclude=exclude) 
    91602 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91603 File
    91604 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91605 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    91606 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    91607 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91608 File
    91609 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91610 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    91611 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    91612 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91613 File
    91614 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91615 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    91616 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    91617 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91618 File
    91619 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91620 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    91621 p = super().first_intercept(mxyz1, mxyz2) 
    91622 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91623 File
    91624 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91625 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    91626 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    91627 exclude=exclude) 
    91628 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91629 File
    91630 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91631 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    91632 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    91633 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91634 File
    91635 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91636 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    91637 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    91638 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91639 File
    91640 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91641 packages/chimerax/graphics/drawing.py", line 1108, in
    91642 _first_intercept_excluding_children 
    91643 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    91644 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91645 File
    91646 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91647 packages/chimerax/geometry/place.py", line 201, in inverse 
    91648 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    91649 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91650 File
    91651 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91652 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    91653 rinv[:, :] = matrix_inverse(r) 
    91654 ^^^^^^^^^^^^^^^^^ 
    91655 File
    91656 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91657 packages/numpy/linalg/linalg.py", line 561, in inv 
    91658 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    91659 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91660 File
    91661 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91662 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    91663 raise LinAlgError("Singular matrix") 
    91664 numpy.linalg.LinAlgError: Singular matrix 
    91665  
    91666 numpy.linalg.LinAlgError: Singular matrix 
    91667  
    91668 File
    91669 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91670 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    91671 raise LinAlgError("Singular matrix") 
    91672  
    91673 See log for complete Python traceback. 
    91674  
    91675 Traceback (most recent call last): 
    91676 File
    91677 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91678 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    91679 self.session.ui.mouse_modes.mouse_pause_tracking() 
    91680 File
    91681 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91682 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    91683 mouse_pause_tracking 
    91684 self._mouse_pause() 
    91685 File
    91686 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91687 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    91688 m.pause(self._mouse_pause_position) 
    91689 File
    91690 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91691 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    91692 p = self.view.picked_object(x, y) 
    91693 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91694 File
    91695 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91696 packages/chimerax/graphics/view.py", line 838, in picked_object 
    91697 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    91698 beyond, 
    91699 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91700 File
    91701 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91702 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    91703 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    91704 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91705 File
    91706 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91707 packages/chimerax/core/models.py", line 143, in first_intercept 
    91708 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    91709 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91710 File
    91711 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91712 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    91713 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    91714 exclude=exclude) 
    91715 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91716 File
    91717 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91718 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    91719 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    91720 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91721 File
    91722 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91723 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    91724 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    91725 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91726 File
    91727 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91728 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    91729 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    91730 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91731 File
    91732 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91733 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    91734 p = super().first_intercept(mxyz1, mxyz2) 
    91735 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91736 File
    91737 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91738 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    91739 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    91740 exclude=exclude) 
    91741 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91742 File
    91743 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91744 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    91745 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    91746 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91747 File
    91748 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91749 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    91750 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    91751 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91752 File
    91753 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91754 packages/chimerax/graphics/drawing.py", line 1108, in
    91755 _first_intercept_excluding_children 
    91756 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    91757 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91758 File
    91759 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91760 packages/chimerax/geometry/place.py", line 201, in inverse 
    91761 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    91762 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91763 File
    91764 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91765 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    91766 rinv[:, :] = matrix_inverse(r) 
    91767 ^^^^^^^^^^^^^^^^^ 
    91768 File
    91769 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91770 packages/numpy/linalg/linalg.py", line 561, in inv 
    91771 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    91772 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91773 File
    91774 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91775 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    91776 raise LinAlgError("Singular matrix") 
    91777 numpy.linalg.LinAlgError: Singular matrix 
    91778  
    91779 numpy.linalg.LinAlgError: Singular matrix 
    91780  
    91781 File
    91782 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91783 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    91784 raise LinAlgError("Singular matrix") 
    91785  
    91786 See log for complete Python traceback. 
    91787  
    91788 Traceback (most recent call last): 
    91789 File
    91790 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91791 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    91792 self.session.ui.mouse_modes.mouse_pause_tracking() 
    91793 File
    91794 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91795 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    91796 mouse_pause_tracking 
    91797 self._mouse_pause() 
    91798 File
    91799 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91800 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    91801 m.pause(self._mouse_pause_position) 
    91802 File
    91803 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91804 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    91805 p = self.view.picked_object(x, y) 
    91806 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91807 File
    91808 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91809 packages/chimerax/graphics/view.py", line 838, in picked_object 
    91810 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    91811 beyond, 
    91812 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91813 File
    91814 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91815 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    91816 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    91817 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91818 File
    91819 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91820 packages/chimerax/core/models.py", line 143, in first_intercept 
    91821 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    91822 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91823 File
    91824 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91825 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    91826 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    91827 exclude=exclude) 
    91828 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91829 File
    91830 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91831 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    91832 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    91833 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91834 File
    91835 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91836 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    91837 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    91838 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91839 File
    91840 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91841 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    91842 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    91843 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91844 File
    91845 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91846 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    91847 p = super().first_intercept(mxyz1, mxyz2) 
    91848 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91849 File
    91850 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91851 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    91852 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    91853 exclude=exclude) 
    91854 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91855 File
    91856 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91857 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    91858 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    91859 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91860 File
    91861 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91862 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    91863 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    91864 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91865 File
    91866 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91867 packages/chimerax/graphics/drawing.py", line 1108, in
    91868 _first_intercept_excluding_children 
    91869 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    91870 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91871 File
    91872 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91873 packages/chimerax/geometry/place.py", line 201, in inverse 
    91874 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    91875 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91876 File
    91877 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91878 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    91879 rinv[:, :] = matrix_inverse(r) 
    91880 ^^^^^^^^^^^^^^^^^ 
    91881 File
    91882 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91883 packages/numpy/linalg/linalg.py", line 561, in inv 
    91884 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    91885 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91886 File
    91887 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91888 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    91889 raise LinAlgError("Singular matrix") 
    91890 numpy.linalg.LinAlgError: Singular matrix 
    91891  
    91892 numpy.linalg.LinAlgError: Singular matrix 
    91893  
    91894 File
    91895 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91896 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    91897 raise LinAlgError("Singular matrix") 
    91898  
    91899 See log for complete Python traceback. 
    91900  
    91901 Traceback (most recent call last): 
    91902 File
    91903 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91904 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    91905 self.session.ui.mouse_modes.mouse_pause_tracking() 
    91906 File
    91907 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91908 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    91909 mouse_pause_tracking 
    91910 self._mouse_pause() 
    91911 File
    91912 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91913 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    91914 m.pause(self._mouse_pause_position) 
    91915 File
    91916 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91917 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    91918 p = self.view.picked_object(x, y) 
    91919 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91920 File
    91921 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91922 packages/chimerax/graphics/view.py", line 838, in picked_object 
    91923 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    91924 beyond, 
    91925 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91926 File
    91927 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91928 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    91929 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    91930 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91931 File
    91932 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91933 packages/chimerax/core/models.py", line 143, in first_intercept 
    91934 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    91935 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91936 File
    91937 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91938 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    91939 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    91940 exclude=exclude) 
    91941 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91942 File
    91943 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91944 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    91945 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    91946 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91947 File
    91948 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91949 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    91950 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    91951 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91952 File
    91953 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91954 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    91955 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    91956 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91957 File
    91958 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91959 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    91960 p = super().first_intercept(mxyz1, mxyz2) 
    91961 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91962 File
    91963 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91964 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    91965 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    91966 exclude=exclude) 
    91967 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91968 File
    91969 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91970 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    91971 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    91972 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91973 File
    91974 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91975 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    91976 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    91977 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91978 File
    91979 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91980 packages/chimerax/graphics/drawing.py", line 1108, in
    91981 _first_intercept_excluding_children 
    91982 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    91983 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91984 File
    91985 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91986 packages/chimerax/geometry/place.py", line 201, in inverse 
    91987 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    91988 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91989 File
    91990 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91991 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    91992 rinv[:, :] = matrix_inverse(r) 
    91993 ^^^^^^^^^^^^^^^^^ 
    91994 File
    91995 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    91996 packages/numpy/linalg/linalg.py", line 561, in inv 
    91997 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    91998 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    91999 File
    92000 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92001 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    92002 raise LinAlgError("Singular matrix") 
    92003 numpy.linalg.LinAlgError: Singular matrix 
    92004  
    92005 numpy.linalg.LinAlgError: Singular matrix 
    92006  
    92007 File
    92008 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92009 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    92010 raise LinAlgError("Singular matrix") 
    92011  
    92012 See log for complete Python traceback. 
    92013  
    92014 Traceback (most recent call last): 
    92015 File
    92016 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92017 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    92018 self.session.ui.mouse_modes.mouse_pause_tracking() 
    92019 File
    92020 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92021 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    92022 mouse_pause_tracking 
    92023 self._mouse_pause() 
    92024 File
    92025 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92026 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    92027 m.pause(self._mouse_pause_position) 
    92028 File
    92029 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92030 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    92031 p = self.view.picked_object(x, y) 
    92032 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92033 File
    92034 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92035 packages/chimerax/graphics/view.py", line 838, in picked_object 
    92036 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    92037 beyond, 
    92038 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92039 File
    92040 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92041 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    92042 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    92043 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92044 File
    92045 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92046 packages/chimerax/core/models.py", line 143, in first_intercept 
    92047 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    92048 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92049 File
    92050 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92051 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    92052 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    92053 exclude=exclude) 
    92054 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92055 File
    92056 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92057 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    92058 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    92059 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92060 File
    92061 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92062 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    92063 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    92064 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92065 File
    92066 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92067 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    92068 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    92069 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92070 File
    92071 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92072 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    92073 p = super().first_intercept(mxyz1, mxyz2) 
    92074 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92075 File
    92076 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92077 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    92078 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    92079 exclude=exclude) 
    92080 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92081 File
    92082 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92083 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    92084 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    92085 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92086 File
    92087 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92088 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    92089 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    92090 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92091 File
    92092 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92093 packages/chimerax/graphics/drawing.py", line 1108, in
    92094 _first_intercept_excluding_children 
    92095 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    92096 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92097 File
    92098 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92099 packages/chimerax/geometry/place.py", line 201, in inverse 
    92100 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    92101 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92102 File
    92103 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92104 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    92105 rinv[:, :] = matrix_inverse(r) 
    92106 ^^^^^^^^^^^^^^^^^ 
    92107 File
    92108 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92109 packages/numpy/linalg/linalg.py", line 561, in inv 
    92110 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    92111 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92112 File
    92113 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92114 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    92115 raise LinAlgError("Singular matrix") 
    92116 numpy.linalg.LinAlgError: Singular matrix 
    92117  
    92118 numpy.linalg.LinAlgError: Singular matrix 
    92119  
    92120 File
    92121 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92122 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    92123 raise LinAlgError("Singular matrix") 
    92124  
    92125 See log for complete Python traceback. 
    92126  
    92127 Traceback (most recent call last): 
    92128 File
    92129 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92130 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    92131 self.session.ui.mouse_modes.mouse_pause_tracking() 
    92132 File
    92133 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92134 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    92135 mouse_pause_tracking 
    92136 self._mouse_pause() 
    92137 File
    92138 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92139 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    92140 m.pause(self._mouse_pause_position) 
    92141 File
    92142 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92143 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    92144 p = self.view.picked_object(x, y) 
    92145 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92146 File
    92147 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92148 packages/chimerax/graphics/view.py", line 838, in picked_object 
    92149 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    92150 beyond, 
    92151 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92152 File
    92153 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92154 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    92155 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    92156 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92157 File
    92158 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92159 packages/chimerax/core/models.py", line 143, in first_intercept 
    92160 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    92161 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92162 File
    92163 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92164 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    92165 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    92166 exclude=exclude) 
    92167 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92168 File
    92169 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92170 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    92171 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    92172 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92173 File
    92174 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92175 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    92176 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    92177 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92178 File
    92179 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92180 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    92181 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    92182 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92183 File
    92184 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92185 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    92186 p = super().first_intercept(mxyz1, mxyz2) 
    92187 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92188 File
    92189 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92190 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    92191 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    92192 exclude=exclude) 
    92193 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92194 File
    92195 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92196 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    92197 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    92198 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92199 File
    92200 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92201 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    92202 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    92203 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92204 File
    92205 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92206 packages/chimerax/graphics/drawing.py", line 1108, in
    92207 _first_intercept_excluding_children 
    92208 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    92209 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92210 File
    92211 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92212 packages/chimerax/geometry/place.py", line 201, in inverse 
    92213 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    92214 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92215 File
    92216 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92217 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    92218 rinv[:, :] = matrix_inverse(r) 
    92219 ^^^^^^^^^^^^^^^^^ 
    92220 File
    92221 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92222 packages/numpy/linalg/linalg.py", line 561, in inv 
    92223 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    92224 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92225 File
    92226 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92227 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    92228 raise LinAlgError("Singular matrix") 
    92229 numpy.linalg.LinAlgError: Singular matrix 
    92230  
    92231 numpy.linalg.LinAlgError: Singular matrix 
    92232  
    92233 File
    92234 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92235 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    92236 raise LinAlgError("Singular matrix") 
    92237  
    92238 See log for complete Python traceback. 
    92239  
    92240 Traceback (most recent call last): 
    92241 File
    92242 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92243 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    92244 self.session.ui.mouse_modes.mouse_pause_tracking() 
    92245 File
    92246 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92247 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    92248 mouse_pause_tracking 
    92249 self._mouse_pause() 
    92250 File
    92251 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92252 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    92253 m.pause(self._mouse_pause_position) 
    92254 File
    92255 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92256 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    92257 p = self.view.picked_object(x, y) 
    92258 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92259 File
    92260 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92261 packages/chimerax/graphics/view.py", line 838, in picked_object 
    92262 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    92263 beyond, 
    92264 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92265 File
    92266 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92267 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    92268 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    92269 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92270 File
    92271 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92272 packages/chimerax/core/models.py", line 143, in first_intercept 
    92273 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    92274 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92275 File
    92276 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92277 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    92278 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    92279 exclude=exclude) 
    92280 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92281 File
    92282 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92283 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    92284 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    92285 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92286 File
    92287 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92288 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    92289 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    92290 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92291 File
    92292 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92293 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    92294 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    92295 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92296 File
    92297 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92298 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    92299 p = super().first_intercept(mxyz1, mxyz2) 
    92300 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92301 File
    92302 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92303 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    92304 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    92305 exclude=exclude) 
    92306 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92307 File
    92308 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92309 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    92310 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    92311 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92312 File
    92313 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92314 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    92315 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    92316 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92317 File
    92318 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92319 packages/chimerax/graphics/drawing.py", line 1108, in
    92320 _first_intercept_excluding_children 
    92321 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    92322 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92323 File
    92324 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92325 packages/chimerax/geometry/place.py", line 201, in inverse 
    92326 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    92327 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92328 File
    92329 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92330 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    92331 rinv[:, :] = matrix_inverse(r) 
    92332 ^^^^^^^^^^^^^^^^^ 
    92333 File
    92334 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92335 packages/numpy/linalg/linalg.py", line 561, in inv 
    92336 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    92337 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92338 File
    92339 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92340 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    92341 raise LinAlgError("Singular matrix") 
    92342 numpy.linalg.LinAlgError: Singular matrix 
    92343  
    92344 numpy.linalg.LinAlgError: Singular matrix 
    92345  
    92346 File
    92347 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92348 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    92349 raise LinAlgError("Singular matrix") 
    92350  
    92351 See log for complete Python traceback. 
    92352  
    92353 Traceback (most recent call last): 
    92354 File
    92355 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92356 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    92357 self.session.ui.mouse_modes.mouse_pause_tracking() 
    92358 File
    92359 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92360 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    92361 mouse_pause_tracking 
    92362 self._mouse_pause() 
    92363 File
    92364 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92365 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    92366 m.pause(self._mouse_pause_position) 
    92367 File
    92368 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92369 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    92370 p = self.view.picked_object(x, y) 
    92371 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92372 File
    92373 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92374 packages/chimerax/graphics/view.py", line 838, in picked_object 
    92375 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    92376 beyond, 
    92377 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92378 File
    92379 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92380 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    92381 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    92382 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92383 File
    92384 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92385 packages/chimerax/core/models.py", line 143, in first_intercept 
    92386 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    92387 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92388 File
    92389 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92390 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    92391 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    92392 exclude=exclude) 
    92393 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92394 File
    92395 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92396 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    92397 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    92398 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92399 File
    92400 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92401 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    92402 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    92403 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92404 File
    92405 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92406 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    92407 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    92408 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92409 File
    92410 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92411 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    92412 p = super().first_intercept(mxyz1, mxyz2) 
    92413 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92414 File
    92415 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92416 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    92417 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    92418 exclude=exclude) 
    92419 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92420 File
    92421 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92422 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    92423 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    92424 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92425 File
    92426 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92427 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    92428 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    92429 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92430 File
    92431 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92432 packages/chimerax/graphics/drawing.py", line 1108, in
    92433 _first_intercept_excluding_children 
    92434 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    92435 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92436 File
    92437 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92438 packages/chimerax/geometry/place.py", line 201, in inverse 
    92439 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    92440 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92441 File
    92442 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92443 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    92444 rinv[:, :] = matrix_inverse(r) 
    92445 ^^^^^^^^^^^^^^^^^ 
    92446 File
    92447 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92448 packages/numpy/linalg/linalg.py", line 561, in inv 
    92449 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    92450 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92451 File
    92452 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92453 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    92454 raise LinAlgError("Singular matrix") 
    92455 numpy.linalg.LinAlgError: Singular matrix 
    92456  
    92457 numpy.linalg.LinAlgError: Singular matrix 
    92458  
    92459 File
    92460 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92461 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    92462 raise LinAlgError("Singular matrix") 
    92463  
    92464 See log for complete Python traceback. 
    92465  
    92466 Traceback (most recent call last): 
    92467 File
    92468 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92469 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    92470 self.session.ui.mouse_modes.mouse_pause_tracking() 
    92471 File
    92472 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92473 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    92474 mouse_pause_tracking 
    92475 self._mouse_pause() 
    92476 File
    92477 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92478 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    92479 m.pause(self._mouse_pause_position) 
    92480 File
    92481 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92482 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    92483 p = self.view.picked_object(x, y) 
    92484 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92485 File
    92486 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92487 packages/chimerax/graphics/view.py", line 838, in picked_object 
    92488 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    92489 beyond, 
    92490 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92491 File
    92492 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92493 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    92494 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    92495 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92496 File
    92497 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92498 packages/chimerax/core/models.py", line 143, in first_intercept 
    92499 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    92500 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92501 File
    92502 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92503 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    92504 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    92505 exclude=exclude) 
    92506 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92507 File
    92508 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92509 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    92510 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    92511 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92512 File
    92513 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92514 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    92515 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    92516 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92517 File
    92518 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92519 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    92520 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    92521 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92522 File
    92523 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92524 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    92525 p = super().first_intercept(mxyz1, mxyz2) 
    92526 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92527 File
    92528 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92529 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    92530 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    92531 exclude=exclude) 
    92532 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92533 File
    92534 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92535 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    92536 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    92537 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92538 File
    92539 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92540 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    92541 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    92542 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92543 File
    92544 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92545 packages/chimerax/graphics/drawing.py", line 1108, in
    92546 _first_intercept_excluding_children 
    92547 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    92548 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92549 File
    92550 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92551 packages/chimerax/geometry/place.py", line 201, in inverse 
    92552 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    92553 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92554 File
    92555 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92556 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    92557 rinv[:, :] = matrix_inverse(r) 
    92558 ^^^^^^^^^^^^^^^^^ 
    92559 File
    92560 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92561 packages/numpy/linalg/linalg.py", line 561, in inv 
    92562 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    92563 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92564 File
    92565 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92566 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    92567 raise LinAlgError("Singular matrix") 
    92568 numpy.linalg.LinAlgError: Singular matrix 
    92569  
    92570 numpy.linalg.LinAlgError: Singular matrix 
    92571  
    92572 File
    92573 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92574 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    92575 raise LinAlgError("Singular matrix") 
    92576  
    92577 See log for complete Python traceback. 
    92578  
    92579 Traceback (most recent call last): 
    92580 File
    92581 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92582 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    92583 self.session.ui.mouse_modes.mouse_pause_tracking() 
    92584 File
    92585 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92586 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    92587 mouse_pause_tracking 
    92588 self._mouse_pause() 
    92589 File
    92590 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92591 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    92592 m.pause(self._mouse_pause_position) 
    92593 File
    92594 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92595 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    92596 p = self.view.picked_object(x, y) 
    92597 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92598 File
    92599 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92600 packages/chimerax/graphics/view.py", line 838, in picked_object 
    92601 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    92602 beyond, 
    92603 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92604 File
    92605 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92606 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    92607 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    92608 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92609 File
    92610 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92611 packages/chimerax/core/models.py", line 143, in first_intercept 
    92612 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    92613 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92614 File
    92615 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92616 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    92617 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    92618 exclude=exclude) 
    92619 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92620 File
    92621 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92622 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    92623 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    92624 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92625 File
    92626 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92627 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    92628 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    92629 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92630 File
    92631 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92632 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    92633 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    92634 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92635 File
    92636 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92637 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    92638 p = super().first_intercept(mxyz1, mxyz2) 
    92639 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92640 File
    92641 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92642 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    92643 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    92644 exclude=exclude) 
    92645 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92646 File
    92647 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92648 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    92649 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    92650 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92651 File
    92652 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92653 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    92654 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    92655 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92656 File
    92657 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92658 packages/chimerax/graphics/drawing.py", line 1108, in
    92659 _first_intercept_excluding_children 
    92660 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    92661 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92662 File
    92663 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92664 packages/chimerax/geometry/place.py", line 201, in inverse 
    92665 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    92666 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92667 File
    92668 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92669 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    92670 rinv[:, :] = matrix_inverse(r) 
    92671 ^^^^^^^^^^^^^^^^^ 
    92672 File
    92673 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92674 packages/numpy/linalg/linalg.py", line 561, in inv 
    92675 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    92676 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92677 File
    92678 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92679 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    92680 raise LinAlgError("Singular matrix") 
    92681 numpy.linalg.LinAlgError: Singular matrix 
    92682  
    92683 numpy.linalg.LinAlgError: Singular matrix 
    92684  
    92685 File
    92686 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92687 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    92688 raise LinAlgError("Singular matrix") 
    92689  
    92690 See log for complete Python traceback. 
    92691  
    92692 Traceback (most recent call last): 
    92693 File
    92694 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92695 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    92696 self.session.ui.mouse_modes.mouse_pause_tracking() 
    92697 File
    92698 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92699 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    92700 mouse_pause_tracking 
    92701 self._mouse_pause() 
    92702 File
    92703 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92704 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    92705 m.pause(self._mouse_pause_position) 
    92706 File
    92707 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92708 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    92709 p = self.view.picked_object(x, y) 
    92710 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92711 File
    92712 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92713 packages/chimerax/graphics/view.py", line 838, in picked_object 
    92714 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    92715 beyond, 
    92716 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92717 File
    92718 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92719 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    92720 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    92721 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92722 File
    92723 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92724 packages/chimerax/core/models.py", line 143, in first_intercept 
    92725 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    92726 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92727 File
    92728 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92729 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    92730 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    92731 exclude=exclude) 
    92732 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92733 File
    92734 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92735 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    92736 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    92737 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92738 File
    92739 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92740 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    92741 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    92742 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92743 File
    92744 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92745 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    92746 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    92747 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92748 File
    92749 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92750 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    92751 p = super().first_intercept(mxyz1, mxyz2) 
    92752 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92753 File
    92754 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92755 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    92756 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    92757 exclude=exclude) 
    92758 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92759 File
    92760 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92761 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    92762 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    92763 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92764 File
    92765 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92766 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    92767 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    92768 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92769 File
    92770 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92771 packages/chimerax/graphics/drawing.py", line 1108, in
    92772 _first_intercept_excluding_children 
    92773 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    92774 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92775 File
    92776 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92777 packages/chimerax/geometry/place.py", line 201, in inverse 
    92778 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    92779 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92780 File
    92781 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92782 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    92783 rinv[:, :] = matrix_inverse(r) 
    92784 ^^^^^^^^^^^^^^^^^ 
    92785 File
    92786 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92787 packages/numpy/linalg/linalg.py", line 561, in inv 
    92788 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    92789 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92790 File
    92791 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92792 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    92793 raise LinAlgError("Singular matrix") 
    92794 numpy.linalg.LinAlgError: Singular matrix 
    92795  
    92796 numpy.linalg.LinAlgError: Singular matrix 
    92797  
    92798 File
    92799 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92800 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    92801 raise LinAlgError("Singular matrix") 
    92802  
    92803 See log for complete Python traceback. 
    92804  
    92805 Traceback (most recent call last): 
    92806 File
    92807 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92808 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    92809 self.session.ui.mouse_modes.mouse_pause_tracking() 
    92810 File
    92811 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92812 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    92813 mouse_pause_tracking 
    92814 self._mouse_pause() 
    92815 File
    92816 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92817 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    92818 m.pause(self._mouse_pause_position) 
    92819 File
    92820 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92821 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    92822 p = self.view.picked_object(x, y) 
    92823 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92824 File
    92825 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92826 packages/chimerax/graphics/view.py", line 838, in picked_object 
    92827 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    92828 beyond, 
    92829 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92830 File
    92831 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92832 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    92833 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    92834 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92835 File
    92836 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92837 packages/chimerax/core/models.py", line 143, in first_intercept 
    92838 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    92839 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92840 File
    92841 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92842 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    92843 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    92844 exclude=exclude) 
    92845 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92846 File
    92847 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92848 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    92849 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    92850 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92851 File
    92852 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92853 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    92854 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    92855 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92856 File
    92857 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92858 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    92859 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    92860 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92861 File
    92862 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92863 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    92864 p = super().first_intercept(mxyz1, mxyz2) 
    92865 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92866 File
    92867 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92868 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    92869 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    92870 exclude=exclude) 
    92871 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92872 File
    92873 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92874 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    92875 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    92876 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92877 File
    92878 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92879 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    92880 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    92881 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92882 File
    92883 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92884 packages/chimerax/graphics/drawing.py", line 1108, in
    92885 _first_intercept_excluding_children 
    92886 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    92887 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92888 File
    92889 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92890 packages/chimerax/geometry/place.py", line 201, in inverse 
    92891 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    92892 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92893 File
    92894 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92895 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    92896 rinv[:, :] = matrix_inverse(r) 
    92897 ^^^^^^^^^^^^^^^^^ 
    92898 File
    92899 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92900 packages/numpy/linalg/linalg.py", line 561, in inv 
    92901 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    92902 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92903 File
    92904 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92905 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    92906 raise LinAlgError("Singular matrix") 
    92907 numpy.linalg.LinAlgError: Singular matrix 
    92908  
    92909 numpy.linalg.LinAlgError: Singular matrix 
    92910  
    92911 File
    92912 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92913 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    92914 raise LinAlgError("Singular matrix") 
    92915  
    92916 See log for complete Python traceback. 
    92917  
    92918 Traceback (most recent call last): 
    92919 File
    92920 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92921 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    92922 self.session.ui.mouse_modes.mouse_pause_tracking() 
    92923 File
    92924 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92925 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    92926 mouse_pause_tracking 
    92927 self._mouse_pause() 
    92928 File
    92929 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92930 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    92931 m.pause(self._mouse_pause_position) 
    92932 File
    92933 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92934 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    92935 p = self.view.picked_object(x, y) 
    92936 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92937 File
    92938 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92939 packages/chimerax/graphics/view.py", line 838, in picked_object 
    92940 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    92941 beyond, 
    92942 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92943 File
    92944 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92945 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    92946 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    92947 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92948 File
    92949 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92950 packages/chimerax/core/models.py", line 143, in first_intercept 
    92951 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    92952 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92953 File
    92954 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92955 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    92956 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    92957 exclude=exclude) 
    92958 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92959 File
    92960 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92961 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    92962 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    92963 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92964 File
    92965 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92966 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    92967 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    92968 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92969 File
    92970 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92971 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    92972 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    92973 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92974 File
    92975 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92976 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    92977 p = super().first_intercept(mxyz1, mxyz2) 
    92978 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92979 File
    92980 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92981 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    92982 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    92983 exclude=exclude) 
    92984 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92985 File
    92986 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92987 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    92988 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    92989 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92990 File
    92991 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92992 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    92993 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    92994 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    92995 File
    92996 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    92997 packages/chimerax/graphics/drawing.py", line 1108, in
    92998 _first_intercept_excluding_children 
    92999 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    93000 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93001 File
    93002 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93003 packages/chimerax/geometry/place.py", line 201, in inverse 
    93004 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    93005 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93006 File
    93007 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93008 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    93009 rinv[:, :] = matrix_inverse(r) 
    93010 ^^^^^^^^^^^^^^^^^ 
    93011 File
    93012 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93013 packages/numpy/linalg/linalg.py", line 561, in inv 
    93014 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    93015 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93016 File
    93017 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93018 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    93019 raise LinAlgError("Singular matrix") 
    93020 numpy.linalg.LinAlgError: Singular matrix 
    93021  
    93022 numpy.linalg.LinAlgError: Singular matrix 
    93023  
    93024 File
    93025 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93026 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    93027 raise LinAlgError("Singular matrix") 
    93028  
    93029 See log for complete Python traceback. 
    93030  
    93031 Traceback (most recent call last): 
    93032 File
    93033 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93034 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    93035 self.session.ui.mouse_modes.mouse_pause_tracking() 
    93036 File
    93037 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93038 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    93039 mouse_pause_tracking 
    93040 self._mouse_pause() 
    93041 File
    93042 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93043 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    93044 m.pause(self._mouse_pause_position) 
    93045 File
    93046 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93047 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    93048 p = self.view.picked_object(x, y) 
    93049 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93050 File
    93051 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93052 packages/chimerax/graphics/view.py", line 838, in picked_object 
    93053 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    93054 beyond, 
    93055 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93056 File
    93057 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93058 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    93059 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    93060 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93061 File
    93062 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93063 packages/chimerax/core/models.py", line 143, in first_intercept 
    93064 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    93065 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93066 File
    93067 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93068 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    93069 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    93070 exclude=exclude) 
    93071 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93072 File
    93073 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93074 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    93075 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    93076 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93077 File
    93078 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93079 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    93080 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    93081 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93082 File
    93083 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93084 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    93085 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    93086 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93087 File
    93088 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93089 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    93090 p = super().first_intercept(mxyz1, mxyz2) 
    93091 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93092 File
    93093 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93094 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    93095 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    93096 exclude=exclude) 
    93097 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93098 File
    93099 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93100 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    93101 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    93102 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93103 File
    93104 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93105 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    93106 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    93107 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93108 File
    93109 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93110 packages/chimerax/graphics/drawing.py", line 1108, in
    93111 _first_intercept_excluding_children 
    93112 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    93113 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93114 File
    93115 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93116 packages/chimerax/geometry/place.py", line 201, in inverse 
    93117 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    93118 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93119 File
    93120 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93121 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    93122 rinv[:, :] = matrix_inverse(r) 
    93123 ^^^^^^^^^^^^^^^^^ 
    93124 File
    93125 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93126 packages/numpy/linalg/linalg.py", line 561, in inv 
    93127 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    93128 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93129 File
    93130 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93131 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    93132 raise LinAlgError("Singular matrix") 
    93133 numpy.linalg.LinAlgError: Singular matrix 
    93134  
    93135 numpy.linalg.LinAlgError: Singular matrix 
    93136  
    93137 File
    93138 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93139 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    93140 raise LinAlgError("Singular matrix") 
    93141  
    93142 See log for complete Python traceback. 
    93143  
    93144 Traceback (most recent call last): 
    93145 File
    93146 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93147 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    93148 self.session.ui.mouse_modes.mouse_pause_tracking() 
    93149 File
    93150 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93151 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    93152 mouse_pause_tracking 
    93153 self._mouse_pause() 
    93154 File
    93155 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93156 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    93157 m.pause(self._mouse_pause_position) 
    93158 File
    93159 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93160 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    93161 p = self.view.picked_object(x, y) 
    93162 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93163 File
    93164 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93165 packages/chimerax/graphics/view.py", line 838, in picked_object 
    93166 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    93167 beyond, 
    93168 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93169 File
    93170 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93171 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    93172 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    93173 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93174 File
    93175 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93176 packages/chimerax/core/models.py", line 143, in first_intercept 
    93177 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    93178 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93179 File
    93180 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93181 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    93182 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    93183 exclude=exclude) 
    93184 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93185 File
    93186 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93187 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    93188 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    93189 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93190 File
    93191 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93192 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    93193 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    93194 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93195 File
    93196 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93197 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    93198 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    93199 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93200 File
    93201 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93202 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    93203 p = super().first_intercept(mxyz1, mxyz2) 
    93204 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93205 File
    93206 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93207 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    93208 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    93209 exclude=exclude) 
    93210 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93211 File
    93212 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93213 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    93214 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    93215 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93216 File
    93217 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93218 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    93219 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    93220 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93221 File
    93222 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93223 packages/chimerax/graphics/drawing.py", line 1108, in
    93224 _first_intercept_excluding_children 
    93225 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    93226 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93227 File
    93228 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93229 packages/chimerax/geometry/place.py", line 201, in inverse 
    93230 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    93231 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93232 File
    93233 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93234 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    93235 rinv[:, :] = matrix_inverse(r) 
    93236 ^^^^^^^^^^^^^^^^^ 
    93237 File
    93238 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93239 packages/numpy/linalg/linalg.py", line 561, in inv 
    93240 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    93241 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93242 File
    93243 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93244 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    93245 raise LinAlgError("Singular matrix") 
    93246 numpy.linalg.LinAlgError: Singular matrix 
    93247  
    93248 numpy.linalg.LinAlgError: Singular matrix 
    93249  
    93250 File
    93251 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93252 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    93253 raise LinAlgError("Singular matrix") 
    93254  
    93255 See log for complete Python traceback. 
    93256  
    93257 Traceback (most recent call last): 
    93258 File
    93259 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93260 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    93261 self.session.ui.mouse_modes.mouse_pause_tracking() 
    93262 File
    93263 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93264 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    93265 mouse_pause_tracking 
    93266 self._mouse_pause() 
    93267 File
    93268 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93269 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    93270 m.pause(self._mouse_pause_position) 
    93271 File
    93272 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93273 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    93274 p = self.view.picked_object(x, y) 
    93275 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93276 File
    93277 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93278 packages/chimerax/graphics/view.py", line 838, in picked_object 
    93279 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    93280 beyond, 
    93281 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93282 File
    93283 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93284 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    93285 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    93286 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93287 File
    93288 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93289 packages/chimerax/core/models.py", line 143, in first_intercept 
    93290 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    93291 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93292 File
    93293 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93294 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    93295 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    93296 exclude=exclude) 
    93297 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93298 File
    93299 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93300 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    93301 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    93302 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93303 File
    93304 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93305 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    93306 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    93307 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93308 File
    93309 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93310 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    93311 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    93312 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93313 File
    93314 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93315 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    93316 p = super().first_intercept(mxyz1, mxyz2) 
    93317 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93318 File
    93319 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93320 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    93321 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    93322 exclude=exclude) 
    93323 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93324 File
    93325 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93326 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    93327 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    93328 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93329 File
    93330 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93331 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    93332 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    93333 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93334 File
    93335 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93336 packages/chimerax/graphics/drawing.py", line 1108, in
    93337 _first_intercept_excluding_children 
    93338 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    93339 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93340 File
    93341 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93342 packages/chimerax/geometry/place.py", line 201, in inverse 
    93343 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    93344 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93345 File
    93346 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93347 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    93348 rinv[:, :] = matrix_inverse(r) 
    93349 ^^^^^^^^^^^^^^^^^ 
    93350 File
    93351 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93352 packages/numpy/linalg/linalg.py", line 561, in inv 
    93353 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    93354 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93355 File
    93356 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93357 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    93358 raise LinAlgError("Singular matrix") 
    93359 numpy.linalg.LinAlgError: Singular matrix 
    93360  
    93361 numpy.linalg.LinAlgError: Singular matrix 
    93362  
    93363 File
    93364 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93365 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    93366 raise LinAlgError("Singular matrix") 
    93367  
    93368 See log for complete Python traceback. 
    93369  
    93370 Traceback (most recent call last): 
    93371 File
    93372 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93373 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    93374 self.session.ui.mouse_modes.mouse_pause_tracking() 
    93375 File
    93376 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93377 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    93378 mouse_pause_tracking 
    93379 self._mouse_pause() 
    93380 File
    93381 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93382 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    93383 m.pause(self._mouse_pause_position) 
    93384 File
    93385 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93386 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    93387 p = self.view.picked_object(x, y) 
    93388 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93389 File
    93390 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93391 packages/chimerax/graphics/view.py", line 838, in picked_object 
    93392 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    93393 beyond, 
    93394 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93395 File
    93396 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93397 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    93398 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    93399 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93400 File
    93401 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93402 packages/chimerax/core/models.py", line 143, in first_intercept 
    93403 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    93404 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93405 File
    93406 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93407 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    93408 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    93409 exclude=exclude) 
    93410 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93411 File
    93412 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93413 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    93414 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    93415 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93416 File
    93417 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93418 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    93419 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    93420 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93421 File
    93422 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93423 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    93424 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    93425 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93426 File
    93427 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93428 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    93429 p = super().first_intercept(mxyz1, mxyz2) 
    93430 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93431 File
    93432 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93433 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    93434 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    93435 exclude=exclude) 
    93436 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93437 File
    93438 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93439 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    93440 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    93441 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93442 File
    93443 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93444 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    93445 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    93446 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93447 File
    93448 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93449 packages/chimerax/graphics/drawing.py", line 1108, in
    93450 _first_intercept_excluding_children 
    93451 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    93452 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93453 File
    93454 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93455 packages/chimerax/geometry/place.py", line 201, in inverse 
    93456 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    93457 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93458 File
    93459 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93460 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    93461 rinv[:, :] = matrix_inverse(r) 
    93462 ^^^^^^^^^^^^^^^^^ 
    93463 File
    93464 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93465 packages/numpy/linalg/linalg.py", line 561, in inv 
    93466 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    93467 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93468 File
    93469 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93470 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    93471 raise LinAlgError("Singular matrix") 
    93472 numpy.linalg.LinAlgError: Singular matrix 
    93473  
    93474 numpy.linalg.LinAlgError: Singular matrix 
    93475  
    93476 File
    93477 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93478 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    93479 raise LinAlgError("Singular matrix") 
    93480  
    93481 See log for complete Python traceback. 
    93482  
    93483 Traceback (most recent call last): 
    93484 File
    93485 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93486 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    93487 self.session.ui.mouse_modes.mouse_pause_tracking() 
    93488 File
    93489 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93490 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    93491 mouse_pause_tracking 
    93492 self._mouse_pause() 
    93493 File
    93494 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93495 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    93496 m.pause(self._mouse_pause_position) 
    93497 File
    93498 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93499 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    93500 p = self.view.picked_object(x, y) 
    93501 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93502 File
    93503 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93504 packages/chimerax/graphics/view.py", line 838, in picked_object 
    93505 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    93506 beyond, 
    93507 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93508 File
    93509 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93510 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    93511 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    93512 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93513 File
    93514 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93515 packages/chimerax/core/models.py", line 143, in first_intercept 
    93516 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    93517 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93518 File
    93519 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93520 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    93521 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    93522 exclude=exclude) 
    93523 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93524 File
    93525 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93526 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    93527 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    93528 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93529 File
    93530 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93531 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    93532 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    93533 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93534 File
    93535 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93536 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    93537 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    93538 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93539 File
    93540 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93541 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    93542 p = super().first_intercept(mxyz1, mxyz2) 
    93543 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93544 File
    93545 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93546 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    93547 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    93548 exclude=exclude) 
    93549 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93550 File
    93551 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93552 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    93553 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    93554 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93555 File
    93556 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93557 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    93558 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    93559 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93560 File
    93561 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93562 packages/chimerax/graphics/drawing.py", line 1108, in
    93563 _first_intercept_excluding_children 
    93564 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    93565 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93566 File
    93567 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93568 packages/chimerax/geometry/place.py", line 201, in inverse 
    93569 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    93570 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93571 File
    93572 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93573 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    93574 rinv[:, :] = matrix_inverse(r) 
    93575 ^^^^^^^^^^^^^^^^^ 
    93576 File
    93577 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93578 packages/numpy/linalg/linalg.py", line 561, in inv 
    93579 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    93580 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93581 File
    93582 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93583 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    93584 raise LinAlgError("Singular matrix") 
    93585 numpy.linalg.LinAlgError: Singular matrix 
    93586  
    93587 numpy.linalg.LinAlgError: Singular matrix 
    93588  
    93589 File
    93590 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93591 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    93592 raise LinAlgError("Singular matrix") 
    93593  
    93594 See log for complete Python traceback. 
    93595  
    93596 Traceback (most recent call last): 
    93597 File
    93598 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93599 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    93600 self.session.ui.mouse_modes.mouse_pause_tracking() 
    93601 File
    93602 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93603 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    93604 mouse_pause_tracking 
    93605 self._mouse_pause() 
    93606 File
    93607 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93608 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    93609 m.pause(self._mouse_pause_position) 
    93610 File
    93611 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93612 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    93613 p = self.view.picked_object(x, y) 
    93614 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93615 File
    93616 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93617 packages/chimerax/graphics/view.py", line 838, in picked_object 
    93618 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    93619 beyond, 
    93620 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93621 File
    93622 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93623 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    93624 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    93625 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93626 File
    93627 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93628 packages/chimerax/core/models.py", line 143, in first_intercept 
    93629 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    93630 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93631 File
    93632 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93633 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    93634 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    93635 exclude=exclude) 
    93636 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93637 File
    93638 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93639 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    93640 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    93641 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93642 File
    93643 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93644 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    93645 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    93646 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93647 File
    93648 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93649 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    93650 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    93651 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93652 File
    93653 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93654 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    93655 p = super().first_intercept(mxyz1, mxyz2) 
    93656 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93657 File
    93658 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93659 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    93660 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    93661 exclude=exclude) 
    93662 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93663 File
    93664 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93665 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    93666 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    93667 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93668 File
    93669 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93670 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    93671 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    93672 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93673 File
    93674 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93675 packages/chimerax/graphics/drawing.py", line 1108, in
    93676 _first_intercept_excluding_children 
    93677 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    93678 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93679 File
    93680 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93681 packages/chimerax/geometry/place.py", line 201, in inverse 
    93682 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    93683 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93684 File
    93685 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93686 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    93687 rinv[:, :] = matrix_inverse(r) 
    93688 ^^^^^^^^^^^^^^^^^ 
    93689 File
    93690 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93691 packages/numpy/linalg/linalg.py", line 561, in inv 
    93692 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    93693 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93694 File
    93695 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93696 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    93697 raise LinAlgError("Singular matrix") 
    93698 numpy.linalg.LinAlgError: Singular matrix 
    93699  
    93700 numpy.linalg.LinAlgError: Singular matrix 
    93701  
    93702 File
    93703 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93704 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    93705 raise LinAlgError("Singular matrix") 
    93706  
    93707 See log for complete Python traceback. 
    93708  
    93709 Traceback (most recent call last): 
    93710 File
    93711 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93712 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    93713 self.session.ui.mouse_modes.mouse_pause_tracking() 
    93714 File
    93715 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93716 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    93717 mouse_pause_tracking 
    93718 self._mouse_pause() 
    93719 File
    93720 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93721 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    93722 m.pause(self._mouse_pause_position) 
    93723 File
    93724 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93725 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    93726 p = self.view.picked_object(x, y) 
    93727 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93728 File
    93729 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93730 packages/chimerax/graphics/view.py", line 838, in picked_object 
    93731 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    93732 beyond, 
    93733 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93734 File
    93735 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93736 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    93737 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    93738 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93739 File
    93740 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93741 packages/chimerax/core/models.py", line 143, in first_intercept 
    93742 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    93743 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93744 File
    93745 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93746 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    93747 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    93748 exclude=exclude) 
    93749 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93750 File
    93751 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93752 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    93753 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    93754 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93755 File
    93756 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93757 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    93758 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    93759 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93760 File
    93761 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93762 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    93763 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    93764 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93765 File
    93766 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93767 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    93768 p = super().first_intercept(mxyz1, mxyz2) 
    93769 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93770 File
    93771 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93772 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    93773 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    93774 exclude=exclude) 
    93775 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93776 File
    93777 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93778 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    93779 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    93780 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93781 File
    93782 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93783 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    93784 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    93785 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93786 File
    93787 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93788 packages/chimerax/graphics/drawing.py", line 1108, in
    93789 _first_intercept_excluding_children 
    93790 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    93791 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93792 File
    93793 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93794 packages/chimerax/geometry/place.py", line 201, in inverse 
    93795 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    93796 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93797 File
    93798 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93799 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    93800 rinv[:, :] = matrix_inverse(r) 
    93801 ^^^^^^^^^^^^^^^^^ 
    93802 File
    93803 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93804 packages/numpy/linalg/linalg.py", line 561, in inv 
    93805 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    93806 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93807 File
    93808 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93809 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    93810 raise LinAlgError("Singular matrix") 
    93811 numpy.linalg.LinAlgError: Singular matrix 
    93812  
    93813 numpy.linalg.LinAlgError: Singular matrix 
    93814  
    93815 File
    93816 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93817 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    93818 raise LinAlgError("Singular matrix") 
    93819  
    93820 See log for complete Python traceback. 
    93821  
    93822 Traceback (most recent call last): 
    93823 File
    93824 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93825 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    93826 self.session.ui.mouse_modes.mouse_pause_tracking() 
    93827 File
    93828 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93829 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    93830 mouse_pause_tracking 
    93831 self._mouse_pause() 
    93832 File
    93833 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93834 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    93835 m.pause(self._mouse_pause_position) 
    93836 File
    93837 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93838 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    93839 p = self.view.picked_object(x, y) 
    93840 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93841 File
    93842 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93843 packages/chimerax/graphics/view.py", line 838, in picked_object 
    93844 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    93845 beyond, 
    93846 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93847 File
    93848 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93849 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    93850 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    93851 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93852 File
    93853 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93854 packages/chimerax/core/models.py", line 143, in first_intercept 
    93855 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    93856 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93857 File
    93858 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93859 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    93860 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    93861 exclude=exclude) 
    93862 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93863 File
    93864 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93865 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    93866 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    93867 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93868 File
    93869 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93870 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    93871 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    93872 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93873 File
    93874 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93875 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    93876 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    93877 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93878 File
    93879 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93880 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    93881 p = super().first_intercept(mxyz1, mxyz2) 
    93882 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93883 File
    93884 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93885 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    93886 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    93887 exclude=exclude) 
    93888 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93889 File
    93890 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93891 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    93892 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    93893 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93894 File
    93895 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93896 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    93897 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    93898 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93899 File
    93900 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93901 packages/chimerax/graphics/drawing.py", line 1108, in
    93902 _first_intercept_excluding_children 
    93903 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    93904 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93905 File
    93906 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93907 packages/chimerax/geometry/place.py", line 201, in inverse 
    93908 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    93909 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93910 File
    93911 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93912 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    93913 rinv[:, :] = matrix_inverse(r) 
    93914 ^^^^^^^^^^^^^^^^^ 
    93915 File
    93916 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93917 packages/numpy/linalg/linalg.py", line 561, in inv 
    93918 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    93919 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93920 File
    93921 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93922 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    93923 raise LinAlgError("Singular matrix") 
    93924 numpy.linalg.LinAlgError: Singular matrix 
    93925  
    93926 numpy.linalg.LinAlgError: Singular matrix 
    93927  
    93928 File
    93929 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93930 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    93931 raise LinAlgError("Singular matrix") 
    93932  
    93933 See log for complete Python traceback. 
    93934  
    93935 Traceback (most recent call last): 
    93936 File
    93937 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93938 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    93939 self.session.ui.mouse_modes.mouse_pause_tracking() 
    93940 File
    93941 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93942 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    93943 mouse_pause_tracking 
    93944 self._mouse_pause() 
    93945 File
    93946 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93947 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    93948 m.pause(self._mouse_pause_position) 
    93949 File
    93950 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93951 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    93952 p = self.view.picked_object(x, y) 
    93953 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93954 File
    93955 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93956 packages/chimerax/graphics/view.py", line 838, in picked_object 
    93957 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    93958 beyond, 
    93959 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93960 File
    93961 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93962 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    93963 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    93964 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93965 File
    93966 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93967 packages/chimerax/core/models.py", line 143, in first_intercept 
    93968 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    93969 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93970 File
    93971 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93972 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    93973 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    93974 exclude=exclude) 
    93975 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93976 File
    93977 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93978 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    93979 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    93980 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93981 File
    93982 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93983 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    93984 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    93985 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93986 File
    93987 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93988 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    93989 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    93990 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93991 File
    93992 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93993 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    93994 p = super().first_intercept(mxyz1, mxyz2) 
    93995 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    93996 File
    93997 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    93998 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    93999 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    94000 exclude=exclude) 
    94001 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94002 File
    94003 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94004 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    94005 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    94006 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94007 File
    94008 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94009 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    94010 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    94011 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94012 File
    94013 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94014 packages/chimerax/graphics/drawing.py", line 1108, in
    94015 _first_intercept_excluding_children 
    94016 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    94017 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94018 File
    94019 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94020 packages/chimerax/geometry/place.py", line 201, in inverse 
    94021 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    94022 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94023 File
    94024 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94025 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    94026 rinv[:, :] = matrix_inverse(r) 
    94027 ^^^^^^^^^^^^^^^^^ 
    94028 File
    94029 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94030 packages/numpy/linalg/linalg.py", line 561, in inv 
    94031 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    94032 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94033 File
    94034 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94035 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    94036 raise LinAlgError("Singular matrix") 
    94037 numpy.linalg.LinAlgError: Singular matrix 
    94038  
    94039 numpy.linalg.LinAlgError: Singular matrix 
    94040  
    94041 File
    94042 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94043 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    94044 raise LinAlgError("Singular matrix") 
    94045  
    94046 See log for complete Python traceback. 
    94047  
    94048 Traceback (most recent call last): 
    94049 File
    94050 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94051 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    94052 self.session.ui.mouse_modes.mouse_pause_tracking() 
    94053 File
    94054 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94055 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    94056 mouse_pause_tracking 
    94057 self._mouse_pause() 
    94058 File
    94059 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94060 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    94061 m.pause(self._mouse_pause_position) 
    94062 File
    94063 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94064 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    94065 p = self.view.picked_object(x, y) 
    94066 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94067 File
    94068 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94069 packages/chimerax/graphics/view.py", line 838, in picked_object 
    94070 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    94071 beyond, 
    94072 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94073 File
    94074 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94075 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    94076 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    94077 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94078 File
    94079 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94080 packages/chimerax/core/models.py", line 143, in first_intercept 
    94081 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    94082 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94083 File
    94084 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94085 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    94086 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    94087 exclude=exclude) 
    94088 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94089 File
    94090 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94091 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    94092 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    94093 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94094 File
    94095 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94096 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    94097 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    94098 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94099 File
    94100 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94101 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    94102 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    94103 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94104 File
    94105 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94106 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    94107 p = super().first_intercept(mxyz1, mxyz2) 
    94108 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94109 File
    94110 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94111 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    94112 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    94113 exclude=exclude) 
    94114 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94115 File
    94116 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94117 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    94118 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    94119 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94120 File
    94121 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94122 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    94123 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    94124 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94125 File
    94126 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94127 packages/chimerax/graphics/drawing.py", line 1108, in
    94128 _first_intercept_excluding_children 
    94129 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    94130 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94131 File
    94132 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94133 packages/chimerax/geometry/place.py", line 201, in inverse 
    94134 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    94135 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94136 File
    94137 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94138 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    94139 rinv[:, :] = matrix_inverse(r) 
    94140 ^^^^^^^^^^^^^^^^^ 
    94141 File
    94142 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94143 packages/numpy/linalg/linalg.py", line 561, in inv 
    94144 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    94145 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94146 File
    94147 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94148 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    94149 raise LinAlgError("Singular matrix") 
    94150 numpy.linalg.LinAlgError: Singular matrix 
    94151  
    94152 numpy.linalg.LinAlgError: Singular matrix 
    94153  
    94154 File
    94155 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94156 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    94157 raise LinAlgError("Singular matrix") 
    94158  
    94159 See log for complete Python traceback. 
    94160  
    94161 Traceback (most recent call last): 
    94162 File
    94163 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94164 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    94165 self.session.ui.mouse_modes.mouse_pause_tracking() 
    94166 File
    94167 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94168 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    94169 mouse_pause_tracking 
    94170 self._mouse_pause() 
    94171 File
    94172 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94173 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    94174 m.pause(self._mouse_pause_position) 
    94175 File
    94176 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94177 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    94178 p = self.view.picked_object(x, y) 
    94179 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94180 File
    94181 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94182 packages/chimerax/graphics/view.py", line 838, in picked_object 
    94183 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    94184 beyond, 
    94185 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94186 File
    94187 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94188 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    94189 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    94190 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94191 File
    94192 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94193 packages/chimerax/core/models.py", line 143, in first_intercept 
    94194 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    94195 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94196 File
    94197 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94198 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    94199 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    94200 exclude=exclude) 
    94201 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94202 File
    94203 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94204 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    94205 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    94206 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94207 File
    94208 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94209 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    94210 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    94211 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94212 File
    94213 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94214 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    94215 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    94216 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94217 File
    94218 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94219 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    94220 p = super().first_intercept(mxyz1, mxyz2) 
    94221 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94222 File
    94223 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94224 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    94225 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    94226 exclude=exclude) 
    94227 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94228 File
    94229 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94230 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    94231 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    94232 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94233 File
    94234 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94235 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    94236 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    94237 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94238 File
    94239 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94240 packages/chimerax/graphics/drawing.py", line 1108, in
    94241 _first_intercept_excluding_children 
    94242 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    94243 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94244 File
    94245 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94246 packages/chimerax/geometry/place.py", line 201, in inverse 
    94247 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    94248 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94249 File
    94250 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94251 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    94252 rinv[:, :] = matrix_inverse(r) 
    94253 ^^^^^^^^^^^^^^^^^ 
    94254 File
    94255 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94256 packages/numpy/linalg/linalg.py", line 561, in inv 
    94257 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    94258 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94259 File
    94260 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94261 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    94262 raise LinAlgError("Singular matrix") 
    94263 numpy.linalg.LinAlgError: Singular matrix 
    94264  
    94265 numpy.linalg.LinAlgError: Singular matrix 
    94266  
    94267 File
    94268 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94269 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    94270 raise LinAlgError("Singular matrix") 
    94271  
    94272 See log for complete Python traceback. 
    94273  
    94274 Traceback (most recent call last): 
    94275 File
    94276 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94277 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    94278 self.session.ui.mouse_modes.mouse_pause_tracking() 
    94279 File
    94280 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94281 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    94282 mouse_pause_tracking 
    94283 self._mouse_pause() 
    94284 File
    94285 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94286 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    94287 m.pause(self._mouse_pause_position) 
    94288 File
    94289 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94290 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    94291 p = self.view.picked_object(x, y) 
    94292 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94293 File
    94294 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94295 packages/chimerax/graphics/view.py", line 838, in picked_object 
    94296 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    94297 beyond, 
    94298 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94299 File
    94300 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94301 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    94302 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    94303 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94304 File
    94305 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94306 packages/chimerax/core/models.py", line 143, in first_intercept 
    94307 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    94308 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94309 File
    94310 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94311 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    94312 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    94313 exclude=exclude) 
    94314 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94315 File
    94316 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94317 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    94318 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    94319 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94320 File
    94321 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94322 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    94323 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    94324 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94325 File
    94326 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94327 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    94328 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    94329 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94330 File
    94331 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94332 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    94333 p = super().first_intercept(mxyz1, mxyz2) 
    94334 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94335 File
    94336 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94337 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    94338 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    94339 exclude=exclude) 
    94340 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94341 File
    94342 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94343 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    94344 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    94345 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94346 File
    94347 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94348 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    94349 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    94350 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94351 File
    94352 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94353 packages/chimerax/graphics/drawing.py", line 1108, in
    94354 _first_intercept_excluding_children 
    94355 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    94356 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94357 File
    94358 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94359 packages/chimerax/geometry/place.py", line 201, in inverse 
    94360 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    94361 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94362 File
    94363 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94364 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    94365 rinv[:, :] = matrix_inverse(r) 
    94366 ^^^^^^^^^^^^^^^^^ 
    94367 File
    94368 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94369 packages/numpy/linalg/linalg.py", line 561, in inv 
    94370 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    94371 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94372 File
    94373 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94374 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    94375 raise LinAlgError("Singular matrix") 
    94376 numpy.linalg.LinAlgError: Singular matrix 
    94377  
    94378 numpy.linalg.LinAlgError: Singular matrix 
    94379  
    94380 File
    94381 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94382 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    94383 raise LinAlgError("Singular matrix") 
    94384  
    94385 See log for complete Python traceback. 
    94386  
    94387 Traceback (most recent call last): 
    94388 File
    94389 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94390 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    94391 self.session.ui.mouse_modes.mouse_pause_tracking() 
    94392 File
    94393 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94394 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    94395 mouse_pause_tracking 
    94396 self._mouse_pause() 
    94397 File
    94398 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94399 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    94400 m.pause(self._mouse_pause_position) 
    94401 File
    94402 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94403 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    94404 p = self.view.picked_object(x, y) 
    94405 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94406 File
    94407 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94408 packages/chimerax/graphics/view.py", line 838, in picked_object 
    94409 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    94410 beyond, 
    94411 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94412 File
    94413 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94414 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    94415 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    94416 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94417 File
    94418 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94419 packages/chimerax/core/models.py", line 143, in first_intercept 
    94420 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    94421 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94422 File
    94423 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94424 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    94425 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    94426 exclude=exclude) 
    94427 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94428 File
    94429 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94430 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    94431 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    94432 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94433 File
    94434 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94435 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    94436 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    94437 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94438 File
    94439 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94440 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    94441 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    94442 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94443 File
    94444 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94445 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    94446 p = super().first_intercept(mxyz1, mxyz2) 
    94447 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94448 File
    94449 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94450 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    94451 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    94452 exclude=exclude) 
    94453 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94454 File
    94455 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94456 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    94457 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    94458 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94459 File
    94460 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94461 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    94462 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    94463 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94464 File
    94465 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94466 packages/chimerax/graphics/drawing.py", line 1108, in
    94467 _first_intercept_excluding_children 
    94468 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    94469 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94470 File
    94471 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94472 packages/chimerax/geometry/place.py", line 201, in inverse 
    94473 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    94474 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94475 File
    94476 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94477 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    94478 rinv[:, :] = matrix_inverse(r) 
    94479 ^^^^^^^^^^^^^^^^^ 
    94480 File
    94481 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94482 packages/numpy/linalg/linalg.py", line 561, in inv 
    94483 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    94484 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94485 File
    94486 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94487 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    94488 raise LinAlgError("Singular matrix") 
    94489 numpy.linalg.LinAlgError: Singular matrix 
    94490  
    94491 numpy.linalg.LinAlgError: Singular matrix 
    94492  
    94493 File
    94494 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94495 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    94496 raise LinAlgError("Singular matrix") 
    94497  
    94498 See log for complete Python traceback. 
    94499  
    94500 Traceback (most recent call last): 
    94501 File
    94502 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94503 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    94504 self.session.ui.mouse_modes.mouse_pause_tracking() 
    94505 File
    94506 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94507 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    94508 mouse_pause_tracking 
    94509 self._mouse_pause() 
    94510 File
    94511 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94512 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    94513 m.pause(self._mouse_pause_position) 
    94514 File
    94515 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94516 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    94517 p = self.view.picked_object(x, y) 
    94518 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94519 File
    94520 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94521 packages/chimerax/graphics/view.py", line 838, in picked_object 
    94522 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    94523 beyond, 
    94524 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94525 File
    94526 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94527 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    94528 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    94529 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94530 File
    94531 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94532 packages/chimerax/core/models.py", line 143, in first_intercept 
    94533 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    94534 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94535 File
    94536 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94537 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    94538 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    94539 exclude=exclude) 
    94540 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94541 File
    94542 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94543 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    94544 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    94545 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94546 File
    94547 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94548 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    94549 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    94550 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94551 File
    94552 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94553 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    94554 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    94555 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94556 File
    94557 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94558 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    94559 p = super().first_intercept(mxyz1, mxyz2) 
    94560 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94561 File
    94562 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94563 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    94564 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    94565 exclude=exclude) 
    94566 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94567 File
    94568 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94569 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    94570 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    94571 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94572 File
    94573 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94574 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    94575 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    94576 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94577 File
    94578 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94579 packages/chimerax/graphics/drawing.py", line 1108, in
    94580 _first_intercept_excluding_children 
    94581 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    94582 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94583 File
    94584 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94585 packages/chimerax/geometry/place.py", line 201, in inverse 
    94586 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    94587 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94588 File
    94589 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94590 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    94591 rinv[:, :] = matrix_inverse(r) 
    94592 ^^^^^^^^^^^^^^^^^ 
    94593 File
    94594 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94595 packages/numpy/linalg/linalg.py", line 561, in inv 
    94596 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    94597 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94598 File
    94599 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94600 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    94601 raise LinAlgError("Singular matrix") 
    94602 numpy.linalg.LinAlgError: Singular matrix 
    94603  
    94604 numpy.linalg.LinAlgError: Singular matrix 
    94605  
    94606 File
    94607 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94608 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    94609 raise LinAlgError("Singular matrix") 
    94610  
    94611 See log for complete Python traceback. 
    94612  
    94613 Traceback (most recent call last): 
    94614 File
    94615 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94616 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    94617 self.session.ui.mouse_modes.mouse_pause_tracking() 
    94618 File
    94619 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94620 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    94621 mouse_pause_tracking 
    94622 self._mouse_pause() 
    94623 File
    94624 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94625 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    94626 m.pause(self._mouse_pause_position) 
    94627 File
    94628 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94629 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    94630 p = self.view.picked_object(x, y) 
    94631 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94632 File
    94633 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94634 packages/chimerax/graphics/view.py", line 838, in picked_object 
    94635 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    94636 beyond, 
    94637 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94638 File
    94639 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94640 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    94641 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    94642 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94643 File
    94644 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94645 packages/chimerax/core/models.py", line 143, in first_intercept 
    94646 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    94647 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94648 File
    94649 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94650 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    94651 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    94652 exclude=exclude) 
    94653 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94654 File
    94655 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94656 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    94657 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    94658 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94659 File
    94660 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94661 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    94662 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    94663 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94664 File
    94665 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94666 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    94667 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    94668 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94669 File
    94670 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94671 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    94672 p = super().first_intercept(mxyz1, mxyz2) 
    94673 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94674 File
    94675 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94676 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    94677 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    94678 exclude=exclude) 
    94679 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94680 File
    94681 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94682 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    94683 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    94684 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94685 File
    94686 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94687 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    94688 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    94689 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94690 File
    94691 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94692 packages/chimerax/graphics/drawing.py", line 1108, in
    94693 _first_intercept_excluding_children 
    94694 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    94695 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94696 File
    94697 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94698 packages/chimerax/geometry/place.py", line 201, in inverse 
    94699 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    94700 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94701 File
    94702 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94703 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    94704 rinv[:, :] = matrix_inverse(r) 
    94705 ^^^^^^^^^^^^^^^^^ 
    94706 File
    94707 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94708 packages/numpy/linalg/linalg.py", line 561, in inv 
    94709 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    94710 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94711 File
    94712 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94713 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    94714 raise LinAlgError("Singular matrix") 
    94715 numpy.linalg.LinAlgError: Singular matrix 
    94716  
    94717 numpy.linalg.LinAlgError: Singular matrix 
    94718  
    94719 File
    94720 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94721 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    94722 raise LinAlgError("Singular matrix") 
    94723  
    94724 See log for complete Python traceback. 
    94725  
    94726 Traceback (most recent call last): 
    94727 File
    94728 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94729 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    94730 self.session.ui.mouse_modes.mouse_pause_tracking() 
    94731 File
    94732 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94733 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    94734 mouse_pause_tracking 
    94735 self._mouse_pause() 
    94736 File
    94737 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94738 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    94739 m.pause(self._mouse_pause_position) 
    94740 File
    94741 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94742 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    94743 p = self.view.picked_object(x, y) 
    94744 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94745 File
    94746 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94747 packages/chimerax/graphics/view.py", line 838, in picked_object 
    94748 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    94749 beyond, 
    94750 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94751 File
    94752 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94753 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    94754 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    94755 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94756 File
    94757 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94758 packages/chimerax/core/models.py", line 143, in first_intercept 
    94759 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    94760 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94761 File
    94762 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94763 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    94764 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    94765 exclude=exclude) 
    94766 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94767 File
    94768 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94769 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    94770 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    94771 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94772 File
    94773 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94774 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    94775 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    94776 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94777 File
    94778 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94779 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    94780 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    94781 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94782 File
    94783 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94784 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    94785 p = super().first_intercept(mxyz1, mxyz2) 
    94786 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94787 File
    94788 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94789 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    94790 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    94791 exclude=exclude) 
    94792 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94793 File
    94794 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94795 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    94796 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    94797 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94798 File
    94799 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94800 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    94801 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    94802 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94803 File
    94804 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94805 packages/chimerax/graphics/drawing.py", line 1108, in
    94806 _first_intercept_excluding_children 
    94807 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    94808 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94809 File
    94810 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94811 packages/chimerax/geometry/place.py", line 201, in inverse 
    94812 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    94813 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94814 File
    94815 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94816 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    94817 rinv[:, :] = matrix_inverse(r) 
    94818 ^^^^^^^^^^^^^^^^^ 
    94819 File
    94820 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94821 packages/numpy/linalg/linalg.py", line 561, in inv 
    94822 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    94823 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94824 File
    94825 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94826 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    94827 raise LinAlgError("Singular matrix") 
    94828 numpy.linalg.LinAlgError: Singular matrix 
    94829  
    94830 numpy.linalg.LinAlgError: Singular matrix 
    94831  
    94832 File
    94833 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94834 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    94835 raise LinAlgError("Singular matrix") 
    94836  
    94837 See log for complete Python traceback. 
    94838  
    94839 Traceback (most recent call last): 
    94840 File
    94841 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94842 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    94843 self.session.ui.mouse_modes.mouse_pause_tracking() 
    94844 File
    94845 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94846 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    94847 mouse_pause_tracking 
    94848 self._mouse_pause() 
    94849 File
    94850 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94851 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    94852 m.pause(self._mouse_pause_position) 
    94853 File
    94854 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94855 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    94856 p = self.view.picked_object(x, y) 
    94857 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94858 File
    94859 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94860 packages/chimerax/graphics/view.py", line 838, in picked_object 
    94861 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    94862 beyond, 
    94863 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94864 File
    94865 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94866 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    94867 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    94868 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94869 File
    94870 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94871 packages/chimerax/core/models.py", line 143, in first_intercept 
    94872 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    94873 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94874 File
    94875 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94876 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    94877 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    94878 exclude=exclude) 
    94879 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94880 File
    94881 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94882 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    94883 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    94884 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94885 File
    94886 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94887 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    94888 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    94889 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94890 File
    94891 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94892 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    94893 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    94894 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94895 File
    94896 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94897 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    94898 p = super().first_intercept(mxyz1, mxyz2) 
    94899 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94900 File
    94901 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94902 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    94903 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    94904 exclude=exclude) 
    94905 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94906 File
    94907 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94908 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    94909 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    94910 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94911 File
    94912 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94913 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    94914 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    94915 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94916 File
    94917 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94918 packages/chimerax/graphics/drawing.py", line 1108, in
    94919 _first_intercept_excluding_children 
    94920 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    94921 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94922 File
    94923 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94924 packages/chimerax/geometry/place.py", line 201, in inverse 
    94925 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    94926 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94927 File
    94928 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94929 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    94930 rinv[:, :] = matrix_inverse(r) 
    94931 ^^^^^^^^^^^^^^^^^ 
    94932 File
    94933 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94934 packages/numpy/linalg/linalg.py", line 561, in inv 
    94935 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    94936 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94937 File
    94938 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94939 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    94940 raise LinAlgError("Singular matrix") 
    94941 numpy.linalg.LinAlgError: Singular matrix 
    94942  
    94943 numpy.linalg.LinAlgError: Singular matrix 
    94944  
    94945 File
    94946 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94947 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    94948 raise LinAlgError("Singular matrix") 
    94949  
    94950 See log for complete Python traceback. 
    94951  
    94952 Traceback (most recent call last): 
    94953 File
    94954 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94955 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    94956 self.session.ui.mouse_modes.mouse_pause_tracking() 
    94957 File
    94958 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94959 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    94960 mouse_pause_tracking 
    94961 self._mouse_pause() 
    94962 File
    94963 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94964 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    94965 m.pause(self._mouse_pause_position) 
    94966 File
    94967 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94968 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    94969 p = self.view.picked_object(x, y) 
    94970 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94971 File
    94972 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94973 packages/chimerax/graphics/view.py", line 838, in picked_object 
    94974 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    94975 beyond, 
    94976 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94977 File
    94978 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94979 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    94980 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    94981 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94982 File
    94983 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94984 packages/chimerax/core/models.py", line 143, in first_intercept 
    94985 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    94986 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94987 File
    94988 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94989 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    94990 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    94991 exclude=exclude) 
    94992 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94993 File
    94994 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    94995 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    94996 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    94997 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    94998 File
    94999 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95000 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    95001 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    95002 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95003 File
    95004 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95005 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    95006 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    95007 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95008 File
    95009 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95010 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    95011 p = super().first_intercept(mxyz1, mxyz2) 
    95012 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95013 File
    95014 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95015 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    95016 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    95017 exclude=exclude) 
    95018 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95019 File
    95020 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95021 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    95022 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    95023 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95024 File
    95025 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95026 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    95027 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    95028 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95029 File
    95030 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95031 packages/chimerax/graphics/drawing.py", line 1108, in
    95032 _first_intercept_excluding_children 
    95033 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    95034 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95035 File
    95036 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95037 packages/chimerax/geometry/place.py", line 201, in inverse 
    95038 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    95039 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95040 File
    95041 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95042 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    95043 rinv[:, :] = matrix_inverse(r) 
    95044 ^^^^^^^^^^^^^^^^^ 
    95045 File
    95046 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95047 packages/numpy/linalg/linalg.py", line 561, in inv 
    95048 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    95049 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95050 File
    95051 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95052 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    95053 raise LinAlgError("Singular matrix") 
    95054 numpy.linalg.LinAlgError: Singular matrix 
    95055  
    95056 numpy.linalg.LinAlgError: Singular matrix 
    95057  
    95058 File
    95059 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95060 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    95061 raise LinAlgError("Singular matrix") 
    95062  
    95063 See log for complete Python traceback. 
    95064  
    95065 
    95066 > select add #5/E:2207@O
    95067 
    95068 1 atom, 1 residue, 1 model selected 
    95069 
    95070 > select add #5/B:1105@O
    95071 
    95072 2 atoms, 2 residues, 1 model selected 
    95073 
    95074 > hide sel atoms
    95075 
    95076 > save /Users/angela/Desktop/Structure/Ab_5cdq_Asp.png width 2000 height 1151
    95077 > supersample 3 transparentBackground true
    95078 
    95079 Traceback (most recent call last): 
    95080 File
    95081 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95082 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    95083 self.session.ui.mouse_modes.mouse_pause_tracking() 
    95084 File
    95085 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95086 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    95087 mouse_pause_tracking 
    95088 self._mouse_pause() 
    95089 File
    95090 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95091 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    95092 m.pause(self._mouse_pause_position) 
    95093 File
    95094 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95095 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    95096 p = self.view.picked_object(x, y) 
    95097 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95098 File
    95099 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95100 packages/chimerax/graphics/view.py", line 838, in picked_object 
    95101 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    95102 beyond, 
    95103 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95104 File
    95105 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95106 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    95107 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    95108 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95109 File
    95110 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95111 packages/chimerax/core/models.py", line 143, in first_intercept 
    95112 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    95113 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95114 File
    95115 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95116 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    95117 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    95118 exclude=exclude) 
    95119 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95120 File
    95121 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95122 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    95123 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    95124 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95125 File
    95126 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95127 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    95128 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    95129 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95130 File
    95131 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95132 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    95133 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    95134 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95135 File
    95136 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95137 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    95138 p = super().first_intercept(mxyz1, mxyz2) 
    95139 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95140 File
    95141 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95142 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    95143 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    95144 exclude=exclude) 
    95145 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95146 File
    95147 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95148 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    95149 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    95150 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95151 File
    95152 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95153 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    95154 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    95155 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95156 File
    95157 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95158 packages/chimerax/graphics/drawing.py", line 1108, in
    95159 _first_intercept_excluding_children 
    95160 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    95161 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95162 File
    95163 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95164 packages/chimerax/geometry/place.py", line 201, in inverse 
    95165 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    95166 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95167 File
    95168 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95169 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    95170 rinv[:, :] = matrix_inverse(r) 
    95171 ^^^^^^^^^^^^^^^^^ 
    95172 File
    95173 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95174 packages/numpy/linalg/linalg.py", line 561, in inv 
    95175 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    95176 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95177 File
    95178 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95179 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    95180 raise LinAlgError("Singular matrix") 
    95181 numpy.linalg.LinAlgError: Singular matrix 
    95182  
    95183 numpy.linalg.LinAlgError: Singular matrix 
    95184  
    95185 File
    95186 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95187 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    95188 raise LinAlgError("Singular matrix") 
    95189  
    95190 See log for complete Python traceback. 
    95191  
    95192 Traceback (most recent call last): 
    95193 File
    95194 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95195 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    95196 self.session.ui.mouse_modes.mouse_pause_tracking() 
    95197 File
    95198 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95199 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    95200 mouse_pause_tracking 
    95201 self._mouse_pause() 
    95202 File
    95203 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95204 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    95205 m.pause(self._mouse_pause_position) 
    95206 File
    95207 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95208 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    95209 p = self.view.picked_object(x, y) 
    95210 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95211 File
    95212 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95213 packages/chimerax/graphics/view.py", line 838, in picked_object 
    95214 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    95215 beyond, 
    95216 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95217 File
    95218 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95219 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    95220 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    95221 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95222 File
    95223 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95224 packages/chimerax/core/models.py", line 143, in first_intercept 
    95225 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    95226 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95227 File
    95228 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95229 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    95230 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    95231 exclude=exclude) 
    95232 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95233 File
    95234 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95235 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    95236 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    95237 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95238 File
    95239 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95240 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    95241 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    95242 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95243 File
    95244 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95245 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    95246 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    95247 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95248 File
    95249 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95250 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    95251 p = super().first_intercept(mxyz1, mxyz2) 
    95252 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95253 File
    95254 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95255 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    95256 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    95257 exclude=exclude) 
    95258 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95259 File
    95260 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95261 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    95262 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    95263 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95264 File
    95265 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95266 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    95267 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    95268 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95269 File
    95270 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95271 packages/chimerax/graphics/drawing.py", line 1108, in
    95272 _first_intercept_excluding_children 
    95273 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    95274 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95275 File
    95276 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95277 packages/chimerax/geometry/place.py", line 201, in inverse 
    95278 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    95279 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95280 File
    95281 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95282 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    95283 rinv[:, :] = matrix_inverse(r) 
    95284 ^^^^^^^^^^^^^^^^^ 
    95285 File
    95286 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95287 packages/numpy/linalg/linalg.py", line 561, in inv 
    95288 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    95289 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95290 File
    95291 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95292 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    95293 raise LinAlgError("Singular matrix") 
    95294 numpy.linalg.LinAlgError: Singular matrix 
    95295  
    95296 numpy.linalg.LinAlgError: Singular matrix 
    95297  
    95298 File
    95299 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95300 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    95301 raise LinAlgError("Singular matrix") 
    95302  
    95303 See log for complete Python traceback. 
    95304  
    95305 Traceback (most recent call last): 
    95306 File
    95307 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95308 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    95309 self.session.ui.mouse_modes.mouse_pause_tracking() 
    95310 File
    95311 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95312 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    95313 mouse_pause_tracking 
    95314 self._mouse_pause() 
    95315 File
    95316 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95317 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    95318 m.pause(self._mouse_pause_position) 
    95319 File
    95320 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95321 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    95322 p = self.view.picked_object(x, y) 
    95323 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95324 File
    95325 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95326 packages/chimerax/graphics/view.py", line 838, in picked_object 
    95327 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    95328 beyond, 
    95329 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95330 File
    95331 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95332 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    95333 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    95334 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95335 File
    95336 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95337 packages/chimerax/core/models.py", line 143, in first_intercept 
    95338 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    95339 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95340 File
    95341 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95342 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    95343 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    95344 exclude=exclude) 
    95345 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95346 File
    95347 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95348 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    95349 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    95350 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95351 File
    95352 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95353 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    95354 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    95355 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95356 File
    95357 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95358 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    95359 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    95360 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95361 File
    95362 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95363 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    95364 p = super().first_intercept(mxyz1, mxyz2) 
    95365 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95366 File
    95367 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95368 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    95369 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    95370 exclude=exclude) 
    95371 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95372 File
    95373 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95374 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    95375 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    95376 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95377 File
    95378 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95379 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    95380 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    95381 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95382 File
    95383 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95384 packages/chimerax/graphics/drawing.py", line 1108, in
    95385 _first_intercept_excluding_children 
    95386 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    95387 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95388 File
    95389 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95390 packages/chimerax/geometry/place.py", line 201, in inverse 
    95391 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    95392 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95393 File
    95394 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95395 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    95396 rinv[:, :] = matrix_inverse(r) 
    95397 ^^^^^^^^^^^^^^^^^ 
    95398 File
    95399 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95400 packages/numpy/linalg/linalg.py", line 561, in inv 
    95401 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    95402 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95403 File
    95404 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95405 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    95406 raise LinAlgError("Singular matrix") 
    95407 numpy.linalg.LinAlgError: Singular matrix 
    95408  
    95409 numpy.linalg.LinAlgError: Singular matrix 
    95410  
    95411 File
    95412 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95413 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    95414 raise LinAlgError("Singular matrix") 
    95415  
    95416 See log for complete Python traceback. 
    95417  
    95418 Traceback (most recent call last): 
    95419 File
    95420 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95421 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    95422 self.session.ui.mouse_modes.mouse_pause_tracking() 
    95423 File
    95424 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95425 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    95426 mouse_pause_tracking 
    95427 self._mouse_pause() 
    95428 File
    95429 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95430 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    95431 m.pause(self._mouse_pause_position) 
    95432 File
    95433 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95434 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    95435 p = self.view.picked_object(x, y) 
    95436 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95437 File
    95438 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95439 packages/chimerax/graphics/view.py", line 838, in picked_object 
    95440 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    95441 beyond, 
    95442 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95443 File
    95444 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95445 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    95446 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    95447 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95448 File
    95449 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95450 packages/chimerax/core/models.py", line 143, in first_intercept 
    95451 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    95452 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95453 File
    95454 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95455 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    95456 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    95457 exclude=exclude) 
    95458 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95459 File
    95460 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95461 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    95462 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    95463 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95464 File
    95465 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95466 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    95467 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    95468 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95469 File
    95470 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95471 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    95472 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    95473 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95474 File
    95475 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95476 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    95477 p = super().first_intercept(mxyz1, mxyz2) 
    95478 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95479 File
    95480 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95481 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    95482 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    95483 exclude=exclude) 
    95484 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95485 File
    95486 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95487 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    95488 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    95489 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95490 File
    95491 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95492 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    95493 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    95494 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95495 File
    95496 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95497 packages/chimerax/graphics/drawing.py", line 1108, in
    95498 _first_intercept_excluding_children 
    95499 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    95500 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95501 File
    95502 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95503 packages/chimerax/geometry/place.py", line 201, in inverse 
    95504 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    95505 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95506 File
    95507 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95508 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    95509 rinv[:, :] = matrix_inverse(r) 
    95510 ^^^^^^^^^^^^^^^^^ 
    95511 File
    95512 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95513 packages/numpy/linalg/linalg.py", line 561, in inv 
    95514 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    95515 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95516 File
    95517 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95518 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    95519 raise LinAlgError("Singular matrix") 
    95520 numpy.linalg.LinAlgError: Singular matrix 
    95521  
    95522 numpy.linalg.LinAlgError: Singular matrix 
    95523  
    95524 File
    95525 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95526 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    95527 raise LinAlgError("Singular matrix") 
    95528  
    95529 See log for complete Python traceback. 
    95530  
    95531 Traceback (most recent call last): 
    95532 File
    95533 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95534 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    95535 self.session.ui.mouse_modes.mouse_pause_tracking() 
    95536 File
    95537 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95538 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    95539 mouse_pause_tracking 
    95540 self._mouse_pause() 
    95541 File
    95542 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95543 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    95544 m.pause(self._mouse_pause_position) 
    95545 File
    95546 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95547 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    95548 p = self.view.picked_object(x, y) 
    95549 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95550 File
    95551 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95552 packages/chimerax/graphics/view.py", line 838, in picked_object 
    95553 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    95554 beyond, 
    95555 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95556 File
    95557 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95558 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    95559 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    95560 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95561 File
    95562 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95563 packages/chimerax/core/models.py", line 143, in first_intercept 
    95564 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    95565 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95566 File
    95567 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95568 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    95569 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    95570 exclude=exclude) 
    95571 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95572 File
    95573 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95574 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    95575 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    95576 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95577 File
    95578 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95579 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    95580 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    95581 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95582 File
    95583 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95584 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    95585 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    95586 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95587 File
    95588 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95589 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    95590 p = super().first_intercept(mxyz1, mxyz2) 
    95591 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95592 File
    95593 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95594 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    95595 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    95596 exclude=exclude) 
    95597 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95598 File
    95599 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95600 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    95601 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    95602 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95603 File
    95604 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95605 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    95606 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    95607 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95608 File
    95609 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95610 packages/chimerax/graphics/drawing.py", line 1108, in
    95611 _first_intercept_excluding_children 
    95612 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    95613 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95614 File
    95615 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95616 packages/chimerax/geometry/place.py", line 201, in inverse 
    95617 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    95618 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95619 File
    95620 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95621 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    95622 rinv[:, :] = matrix_inverse(r) 
    95623 ^^^^^^^^^^^^^^^^^ 
    95624 File
    95625 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95626 packages/numpy/linalg/linalg.py", line 561, in inv 
    95627 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    95628 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95629 File
    95630 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95631 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    95632 raise LinAlgError("Singular matrix") 
    95633 numpy.linalg.LinAlgError: Singular matrix 
    95634  
    95635 numpy.linalg.LinAlgError: Singular matrix 
    95636  
    95637 File
    95638 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95639 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    95640 raise LinAlgError("Singular matrix") 
    95641  
    95642 See log for complete Python traceback. 
    95643  
    95644 Traceback (most recent call last): 
    95645 File
    95646 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95647 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    95648 self.session.ui.mouse_modes.mouse_pause_tracking() 
    95649 File
    95650 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95651 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    95652 mouse_pause_tracking 
    95653 self._mouse_pause() 
    95654 File
    95655 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95656 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    95657 m.pause(self._mouse_pause_position) 
    95658 File
    95659 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95660 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    95661 p = self.view.picked_object(x, y) 
    95662 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95663 File
    95664 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95665 packages/chimerax/graphics/view.py", line 838, in picked_object 
    95666 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    95667 beyond, 
    95668 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95669 File
    95670 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95671 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    95672 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    95673 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95674 File
    95675 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95676 packages/chimerax/core/models.py", line 143, in first_intercept 
    95677 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    95678 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95679 File
    95680 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95681 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    95682 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    95683 exclude=exclude) 
    95684 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95685 File
    95686 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95687 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    95688 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    95689 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95690 File
    95691 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95692 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    95693 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    95694 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95695 File
    95696 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95697 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    95698 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    95699 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95700 File
    95701 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95702 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    95703 p = super().first_intercept(mxyz1, mxyz2) 
    95704 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95705 File
    95706 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95707 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    95708 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    95709 exclude=exclude) 
    95710 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95711 File
    95712 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95713 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    95714 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    95715 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95716 File
    95717 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95718 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    95719 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    95720 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95721 File
    95722 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95723 packages/chimerax/graphics/drawing.py", line 1108, in
    95724 _first_intercept_excluding_children 
    95725 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    95726 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95727 File
    95728 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95729 packages/chimerax/geometry/place.py", line 201, in inverse 
    95730 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    95731 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95732 File
    95733 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95734 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    95735 rinv[:, :] = matrix_inverse(r) 
    95736 ^^^^^^^^^^^^^^^^^ 
    95737 File
    95738 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95739 packages/numpy/linalg/linalg.py", line 561, in inv 
    95740 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    95741 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95742 File
    95743 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95744 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    95745 raise LinAlgError("Singular matrix") 
    95746 numpy.linalg.LinAlgError: Singular matrix 
    95747  
    95748 numpy.linalg.LinAlgError: Singular matrix 
    95749  
    95750 File
    95751 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95752 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    95753 raise LinAlgError("Singular matrix") 
    95754  
    95755 See log for complete Python traceback. 
    95756  
    95757 Traceback (most recent call last): 
    95758 File
    95759 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95760 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    95761 self.session.ui.mouse_modes.mouse_pause_tracking() 
    95762 File
    95763 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95764 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    95765 mouse_pause_tracking 
    95766 self._mouse_pause() 
    95767 File
    95768 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95769 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    95770 m.pause(self._mouse_pause_position) 
    95771 File
    95772 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95773 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    95774 p = self.view.picked_object(x, y) 
    95775 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95776 File
    95777 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95778 packages/chimerax/graphics/view.py", line 838, in picked_object 
    95779 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    95780 beyond, 
    95781 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95782 File
    95783 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95784 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    95785 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    95786 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95787 File
    95788 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95789 packages/chimerax/core/models.py", line 143, in first_intercept 
    95790 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    95791 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95792 File
    95793 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95794 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    95795 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    95796 exclude=exclude) 
    95797 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95798 File
    95799 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95800 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    95801 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    95802 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95803 File
    95804 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95805 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    95806 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    95807 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95808 File
    95809 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95810 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    95811 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    95812 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95813 File
    95814 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95815 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    95816 p = super().first_intercept(mxyz1, mxyz2) 
    95817 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95818 File
    95819 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95820 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    95821 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    95822 exclude=exclude) 
    95823 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95824 File
    95825 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95826 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    95827 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    95828 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95829 File
    95830 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95831 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    95832 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    95833 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95834 File
    95835 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95836 packages/chimerax/graphics/drawing.py", line 1108, in
    95837 _first_intercept_excluding_children 
    95838 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    95839 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95840 File
    95841 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95842 packages/chimerax/geometry/place.py", line 201, in inverse 
    95843 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    95844 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95845 File
    95846 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95847 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    95848 rinv[:, :] = matrix_inverse(r) 
    95849 ^^^^^^^^^^^^^^^^^ 
    95850 File
    95851 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95852 packages/numpy/linalg/linalg.py", line 561, in inv 
    95853 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    95854 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95855 File
    95856 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95857 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    95858 raise LinAlgError("Singular matrix") 
    95859 numpy.linalg.LinAlgError: Singular matrix 
    95860  
    95861 numpy.linalg.LinAlgError: Singular matrix 
    95862  
    95863 File
    95864 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95865 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    95866 raise LinAlgError("Singular matrix") 
    95867  
    95868 See log for complete Python traceback. 
    95869  
    95870 Traceback (most recent call last): 
    95871 File
    95872 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95873 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    95874 self.session.ui.mouse_modes.mouse_pause_tracking() 
    95875 File
    95876 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95877 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    95878 mouse_pause_tracking 
    95879 self._mouse_pause() 
    95880 File
    95881 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95882 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    95883 m.pause(self._mouse_pause_position) 
    95884 File
    95885 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95886 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    95887 p = self.view.picked_object(x, y) 
    95888 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95889 File
    95890 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95891 packages/chimerax/graphics/view.py", line 838, in picked_object 
    95892 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    95893 beyond, 
    95894 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95895 File
    95896 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95897 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    95898 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    95899 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95900 File
    95901 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95902 packages/chimerax/core/models.py", line 143, in first_intercept 
    95903 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    95904 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95905 File
    95906 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95907 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    95908 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    95909 exclude=exclude) 
    95910 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95911 File
    95912 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95913 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    95914 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    95915 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95916 File
    95917 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95918 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    95919 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    95920 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95921 File
    95922 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95923 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    95924 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    95925 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95926 File
    95927 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95928 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    95929 p = super().first_intercept(mxyz1, mxyz2) 
    95930 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95931 File
    95932 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95933 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    95934 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    95935 exclude=exclude) 
    95936 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95937 File
    95938 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95939 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    95940 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    95941 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95942 File
    95943 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95944 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    95945 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    95946 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95947 File
    95948 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95949 packages/chimerax/graphics/drawing.py", line 1108, in
    95950 _first_intercept_excluding_children 
    95951 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    95952 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95953 File
    95954 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95955 packages/chimerax/geometry/place.py", line 201, in inverse 
    95956 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    95957 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95958 File
    95959 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95960 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    95961 rinv[:, :] = matrix_inverse(r) 
    95962 ^^^^^^^^^^^^^^^^^ 
    95963 File
    95964 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95965 packages/numpy/linalg/linalg.py", line 561, in inv 
    95966 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    95967 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    95968 File
    95969 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95970 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    95971 raise LinAlgError("Singular matrix") 
    95972 numpy.linalg.LinAlgError: Singular matrix 
    95973  
    95974 numpy.linalg.LinAlgError: Singular matrix 
    95975  
    95976 File
    95977 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95978 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    95979 raise LinAlgError("Singular matrix") 
    95980  
    95981 See log for complete Python traceback. 
    95982  
    95983 Traceback (most recent call last): 
    95984 File
    95985 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95986 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    95987 self.session.ui.mouse_modes.mouse_pause_tracking() 
    95988 File
    95989 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95990 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    95991 mouse_pause_tracking 
    95992 self._mouse_pause() 
    95993 File
    95994 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95995 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    95996 m.pause(self._mouse_pause_position) 
    95997 File
    95998 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    95999 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    96000 p = self.view.picked_object(x, y) 
    96001 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96002 File
    96003 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96004 packages/chimerax/graphics/view.py", line 838, in picked_object 
    96005 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    96006 beyond, 
    96007 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96008 File
    96009 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96010 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    96011 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    96012 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96013 File
    96014 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96015 packages/chimerax/core/models.py", line 143, in first_intercept 
    96016 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    96017 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96018 File
    96019 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96020 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    96021 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    96022 exclude=exclude) 
    96023 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96024 File
    96025 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96026 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    96027 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    96028 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96029 File
    96030 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96031 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    96032 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    96033 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96034 File
    96035 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96036 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    96037 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    96038 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96039 File
    96040 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96041 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    96042 p = super().first_intercept(mxyz1, mxyz2) 
    96043 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96044 File
    96045 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96046 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    96047 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    96048 exclude=exclude) 
    96049 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96050 File
    96051 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96052 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    96053 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    96054 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96055 File
    96056 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96057 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    96058 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    96059 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96060 File
    96061 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96062 packages/chimerax/graphics/drawing.py", line 1108, in
    96063 _first_intercept_excluding_children 
    96064 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    96065 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96066 File
    96067 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96068 packages/chimerax/geometry/place.py", line 201, in inverse 
    96069 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    96070 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96071 File
    96072 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96073 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    96074 rinv[:, :] = matrix_inverse(r) 
    96075 ^^^^^^^^^^^^^^^^^ 
    96076 File
    96077 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96078 packages/numpy/linalg/linalg.py", line 561, in inv 
    96079 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    96080 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96081 File
    96082 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96083 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    96084 raise LinAlgError("Singular matrix") 
    96085 numpy.linalg.LinAlgError: Singular matrix 
    96086  
    96087 numpy.linalg.LinAlgError: Singular matrix 
    96088  
    96089 File
    96090 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96091 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    96092 raise LinAlgError("Singular matrix") 
    96093  
    96094 See log for complete Python traceback. 
    96095  
    96096 Traceback (most recent call last): 
    96097 File
    96098 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96099 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    96100 self.session.ui.mouse_modes.mouse_pause_tracking() 
    96101 File
    96102 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96103 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    96104 mouse_pause_tracking 
    96105 self._mouse_pause() 
    96106 File
    96107 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96108 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    96109 m.pause(self._mouse_pause_position) 
    96110 File
    96111 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96112 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    96113 p = self.view.picked_object(x, y) 
    96114 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96115 File
    96116 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96117 packages/chimerax/graphics/view.py", line 838, in picked_object 
    96118 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    96119 beyond, 
    96120 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96121 File
    96122 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96123 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    96124 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    96125 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96126 File
    96127 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96128 packages/chimerax/core/models.py", line 143, in first_intercept 
    96129 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    96130 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96131 File
    96132 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96133 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    96134 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    96135 exclude=exclude) 
    96136 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96137 File
    96138 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96139 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    96140 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    96141 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96142 File
    96143 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96144 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    96145 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    96146 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96147 File
    96148 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96149 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    96150 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    96151 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96152 File
    96153 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96154 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    96155 p = super().first_intercept(mxyz1, mxyz2) 
    96156 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96157 File
    96158 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96159 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    96160 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    96161 exclude=exclude) 
    96162 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96163 File
    96164 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96165 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    96166 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    96167 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96168 File
    96169 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96170 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    96171 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    96172 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96173 File
    96174 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96175 packages/chimerax/graphics/drawing.py", line 1108, in
    96176 _first_intercept_excluding_children 
    96177 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    96178 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96179 File
    96180 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96181 packages/chimerax/geometry/place.py", line 201, in inverse 
    96182 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    96183 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96184 File
    96185 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96186 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    96187 rinv[:, :] = matrix_inverse(r) 
    96188 ^^^^^^^^^^^^^^^^^ 
    96189 File
    96190 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96191 packages/numpy/linalg/linalg.py", line 561, in inv 
    96192 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    96193 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96194 File
    96195 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96196 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    96197 raise LinAlgError("Singular matrix") 
    96198 numpy.linalg.LinAlgError: Singular matrix 
    96199  
    96200 numpy.linalg.LinAlgError: Singular matrix 
    96201  
    96202 File
    96203 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96204 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    96205 raise LinAlgError("Singular matrix") 
    96206  
    96207 See log for complete Python traceback. 
    96208  
    96209 Traceback (most recent call last): 
    96210 File
    96211 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96212 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    96213 self.session.ui.mouse_modes.mouse_pause_tracking() 
    96214 File
    96215 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96216 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    96217 mouse_pause_tracking 
    96218 self._mouse_pause() 
    96219 File
    96220 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96221 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    96222 m.pause(self._mouse_pause_position) 
    96223 File
    96224 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96225 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    96226 p = self.view.picked_object(x, y) 
    96227 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96228 File
    96229 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96230 packages/chimerax/graphics/view.py", line 838, in picked_object 
    96231 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    96232 beyond, 
    96233 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96234 File
    96235 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96236 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    96237 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    96238 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96239 File
    96240 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96241 packages/chimerax/core/models.py", line 143, in first_intercept 
    96242 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    96243 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96244 File
    96245 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96246 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    96247 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    96248 exclude=exclude) 
    96249 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96250 File
    96251 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96252 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    96253 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    96254 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96255 File
    96256 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96257 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    96258 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    96259 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96260 File
    96261 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96262 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    96263 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    96264 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96265 File
    96266 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96267 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    96268 p = super().first_intercept(mxyz1, mxyz2) 
    96269 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96270 File
    96271 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96272 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    96273 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    96274 exclude=exclude) 
    96275 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96276 File
    96277 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96278 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    96279 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    96280 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96281 File
    96282 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96283 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    96284 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    96285 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96286 File
    96287 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96288 packages/chimerax/graphics/drawing.py", line 1108, in
    96289 _first_intercept_excluding_children 
    96290 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    96291 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96292 File
    96293 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96294 packages/chimerax/geometry/place.py", line 201, in inverse 
    96295 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    96296 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96297 File
    96298 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96299 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    96300 rinv[:, :] = matrix_inverse(r) 
    96301 ^^^^^^^^^^^^^^^^^ 
    96302 File
    96303 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96304 packages/numpy/linalg/linalg.py", line 561, in inv 
    96305 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    96306 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96307 File
    96308 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96309 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    96310 raise LinAlgError("Singular matrix") 
    96311 numpy.linalg.LinAlgError: Singular matrix 
    96312  
    96313 numpy.linalg.LinAlgError: Singular matrix 
    96314  
    96315 File
    96316 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96317 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    96318 raise LinAlgError("Singular matrix") 
    96319  
    96320 See log for complete Python traceback. 
    96321  
    96322 Traceback (most recent call last): 
    96323 File
    96324 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96325 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    96326 self.session.ui.mouse_modes.mouse_pause_tracking() 
    96327 File
    96328 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96329 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    96330 mouse_pause_tracking 
    96331 self._mouse_pause() 
    96332 File
    96333 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96334 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    96335 m.pause(self._mouse_pause_position) 
    96336 File
    96337 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96338 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    96339 p = self.view.picked_object(x, y) 
    96340 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96341 File
    96342 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96343 packages/chimerax/graphics/view.py", line 838, in picked_object 
    96344 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    96345 beyond, 
    96346 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96347 File
    96348 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96349 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    96350 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    96351 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96352 File
    96353 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96354 packages/chimerax/core/models.py", line 143, in first_intercept 
    96355 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    96356 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96357 File
    96358 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96359 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    96360 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    96361 exclude=exclude) 
    96362 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96363 File
    96364 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96365 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    96366 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    96367 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96368 File
    96369 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96370 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    96371 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    96372 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96373 File
    96374 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96375 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    96376 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    96377 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96378 File
    96379 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96380 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    96381 p = super().first_intercept(mxyz1, mxyz2) 
    96382 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96383 File
    96384 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96385 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    96386 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    96387 exclude=exclude) 
    96388 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96389 File
    96390 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96391 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    96392 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    96393 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96394 File
    96395 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96396 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    96397 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    96398 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96399 File
    96400 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96401 packages/chimerax/graphics/drawing.py", line 1108, in
    96402 _first_intercept_excluding_children 
    96403 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    96404 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96405 File
    96406 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96407 packages/chimerax/geometry/place.py", line 201, in inverse 
    96408 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    96409 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96410 File
    96411 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96412 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    96413 rinv[:, :] = matrix_inverse(r) 
    96414 ^^^^^^^^^^^^^^^^^ 
    96415 File
    96416 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96417 packages/numpy/linalg/linalg.py", line 561, in inv 
    96418 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    96419 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96420 File
    96421 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96422 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    96423 raise LinAlgError("Singular matrix") 
    96424 numpy.linalg.LinAlgError: Singular matrix 
    96425  
    96426 numpy.linalg.LinAlgError: Singular matrix 
    96427  
    96428 File
    96429 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96430 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    96431 raise LinAlgError("Singular matrix") 
    96432  
    96433 See log for complete Python traceback. 
    96434  
    96435 Traceback (most recent call last): 
    96436 File
    96437 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96438 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    96439 self.session.ui.mouse_modes.mouse_pause_tracking() 
    96440 File
    96441 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96442 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    96443 mouse_pause_tracking 
    96444 self._mouse_pause() 
    96445 File
    96446 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96447 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    96448 m.pause(self._mouse_pause_position) 
    96449 File
    96450 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96451 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    96452 p = self.view.picked_object(x, y) 
    96453 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96454 File
    96455 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96456 packages/chimerax/graphics/view.py", line 838, in picked_object 
    96457 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    96458 beyond, 
    96459 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96460 File
    96461 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96462 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    96463 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    96464 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96465 File
    96466 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96467 packages/chimerax/core/models.py", line 143, in first_intercept 
    96468 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    96469 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96470 File
    96471 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96472 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    96473 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    96474 exclude=exclude) 
    96475 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96476 File
    96477 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96478 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    96479 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    96480 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96481 File
    96482 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96483 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    96484 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    96485 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96486 File
    96487 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96488 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    96489 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    96490 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96491 File
    96492 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96493 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    96494 p = super().first_intercept(mxyz1, mxyz2) 
    96495 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96496 File
    96497 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96498 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    96499 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    96500 exclude=exclude) 
    96501 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96502 File
    96503 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96504 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    96505 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    96506 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96507 File
    96508 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96509 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    96510 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    96511 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96512 File
    96513 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96514 packages/chimerax/graphics/drawing.py", line 1108, in
    96515 _first_intercept_excluding_children 
    96516 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    96517 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96518 File
    96519 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96520 packages/chimerax/geometry/place.py", line 201, in inverse 
    96521 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    96522 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96523 File
    96524 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96525 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    96526 rinv[:, :] = matrix_inverse(r) 
    96527 ^^^^^^^^^^^^^^^^^ 
    96528 File
    96529 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96530 packages/numpy/linalg/linalg.py", line 561, in inv 
    96531 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    96532 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96533 File
    96534 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96535 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    96536 raise LinAlgError("Singular matrix") 
    96537 numpy.linalg.LinAlgError: Singular matrix 
    96538  
    96539 numpy.linalg.LinAlgError: Singular matrix 
    96540  
    96541 File
    96542 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96543 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    96544 raise LinAlgError("Singular matrix") 
    96545  
    96546 See log for complete Python traceback. 
    96547  
    96548 Traceback (most recent call last): 
    96549 File
    96550 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96551 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    96552 self.session.ui.mouse_modes.mouse_pause_tracking() 
    96553 File
    96554 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96555 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    96556 mouse_pause_tracking 
    96557 self._mouse_pause() 
    96558 File
    96559 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96560 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    96561 m.pause(self._mouse_pause_position) 
    96562 File
    96563 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96564 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    96565 p = self.view.picked_object(x, y) 
    96566 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96567 File
    96568 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96569 packages/chimerax/graphics/view.py", line 838, in picked_object 
    96570 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    96571 beyond, 
    96572 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96573 File
    96574 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96575 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    96576 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    96577 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96578 File
    96579 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96580 packages/chimerax/core/models.py", line 143, in first_intercept 
    96581 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    96582 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96583 File
    96584 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96585 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    96586 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    96587 exclude=exclude) 
    96588 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96589 File
    96590 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96591 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    96592 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    96593 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96594 File
    96595 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96596 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    96597 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    96598 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96599 File
    96600 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96601 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    96602 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    96603 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96604 File
    96605 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96606 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    96607 p = super().first_intercept(mxyz1, mxyz2) 
    96608 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96609 File
    96610 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96611 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    96612 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    96613 exclude=exclude) 
    96614 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96615 File
    96616 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96617 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    96618 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    96619 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96620 File
    96621 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96622 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    96623 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    96624 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96625 File
    96626 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96627 packages/chimerax/graphics/drawing.py", line 1108, in
    96628 _first_intercept_excluding_children 
    96629 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    96630 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96631 File
    96632 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96633 packages/chimerax/geometry/place.py", line 201, in inverse 
    96634 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    96635 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96636 File
    96637 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96638 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    96639 rinv[:, :] = matrix_inverse(r) 
    96640 ^^^^^^^^^^^^^^^^^ 
    96641 File
    96642 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96643 packages/numpy/linalg/linalg.py", line 561, in inv 
    96644 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    96645 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96646 File
    96647 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96648 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    96649 raise LinAlgError("Singular matrix") 
    96650 numpy.linalg.LinAlgError: Singular matrix 
    96651  
    96652 numpy.linalg.LinAlgError: Singular matrix 
    96653  
    96654 File
    96655 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96656 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    96657 raise LinAlgError("Singular matrix") 
    96658  
    96659 See log for complete Python traceback. 
    96660  
    96661 Traceback (most recent call last): 
    96662 File
    96663 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96664 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    96665 self.session.ui.mouse_modes.mouse_pause_tracking() 
    96666 File
    96667 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96668 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    96669 mouse_pause_tracking 
    96670 self._mouse_pause() 
    96671 File
    96672 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96673 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    96674 m.pause(self._mouse_pause_position) 
    96675 File
    96676 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96677 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    96678 p = self.view.picked_object(x, y) 
    96679 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96680 File
    96681 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96682 packages/chimerax/graphics/view.py", line 838, in picked_object 
    96683 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    96684 beyond, 
    96685 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96686 File
    96687 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96688 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    96689 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    96690 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96691 File
    96692 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96693 packages/chimerax/core/models.py", line 143, in first_intercept 
    96694 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    96695 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96696 File
    96697 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96698 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    96699 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    96700 exclude=exclude) 
    96701 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96702 File
    96703 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96704 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    96705 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    96706 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96707 File
    96708 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96709 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    96710 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    96711 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96712 File
    96713 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96714 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    96715 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    96716 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96717 File
    96718 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96719 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    96720 p = super().first_intercept(mxyz1, mxyz2) 
    96721 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96722 File
    96723 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96724 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    96725 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    96726 exclude=exclude) 
    96727 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96728 File
    96729 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96730 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    96731 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    96732 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96733 File
    96734 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96735 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    96736 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    96737 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96738 File
    96739 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96740 packages/chimerax/graphics/drawing.py", line 1108, in
    96741 _first_intercept_excluding_children 
    96742 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    96743 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96744 File
    96745 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96746 packages/chimerax/geometry/place.py", line 201, in inverse 
    96747 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    96748 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96749 File
    96750 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96751 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    96752 rinv[:, :] = matrix_inverse(r) 
    96753 ^^^^^^^^^^^^^^^^^ 
    96754 File
    96755 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96756 packages/numpy/linalg/linalg.py", line 561, in inv 
    96757 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    96758 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96759 File
    96760 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96761 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    96762 raise LinAlgError("Singular matrix") 
    96763 numpy.linalg.LinAlgError: Singular matrix 
    96764  
    96765 numpy.linalg.LinAlgError: Singular matrix 
    96766  
    96767 File
    96768 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96769 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    96770 raise LinAlgError("Singular matrix") 
    96771  
    96772 See log for complete Python traceback. 
    96773  
    96774 Traceback (most recent call last): 
    96775 File
    96776 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96777 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    96778 self.session.ui.mouse_modes.mouse_pause_tracking() 
    96779 File
    96780 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96781 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    96782 mouse_pause_tracking 
    96783 self._mouse_pause() 
    96784 File
    96785 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96786 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    96787 m.pause(self._mouse_pause_position) 
    96788 File
    96789 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96790 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    96791 p = self.view.picked_object(x, y) 
    96792 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96793 File
    96794 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96795 packages/chimerax/graphics/view.py", line 838, in picked_object 
    96796 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    96797 beyond, 
    96798 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96799 File
    96800 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96801 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    96802 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    96803 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96804 File
    96805 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96806 packages/chimerax/core/models.py", line 143, in first_intercept 
    96807 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    96808 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96809 File
    96810 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96811 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    96812 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    96813 exclude=exclude) 
    96814 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96815 File
    96816 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96817 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    96818 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    96819 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96820 File
    96821 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96822 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    96823 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    96824 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96825 File
    96826 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96827 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    96828 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    96829 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96830 File
    96831 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96832 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    96833 p = super().first_intercept(mxyz1, mxyz2) 
    96834 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96835 File
    96836 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96837 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    96838 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    96839 exclude=exclude) 
    96840 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96841 File
    96842 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96843 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    96844 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    96845 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96846 File
    96847 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96848 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    96849 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    96850 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96851 File
    96852 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96853 packages/chimerax/graphics/drawing.py", line 1108, in
    96854 _first_intercept_excluding_children 
    96855 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    96856 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96857 File
    96858 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96859 packages/chimerax/geometry/place.py", line 201, in inverse 
    96860 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    96861 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96862 File
    96863 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96864 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    96865 rinv[:, :] = matrix_inverse(r) 
    96866 ^^^^^^^^^^^^^^^^^ 
    96867 File
    96868 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96869 packages/numpy/linalg/linalg.py", line 561, in inv 
    96870 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    96871 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96872 File
    96873 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96874 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    96875 raise LinAlgError("Singular matrix") 
    96876 numpy.linalg.LinAlgError: Singular matrix 
    96877  
    96878 numpy.linalg.LinAlgError: Singular matrix 
    96879  
    96880 File
    96881 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96882 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    96883 raise LinAlgError("Singular matrix") 
    96884  
    96885 See log for complete Python traceback. 
    96886  
    96887 Traceback (most recent call last): 
    96888 File
    96889 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96890 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    96891 self.session.ui.mouse_modes.mouse_pause_tracking() 
    96892 File
    96893 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96894 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    96895 mouse_pause_tracking 
    96896 self._mouse_pause() 
    96897 File
    96898 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96899 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    96900 m.pause(self._mouse_pause_position) 
    96901 File
    96902 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96903 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    96904 p = self.view.picked_object(x, y) 
    96905 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96906 File
    96907 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96908 packages/chimerax/graphics/view.py", line 838, in picked_object 
    96909 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    96910 beyond, 
    96911 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96912 File
    96913 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96914 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    96915 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    96916 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96917 File
    96918 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96919 packages/chimerax/core/models.py", line 143, in first_intercept 
    96920 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    96921 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96922 File
    96923 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96924 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    96925 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    96926 exclude=exclude) 
    96927 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96928 File
    96929 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96930 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    96931 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    96932 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96933 File
    96934 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96935 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    96936 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    96937 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96938 File
    96939 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96940 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    96941 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    96942 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96943 File
    96944 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96945 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    96946 p = super().first_intercept(mxyz1, mxyz2) 
    96947 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96948 File
    96949 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96950 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    96951 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    96952 exclude=exclude) 
    96953 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96954 File
    96955 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96956 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    96957 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    96958 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96959 File
    96960 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96961 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    96962 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    96963 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96964 File
    96965 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96966 packages/chimerax/graphics/drawing.py", line 1108, in
    96967 _first_intercept_excluding_children 
    96968 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    96969 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96970 File
    96971 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96972 packages/chimerax/geometry/place.py", line 201, in inverse 
    96973 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    96974 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96975 File
    96976 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96977 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    96978 rinv[:, :] = matrix_inverse(r) 
    96979 ^^^^^^^^^^^^^^^^^ 
    96980 File
    96981 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96982 packages/numpy/linalg/linalg.py", line 561, in inv 
    96983 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    96984 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    96985 File
    96986 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96987 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    96988 raise LinAlgError("Singular matrix") 
    96989 numpy.linalg.LinAlgError: Singular matrix 
    96990  
    96991 numpy.linalg.LinAlgError: Singular matrix 
    96992  
    96993 File
    96994 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    96995 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    96996 raise LinAlgError("Singular matrix") 
    96997  
    96998 See log for complete Python traceback. 
    96999  
    97000 Traceback (most recent call last): 
    97001 File
    97002 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97003 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    97004 self.session.ui.mouse_modes.mouse_pause_tracking() 
    97005 File
    97006 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97007 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    97008 mouse_pause_tracking 
    97009 self._mouse_pause() 
    97010 File
    97011 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97012 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    97013 m.pause(self._mouse_pause_position) 
    97014 File
    97015 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97016 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    97017 p = self.view.picked_object(x, y) 
    97018 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97019 File
    97020 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97021 packages/chimerax/graphics/view.py", line 838, in picked_object 
    97022 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    97023 beyond, 
    97024 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97025 File
    97026 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97027 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    97028 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    97029 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97030 File
    97031 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97032 packages/chimerax/core/models.py", line 143, in first_intercept 
    97033 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    97034 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97035 File
    97036 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97037 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    97038 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    97039 exclude=exclude) 
    97040 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97041 File
    97042 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97043 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    97044 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    97045 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97046 File
    97047 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97048 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    97049 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    97050 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97051 File
    97052 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97053 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    97054 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    97055 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97056 File
    97057 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97058 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    97059 p = super().first_intercept(mxyz1, mxyz2) 
    97060 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97061 File
    97062 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97063 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    97064 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    97065 exclude=exclude) 
    97066 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97067 File
    97068 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97069 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    97070 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    97071 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97072 File
    97073 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97074 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    97075 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    97076 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97077 File
    97078 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97079 packages/chimerax/graphics/drawing.py", line 1108, in
    97080 _first_intercept_excluding_children 
    97081 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    97082 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97083 File
    97084 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97085 packages/chimerax/geometry/place.py", line 201, in inverse 
    97086 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    97087 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97088 File
    97089 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97090 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    97091 rinv[:, :] = matrix_inverse(r) 
    97092 ^^^^^^^^^^^^^^^^^ 
    97093 File
    97094 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97095 packages/numpy/linalg/linalg.py", line 561, in inv 
    97096 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    97097 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97098 File
    97099 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97100 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    97101 raise LinAlgError("Singular matrix") 
    97102 numpy.linalg.LinAlgError: Singular matrix 
    97103  
    97104 numpy.linalg.LinAlgError: Singular matrix 
    97105  
    97106 File
    97107 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97108 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    97109 raise LinAlgError("Singular matrix") 
    97110  
    97111 See log for complete Python traceback. 
    97112  
    97113 Traceback (most recent call last): 
    97114 File
    97115 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97116 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    97117 self.session.ui.mouse_modes.mouse_pause_tracking() 
    97118 File
    97119 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97120 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    97121 mouse_pause_tracking 
    97122 self._mouse_pause() 
    97123 File
    97124 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97125 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    97126 m.pause(self._mouse_pause_position) 
    97127 File
    97128 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97129 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    97130 p = self.view.picked_object(x, y) 
    97131 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97132 File
    97133 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97134 packages/chimerax/graphics/view.py", line 838, in picked_object 
    97135 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    97136 beyond, 
    97137 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97138 File
    97139 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97140 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    97141 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    97142 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97143 File
    97144 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97145 packages/chimerax/core/models.py", line 143, in first_intercept 
    97146 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    97147 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97148 File
    97149 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97150 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    97151 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    97152 exclude=exclude) 
    97153 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97154 File
    97155 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97156 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    97157 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    97158 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97159 File
    97160 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97161 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    97162 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    97163 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97164 File
    97165 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97166 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    97167 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    97168 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97169 File
    97170 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97171 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    97172 p = super().first_intercept(mxyz1, mxyz2) 
    97173 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97174 File
    97175 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97176 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    97177 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    97178 exclude=exclude) 
    97179 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97180 File
    97181 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97182 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    97183 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    97184 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97185 File
    97186 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97187 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    97188 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    97189 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97190 File
    97191 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97192 packages/chimerax/graphics/drawing.py", line 1108, in
    97193 _first_intercept_excluding_children 
    97194 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    97195 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97196 File
    97197 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97198 packages/chimerax/geometry/place.py", line 201, in inverse 
    97199 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    97200 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97201 File
    97202 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97203 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    97204 rinv[:, :] = matrix_inverse(r) 
    97205 ^^^^^^^^^^^^^^^^^ 
    97206 File
    97207 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97208 packages/numpy/linalg/linalg.py", line 561, in inv 
    97209 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    97210 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97211 File
    97212 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97213 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    97214 raise LinAlgError("Singular matrix") 
    97215 numpy.linalg.LinAlgError: Singular matrix 
    97216  
    97217 numpy.linalg.LinAlgError: Singular matrix 
    97218  
    97219 File
    97220 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97221 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    97222 raise LinAlgError("Singular matrix") 
    97223  
    97224 See log for complete Python traceback. 
    97225  
    97226 Traceback (most recent call last): 
    97227 File
    97228 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97229 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    97230 self.session.ui.mouse_modes.mouse_pause_tracking() 
    97231 File
    97232 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97233 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    97234 mouse_pause_tracking 
    97235 self._mouse_pause() 
    97236 File
    97237 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97238 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    97239 m.pause(self._mouse_pause_position) 
    97240 File
    97241 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97242 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    97243 p = self.view.picked_object(x, y) 
    97244 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97245 File
    97246 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97247 packages/chimerax/graphics/view.py", line 838, in picked_object 
    97248 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    97249 beyond, 
    97250 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97251 File
    97252 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97253 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    97254 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    97255 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97256 File
    97257 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97258 packages/chimerax/core/models.py", line 143, in first_intercept 
    97259 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    97260 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97261 File
    97262 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97263 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    97264 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    97265 exclude=exclude) 
    97266 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97267 File
    97268 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97269 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    97270 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    97271 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97272 File
    97273 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97274 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    97275 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    97276 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97277 File
    97278 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97279 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    97280 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    97281 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97282 File
    97283 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97284 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    97285 p = super().first_intercept(mxyz1, mxyz2) 
    97286 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97287 File
    97288 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97289 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    97290 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    97291 exclude=exclude) 
    97292 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97293 File
    97294 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97295 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    97296 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    97297 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97298 File
    97299 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97300 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    97301 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    97302 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97303 File
    97304 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97305 packages/chimerax/graphics/drawing.py", line 1108, in
    97306 _first_intercept_excluding_children 
    97307 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    97308 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97309 File
    97310 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97311 packages/chimerax/geometry/place.py", line 201, in inverse 
    97312 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    97313 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97314 File
    97315 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97316 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    97317 rinv[:, :] = matrix_inverse(r) 
    97318 ^^^^^^^^^^^^^^^^^ 
    97319 File
    97320 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97321 packages/numpy/linalg/linalg.py", line 561, in inv 
    97322 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    97323 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97324 File
    97325 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97326 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    97327 raise LinAlgError("Singular matrix") 
    97328 numpy.linalg.LinAlgError: Singular matrix 
    97329  
    97330 numpy.linalg.LinAlgError: Singular matrix 
    97331  
    97332 File
    97333 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97334 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    97335 raise LinAlgError("Singular matrix") 
    97336  
    97337 See log for complete Python traceback. 
    97338  
    97339 Traceback (most recent call last): 
    97340 File
    97341 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97342 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    97343 self.session.ui.mouse_modes.mouse_pause_tracking() 
    97344 File
    97345 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97346 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    97347 mouse_pause_tracking 
    97348 self._mouse_pause() 
    97349 File
    97350 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97351 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    97352 m.pause(self._mouse_pause_position) 
    97353 File
    97354 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97355 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    97356 p = self.view.picked_object(x, y) 
    97357 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97358 File
    97359 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97360 packages/chimerax/graphics/view.py", line 838, in picked_object 
    97361 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    97362 beyond, 
    97363 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97364 File
    97365 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97366 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    97367 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    97368 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97369 File
    97370 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97371 packages/chimerax/core/models.py", line 143, in first_intercept 
    97372 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    97373 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97374 File
    97375 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97376 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    97377 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    97378 exclude=exclude) 
    97379 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97380 File
    97381 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97382 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    97383 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    97384 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97385 File
    97386 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97387 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    97388 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    97389 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97390 File
    97391 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97392 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    97393 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    97394 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97395 File
    97396 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97397 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    97398 p = super().first_intercept(mxyz1, mxyz2) 
    97399 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97400 File
    97401 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97402 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    97403 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    97404 exclude=exclude) 
    97405 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97406 File
    97407 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97408 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    97409 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    97410 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97411 File
    97412 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97413 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    97414 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    97415 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97416 File
    97417 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97418 packages/chimerax/graphics/drawing.py", line 1108, in
    97419 _first_intercept_excluding_children 
    97420 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    97421 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97422 File
    97423 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97424 packages/chimerax/geometry/place.py", line 201, in inverse 
    97425 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    97426 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97427 File
    97428 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97429 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    97430 rinv[:, :] = matrix_inverse(r) 
    97431 ^^^^^^^^^^^^^^^^^ 
    97432 File
    97433 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97434 packages/numpy/linalg/linalg.py", line 561, in inv 
    97435 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    97436 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97437 File
    97438 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97439 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    97440 raise LinAlgError("Singular matrix") 
    97441 numpy.linalg.LinAlgError: Singular matrix 
    97442  
    97443 numpy.linalg.LinAlgError: Singular matrix 
    97444  
    97445 File
    97446 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97447 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    97448 raise LinAlgError("Singular matrix") 
    97449  
    97450 See log for complete Python traceback. 
    97451  
    97452 Traceback (most recent call last): 
    97453 File
    97454 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97455 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    97456 self.session.ui.mouse_modes.mouse_pause_tracking() 
    97457 File
    97458 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97459 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    97460 mouse_pause_tracking 
    97461 self._mouse_pause() 
    97462 File
    97463 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97464 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    97465 m.pause(self._mouse_pause_position) 
    97466 File
    97467 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97468 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    97469 p = self.view.picked_object(x, y) 
    97470 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97471 File
    97472 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97473 packages/chimerax/graphics/view.py", line 838, in picked_object 
    97474 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    97475 beyond, 
    97476 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97477 File
    97478 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97479 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    97480 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    97481 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97482 File
    97483 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97484 packages/chimerax/core/models.py", line 143, in first_intercept 
    97485 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    97486 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97487 File
    97488 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97489 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    97490 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    97491 exclude=exclude) 
    97492 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97493 File
    97494 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97495 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    97496 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    97497 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97498 File
    97499 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97500 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    97501 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    97502 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97503 File
    97504 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97505 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    97506 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    97507 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97508 File
    97509 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97510 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    97511 p = super().first_intercept(mxyz1, mxyz2) 
    97512 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97513 File
    97514 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97515 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    97516 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    97517 exclude=exclude) 
    97518 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97519 File
    97520 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97521 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    97522 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    97523 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97524 File
    97525 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97526 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    97527 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    97528 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97529 File
    97530 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97531 packages/chimerax/graphics/drawing.py", line 1108, in
    97532 _first_intercept_excluding_children 
    97533 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    97534 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97535 File
    97536 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97537 packages/chimerax/geometry/place.py", line 201, in inverse 
    97538 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    97539 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97540 File
    97541 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97542 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    97543 rinv[:, :] = matrix_inverse(r) 
    97544 ^^^^^^^^^^^^^^^^^ 
    97545 File
    97546 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97547 packages/numpy/linalg/linalg.py", line 561, in inv 
    97548 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    97549 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97550 File
    97551 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97552 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    97553 raise LinAlgError("Singular matrix") 
    97554 numpy.linalg.LinAlgError: Singular matrix 
    97555  
    97556 numpy.linalg.LinAlgError: Singular matrix 
    97557  
    97558 File
    97559 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97560 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    97561 raise LinAlgError("Singular matrix") 
    97562  
    97563 See log for complete Python traceback. 
    97564  
    97565 Traceback (most recent call last): 
    97566 File
    97567 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97568 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    97569 self.session.ui.mouse_modes.mouse_pause_tracking() 
    97570 File
    97571 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97572 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    97573 mouse_pause_tracking 
    97574 self._mouse_pause() 
    97575 File
    97576 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97577 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    97578 m.pause(self._mouse_pause_position) 
    97579 File
    97580 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97581 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    97582 p = self.view.picked_object(x, y) 
    97583 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97584 File
    97585 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97586 packages/chimerax/graphics/view.py", line 838, in picked_object 
    97587 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    97588 beyond, 
    97589 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97590 File
    97591 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97592 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    97593 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    97594 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97595 File
    97596 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97597 packages/chimerax/core/models.py", line 143, in first_intercept 
    97598 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    97599 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97600 File
    97601 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97602 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    97603 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    97604 exclude=exclude) 
    97605 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97606 File
    97607 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97608 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    97609 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    97610 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97611 File
    97612 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97613 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    97614 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    97615 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97616 File
    97617 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97618 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    97619 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    97620 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97621 File
    97622 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97623 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    97624 p = super().first_intercept(mxyz1, mxyz2) 
    97625 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97626 File
    97627 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97628 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    97629 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    97630 exclude=exclude) 
    97631 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97632 File
    97633 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97634 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    97635 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    97636 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97637 File
    97638 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97639 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    97640 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    97641 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97642 File
    97643 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97644 packages/chimerax/graphics/drawing.py", line 1108, in
    97645 _first_intercept_excluding_children 
    97646 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    97647 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97648 File
    97649 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97650 packages/chimerax/geometry/place.py", line 201, in inverse 
    97651 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    97652 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97653 File
    97654 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97655 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    97656 rinv[:, :] = matrix_inverse(r) 
    97657 ^^^^^^^^^^^^^^^^^ 
    97658 File
    97659 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97660 packages/numpy/linalg/linalg.py", line 561, in inv 
    97661 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    97662 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97663 File
    97664 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97665 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    97666 raise LinAlgError("Singular matrix") 
    97667 numpy.linalg.LinAlgError: Singular matrix 
    97668  
    97669 numpy.linalg.LinAlgError: Singular matrix 
    97670  
    97671 File
    97672 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97673 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    97674 raise LinAlgError("Singular matrix") 
    97675  
    97676 See log for complete Python traceback. 
    97677  
    97678 Traceback (most recent call last): 
    97679 File
    97680 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97681 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    97682 self.session.ui.mouse_modes.mouse_pause_tracking() 
    97683 File
    97684 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97685 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    97686 mouse_pause_tracking 
    97687 self._mouse_pause() 
    97688 File
    97689 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97690 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    97691 m.pause(self._mouse_pause_position) 
    97692 File
    97693 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97694 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    97695 p = self.view.picked_object(x, y) 
    97696 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97697 File
    97698 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97699 packages/chimerax/graphics/view.py", line 838, in picked_object 
    97700 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    97701 beyond, 
    97702 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97703 File
    97704 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97705 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    97706 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    97707 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97708 File
    97709 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97710 packages/chimerax/core/models.py", line 143, in first_intercept 
    97711 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    97712 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97713 File
    97714 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97715 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    97716 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    97717 exclude=exclude) 
    97718 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97719 File
    97720 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97721 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    97722 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    97723 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97724 File
    97725 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97726 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    97727 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    97728 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97729 File
    97730 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97731 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    97732 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    97733 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97734 File
    97735 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97736 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    97737 p = super().first_intercept(mxyz1, mxyz2) 
    97738 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97739 File
    97740 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97741 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    97742 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    97743 exclude=exclude) 
    97744 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97745 File
    97746 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97747 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    97748 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    97749 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97750 File
    97751 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97752 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    97753 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    97754 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97755 File
    97756 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97757 packages/chimerax/graphics/drawing.py", line 1108, in
    97758 _first_intercept_excluding_children 
    97759 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    97760 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97761 File
    97762 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97763 packages/chimerax/geometry/place.py", line 201, in inverse 
    97764 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    97765 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97766 File
    97767 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97768 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    97769 rinv[:, :] = matrix_inverse(r) 
    97770 ^^^^^^^^^^^^^^^^^ 
    97771 File
    97772 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97773 packages/numpy/linalg/linalg.py", line 561, in inv 
    97774 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    97775 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97776 File
    97777 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97778 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    97779 raise LinAlgError("Singular matrix") 
    97780 numpy.linalg.LinAlgError: Singular matrix 
    97781  
    97782 numpy.linalg.LinAlgError: Singular matrix 
    97783  
    97784 File
    97785 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97786 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    97787 raise LinAlgError("Singular matrix") 
    97788  
    97789 See log for complete Python traceback. 
    97790  
    97791 Traceback (most recent call last): 
    97792 File
    97793 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97794 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    97795 self.session.ui.mouse_modes.mouse_pause_tracking() 
    97796 File
    97797 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97798 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    97799 mouse_pause_tracking 
    97800 self._mouse_pause() 
    97801 File
    97802 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97803 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    97804 m.pause(self._mouse_pause_position) 
    97805 File
    97806 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97807 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    97808 p = self.view.picked_object(x, y) 
    97809 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97810 File
    97811 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97812 packages/chimerax/graphics/view.py", line 838, in picked_object 
    97813 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    97814 beyond, 
    97815 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97816 File
    97817 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97818 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    97819 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    97820 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97821 File
    97822 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97823 packages/chimerax/core/models.py", line 143, in first_intercept 
    97824 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    97825 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97826 File
    97827 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97828 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    97829 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    97830 exclude=exclude) 
    97831 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97832 File
    97833 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97834 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    97835 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    97836 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97837 File
    97838 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97839 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    97840 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    97841 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97842 File
    97843 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97844 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    97845 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    97846 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97847 File
    97848 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97849 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    97850 p = super().first_intercept(mxyz1, mxyz2) 
    97851 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97852 File
    97853 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97854 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    97855 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    97856 exclude=exclude) 
    97857 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97858 File
    97859 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97860 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    97861 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    97862 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97863 File
    97864 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97865 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    97866 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    97867 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97868 File
    97869 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97870 packages/chimerax/graphics/drawing.py", line 1108, in
    97871 _first_intercept_excluding_children 
    97872 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    97873 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97874 File
    97875 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97876 packages/chimerax/geometry/place.py", line 201, in inverse 
    97877 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    97878 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97879 File
    97880 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97881 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    97882 rinv[:, :] = matrix_inverse(r) 
    97883 ^^^^^^^^^^^^^^^^^ 
    97884 File
    97885 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97886 packages/numpy/linalg/linalg.py", line 561, in inv 
    97887 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    97888 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97889 File
    97890 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97891 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    97892 raise LinAlgError("Singular matrix") 
    97893 numpy.linalg.LinAlgError: Singular matrix 
    97894  
    97895 numpy.linalg.LinAlgError: Singular matrix 
    97896  
    97897 File
    97898 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97899 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    97900 raise LinAlgError("Singular matrix") 
    97901  
    97902 See log for complete Python traceback. 
    97903  
    97904 Traceback (most recent call last): 
    97905 File
    97906 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97907 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    97908 self.session.ui.mouse_modes.mouse_pause_tracking() 
    97909 File
    97910 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97911 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    97912 mouse_pause_tracking 
    97913 self._mouse_pause() 
    97914 File
    97915 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97916 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    97917 m.pause(self._mouse_pause_position) 
    97918 File
    97919 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97920 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    97921 p = self.view.picked_object(x, y) 
    97922 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97923 File
    97924 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97925 packages/chimerax/graphics/view.py", line 838, in picked_object 
    97926 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    97927 beyond, 
    97928 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97929 File
    97930 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97931 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    97932 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    97933 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97934 File
    97935 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97936 packages/chimerax/core/models.py", line 143, in first_intercept 
    97937 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    97938 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97939 File
    97940 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97941 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    97942 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    97943 exclude=exclude) 
    97944 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97945 File
    97946 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97947 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    97948 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    97949 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97950 File
    97951 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97952 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    97953 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    97954 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97955 File
    97956 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97957 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    97958 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    97959 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97960 File
    97961 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97962 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    97963 p = super().first_intercept(mxyz1, mxyz2) 
    97964 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97965 File
    97966 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97967 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    97968 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    97969 exclude=exclude) 
    97970 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97971 File
    97972 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97973 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    97974 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    97975 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97976 File
    97977 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97978 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    97979 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    97980 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97981 File
    97982 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97983 packages/chimerax/graphics/drawing.py", line 1108, in
    97984 _first_intercept_excluding_children 
    97985 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    97986 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97987 File
    97988 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97989 packages/chimerax/geometry/place.py", line 201, in inverse 
    97990 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    97991 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    97992 File
    97993 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97994 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    97995 rinv[:, :] = matrix_inverse(r) 
    97996 ^^^^^^^^^^^^^^^^^ 
    97997 File
    97998 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    97999 packages/numpy/linalg/linalg.py", line 561, in inv 
    98000 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    98001 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98002 File
    98003 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98004 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    98005 raise LinAlgError("Singular matrix") 
    98006 numpy.linalg.LinAlgError: Singular matrix 
    98007  
    98008 numpy.linalg.LinAlgError: Singular matrix 
    98009  
    98010 File
    98011 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98012 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    98013 raise LinAlgError("Singular matrix") 
    98014  
    98015 See log for complete Python traceback. 
    98016  
    98017 Traceback (most recent call last): 
    98018 File
    98019 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98020 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    98021 self.session.ui.mouse_modes.mouse_pause_tracking() 
    98022 File
    98023 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98024 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    98025 mouse_pause_tracking 
    98026 self._mouse_pause() 
    98027 File
    98028 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98029 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    98030 m.pause(self._mouse_pause_position) 
    98031 File
    98032 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98033 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    98034 p = self.view.picked_object(x, y) 
    98035 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98036 File
    98037 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98038 packages/chimerax/graphics/view.py", line 838, in picked_object 
    98039 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    98040 beyond, 
    98041 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98042 File
    98043 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98044 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    98045 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    98046 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98047 File
    98048 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98049 packages/chimerax/core/models.py", line 143, in first_intercept 
    98050 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    98051 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98052 File
    98053 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98054 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    98055 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    98056 exclude=exclude) 
    98057 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98058 File
    98059 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98060 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    98061 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    98062 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98063 File
    98064 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98065 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    98066 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    98067 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98068 File
    98069 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98070 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    98071 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    98072 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98073 File
    98074 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98075 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    98076 p = super().first_intercept(mxyz1, mxyz2) 
    98077 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98078 File
    98079 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98080 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    98081 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    98082 exclude=exclude) 
    98083 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98084 File
    98085 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98086 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    98087 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    98088 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98089 File
    98090 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98091 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    98092 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    98093 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98094 File
    98095 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98096 packages/chimerax/graphics/drawing.py", line 1108, in
    98097 _first_intercept_excluding_children 
    98098 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    98099 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98100 File
    98101 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98102 packages/chimerax/geometry/place.py", line 201, in inverse 
    98103 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    98104 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98105 File
    98106 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98107 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    98108 rinv[:, :] = matrix_inverse(r) 
    98109 ^^^^^^^^^^^^^^^^^ 
    98110 File
    98111 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98112 packages/numpy/linalg/linalg.py", line 561, in inv 
    98113 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    98114 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98115 File
    98116 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98117 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    98118 raise LinAlgError("Singular matrix") 
    98119 numpy.linalg.LinAlgError: Singular matrix 
    98120  
    98121 numpy.linalg.LinAlgError: Singular matrix 
    98122  
    98123 File
    98124 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98125 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    98126 raise LinAlgError("Singular matrix") 
    98127  
    98128 See log for complete Python traceback. 
    98129  
    98130 Traceback (most recent call last): 
    98131 File
    98132 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98133 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    98134 self.session.ui.mouse_modes.mouse_pause_tracking() 
    98135 File
    98136 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98137 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    98138 mouse_pause_tracking 
    98139 self._mouse_pause() 
    98140 File
    98141 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98142 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    98143 m.pause(self._mouse_pause_position) 
    98144 File
    98145 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98146 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    98147 p = self.view.picked_object(x, y) 
    98148 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98149 File
    98150 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98151 packages/chimerax/graphics/view.py", line 838, in picked_object 
    98152 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    98153 beyond, 
    98154 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98155 File
    98156 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98157 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    98158 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    98159 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98160 File
    98161 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98162 packages/chimerax/core/models.py", line 143, in first_intercept 
    98163 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    98164 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98165 File
    98166 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98167 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    98168 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    98169 exclude=exclude) 
    98170 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98171 File
    98172 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98173 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    98174 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    98175 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98176 File
    98177 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98178 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    98179 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    98180 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98181 File
    98182 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98183 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    98184 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    98185 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98186 File
    98187 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98188 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    98189 p = super().first_intercept(mxyz1, mxyz2) 
    98190 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98191 File
    98192 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98193 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    98194 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    98195 exclude=exclude) 
    98196 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98197 File
    98198 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98199 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    98200 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    98201 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98202 File
    98203 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98204 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    98205 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    98206 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98207 File
    98208 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98209 packages/chimerax/graphics/drawing.py", line 1108, in
    98210 _first_intercept_excluding_children 
    98211 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    98212 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98213 File
    98214 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98215 packages/chimerax/geometry/place.py", line 201, in inverse 
    98216 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    98217 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98218 File
    98219 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98220 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    98221 rinv[:, :] = matrix_inverse(r) 
    98222 ^^^^^^^^^^^^^^^^^ 
    98223 File
    98224 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98225 packages/numpy/linalg/linalg.py", line 561, in inv 
    98226 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    98227 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98228 File
    98229 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98230 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    98231 raise LinAlgError("Singular matrix") 
    98232 numpy.linalg.LinAlgError: Singular matrix 
    98233  
    98234 numpy.linalg.LinAlgError: Singular matrix 
    98235  
    98236 File
    98237 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98238 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    98239 raise LinAlgError("Singular matrix") 
    98240  
    98241 See log for complete Python traceback. 
    98242  
    98243 Traceback (most recent call last): 
    98244 File
    98245 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98246 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    98247 self.session.ui.mouse_modes.mouse_pause_tracking() 
    98248 File
    98249 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98250 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    98251 mouse_pause_tracking 
    98252 self._mouse_pause() 
    98253 File
    98254 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98255 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    98256 m.pause(self._mouse_pause_position) 
    98257 File
    98258 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98259 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    98260 p = self.view.picked_object(x, y) 
    98261 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98262 File
    98263 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98264 packages/chimerax/graphics/view.py", line 838, in picked_object 
    98265 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    98266 beyond, 
    98267 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98268 File
    98269 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98270 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    98271 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    98272 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98273 File
    98274 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98275 packages/chimerax/core/models.py", line 143, in first_intercept 
    98276 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    98277 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98278 File
    98279 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98280 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    98281 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    98282 exclude=exclude) 
    98283 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98284 File
    98285 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98286 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    98287 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    98288 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98289 File
    98290 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98291 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    98292 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    98293 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98294 File
    98295 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98296 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    98297 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    98298 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98299 File
    98300 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98301 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    98302 p = super().first_intercept(mxyz1, mxyz2) 
    98303 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98304 File
    98305 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98306 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    98307 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    98308 exclude=exclude) 
    98309 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98310 File
    98311 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98312 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    98313 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    98314 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98315 File
    98316 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98317 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    98318 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    98319 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98320 File
    98321 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98322 packages/chimerax/graphics/drawing.py", line 1108, in
    98323 _first_intercept_excluding_children 
    98324 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    98325 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98326 File
    98327 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98328 packages/chimerax/geometry/place.py", line 201, in inverse 
    98329 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    98330 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98331 File
    98332 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98333 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    98334 rinv[:, :] = matrix_inverse(r) 
    98335 ^^^^^^^^^^^^^^^^^ 
    98336 File
    98337 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98338 packages/numpy/linalg/linalg.py", line 561, in inv 
    98339 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    98340 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98341 File
    98342 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98343 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    98344 raise LinAlgError("Singular matrix") 
    98345 numpy.linalg.LinAlgError: Singular matrix 
    98346  
    98347 numpy.linalg.LinAlgError: Singular matrix 
    98348  
    98349 File
    98350 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98351 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    98352 raise LinAlgError("Singular matrix") 
    98353  
    98354 See log for complete Python traceback. 
    98355  
    98356 Traceback (most recent call last): 
    98357 File
    98358 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98359 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    98360 self.session.ui.mouse_modes.mouse_pause_tracking() 
    98361 File
    98362 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98363 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    98364 mouse_pause_tracking 
    98365 self._mouse_pause() 
    98366 File
    98367 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98368 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    98369 m.pause(self._mouse_pause_position) 
    98370 File
    98371 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98372 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    98373 p = self.view.picked_object(x, y) 
    98374 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98375 File
    98376 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98377 packages/chimerax/graphics/view.py", line 838, in picked_object 
    98378 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    98379 beyond, 
    98380 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98381 File
    98382 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98383 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    98384 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    98385 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98386 File
    98387 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98388 packages/chimerax/core/models.py", line 143, in first_intercept 
    98389 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    98390 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98391 File
    98392 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98393 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    98394 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    98395 exclude=exclude) 
    98396 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98397 File
    98398 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98399 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    98400 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    98401 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98402 File
    98403 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98404 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    98405 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    98406 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98407 File
    98408 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98409 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    98410 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    98411 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98412 File
    98413 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98414 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    98415 p = super().first_intercept(mxyz1, mxyz2) 
    98416 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98417 File
    98418 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98419 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    98420 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    98421 exclude=exclude) 
    98422 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98423 File
    98424 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98425 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    98426 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    98427 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98428 File
    98429 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98430 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    98431 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    98432 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98433 File
    98434 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98435 packages/chimerax/graphics/drawing.py", line 1108, in
    98436 _first_intercept_excluding_children 
    98437 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    98438 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98439 File
    98440 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98441 packages/chimerax/geometry/place.py", line 201, in inverse 
    98442 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    98443 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98444 File
    98445 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98446 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    98447 rinv[:, :] = matrix_inverse(r) 
    98448 ^^^^^^^^^^^^^^^^^ 
    98449 File
    98450 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98451 packages/numpy/linalg/linalg.py", line 561, in inv 
    98452 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    98453 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98454 File
    98455 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98456 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    98457 raise LinAlgError("Singular matrix") 
    98458 numpy.linalg.LinAlgError: Singular matrix 
    98459  
    98460 numpy.linalg.LinAlgError: Singular matrix 
    98461  
    98462 File
    98463 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98464 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    98465 raise LinAlgError("Singular matrix") 
    98466  
    98467 See log for complete Python traceback. 
    98468  
    98469 Traceback (most recent call last): 
    98470 File
    98471 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98472 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    98473 self.session.ui.mouse_modes.mouse_pause_tracking() 
    98474 File
    98475 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98476 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    98477 mouse_pause_tracking 
    98478 self._mouse_pause() 
    98479 File
    98480 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98481 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    98482 m.pause(self._mouse_pause_position) 
    98483 File
    98484 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98485 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    98486 p = self.view.picked_object(x, y) 
    98487 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98488 File
    98489 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98490 packages/chimerax/graphics/view.py", line 838, in picked_object 
    98491 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    98492 beyond, 
    98493 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98494 File
    98495 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98496 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    98497 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    98498 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98499 File
    98500 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98501 packages/chimerax/core/models.py", line 143, in first_intercept 
    98502 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    98503 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98504 File
    98505 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98506 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    98507 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    98508 exclude=exclude) 
    98509 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98510 File
    98511 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98512 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    98513 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    98514 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98515 File
    98516 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98517 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    98518 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    98519 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98520 File
    98521 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98522 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    98523 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    98524 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98525 File
    98526 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98527 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    98528 p = super().first_intercept(mxyz1, mxyz2) 
    98529 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98530 File
    98531 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98532 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    98533 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    98534 exclude=exclude) 
    98535 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98536 File
    98537 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98538 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    98539 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    98540 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98541 File
    98542 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98543 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    98544 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    98545 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98546 File
    98547 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98548 packages/chimerax/graphics/drawing.py", line 1108, in
    98549 _first_intercept_excluding_children 
    98550 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    98551 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98552 File
    98553 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98554 packages/chimerax/geometry/place.py", line 201, in inverse 
    98555 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    98556 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98557 File
    98558 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98559 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    98560 rinv[:, :] = matrix_inverse(r) 
    98561 ^^^^^^^^^^^^^^^^^ 
    98562 File
    98563 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98564 packages/numpy/linalg/linalg.py", line 561, in inv 
    98565 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    98566 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98567 File
    98568 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98569 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    98570 raise LinAlgError("Singular matrix") 
    98571 numpy.linalg.LinAlgError: Singular matrix 
    98572  
    98573 numpy.linalg.LinAlgError: Singular matrix 
    98574  
    98575 File
    98576 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98577 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    98578 raise LinAlgError("Singular matrix") 
    98579  
    98580 See log for complete Python traceback. 
    98581  
    98582 Traceback (most recent call last): 
    98583 File
    98584 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98585 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    98586 self.session.ui.mouse_modes.mouse_pause_tracking() 
    98587 File
    98588 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98589 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    98590 mouse_pause_tracking 
    98591 self._mouse_pause() 
    98592 File
    98593 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98594 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    98595 m.pause(self._mouse_pause_position) 
    98596 File
    98597 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98598 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    98599 p = self.view.picked_object(x, y) 
    98600 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98601 File
    98602 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98603 packages/chimerax/graphics/view.py", line 838, in picked_object 
    98604 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    98605 beyond, 
    98606 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98607 File
    98608 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98609 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    98610 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    98611 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98612 File
    98613 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98614 packages/chimerax/core/models.py", line 143, in first_intercept 
    98615 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    98616 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98617 File
    98618 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98619 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    98620 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    98621 exclude=exclude) 
    98622 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98623 File
    98624 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98625 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    98626 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    98627 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98628 File
    98629 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98630 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    98631 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    98632 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98633 File
    98634 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98635 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    98636 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    98637 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98638 File
    98639 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98640 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    98641 p = super().first_intercept(mxyz1, mxyz2) 
    98642 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98643 File
    98644 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98645 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    98646 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    98647 exclude=exclude) 
    98648 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98649 File
    98650 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98651 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    98652 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    98653 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98654 File
    98655 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98656 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    98657 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    98658 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98659 File
    98660 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98661 packages/chimerax/graphics/drawing.py", line 1108, in
    98662 _first_intercept_excluding_children 
    98663 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    98664 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98665 File
    98666 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98667 packages/chimerax/geometry/place.py", line 201, in inverse 
    98668 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    98669 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98670 File
    98671 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98672 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    98673 rinv[:, :] = matrix_inverse(r) 
    98674 ^^^^^^^^^^^^^^^^^ 
    98675 File
    98676 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98677 packages/numpy/linalg/linalg.py", line 561, in inv 
    98678 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    98679 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98680 File
    98681 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98682 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    98683 raise LinAlgError("Singular matrix") 
    98684 numpy.linalg.LinAlgError: Singular matrix 
    98685  
    98686 numpy.linalg.LinAlgError: Singular matrix 
    98687  
    98688 File
    98689 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98690 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    98691 raise LinAlgError("Singular matrix") 
    98692  
    98693 See log for complete Python traceback. 
    98694  
    98695 Traceback (most recent call last): 
    98696 File
    98697 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98698 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    98699 self.session.ui.mouse_modes.mouse_pause_tracking() 
    98700 File
    98701 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98702 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    98703 mouse_pause_tracking 
    98704 self._mouse_pause() 
    98705 File
    98706 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98707 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    98708 m.pause(self._mouse_pause_position) 
    98709 File
    98710 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98711 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    98712 p = self.view.picked_object(x, y) 
    98713 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98714 File
    98715 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98716 packages/chimerax/graphics/view.py", line 838, in picked_object 
    98717 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    98718 beyond, 
    98719 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98720 File
    98721 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98722 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    98723 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    98724 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98725 File
    98726 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98727 packages/chimerax/core/models.py", line 143, in first_intercept 
    98728 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    98729 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98730 File
    98731 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98732 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    98733 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    98734 exclude=exclude) 
    98735 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98736 File
    98737 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98738 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    98739 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    98740 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98741 File
    98742 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98743 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    98744 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    98745 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98746 File
    98747 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98748 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    98749 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    98750 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98751 File
    98752 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98753 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    98754 p = super().first_intercept(mxyz1, mxyz2) 
    98755 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98756 File
    98757 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98758 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    98759 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    98760 exclude=exclude) 
    98761 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98762 File
    98763 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98764 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    98765 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    98766 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98767 File
    98768 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98769 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    98770 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    98771 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98772 File
    98773 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98774 packages/chimerax/graphics/drawing.py", line 1108, in
    98775 _first_intercept_excluding_children 
    98776 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    98777 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98778 File
    98779 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98780 packages/chimerax/geometry/place.py", line 201, in inverse 
    98781 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    98782 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98783 File
    98784 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98785 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    98786 rinv[:, :] = matrix_inverse(r) 
    98787 ^^^^^^^^^^^^^^^^^ 
    98788 File
    98789 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98790 packages/numpy/linalg/linalg.py", line 561, in inv 
    98791 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    98792 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98793 File
    98794 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98795 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    98796 raise LinAlgError("Singular matrix") 
    98797 numpy.linalg.LinAlgError: Singular matrix 
    98798  
    98799 numpy.linalg.LinAlgError: Singular matrix 
    98800  
    98801 File
    98802 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98803 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    98804 raise LinAlgError("Singular matrix") 
    98805  
    98806 See log for complete Python traceback. 
    98807  
    98808 Traceback (most recent call last): 
    98809 File
    98810 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98811 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    98812 self.session.ui.mouse_modes.mouse_pause_tracking() 
    98813 File
    98814 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98815 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    98816 mouse_pause_tracking 
    98817 self._mouse_pause() 
    98818 File
    98819 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98820 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    98821 m.pause(self._mouse_pause_position) 
    98822 File
    98823 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98824 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    98825 p = self.view.picked_object(x, y) 
    98826 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98827 File
    98828 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98829 packages/chimerax/graphics/view.py", line 838, in picked_object 
    98830 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    98831 beyond, 
    98832 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98833 File
    98834 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98835 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    98836 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    98837 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98838 File
    98839 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98840 packages/chimerax/core/models.py", line 143, in first_intercept 
    98841 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    98842 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98843 File
    98844 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98845 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    98846 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    98847 exclude=exclude) 
    98848 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98849 File
    98850 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98851 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    98852 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    98853 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98854 File
    98855 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98856 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    98857 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    98858 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98859 File
    98860 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98861 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    98862 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    98863 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98864 File
    98865 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98866 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    98867 p = super().first_intercept(mxyz1, mxyz2) 
    98868 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98869 File
    98870 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98871 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    98872 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    98873 exclude=exclude) 
    98874 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98875 File
    98876 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98877 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    98878 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    98879 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98880 File
    98881 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98882 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    98883 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    98884 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98885 File
    98886 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98887 packages/chimerax/graphics/drawing.py", line 1108, in
    98888 _first_intercept_excluding_children 
    98889 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    98890 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98891 File
    98892 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98893 packages/chimerax/geometry/place.py", line 201, in inverse 
    98894 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    98895 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98896 File
    98897 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98898 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    98899 rinv[:, :] = matrix_inverse(r) 
    98900 ^^^^^^^^^^^^^^^^^ 
    98901 File
    98902 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98903 packages/numpy/linalg/linalg.py", line 561, in inv 
    98904 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    98905 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98906 File
    98907 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98908 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    98909 raise LinAlgError("Singular matrix") 
    98910 numpy.linalg.LinAlgError: Singular matrix 
    98911  
    98912 numpy.linalg.LinAlgError: Singular matrix 
    98913  
    98914 File
    98915 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98916 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    98917 raise LinAlgError("Singular matrix") 
    98918  
    98919 See log for complete Python traceback. 
    98920  
    98921 Traceback (most recent call last): 
    98922 File
    98923 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98924 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    98925 self.session.ui.mouse_modes.mouse_pause_tracking() 
    98926 File
    98927 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98928 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    98929 mouse_pause_tracking 
    98930 self._mouse_pause() 
    98931 File
    98932 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98933 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    98934 m.pause(self._mouse_pause_position) 
    98935 File
    98936 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98937 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    98938 p = self.view.picked_object(x, y) 
    98939 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98940 File
    98941 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98942 packages/chimerax/graphics/view.py", line 838, in picked_object 
    98943 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    98944 beyond, 
    98945 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98946 File
    98947 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98948 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    98949 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    98950 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98951 File
    98952 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98953 packages/chimerax/core/models.py", line 143, in first_intercept 
    98954 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    98955 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98956 File
    98957 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98958 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    98959 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    98960 exclude=exclude) 
    98961 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98962 File
    98963 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98964 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    98965 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    98966 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98967 File
    98968 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98969 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    98970 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    98971 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98972 File
    98973 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98974 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    98975 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    98976 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98977 File
    98978 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98979 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    98980 p = super().first_intercept(mxyz1, mxyz2) 
    98981 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98982 File
    98983 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98984 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    98985 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    98986 exclude=exclude) 
    98987 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98988 File
    98989 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98990 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    98991 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    98992 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98993 File
    98994 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    98995 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    98996 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    98997 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    98998 File
    98999 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99000 packages/chimerax/graphics/drawing.py", line 1108, in
    99001 _first_intercept_excluding_children 
    99002 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    99003 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99004 File
    99005 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99006 packages/chimerax/geometry/place.py", line 201, in inverse 
    99007 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    99008 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99009 File
    99010 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99011 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    99012 rinv[:, :] = matrix_inverse(r) 
    99013 ^^^^^^^^^^^^^^^^^ 
    99014 File
    99015 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99016 packages/numpy/linalg/linalg.py", line 561, in inv 
    99017 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    99018 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99019 File
    99020 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99021 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    99022 raise LinAlgError("Singular matrix") 
    99023 numpy.linalg.LinAlgError: Singular matrix 
    99024  
    99025 numpy.linalg.LinAlgError: Singular matrix 
    99026  
    99027 File
    99028 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99029 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    99030 raise LinAlgError("Singular matrix") 
    99031  
    99032 See log for complete Python traceback. 
    99033  
    99034 Traceback (most recent call last): 
    99035 File
    99036 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99037 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    99038 self.session.ui.mouse_modes.mouse_pause_tracking() 
    99039 File
    99040 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99041 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    99042 mouse_pause_tracking 
    99043 self._mouse_pause() 
    99044 File
    99045 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99046 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    99047 m.pause(self._mouse_pause_position) 
    99048 File
    99049 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99050 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    99051 p = self.view.picked_object(x, y) 
    99052 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99053 File
    99054 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99055 packages/chimerax/graphics/view.py", line 838, in picked_object 
    99056 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    99057 beyond, 
    99058 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99059 File
    99060 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99061 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    99062 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    99063 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99064 File
    99065 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99066 packages/chimerax/core/models.py", line 143, in first_intercept 
    99067 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    99068 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99069 File
    99070 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99071 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    99072 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    99073 exclude=exclude) 
    99074 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99075 File
    99076 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99077 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    99078 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    99079 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99080 File
    99081 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99082 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    99083 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    99084 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99085 File
    99086 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99087 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    99088 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    99089 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99090 File
    99091 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99092 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    99093 p = super().first_intercept(mxyz1, mxyz2) 
    99094 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99095 File
    99096 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99097 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    99098 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    99099 exclude=exclude) 
    99100 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99101 File
    99102 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99103 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    99104 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    99105 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99106 File
    99107 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99108 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    99109 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    99110 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99111 File
    99112 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99113 packages/chimerax/graphics/drawing.py", line 1108, in
    99114 _first_intercept_excluding_children 
    99115 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    99116 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99117 File
    99118 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99119 packages/chimerax/geometry/place.py", line 201, in inverse 
    99120 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    99121 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99122 File
    99123 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99124 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    99125 rinv[:, :] = matrix_inverse(r) 
    99126 ^^^^^^^^^^^^^^^^^ 
    99127 File
    99128 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99129 packages/numpy/linalg/linalg.py", line 561, in inv 
    99130 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    99131 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99132 File
    99133 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99134 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    99135 raise LinAlgError("Singular matrix") 
    99136 numpy.linalg.LinAlgError: Singular matrix 
    99137  
    99138 numpy.linalg.LinAlgError: Singular matrix 
    99139  
    99140 File
    99141 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99142 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    99143 raise LinAlgError("Singular matrix") 
    99144  
    99145 See log for complete Python traceback. 
    99146  
    99147 Traceback (most recent call last): 
    99148 File
    99149 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99150 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    99151 self.session.ui.mouse_modes.mouse_pause_tracking() 
    99152 File
    99153 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99154 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    99155 mouse_pause_tracking 
    99156 self._mouse_pause() 
    99157 File
    99158 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99159 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    99160 m.pause(self._mouse_pause_position) 
    99161 File
    99162 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99163 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    99164 p = self.view.picked_object(x, y) 
    99165 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99166 File
    99167 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99168 packages/chimerax/graphics/view.py", line 838, in picked_object 
    99169 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    99170 beyond, 
    99171 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99172 File
    99173 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99174 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    99175 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    99176 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99177 File
    99178 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99179 packages/chimerax/core/models.py", line 143, in first_intercept 
    99180 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    99181 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99182 File
    99183 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99184 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    99185 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    99186 exclude=exclude) 
    99187 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99188 File
    99189 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99190 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    99191 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    99192 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99193 File
    99194 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99195 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    99196 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    99197 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99198 File
    99199 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99200 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    99201 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    99202 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99203 File
    99204 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99205 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    99206 p = super().first_intercept(mxyz1, mxyz2) 
    99207 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99208 File
    99209 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99210 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    99211 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    99212 exclude=exclude) 
    99213 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99214 File
    99215 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99216 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    99217 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    99218 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99219 File
    99220 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99221 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    99222 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    99223 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99224 File
    99225 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99226 packages/chimerax/graphics/drawing.py", line 1108, in
    99227 _first_intercept_excluding_children 
    99228 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    99229 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99230 File
    99231 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99232 packages/chimerax/geometry/place.py", line 201, in inverse 
    99233 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    99234 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99235 File
    99236 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99237 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    99238 rinv[:, :] = matrix_inverse(r) 
    99239 ^^^^^^^^^^^^^^^^^ 
    99240 File
    99241 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99242 packages/numpy/linalg/linalg.py", line 561, in inv 
    99243 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    99244 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99245 File
    99246 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99247 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    99248 raise LinAlgError("Singular matrix") 
    99249 numpy.linalg.LinAlgError: Singular matrix 
    99250  
    99251 numpy.linalg.LinAlgError: Singular matrix 
    99252  
    99253 File
    99254 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99255 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    99256 raise LinAlgError("Singular matrix") 
    99257  
    99258 See log for complete Python traceback. 
    99259  
    99260 Traceback (most recent call last): 
    99261 File
    99262 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99263 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    99264 self.session.ui.mouse_modes.mouse_pause_tracking() 
    99265 File
    99266 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99267 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    99268 mouse_pause_tracking 
    99269 self._mouse_pause() 
    99270 File
    99271 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99272 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    99273 m.pause(self._mouse_pause_position) 
    99274 File
    99275 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99276 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    99277 p = self.view.picked_object(x, y) 
    99278 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99279 File
    99280 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99281 packages/chimerax/graphics/view.py", line 838, in picked_object 
    99282 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    99283 beyond, 
    99284 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99285 File
    99286 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99287 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    99288 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    99289 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99290 File
    99291 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99292 packages/chimerax/core/models.py", line 143, in first_intercept 
    99293 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    99294 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99295 File
    99296 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99297 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    99298 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    99299 exclude=exclude) 
    99300 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99301 File
    99302 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99303 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    99304 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    99305 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99306 File
    99307 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99308 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    99309 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    99310 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99311 File
    99312 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99313 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    99314 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    99315 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99316 File
    99317 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99318 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    99319 p = super().first_intercept(mxyz1, mxyz2) 
    99320 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99321 File
    99322 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99323 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    99324 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    99325 exclude=exclude) 
    99326 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99327 File
    99328 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99329 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    99330 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    99331 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99332 File
    99333 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99334 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    99335 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    99336 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99337 File
    99338 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99339 packages/chimerax/graphics/drawing.py", line 1108, in
    99340 _first_intercept_excluding_children 
    99341 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    99342 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99343 File
    99344 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99345 packages/chimerax/geometry/place.py", line 201, in inverse 
    99346 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    99347 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99348 File
    99349 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99350 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    99351 rinv[:, :] = matrix_inverse(r) 
    99352 ^^^^^^^^^^^^^^^^^ 
    99353 File
    99354 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99355 packages/numpy/linalg/linalg.py", line 561, in inv 
    99356 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    99357 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99358 File
    99359 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99360 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    99361 raise LinAlgError("Singular matrix") 
    99362 numpy.linalg.LinAlgError: Singular matrix 
    99363  
    99364 numpy.linalg.LinAlgError: Singular matrix 
    99365  
    99366 File
    99367 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99368 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    99369 raise LinAlgError("Singular matrix") 
    99370  
    99371 See log for complete Python traceback. 
    99372  
    99373 Traceback (most recent call last): 
    99374 File
    99375 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99376 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    99377 self.session.ui.mouse_modes.mouse_pause_tracking() 
    99378 File
    99379 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99380 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    99381 mouse_pause_tracking 
    99382 self._mouse_pause() 
    99383 File
    99384 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99385 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    99386 m.pause(self._mouse_pause_position) 
    99387 File
    99388 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99389 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    99390 p = self.view.picked_object(x, y) 
    99391 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99392 File
    99393 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99394 packages/chimerax/graphics/view.py", line 838, in picked_object 
    99395 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    99396 beyond, 
    99397 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99398 File
    99399 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99400 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    99401 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    99402 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99403 File
    99404 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99405 packages/chimerax/core/models.py", line 143, in first_intercept 
    99406 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    99407 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99408 File
    99409 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99410 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    99411 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    99412 exclude=exclude) 
    99413 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99414 File
    99415 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99416 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    99417 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    99418 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99419 File
    99420 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99421 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    99422 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    99423 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99424 File
    99425 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99426 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    99427 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    99428 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99429 File
    99430 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99431 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    99432 p = super().first_intercept(mxyz1, mxyz2) 
    99433 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99434 File
    99435 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99436 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    99437 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    99438 exclude=exclude) 
    99439 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99440 File
    99441 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99442 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    99443 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    99444 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99445 File
    99446 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99447 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    99448 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    99449 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99450 File
    99451 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99452 packages/chimerax/graphics/drawing.py", line 1108, in
    99453 _first_intercept_excluding_children 
    99454 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    99455 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99456 File
    99457 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99458 packages/chimerax/geometry/place.py", line 201, in inverse 
    99459 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    99460 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99461 File
    99462 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99463 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    99464 rinv[:, :] = matrix_inverse(r) 
    99465 ^^^^^^^^^^^^^^^^^ 
    99466 File
    99467 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99468 packages/numpy/linalg/linalg.py", line 561, in inv 
    99469 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    99470 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99471 File
    99472 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99473 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    99474 raise LinAlgError("Singular matrix") 
    99475 numpy.linalg.LinAlgError: Singular matrix 
    99476  
    99477 numpy.linalg.LinAlgError: Singular matrix 
    99478  
    99479 File
    99480 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99481 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    99482 raise LinAlgError("Singular matrix") 
    99483  
    99484 See log for complete Python traceback. 
    99485  
    99486 Traceback (most recent call last): 
    99487 File
    99488 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99489 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    99490 self.session.ui.mouse_modes.mouse_pause_tracking() 
    99491 File
    99492 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99493 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    99494 mouse_pause_tracking 
    99495 self._mouse_pause() 
    99496 File
    99497 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99498 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    99499 m.pause(self._mouse_pause_position) 
    99500 File
    99501 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99502 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    99503 p = self.view.picked_object(x, y) 
    99504 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99505 File
    99506 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99507 packages/chimerax/graphics/view.py", line 838, in picked_object 
    99508 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    99509 beyond, 
    99510 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99511 File
    99512 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99513 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    99514 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    99515 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99516 File
    99517 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99518 packages/chimerax/core/models.py", line 143, in first_intercept 
    99519 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    99520 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99521 File
    99522 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99523 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    99524 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    99525 exclude=exclude) 
    99526 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99527 File
    99528 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99529 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    99530 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    99531 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99532 File
    99533 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99534 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    99535 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    99536 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99537 File
    99538 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99539 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    99540 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    99541 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99542 File
    99543 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99544 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    99545 p = super().first_intercept(mxyz1, mxyz2) 
    99546 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99547 File
    99548 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99549 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    99550 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    99551 exclude=exclude) 
    99552 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99553 File
    99554 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99555 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    99556 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    99557 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99558 File
    99559 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99560 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    99561 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    99562 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99563 File
    99564 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99565 packages/chimerax/graphics/drawing.py", line 1108, in
    99566 _first_intercept_excluding_children 
    99567 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    99568 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99569 File
    99570 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99571 packages/chimerax/geometry/place.py", line 201, in inverse 
    99572 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    99573 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99574 File
    99575 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99576 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    99577 rinv[:, :] = matrix_inverse(r) 
    99578 ^^^^^^^^^^^^^^^^^ 
    99579 File
    99580 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99581 packages/numpy/linalg/linalg.py", line 561, in inv 
    99582 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    99583 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99584 File
    99585 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99586 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    99587 raise LinAlgError("Singular matrix") 
    99588 numpy.linalg.LinAlgError: Singular matrix 
    99589  
    99590 numpy.linalg.LinAlgError: Singular matrix 
    99591  
    99592 File
    99593 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99594 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    99595 raise LinAlgError("Singular matrix") 
    99596  
    99597 See log for complete Python traceback. 
    99598  
    99599 Traceback (most recent call last): 
    99600 File
    99601 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99602 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    99603 self.session.ui.mouse_modes.mouse_pause_tracking() 
    99604 File
    99605 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99606 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    99607 mouse_pause_tracking 
    99608 self._mouse_pause() 
    99609 File
    99610 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99611 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    99612 m.pause(self._mouse_pause_position) 
    99613 File
    99614 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99615 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    99616 p = self.view.picked_object(x, y) 
    99617 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99618 File
    99619 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99620 packages/chimerax/graphics/view.py", line 838, in picked_object 
    99621 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    99622 beyond, 
    99623 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99624 File
    99625 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99626 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    99627 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    99628 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99629 File
    99630 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99631 packages/chimerax/core/models.py", line 143, in first_intercept 
    99632 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    99633 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99634 File
    99635 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99636 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    99637 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    99638 exclude=exclude) 
    99639 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99640 File
    99641 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99642 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    99643 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    99644 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99645 File
    99646 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99647 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    99648 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    99649 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99650 File
    99651 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99652 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    99653 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    99654 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99655 File
    99656 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99657 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    99658 p = super().first_intercept(mxyz1, mxyz2) 
    99659 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99660 File
    99661 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99662 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    99663 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    99664 exclude=exclude) 
    99665 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99666 File
    99667 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99668 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    99669 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    99670 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99671 File
    99672 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99673 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    99674 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    99675 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99676 File
    99677 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99678 packages/chimerax/graphics/drawing.py", line 1108, in
    99679 _first_intercept_excluding_children 
    99680 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    99681 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99682 File
    99683 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99684 packages/chimerax/geometry/place.py", line 201, in inverse 
    99685 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    99686 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99687 File
    99688 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99689 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    99690 rinv[:, :] = matrix_inverse(r) 
    99691 ^^^^^^^^^^^^^^^^^ 
    99692 File
    99693 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99694 packages/numpy/linalg/linalg.py", line 561, in inv 
    99695 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    99696 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99697 File
    99698 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99699 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    99700 raise LinAlgError("Singular matrix") 
    99701 numpy.linalg.LinAlgError: Singular matrix 
    99702  
    99703 numpy.linalg.LinAlgError: Singular matrix 
    99704  
    99705 File
    99706 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99707 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    99708 raise LinAlgError("Singular matrix") 
    99709  
    99710 See log for complete Python traceback. 
    99711  
    99712 Traceback (most recent call last): 
    99713 File
    99714 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99715 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    99716 self.session.ui.mouse_modes.mouse_pause_tracking() 
    99717 File
    99718 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99719 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    99720 mouse_pause_tracking 
    99721 self._mouse_pause() 
    99722 File
    99723 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99724 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    99725 m.pause(self._mouse_pause_position) 
    99726 File
    99727 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99728 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    99729 p = self.view.picked_object(x, y) 
    99730 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99731 File
    99732 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99733 packages/chimerax/graphics/view.py", line 838, in picked_object 
    99734 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    99735 beyond, 
    99736 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99737 File
    99738 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99739 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    99740 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    99741 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99742 File
    99743 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99744 packages/chimerax/core/models.py", line 143, in first_intercept 
    99745 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    99746 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99747 File
    99748 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99749 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    99750 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    99751 exclude=exclude) 
    99752 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99753 File
    99754 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99755 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    99756 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    99757 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99758 File
    99759 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99760 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    99761 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    99762 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99763 File
    99764 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99765 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    99766 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    99767 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99768 File
    99769 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99770 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    99771 p = super().first_intercept(mxyz1, mxyz2) 
    99772 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99773 File
    99774 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99775 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    99776 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    99777 exclude=exclude) 
    99778 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99779 File
    99780 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99781 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    99782 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    99783 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99784 File
    99785 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99786 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    99787 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    99788 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99789 File
    99790 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99791 packages/chimerax/graphics/drawing.py", line 1108, in
    99792 _first_intercept_excluding_children 
    99793 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    99794 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99795 File
    99796 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99797 packages/chimerax/geometry/place.py", line 201, in inverse 
    99798 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    99799 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99800 File
    99801 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99802 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    99803 rinv[:, :] = matrix_inverse(r) 
    99804 ^^^^^^^^^^^^^^^^^ 
    99805 File
    99806 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99807 packages/numpy/linalg/linalg.py", line 561, in inv 
    99808 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    99809 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99810 File
    99811 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99812 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    99813 raise LinAlgError("Singular matrix") 
    99814 numpy.linalg.LinAlgError: Singular matrix 
    99815  
    99816 numpy.linalg.LinAlgError: Singular matrix 
    99817  
    99818 File
    99819 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99820 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    99821 raise LinAlgError("Singular matrix") 
    99822  
    99823 See log for complete Python traceback. 
    99824  
    99825 Traceback (most recent call last): 
    99826 File
    99827 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99828 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    99829 self.session.ui.mouse_modes.mouse_pause_tracking() 
    99830 File
    99831 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99832 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    99833 mouse_pause_tracking 
    99834 self._mouse_pause() 
    99835 File
    99836 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99837 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    99838 m.pause(self._mouse_pause_position) 
    99839 File
    99840 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99841 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    99842 p = self.view.picked_object(x, y) 
    99843 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99844 File
    99845 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99846 packages/chimerax/graphics/view.py", line 838, in picked_object 
    99847 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    99848 beyond, 
    99849 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99850 File
    99851 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99852 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    99853 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    99854 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99855 File
    99856 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99857 packages/chimerax/core/models.py", line 143, in first_intercept 
    99858 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    99859 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99860 File
    99861 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99862 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    99863 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    99864 exclude=exclude) 
    99865 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99866 File
    99867 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99868 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    99869 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    99870 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99871 File
    99872 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99873 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    99874 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    99875 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99876 File
    99877 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99878 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    99879 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    99880 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99881 File
    99882 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99883 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    99884 p = super().first_intercept(mxyz1, mxyz2) 
    99885 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99886 File
    99887 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99888 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    99889 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    99890 exclude=exclude) 
    99891 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99892 File
    99893 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99894 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    99895 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    99896 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99897 File
    99898 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99899 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    99900 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    99901 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99902 File
    99903 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99904 packages/chimerax/graphics/drawing.py", line 1108, in
    99905 _first_intercept_excluding_children 
    99906 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    99907 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99908 File
    99909 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99910 packages/chimerax/geometry/place.py", line 201, in inverse 
    99911 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    99912 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99913 File
    99914 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99915 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    99916 rinv[:, :] = matrix_inverse(r) 
    99917 ^^^^^^^^^^^^^^^^^ 
    99918 File
    99919 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99920 packages/numpy/linalg/linalg.py", line 561, in inv 
    99921 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    99922 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99923 File
    99924 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99925 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    99926 raise LinAlgError("Singular matrix") 
    99927 numpy.linalg.LinAlgError: Singular matrix 
    99928  
    99929 numpy.linalg.LinAlgError: Singular matrix 
    99930  
    99931 File
    99932 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99933 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    99934 raise LinAlgError("Singular matrix") 
    99935  
    99936 See log for complete Python traceback. 
    99937  
    99938 Traceback (most recent call last): 
    99939 File
    99940 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99941 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    99942 self.session.ui.mouse_modes.mouse_pause_tracking() 
    99943 File
    99944 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99945 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    99946 mouse_pause_tracking 
    99947 self._mouse_pause() 
    99948 File
    99949 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99950 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    99951 m.pause(self._mouse_pause_position) 
    99952 File
    99953 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99954 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    99955 p = self.view.picked_object(x, y) 
    99956 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99957 File
    99958 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99959 packages/chimerax/graphics/view.py", line 838, in picked_object 
    99960 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    99961 beyond, 
    99962 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99963 File
    99964 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99965 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    99966 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    99967 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99968 File
    99969 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99970 packages/chimerax/core/models.py", line 143, in first_intercept 
    99971 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    99972 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99973 File
    99974 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99975 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    99976 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    99977 exclude=exclude) 
    99978 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99979 File
    99980 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99981 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    99982 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    99983 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99984 File
    99985 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99986 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    99987 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    99988 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99989 File
    99990 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99991 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    99992 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    99993 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99994 File
    99995 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    99996 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    99997 p = super().first_intercept(mxyz1, mxyz2) 
    99998 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    99999 File
    100000 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100001 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    100002 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    100003 exclude=exclude) 
    100004 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100005 File
    100006 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100007 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    100008 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    100009 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100010 File
    100011 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100012 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    100013 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    100014 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100015 File
    100016 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100017 packages/chimerax/graphics/drawing.py", line 1108, in
    100018 _first_intercept_excluding_children 
    100019 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    100020 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100021 File
    100022 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100023 packages/chimerax/geometry/place.py", line 201, in inverse 
    100024 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    100025 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100026 File
    100027 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100028 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    100029 rinv[:, :] = matrix_inverse(r) 
    100030 ^^^^^^^^^^^^^^^^^ 
    100031 File
    100032 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100033 packages/numpy/linalg/linalg.py", line 561, in inv 
    100034 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    100035 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100036 File
    100037 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100038 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    100039 raise LinAlgError("Singular matrix") 
    100040 numpy.linalg.LinAlgError: Singular matrix 
    100041  
    100042 numpy.linalg.LinAlgError: Singular matrix 
    100043  
    100044 File
    100045 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100046 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    100047 raise LinAlgError("Singular matrix") 
    100048  
    100049 See log for complete Python traceback. 
    100050  
    100051 Traceback (most recent call last): 
    100052 File
    100053 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100054 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    100055 self.session.ui.mouse_modes.mouse_pause_tracking() 
    100056 File
    100057 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100058 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    100059 mouse_pause_tracking 
    100060 self._mouse_pause() 
    100061 File
    100062 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100063 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    100064 m.pause(self._mouse_pause_position) 
    100065 File
    100066 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100067 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    100068 p = self.view.picked_object(x, y) 
    100069 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100070 File
    100071 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100072 packages/chimerax/graphics/view.py", line 838, in picked_object 
    100073 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    100074 beyond, 
    100075 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100076 File
    100077 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100078 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    100079 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    100080 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100081 File
    100082 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100083 packages/chimerax/core/models.py", line 143, in first_intercept 
    100084 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    100085 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100086 File
    100087 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100088 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    100089 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    100090 exclude=exclude) 
    100091 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100092 File
    100093 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100094 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    100095 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    100096 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100097 File
    100098 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100099 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    100100 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    100101 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100102 File
    100103 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100104 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    100105 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    100106 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100107 File
    100108 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100109 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    100110 p = super().first_intercept(mxyz1, mxyz2) 
    100111 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100112 File
    100113 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100114 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    100115 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    100116 exclude=exclude) 
    100117 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100118 File
    100119 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100120 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    100121 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    100122 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100123 File
    100124 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100125 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    100126 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    100127 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100128 File
    100129 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100130 packages/chimerax/graphics/drawing.py", line 1108, in
    100131 _first_intercept_excluding_children 
    100132 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    100133 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100134 File
    100135 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100136 packages/chimerax/geometry/place.py", line 201, in inverse 
    100137 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    100138 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100139 File
    100140 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100141 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    100142 rinv[:, :] = matrix_inverse(r) 
    100143 ^^^^^^^^^^^^^^^^^ 
    100144 File
    100145 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100146 packages/numpy/linalg/linalg.py", line 561, in inv 
    100147 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    100148 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100149 File
    100150 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100151 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    100152 raise LinAlgError("Singular matrix") 
    100153 numpy.linalg.LinAlgError: Singular matrix 
    100154  
    100155 numpy.linalg.LinAlgError: Singular matrix 
    100156  
    100157 File
    100158 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100159 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    100160 raise LinAlgError("Singular matrix") 
    100161  
    100162 See log for complete Python traceback. 
    100163  
    100164 Traceback (most recent call last): 
    100165 File
    100166 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100167 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    100168 self.session.ui.mouse_modes.mouse_pause_tracking() 
    100169 File
    100170 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100171 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    100172 mouse_pause_tracking 
    100173 self._mouse_pause() 
    100174 File
    100175 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100176 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    100177 m.pause(self._mouse_pause_position) 
    100178 File
    100179 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100180 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    100181 p = self.view.picked_object(x, y) 
    100182 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100183 File
    100184 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100185 packages/chimerax/graphics/view.py", line 838, in picked_object 
    100186 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    100187 beyond, 
    100188 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100189 File
    100190 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100191 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    100192 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    100193 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100194 File
    100195 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100196 packages/chimerax/core/models.py", line 143, in first_intercept 
    100197 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    100198 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100199 File
    100200 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100201 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    100202 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    100203 exclude=exclude) 
    100204 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100205 File
    100206 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100207 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    100208 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    100209 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100210 File
    100211 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100212 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    100213 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    100214 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100215 File
    100216 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100217 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    100218 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    100219 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100220 File
    100221 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100222 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    100223 p = super().first_intercept(mxyz1, mxyz2) 
    100224 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100225 File
    100226 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100227 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    100228 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    100229 exclude=exclude) 
    100230 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100231 File
    100232 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100233 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    100234 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    100235 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100236 File
    100237 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100238 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    100239 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    100240 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100241 File
    100242 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100243 packages/chimerax/graphics/drawing.py", line 1108, in
    100244 _first_intercept_excluding_children 
    100245 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    100246 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100247 File
    100248 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100249 packages/chimerax/geometry/place.py", line 201, in inverse 
    100250 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    100251 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100252 File
    100253 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100254 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    100255 rinv[:, :] = matrix_inverse(r) 
    100256 ^^^^^^^^^^^^^^^^^ 
    100257 File
    100258 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100259 packages/numpy/linalg/linalg.py", line 561, in inv 
    100260 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    100261 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100262 File
    100263 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100264 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    100265 raise LinAlgError("Singular matrix") 
    100266 numpy.linalg.LinAlgError: Singular matrix 
    100267  
    100268 numpy.linalg.LinAlgError: Singular matrix 
    100269  
    100270 File
    100271 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100272 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    100273 raise LinAlgError("Singular matrix") 
    100274  
    100275 See log for complete Python traceback. 
    100276  
    100277 Traceback (most recent call last): 
    100278 File
    100279 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100280 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    100281 self.session.ui.mouse_modes.mouse_pause_tracking() 
    100282 File
    100283 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100284 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    100285 mouse_pause_tracking 
    100286 self._mouse_pause() 
    100287 File
    100288 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100289 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    100290 m.pause(self._mouse_pause_position) 
    100291 File
    100292 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100293 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    100294 p = self.view.picked_object(x, y) 
    100295 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100296 File
    100297 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100298 packages/chimerax/graphics/view.py", line 838, in picked_object 
    100299 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    100300 beyond, 
    100301 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100302 File
    100303 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100304 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    100305 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    100306 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100307 File
    100308 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100309 packages/chimerax/core/models.py", line 143, in first_intercept 
    100310 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    100311 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100312 File
    100313 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100314 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    100315 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    100316 exclude=exclude) 
    100317 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100318 File
    100319 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100320 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    100321 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    100322 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100323 File
    100324 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100325 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    100326 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    100327 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100328 File
    100329 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100330 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    100331 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    100332 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100333 File
    100334 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100335 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    100336 p = super().first_intercept(mxyz1, mxyz2) 
    100337 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100338 File
    100339 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100340 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    100341 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    100342 exclude=exclude) 
    100343 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100344 File
    100345 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100346 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    100347 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    100348 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100349 File
    100350 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100351 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    100352 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    100353 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100354 File
    100355 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100356 packages/chimerax/graphics/drawing.py", line 1108, in
    100357 _first_intercept_excluding_children 
    100358 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    100359 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100360 File
    100361 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100362 packages/chimerax/geometry/place.py", line 201, in inverse 
    100363 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    100364 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100365 File
    100366 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100367 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    100368 rinv[:, :] = matrix_inverse(r) 
    100369 ^^^^^^^^^^^^^^^^^ 
    100370 File
    100371 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100372 packages/numpy/linalg/linalg.py", line 561, in inv 
    100373 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    100374 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100375 File
    100376 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100377 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    100378 raise LinAlgError("Singular matrix") 
    100379 numpy.linalg.LinAlgError: Singular matrix 
    100380  
    100381 numpy.linalg.LinAlgError: Singular matrix 
    100382  
    100383 File
    100384 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100385 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    100386 raise LinAlgError("Singular matrix") 
    100387  
    100388 See log for complete Python traceback. 
    100389  
    100390 Traceback (most recent call last): 
    100391 File
    100392 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100393 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    100394 self.session.ui.mouse_modes.mouse_pause_tracking() 
    100395 File
    100396 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100397 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    100398 mouse_pause_tracking 
    100399 self._mouse_pause() 
    100400 File
    100401 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100402 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    100403 m.pause(self._mouse_pause_position) 
    100404 File
    100405 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100406 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    100407 p = self.view.picked_object(x, y) 
    100408 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100409 File
    100410 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100411 packages/chimerax/graphics/view.py", line 838, in picked_object 
    100412 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    100413 beyond, 
    100414 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100415 File
    100416 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100417 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    100418 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    100419 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100420 File
    100421 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100422 packages/chimerax/core/models.py", line 143, in first_intercept 
    100423 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    100424 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100425 File
    100426 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100427 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    100428 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    100429 exclude=exclude) 
    100430 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100431 File
    100432 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100433 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    100434 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    100435 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100436 File
    100437 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100438 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    100439 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    100440 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100441 File
    100442 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100443 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    100444 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    100445 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100446 File
    100447 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100448 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    100449 p = super().first_intercept(mxyz1, mxyz2) 
    100450 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100451 File
    100452 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100453 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    100454 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    100455 exclude=exclude) 
    100456 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100457 File
    100458 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100459 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    100460 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    100461 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100462 File
    100463 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100464 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    100465 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    100466 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100467 File
    100468 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100469 packages/chimerax/graphics/drawing.py", line 1108, in
    100470 _first_intercept_excluding_children 
    100471 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    100472 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100473 File
    100474 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100475 packages/chimerax/geometry/place.py", line 201, in inverse 
    100476 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    100477 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100478 File
    100479 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100480 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    100481 rinv[:, :] = matrix_inverse(r) 
    100482 ^^^^^^^^^^^^^^^^^ 
    100483 File
    100484 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100485 packages/numpy/linalg/linalg.py", line 561, in inv 
    100486 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    100487 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100488 File
    100489 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100490 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    100491 raise LinAlgError("Singular matrix") 
    100492 numpy.linalg.LinAlgError: Singular matrix 
    100493  
    100494 numpy.linalg.LinAlgError: Singular matrix 
    100495  
    100496 File
    100497 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100498 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    100499 raise LinAlgError("Singular matrix") 
    100500  
    100501 See log for complete Python traceback. 
    100502  
    100503 Traceback (most recent call last): 
    100504 File
    100505 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100506 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    100507 self.session.ui.mouse_modes.mouse_pause_tracking() 
    100508 File
    100509 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100510 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    100511 mouse_pause_tracking 
    100512 self._mouse_pause() 
    100513 File
    100514 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100515 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    100516 m.pause(self._mouse_pause_position) 
    100517 File
    100518 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100519 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    100520 p = self.view.picked_object(x, y) 
    100521 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100522 File
    100523 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100524 packages/chimerax/graphics/view.py", line 838, in picked_object 
    100525 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    100526 beyond, 
    100527 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100528 File
    100529 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100530 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    100531 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    100532 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100533 File
    100534 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100535 packages/chimerax/core/models.py", line 143, in first_intercept 
    100536 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    100537 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100538 File
    100539 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100540 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    100541 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    100542 exclude=exclude) 
    100543 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100544 File
    100545 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100546 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    100547 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    100548 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100549 File
    100550 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100551 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    100552 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    100553 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100554 File
    100555 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100556 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    100557 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    100558 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100559 File
    100560 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100561 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    100562 p = super().first_intercept(mxyz1, mxyz2) 
    100563 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100564 File
    100565 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100566 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    100567 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    100568 exclude=exclude) 
    100569 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100570 File
    100571 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100572 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    100573 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    100574 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100575 File
    100576 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100577 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    100578 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    100579 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100580 File
    100581 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100582 packages/chimerax/graphics/drawing.py", line 1108, in
    100583 _first_intercept_excluding_children 
    100584 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    100585 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100586 File
    100587 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100588 packages/chimerax/geometry/place.py", line 201, in inverse 
    100589 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    100590 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100591 File
    100592 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100593 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    100594 rinv[:, :] = matrix_inverse(r) 
    100595 ^^^^^^^^^^^^^^^^^ 
    100596 File
    100597 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100598 packages/numpy/linalg/linalg.py", line 561, in inv 
    100599 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    100600 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100601 File
    100602 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100603 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    100604 raise LinAlgError("Singular matrix") 
    100605 numpy.linalg.LinAlgError: Singular matrix 
    100606  
    100607 numpy.linalg.LinAlgError: Singular matrix 
    100608  
    100609 File
    100610 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100611 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    100612 raise LinAlgError("Singular matrix") 
    100613  
    100614 See log for complete Python traceback. 
    100615  
    100616 Traceback (most recent call last): 
    100617 File
    100618 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100619 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    100620 self.session.ui.mouse_modes.mouse_pause_tracking() 
    100621 File
    100622 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100623 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    100624 mouse_pause_tracking 
    100625 self._mouse_pause() 
    100626 File
    100627 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100628 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    100629 m.pause(self._mouse_pause_position) 
    100630 File
    100631 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100632 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    100633 p = self.view.picked_object(x, y) 
    100634 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100635 File
    100636 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100637 packages/chimerax/graphics/view.py", line 838, in picked_object 
    100638 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    100639 beyond, 
    100640 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100641 File
    100642 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100643 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    100644 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    100645 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100646 File
    100647 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100648 packages/chimerax/core/models.py", line 143, in first_intercept 
    100649 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    100650 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100651 File
    100652 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100653 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    100654 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    100655 exclude=exclude) 
    100656 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100657 File
    100658 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100659 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    100660 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    100661 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100662 File
    100663 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100664 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    100665 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    100666 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100667 File
    100668 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100669 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    100670 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    100671 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100672 File
    100673 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100674 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    100675 p = super().first_intercept(mxyz1, mxyz2) 
    100676 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100677 File
    100678 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100679 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    100680 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    100681 exclude=exclude) 
    100682 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100683 File
    100684 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100685 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    100686 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    100687 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100688 File
    100689 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100690 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    100691 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    100692 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100693 File
    100694 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100695 packages/chimerax/graphics/drawing.py", line 1108, in
    100696 _first_intercept_excluding_children 
    100697 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    100698 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100699 File
    100700 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100701 packages/chimerax/geometry/place.py", line 201, in inverse 
    100702 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    100703 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100704 File
    100705 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100706 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    100707 rinv[:, :] = matrix_inverse(r) 
    100708 ^^^^^^^^^^^^^^^^^ 
    100709 File
    100710 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100711 packages/numpy/linalg/linalg.py", line 561, in inv 
    100712 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    100713 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100714 File
    100715 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100716 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    100717 raise LinAlgError("Singular matrix") 
    100718 numpy.linalg.LinAlgError: Singular matrix 
    100719  
    100720 numpy.linalg.LinAlgError: Singular matrix 
    100721  
    100722 File
    100723 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100724 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    100725 raise LinAlgError("Singular matrix") 
    100726  
    100727 See log for complete Python traceback. 
    100728  
    100729 Traceback (most recent call last): 
    100730 File
    100731 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100732 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    100733 self.session.ui.mouse_modes.mouse_pause_tracking() 
    100734 File
    100735 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100736 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    100737 mouse_pause_tracking 
    100738 self._mouse_pause() 
    100739 File
    100740 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100741 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    100742 m.pause(self._mouse_pause_position) 
    100743 File
    100744 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100745 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    100746 p = self.view.picked_object(x, y) 
    100747 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100748 File
    100749 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100750 packages/chimerax/graphics/view.py", line 838, in picked_object 
    100751 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    100752 beyond, 
    100753 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100754 File
    100755 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100756 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    100757 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    100758 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100759 File
    100760 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100761 packages/chimerax/core/models.py", line 143, in first_intercept 
    100762 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    100763 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100764 File
    100765 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100766 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    100767 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    100768 exclude=exclude) 
    100769 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100770 File
    100771 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100772 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    100773 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    100774 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100775 File
    100776 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100777 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    100778 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    100779 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100780 File
    100781 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100782 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    100783 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    100784 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100785 File
    100786 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100787 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    100788 p = super().first_intercept(mxyz1, mxyz2) 
    100789 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100790 File
    100791 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100792 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    100793 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    100794 exclude=exclude) 
    100795 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100796 File
    100797 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100798 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    100799 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    100800 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100801 File
    100802 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100803 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    100804 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    100805 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100806 File
    100807 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100808 packages/chimerax/graphics/drawing.py", line 1108, in
    100809 _first_intercept_excluding_children 
    100810 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    100811 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100812 File
    100813 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100814 packages/chimerax/geometry/place.py", line 201, in inverse 
    100815 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    100816 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100817 File
    100818 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100819 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    100820 rinv[:, :] = matrix_inverse(r) 
    100821 ^^^^^^^^^^^^^^^^^ 
    100822 File
    100823 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100824 packages/numpy/linalg/linalg.py", line 561, in inv 
    100825 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    100826 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100827 File
    100828 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100829 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    100830 raise LinAlgError("Singular matrix") 
    100831 numpy.linalg.LinAlgError: Singular matrix 
    100832  
    100833 numpy.linalg.LinAlgError: Singular matrix 
    100834  
    100835 File
    100836 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100837 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    100838 raise LinAlgError("Singular matrix") 
    100839  
    100840 See log for complete Python traceback. 
    100841  
    100842 Traceback (most recent call last): 
    100843 File
    100844 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100845 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    100846 self.session.ui.mouse_modes.mouse_pause_tracking() 
    100847 File
    100848 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100849 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    100850 mouse_pause_tracking 
    100851 self._mouse_pause() 
    100852 File
    100853 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100854 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    100855 m.pause(self._mouse_pause_position) 
    100856 File
    100857 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100858 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    100859 p = self.view.picked_object(x, y) 
    100860 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100861 File
    100862 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100863 packages/chimerax/graphics/view.py", line 838, in picked_object 
    100864 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    100865 beyond, 
    100866 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100867 File
    100868 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100869 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    100870 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    100871 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100872 File
    100873 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100874 packages/chimerax/core/models.py", line 143, in first_intercept 
    100875 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    100876 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100877 File
    100878 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100879 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    100880 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    100881 exclude=exclude) 
    100882 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100883 File
    100884 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100885 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    100886 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    100887 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100888 File
    100889 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100890 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    100891 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    100892 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100893 File
    100894 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100895 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    100896 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    100897 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100898 File
    100899 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100900 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    100901 p = super().first_intercept(mxyz1, mxyz2) 
    100902 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100903 File
    100904 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100905 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    100906 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    100907 exclude=exclude) 
    100908 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100909 File
    100910 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100911 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    100912 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    100913 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100914 File
    100915 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100916 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    100917 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    100918 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100919 File
    100920 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100921 packages/chimerax/graphics/drawing.py", line 1108, in
    100922 _first_intercept_excluding_children 
    100923 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    100924 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100925 File
    100926 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100927 packages/chimerax/geometry/place.py", line 201, in inverse 
    100928 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    100929 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100930 File
    100931 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100932 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    100933 rinv[:, :] = matrix_inverse(r) 
    100934 ^^^^^^^^^^^^^^^^^ 
    100935 File
    100936 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100937 packages/numpy/linalg/linalg.py", line 561, in inv 
    100938 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    100939 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100940 File
    100941 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100942 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    100943 raise LinAlgError("Singular matrix") 
    100944 numpy.linalg.LinAlgError: Singular matrix 
    100945  
    100946 numpy.linalg.LinAlgError: Singular matrix 
    100947  
    100948 File
    100949 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100950 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    100951 raise LinAlgError("Singular matrix") 
    100952  
    100953 See log for complete Python traceback. 
    100954  
    100955 Traceback (most recent call last): 
    100956 File
    100957 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100958 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    100959 self.session.ui.mouse_modes.mouse_pause_tracking() 
    100960 File
    100961 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100962 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    100963 mouse_pause_tracking 
    100964 self._mouse_pause() 
    100965 File
    100966 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100967 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    100968 m.pause(self._mouse_pause_position) 
    100969 File
    100970 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100971 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    100972 p = self.view.picked_object(x, y) 
    100973 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100974 File
    100975 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100976 packages/chimerax/graphics/view.py", line 838, in picked_object 
    100977 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    100978 beyond, 
    100979 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100980 File
    100981 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100982 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    100983 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    100984 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100985 File
    100986 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100987 packages/chimerax/core/models.py", line 143, in first_intercept 
    100988 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    100989 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100990 File
    100991 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100992 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    100993 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    100994 exclude=exclude) 
    100995 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    100996 File
    100997 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    100998 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    100999 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    101000 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101001 File
    101002 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101003 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    101004 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    101005 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101006 File
    101007 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101008 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    101009 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    101010 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101011 File
    101012 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101013 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    101014 p = super().first_intercept(mxyz1, mxyz2) 
    101015 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101016 File
    101017 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101018 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    101019 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    101020 exclude=exclude) 
    101021 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101022 File
    101023 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101024 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    101025 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    101026 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101027 File
    101028 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101029 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    101030 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    101031 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101032 File
    101033 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101034 packages/chimerax/graphics/drawing.py", line 1108, in
    101035 _first_intercept_excluding_children 
    101036 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    101037 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101038 File
    101039 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101040 packages/chimerax/geometry/place.py", line 201, in inverse 
    101041 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    101042 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101043 File
    101044 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101045 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    101046 rinv[:, :] = matrix_inverse(r) 
    101047 ^^^^^^^^^^^^^^^^^ 
    101048 File
    101049 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101050 packages/numpy/linalg/linalg.py", line 561, in inv 
    101051 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    101052 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101053 File
    101054 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101055 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    101056 raise LinAlgError("Singular matrix") 
    101057 numpy.linalg.LinAlgError: Singular matrix 
    101058  
    101059 numpy.linalg.LinAlgError: Singular matrix 
    101060  
    101061 File
    101062 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101063 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    101064 raise LinAlgError("Singular matrix") 
    101065  
    101066 See log for complete Python traceback. 
    101067  
    101068 Traceback (most recent call last): 
    101069 File
    101070 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101071 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    101072 self.session.ui.mouse_modes.mouse_pause_tracking() 
    101073 File
    101074 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101075 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    101076 mouse_pause_tracking 
    101077 self._mouse_pause() 
    101078 File
    101079 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101080 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    101081 m.pause(self._mouse_pause_position) 
    101082 File
    101083 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101084 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    101085 p = self.view.picked_object(x, y) 
    101086 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101087 File
    101088 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101089 packages/chimerax/graphics/view.py", line 838, in picked_object 
    101090 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    101091 beyond, 
    101092 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101093 File
    101094 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101095 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    101096 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    101097 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101098 File
    101099 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101100 packages/chimerax/core/models.py", line 143, in first_intercept 
    101101 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    101102 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101103 File
    101104 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101105 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    101106 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    101107 exclude=exclude) 
    101108 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101109 File
    101110 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101111 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    101112 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    101113 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101114 File
    101115 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101116 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    101117 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    101118 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101119 File
    101120 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101121 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    101122 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    101123 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101124 File
    101125 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101126 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    101127 p = super().first_intercept(mxyz1, mxyz2) 
    101128 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101129 File
    101130 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101131 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    101132 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    101133 exclude=exclude) 
    101134 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101135 File
    101136 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101137 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    101138 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    101139 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101140 File
    101141 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101142 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    101143 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    101144 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101145 File
    101146 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101147 packages/chimerax/graphics/drawing.py", line 1108, in
    101148 _first_intercept_excluding_children 
    101149 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    101150 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101151 File
    101152 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101153 packages/chimerax/geometry/place.py", line 201, in inverse 
    101154 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    101155 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101156 File
    101157 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101158 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    101159 rinv[:, :] = matrix_inverse(r) 
    101160 ^^^^^^^^^^^^^^^^^ 
    101161 File
    101162 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101163 packages/numpy/linalg/linalg.py", line 561, in inv 
    101164 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    101165 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101166 File
    101167 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101168 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    101169 raise LinAlgError("Singular matrix") 
    101170 numpy.linalg.LinAlgError: Singular matrix 
    101171  
    101172 numpy.linalg.LinAlgError: Singular matrix 
    101173  
    101174 File
    101175 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101176 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    101177 raise LinAlgError("Singular matrix") 
    101178  
    101179 See log for complete Python traceback. 
    101180  
    101181 Traceback (most recent call last): 
    101182 File
    101183 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101184 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    101185 self.session.ui.mouse_modes.mouse_pause_tracking() 
    101186 File
    101187 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101188 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    101189 mouse_pause_tracking 
    101190 self._mouse_pause() 
    101191 File
    101192 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101193 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    101194 m.pause(self._mouse_pause_position) 
    101195 File
    101196 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101197 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    101198 p = self.view.picked_object(x, y) 
    101199 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101200 File
    101201 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101202 packages/chimerax/graphics/view.py", line 838, in picked_object 
    101203 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    101204 beyond, 
    101205 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101206 File
    101207 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101208 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    101209 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    101210 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101211 File
    101212 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101213 packages/chimerax/core/models.py", line 143, in first_intercept 
    101214 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    101215 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101216 File
    101217 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101218 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    101219 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    101220 exclude=exclude) 
    101221 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101222 File
    101223 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101224 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    101225 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    101226 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101227 File
    101228 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101229 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    101230 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    101231 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101232 File
    101233 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101234 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    101235 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    101236 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101237 File
    101238 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101239 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    101240 p = super().first_intercept(mxyz1, mxyz2) 
    101241 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101242 File
    101243 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101244 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    101245 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    101246 exclude=exclude) 
    101247 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101248 File
    101249 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101250 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    101251 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    101252 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101253 File
    101254 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101255 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    101256 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    101257 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101258 File
    101259 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101260 packages/chimerax/graphics/drawing.py", line 1108, in
    101261 _first_intercept_excluding_children 
    101262 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    101263 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101264 File
    101265 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101266 packages/chimerax/geometry/place.py", line 201, in inverse 
    101267 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    101268 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101269 File
    101270 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101271 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    101272 rinv[:, :] = matrix_inverse(r) 
    101273 ^^^^^^^^^^^^^^^^^ 
    101274 File
    101275 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101276 packages/numpy/linalg/linalg.py", line 561, in inv 
    101277 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    101278 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101279 File
    101280 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101281 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    101282 raise LinAlgError("Singular matrix") 
    101283 numpy.linalg.LinAlgError: Singular matrix 
    101284  
    101285 numpy.linalg.LinAlgError: Singular matrix 
    101286  
    101287 File
    101288 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101289 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    101290 raise LinAlgError("Singular matrix") 
    101291  
    101292 See log for complete Python traceback. 
    101293  
    101294 Traceback (most recent call last): 
    101295 File
    101296 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101297 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    101298 self.session.ui.mouse_modes.mouse_pause_tracking() 
    101299 File
    101300 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101301 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    101302 mouse_pause_tracking 
    101303 self._mouse_pause() 
    101304 File
    101305 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101306 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    101307 m.pause(self._mouse_pause_position) 
    101308 File
    101309 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101310 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    101311 p = self.view.picked_object(x, y) 
    101312 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101313 File
    101314 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101315 packages/chimerax/graphics/view.py", line 838, in picked_object 
    101316 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    101317 beyond, 
    101318 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101319 File
    101320 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101321 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    101322 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    101323 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101324 File
    101325 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101326 packages/chimerax/core/models.py", line 143, in first_intercept 
    101327 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    101328 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101329 File
    101330 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101331 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    101332 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    101333 exclude=exclude) 
    101334 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101335 File
    101336 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101337 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    101338 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    101339 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101340 File
    101341 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101342 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    101343 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    101344 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101345 File
    101346 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101347 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    101348 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    101349 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101350 File
    101351 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101352 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    101353 p = super().first_intercept(mxyz1, mxyz2) 
    101354 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101355 File
    101356 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101357 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    101358 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    101359 exclude=exclude) 
    101360 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101361 File
    101362 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101363 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    101364 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    101365 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101366 File
    101367 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101368 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    101369 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    101370 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101371 File
    101372 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101373 packages/chimerax/graphics/drawing.py", line 1108, in
    101374 _first_intercept_excluding_children 
    101375 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    101376 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101377 File
    101378 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101379 packages/chimerax/geometry/place.py", line 201, in inverse 
    101380 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    101381 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101382 File
    101383 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101384 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    101385 rinv[:, :] = matrix_inverse(r) 
    101386 ^^^^^^^^^^^^^^^^^ 
    101387 File
    101388 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101389 packages/numpy/linalg/linalg.py", line 561, in inv 
    101390 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    101391 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101392 File
    101393 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101394 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    101395 raise LinAlgError("Singular matrix") 
    101396 numpy.linalg.LinAlgError: Singular matrix 
    101397  
    101398 numpy.linalg.LinAlgError: Singular matrix 
    101399  
    101400 File
    101401 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101402 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    101403 raise LinAlgError("Singular matrix") 
    101404  
    101405 See log for complete Python traceback. 
    101406  
    101407 Traceback (most recent call last): 
    101408 File
    101409 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101410 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    101411 self.session.ui.mouse_modes.mouse_pause_tracking() 
    101412 File
    101413 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101414 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    101415 mouse_pause_tracking 
    101416 self._mouse_pause() 
    101417 File
    101418 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101419 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    101420 m.pause(self._mouse_pause_position) 
    101421 File
    101422 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101423 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    101424 p = self.view.picked_object(x, y) 
    101425 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101426 File
    101427 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101428 packages/chimerax/graphics/view.py", line 838, in picked_object 
    101429 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    101430 beyond, 
    101431 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101432 File
    101433 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101434 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    101435 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    101436 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101437 File
    101438 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101439 packages/chimerax/core/models.py", line 143, in first_intercept 
    101440 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    101441 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101442 File
    101443 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101444 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    101445 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    101446 exclude=exclude) 
    101447 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101448 File
    101449 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101450 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    101451 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    101452 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101453 File
    101454 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101455 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    101456 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    101457 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101458 File
    101459 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101460 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    101461 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    101462 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101463 File
    101464 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101465 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    101466 p = super().first_intercept(mxyz1, mxyz2) 
    101467 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101468 File
    101469 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101470 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    101471 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    101472 exclude=exclude) 
    101473 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101474 File
    101475 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101476 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    101477 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    101478 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101479 File
    101480 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101481 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    101482 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    101483 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101484 File
    101485 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101486 packages/chimerax/graphics/drawing.py", line 1108, in
    101487 _first_intercept_excluding_children 
    101488 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    101489 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101490 File
    101491 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101492 packages/chimerax/geometry/place.py", line 201, in inverse 
    101493 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    101494 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101495 File
    101496 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101497 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    101498 rinv[:, :] = matrix_inverse(r) 
    101499 ^^^^^^^^^^^^^^^^^ 
    101500 File
    101501 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101502 packages/numpy/linalg/linalg.py", line 561, in inv 
    101503 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    101504 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101505 File
    101506 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101507 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    101508 raise LinAlgError("Singular matrix") 
    101509 numpy.linalg.LinAlgError: Singular matrix 
    101510  
    101511 numpy.linalg.LinAlgError: Singular matrix 
    101512  
    101513 File
    101514 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101515 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    101516 raise LinAlgError("Singular matrix") 
    101517  
    101518 See log for complete Python traceback. 
    101519  
    101520 Traceback (most recent call last): 
    101521 File
    101522 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101523 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    101524 self.session.ui.mouse_modes.mouse_pause_tracking() 
    101525 File
    101526 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101527 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    101528 mouse_pause_tracking 
    101529 self._mouse_pause() 
    101530 File
    101531 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101532 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    101533 m.pause(self._mouse_pause_position) 
    101534 File
    101535 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101536 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    101537 p = self.view.picked_object(x, y) 
    101538 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101539 File
    101540 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101541 packages/chimerax/graphics/view.py", line 838, in picked_object 
    101542 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    101543 beyond, 
    101544 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101545 File
    101546 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101547 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    101548 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    101549 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101550 File
    101551 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101552 packages/chimerax/core/models.py", line 143, in first_intercept 
    101553 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    101554 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101555 File
    101556 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101557 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    101558 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    101559 exclude=exclude) 
    101560 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101561 File
    101562 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101563 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    101564 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    101565 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101566 File
    101567 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101568 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    101569 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    101570 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101571 File
    101572 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101573 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    101574 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    101575 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101576 File
    101577 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101578 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    101579 p = super().first_intercept(mxyz1, mxyz2) 
    101580 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101581 File
    101582 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101583 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    101584 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    101585 exclude=exclude) 
    101586 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101587 File
    101588 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101589 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    101590 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    101591 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101592 File
    101593 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101594 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    101595 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    101596 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101597 File
    101598 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101599 packages/chimerax/graphics/drawing.py", line 1108, in
    101600 _first_intercept_excluding_children 
    101601 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    101602 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101603 File
    101604 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101605 packages/chimerax/geometry/place.py", line 201, in inverse 
    101606 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    101607 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101608 File
    101609 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101610 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    101611 rinv[:, :] = matrix_inverse(r) 
    101612 ^^^^^^^^^^^^^^^^^ 
    101613 File
    101614 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101615 packages/numpy/linalg/linalg.py", line 561, in inv 
    101616 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    101617 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101618 File
    101619 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101620 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    101621 raise LinAlgError("Singular matrix") 
    101622 numpy.linalg.LinAlgError: Singular matrix 
    101623  
    101624 numpy.linalg.LinAlgError: Singular matrix 
    101625  
    101626 File
    101627 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101628 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    101629 raise LinAlgError("Singular matrix") 
    101630  
    101631 See log for complete Python traceback. 
    101632  
    101633 Traceback (most recent call last): 
    101634 File
    101635 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101636 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    101637 self.session.ui.mouse_modes.mouse_pause_tracking() 
    101638 File
    101639 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101640 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    101641 mouse_pause_tracking 
    101642 self._mouse_pause() 
    101643 File
    101644 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101645 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    101646 m.pause(self._mouse_pause_position) 
    101647 File
    101648 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101649 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    101650 p = self.view.picked_object(x, y) 
    101651 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101652 File
    101653 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101654 packages/chimerax/graphics/view.py", line 838, in picked_object 
    101655 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    101656 beyond, 
    101657 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101658 File
    101659 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101660 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    101661 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    101662 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101663 File
    101664 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101665 packages/chimerax/core/models.py", line 143, in first_intercept 
    101666 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    101667 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101668 File
    101669 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101670 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    101671 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    101672 exclude=exclude) 
    101673 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101674 File
    101675 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101676 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    101677 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    101678 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101679 File
    101680 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101681 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    101682 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    101683 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101684 File
    101685 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101686 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    101687 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    101688 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101689 File
    101690 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101691 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    101692 p = super().first_intercept(mxyz1, mxyz2) 
    101693 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101694 File
    101695 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101696 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    101697 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    101698 exclude=exclude) 
    101699 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101700 File
    101701 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101702 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    101703 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    101704 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101705 File
    101706 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101707 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    101708 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    101709 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101710 File
    101711 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101712 packages/chimerax/graphics/drawing.py", line 1108, in
    101713 _first_intercept_excluding_children 
    101714 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    101715 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101716 File
    101717 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101718 packages/chimerax/geometry/place.py", line 201, in inverse 
    101719 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    101720 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101721 File
    101722 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101723 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    101724 rinv[:, :] = matrix_inverse(r) 
    101725 ^^^^^^^^^^^^^^^^^ 
    101726 File
    101727 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101728 packages/numpy/linalg/linalg.py", line 561, in inv 
    101729 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    101730 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101731 File
    101732 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101733 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    101734 raise LinAlgError("Singular matrix") 
    101735 numpy.linalg.LinAlgError: Singular matrix 
    101736  
    101737 numpy.linalg.LinAlgError: Singular matrix 
    101738  
    101739 File
    101740 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101741 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    101742 raise LinAlgError("Singular matrix") 
    101743  
    101744 See log for complete Python traceback. 
    101745  
    101746 Traceback (most recent call last): 
    101747 File
    101748 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101749 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    101750 self.session.ui.mouse_modes.mouse_pause_tracking() 
    101751 File
    101752 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101753 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    101754 mouse_pause_tracking 
    101755 self._mouse_pause() 
    101756 File
    101757 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101758 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    101759 m.pause(self._mouse_pause_position) 
    101760 File
    101761 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101762 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    101763 p = self.view.picked_object(x, y) 
    101764 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101765 File
    101766 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101767 packages/chimerax/graphics/view.py", line 838, in picked_object 
    101768 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    101769 beyond, 
    101770 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101771 File
    101772 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101773 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    101774 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    101775 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101776 File
    101777 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101778 packages/chimerax/core/models.py", line 143, in first_intercept 
    101779 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    101780 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101781 File
    101782 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101783 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    101784 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    101785 exclude=exclude) 
    101786 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101787 File
    101788 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101789 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    101790 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    101791 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101792 File
    101793 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101794 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    101795 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    101796 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101797 File
    101798 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101799 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    101800 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    101801 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101802 File
    101803 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101804 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    101805 p = super().first_intercept(mxyz1, mxyz2) 
    101806 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101807 File
    101808 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101809 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    101810 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    101811 exclude=exclude) 
    101812 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101813 File
    101814 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101815 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    101816 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    101817 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101818 File
    101819 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101820 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    101821 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    101822 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101823 File
    101824 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101825 packages/chimerax/graphics/drawing.py", line 1108, in
    101826 _first_intercept_excluding_children 
    101827 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    101828 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101829 File
    101830 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101831 packages/chimerax/geometry/place.py", line 201, in inverse 
    101832 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    101833 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101834 File
    101835 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101836 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    101837 rinv[:, :] = matrix_inverse(r) 
    101838 ^^^^^^^^^^^^^^^^^ 
    101839 File
    101840 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101841 packages/numpy/linalg/linalg.py", line 561, in inv 
    101842 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    101843 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101844 File
    101845 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101846 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    101847 raise LinAlgError("Singular matrix") 
    101848 numpy.linalg.LinAlgError: Singular matrix 
    101849  
    101850 numpy.linalg.LinAlgError: Singular matrix 
    101851  
    101852 File
    101853 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101854 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    101855 raise LinAlgError("Singular matrix") 
    101856  
    101857 See log for complete Python traceback. 
    101858  
    101859 Traceback (most recent call last): 
    101860 File
    101861 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101862 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    101863 self.session.ui.mouse_modes.mouse_pause_tracking() 
    101864 File
    101865 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101866 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    101867 mouse_pause_tracking 
    101868 self._mouse_pause() 
    101869 File
    101870 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101871 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    101872 m.pause(self._mouse_pause_position) 
    101873 File
    101874 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101875 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    101876 p = self.view.picked_object(x, y) 
    101877 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101878 File
    101879 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101880 packages/chimerax/graphics/view.py", line 838, in picked_object 
    101881 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    101882 beyond, 
    101883 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101884 File
    101885 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101886 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    101887 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    101888 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101889 File
    101890 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101891 packages/chimerax/core/models.py", line 143, in first_intercept 
    101892 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    101893 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101894 File
    101895 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101896 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    101897 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    101898 exclude=exclude) 
    101899 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101900 File
    101901 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101902 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    101903 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    101904 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101905 File
    101906 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101907 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    101908 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    101909 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101910 File
    101911 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101912 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    101913 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    101914 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101915 File
    101916 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101917 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    101918 p = super().first_intercept(mxyz1, mxyz2) 
    101919 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101920 File
    101921 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101922 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    101923 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    101924 exclude=exclude) 
    101925 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101926 File
    101927 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101928 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    101929 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    101930 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101931 File
    101932 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101933 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    101934 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    101935 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101936 File
    101937 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101938 packages/chimerax/graphics/drawing.py", line 1108, in
    101939 _first_intercept_excluding_children 
    101940 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    101941 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101942 File
    101943 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101944 packages/chimerax/geometry/place.py", line 201, in inverse 
    101945 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    101946 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101947 File
    101948 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101949 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    101950 rinv[:, :] = matrix_inverse(r) 
    101951 ^^^^^^^^^^^^^^^^^ 
    101952 File
    101953 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101954 packages/numpy/linalg/linalg.py", line 561, in inv 
    101955 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    101956 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101957 File
    101958 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101959 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    101960 raise LinAlgError("Singular matrix") 
    101961 numpy.linalg.LinAlgError: Singular matrix 
    101962  
    101963 numpy.linalg.LinAlgError: Singular matrix 
    101964  
    101965 File
    101966 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101967 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    101968 raise LinAlgError("Singular matrix") 
    101969  
    101970 See log for complete Python traceback. 
    101971  
    101972 Traceback (most recent call last): 
    101973 File
    101974 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101975 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    101976 self.session.ui.mouse_modes.mouse_pause_tracking() 
    101977 File
    101978 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101979 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    101980 mouse_pause_tracking 
    101981 self._mouse_pause() 
    101982 File
    101983 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101984 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    101985 m.pause(self._mouse_pause_position) 
    101986 File
    101987 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101988 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    101989 p = self.view.picked_object(x, y) 
    101990 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101991 File
    101992 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101993 packages/chimerax/graphics/view.py", line 838, in picked_object 
    101994 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    101995 beyond, 
    101996 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    101997 File
    101998 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    101999 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    102000 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    102001 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102002 File
    102003 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102004 packages/chimerax/core/models.py", line 143, in first_intercept 
    102005 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    102006 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102007 File
    102008 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102009 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    102010 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    102011 exclude=exclude) 
    102012 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102013 File
    102014 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102015 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    102016 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    102017 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102018 File
    102019 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102020 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    102021 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    102022 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102023 File
    102024 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102025 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    102026 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    102027 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102028 File
    102029 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102030 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    102031 p = super().first_intercept(mxyz1, mxyz2) 
    102032 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102033 File
    102034 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102035 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    102036 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    102037 exclude=exclude) 
    102038 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102039 File
    102040 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102041 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    102042 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    102043 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102044 File
    102045 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102046 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    102047 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    102048 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102049 File
    102050 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102051 packages/chimerax/graphics/drawing.py", line 1108, in
    102052 _first_intercept_excluding_children 
    102053 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    102054 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102055 File
    102056 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102057 packages/chimerax/geometry/place.py", line 201, in inverse 
    102058 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    102059 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102060 File
    102061 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102062 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    102063 rinv[:, :] = matrix_inverse(r) 
    102064 ^^^^^^^^^^^^^^^^^ 
    102065 File
    102066 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102067 packages/numpy/linalg/linalg.py", line 561, in inv 
    102068 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    102069 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102070 File
    102071 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102072 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    102073 raise LinAlgError("Singular matrix") 
    102074 numpy.linalg.LinAlgError: Singular matrix 
    102075  
    102076 numpy.linalg.LinAlgError: Singular matrix 
    102077  
    102078 File
    102079 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102080 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    102081 raise LinAlgError("Singular matrix") 
    102082  
    102083 See log for complete Python traceback. 
    102084  
    102085 Traceback (most recent call last): 
    102086 File
    102087 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102088 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    102089 self.session.ui.mouse_modes.mouse_pause_tracking() 
    102090 File
    102091 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102092 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    102093 mouse_pause_tracking 
    102094 self._mouse_pause() 
    102095 File
    102096 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102097 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    102098 m.pause(self._mouse_pause_position) 
    102099 File
    102100 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102101 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    102102 p = self.view.picked_object(x, y) 
    102103 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102104 File
    102105 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102106 packages/chimerax/graphics/view.py", line 838, in picked_object 
    102107 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    102108 beyond, 
    102109 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102110 File
    102111 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102112 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    102113 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    102114 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102115 File
    102116 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102117 packages/chimerax/core/models.py", line 143, in first_intercept 
    102118 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    102119 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102120 File
    102121 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102122 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    102123 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    102124 exclude=exclude) 
    102125 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102126 File
    102127 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102128 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    102129 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    102130 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102131 File
    102132 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102133 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    102134 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    102135 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102136 File
    102137 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102138 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    102139 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    102140 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102141 File
    102142 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102143 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    102144 p = super().first_intercept(mxyz1, mxyz2) 
    102145 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102146 File
    102147 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102148 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    102149 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    102150 exclude=exclude) 
    102151 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102152 File
    102153 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102154 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    102155 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    102156 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102157 File
    102158 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102159 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    102160 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    102161 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102162 File
    102163 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102164 packages/chimerax/graphics/drawing.py", line 1108, in
    102165 _first_intercept_excluding_children 
    102166 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    102167 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102168 File
    102169 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102170 packages/chimerax/geometry/place.py", line 201, in inverse 
    102171 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    102172 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102173 File
    102174 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102175 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    102176 rinv[:, :] = matrix_inverse(r) 
    102177 ^^^^^^^^^^^^^^^^^ 
    102178 File
    102179 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102180 packages/numpy/linalg/linalg.py", line 561, in inv 
    102181 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    102182 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102183 File
    102184 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102185 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    102186 raise LinAlgError("Singular matrix") 
    102187 numpy.linalg.LinAlgError: Singular matrix 
    102188  
    102189 numpy.linalg.LinAlgError: Singular matrix 
    102190  
    102191 File
    102192 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102193 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    102194 raise LinAlgError("Singular matrix") 
    102195  
    102196 See log for complete Python traceback. 
    102197  
    102198 Traceback (most recent call last): 
    102199 File
    102200 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102201 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    102202 self.session.ui.mouse_modes.mouse_pause_tracking() 
    102203 File
    102204 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102205 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    102206 mouse_pause_tracking 
    102207 self._mouse_pause() 
    102208 File
    102209 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102210 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    102211 m.pause(self._mouse_pause_position) 
    102212 File
    102213 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102214 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    102215 p = self.view.picked_object(x, y) 
    102216 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102217 File
    102218 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102219 packages/chimerax/graphics/view.py", line 838, in picked_object 
    102220 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    102221 beyond, 
    102222 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102223 File
    102224 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102225 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    102226 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    102227 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102228 File
    102229 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102230 packages/chimerax/core/models.py", line 143, in first_intercept 
    102231 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    102232 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102233 File
    102234 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102235 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    102236 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    102237 exclude=exclude) 
    102238 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102239 File
    102240 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102241 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    102242 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    102243 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102244 File
    102245 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102246 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    102247 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    102248 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102249 File
    102250 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102251 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    102252 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    102253 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102254 File
    102255 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102256 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    102257 p = super().first_intercept(mxyz1, mxyz2) 
    102258 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102259 File
    102260 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102261 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    102262 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    102263 exclude=exclude) 
    102264 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102265 File
    102266 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102267 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    102268 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    102269 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102270 File
    102271 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102272 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    102273 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    102274 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102275 File
    102276 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102277 packages/chimerax/graphics/drawing.py", line 1108, in
    102278 _first_intercept_excluding_children 
    102279 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    102280 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102281 File
    102282 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102283 packages/chimerax/geometry/place.py", line 201, in inverse 
    102284 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    102285 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102286 File
    102287 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102288 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    102289 rinv[:, :] = matrix_inverse(r) 
    102290 ^^^^^^^^^^^^^^^^^ 
    102291 File
    102292 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102293 packages/numpy/linalg/linalg.py", line 561, in inv 
    102294 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    102295 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102296 File
    102297 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102298 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    102299 raise LinAlgError("Singular matrix") 
    102300 numpy.linalg.LinAlgError: Singular matrix 
    102301  
    102302 numpy.linalg.LinAlgError: Singular matrix 
    102303  
    102304 File
    102305 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102306 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    102307 raise LinAlgError("Singular matrix") 
    102308  
    102309 See log for complete Python traceback. 
    102310  
    102311 Traceback (most recent call last): 
    102312 File
    102313 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102314 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    102315 self.session.ui.mouse_modes.mouse_pause_tracking() 
    102316 File
    102317 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102318 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    102319 mouse_pause_tracking 
    102320 self._mouse_pause() 
    102321 File
    102322 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102323 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    102324 m.pause(self._mouse_pause_position) 
    102325 File
    102326 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102327 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    102328 p = self.view.picked_object(x, y) 
    102329 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102330 File
    102331 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102332 packages/chimerax/graphics/view.py", line 838, in picked_object 
    102333 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    102334 beyond, 
    102335 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102336 File
    102337 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102338 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    102339 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    102340 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102341 File
    102342 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102343 packages/chimerax/core/models.py", line 143, in first_intercept 
    102344 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    102345 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102346 File
    102347 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102348 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    102349 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    102350 exclude=exclude) 
    102351 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102352 File
    102353 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102354 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    102355 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    102356 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102357 File
    102358 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102359 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    102360 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    102361 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102362 File
    102363 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102364 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    102365 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    102366 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102367 File
    102368 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102369 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    102370 p = super().first_intercept(mxyz1, mxyz2) 
    102371 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102372 File
    102373 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102374 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    102375 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    102376 exclude=exclude) 
    102377 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102378 File
    102379 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102380 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    102381 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    102382 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102383 File
    102384 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102385 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    102386 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    102387 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102388 File
    102389 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102390 packages/chimerax/graphics/drawing.py", line 1108, in
    102391 _first_intercept_excluding_children 
    102392 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    102393 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102394 File
    102395 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102396 packages/chimerax/geometry/place.py", line 201, in inverse 
    102397 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    102398 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102399 File
    102400 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102401 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    102402 rinv[:, :] = matrix_inverse(r) 
    102403 ^^^^^^^^^^^^^^^^^ 
    102404 File
    102405 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102406 packages/numpy/linalg/linalg.py", line 561, in inv 
    102407 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    102408 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102409 File
    102410 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102411 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    102412 raise LinAlgError("Singular matrix") 
    102413 numpy.linalg.LinAlgError: Singular matrix 
    102414  
    102415 numpy.linalg.LinAlgError: Singular matrix 
    102416  
    102417 File
    102418 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102419 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    102420 raise LinAlgError("Singular matrix") 
    102421  
    102422 See log for complete Python traceback. 
    102423  
    102424 Traceback (most recent call last): 
    102425 File
    102426 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102427 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    102428 self.session.ui.mouse_modes.mouse_pause_tracking() 
    102429 File
    102430 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102431 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    102432 mouse_pause_tracking 
    102433 self._mouse_pause() 
    102434 File
    102435 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102436 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    102437 m.pause(self._mouse_pause_position) 
    102438 File
    102439 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102440 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    102441 p = self.view.picked_object(x, y) 
    102442 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102443 File
    102444 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102445 packages/chimerax/graphics/view.py", line 838, in picked_object 
    102446 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    102447 beyond, 
    102448 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102449 File
    102450 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102451 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    102452 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    102453 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102454 File
    102455 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102456 packages/chimerax/core/models.py", line 143, in first_intercept 
    102457 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    102458 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102459 File
    102460 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102461 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    102462 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    102463 exclude=exclude) 
    102464 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102465 File
    102466 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102467 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    102468 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    102469 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102470 File
    102471 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102472 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    102473 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    102474 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102475 File
    102476 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102477 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    102478 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    102479 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102480 File
    102481 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102482 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    102483 p = super().first_intercept(mxyz1, mxyz2) 
    102484 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102485 File
    102486 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102487 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    102488 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    102489 exclude=exclude) 
    102490 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102491 File
    102492 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102493 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    102494 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    102495 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102496 File
    102497 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102498 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    102499 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    102500 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102501 File
    102502 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102503 packages/chimerax/graphics/drawing.py", line 1108, in
    102504 _first_intercept_excluding_children 
    102505 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    102506 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102507 File
    102508 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102509 packages/chimerax/geometry/place.py", line 201, in inverse 
    102510 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    102511 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102512 File
    102513 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102514 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    102515 rinv[:, :] = matrix_inverse(r) 
    102516 ^^^^^^^^^^^^^^^^^ 
    102517 File
    102518 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102519 packages/numpy/linalg/linalg.py", line 561, in inv 
    102520 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    102521 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102522 File
    102523 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102524 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    102525 raise LinAlgError("Singular matrix") 
    102526 numpy.linalg.LinAlgError: Singular matrix 
    102527  
    102528 numpy.linalg.LinAlgError: Singular matrix 
    102529  
    102530 File
    102531 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102532 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    102533 raise LinAlgError("Singular matrix") 
    102534  
    102535 See log for complete Python traceback. 
    102536  
    102537 Traceback (most recent call last): 
    102538 File
    102539 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102540 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    102541 self.session.ui.mouse_modes.mouse_pause_tracking() 
    102542 File
    102543 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102544 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    102545 mouse_pause_tracking 
    102546 self._mouse_pause() 
    102547 File
    102548 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102549 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    102550 m.pause(self._mouse_pause_position) 
    102551 File
    102552 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102553 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    102554 p = self.view.picked_object(x, y) 
    102555 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102556 File
    102557 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102558 packages/chimerax/graphics/view.py", line 838, in picked_object 
    102559 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    102560 beyond, 
    102561 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102562 File
    102563 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102564 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    102565 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    102566 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102567 File
    102568 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102569 packages/chimerax/core/models.py", line 143, in first_intercept 
    102570 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    102571 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102572 File
    102573 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102574 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    102575 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    102576 exclude=exclude) 
    102577 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102578 File
    102579 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102580 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    102581 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    102582 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102583 File
    102584 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102585 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    102586 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    102587 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102588 File
    102589 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102590 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    102591 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    102592 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102593 File
    102594 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102595 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    102596 p = super().first_intercept(mxyz1, mxyz2) 
    102597 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102598 File
    102599 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102600 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    102601 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    102602 exclude=exclude) 
    102603 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102604 File
    102605 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102606 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    102607 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    102608 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102609 File
    102610 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102611 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    102612 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    102613 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102614 File
    102615 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102616 packages/chimerax/graphics/drawing.py", line 1108, in
    102617 _first_intercept_excluding_children 
    102618 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    102619 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102620 File
    102621 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102622 packages/chimerax/geometry/place.py", line 201, in inverse 
    102623 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    102624 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102625 File
    102626 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102627 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    102628 rinv[:, :] = matrix_inverse(r) 
    102629 ^^^^^^^^^^^^^^^^^ 
    102630 File
    102631 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102632 packages/numpy/linalg/linalg.py", line 561, in inv 
    102633 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    102634 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102635 File
    102636 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102637 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    102638 raise LinAlgError("Singular matrix") 
    102639 numpy.linalg.LinAlgError: Singular matrix 
    102640  
    102641 numpy.linalg.LinAlgError: Singular matrix 
    102642  
    102643 File
    102644 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102645 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    102646 raise LinAlgError("Singular matrix") 
    102647  
    102648 See log for complete Python traceback. 
    102649  
    102650 Traceback (most recent call last): 
    102651 File
    102652 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102653 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    102654 self.session.ui.mouse_modes.mouse_pause_tracking() 
    102655 File
    102656 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102657 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    102658 mouse_pause_tracking 
    102659 self._mouse_pause() 
    102660 File
    102661 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102662 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    102663 m.pause(self._mouse_pause_position) 
    102664 File
    102665 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102666 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    102667 p = self.view.picked_object(x, y) 
    102668 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102669 File
    102670 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102671 packages/chimerax/graphics/view.py", line 838, in picked_object 
    102672 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    102673 beyond, 
    102674 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102675 File
    102676 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102677 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    102678 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    102679 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102680 File
    102681 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102682 packages/chimerax/core/models.py", line 143, in first_intercept 
    102683 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    102684 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102685 File
    102686 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102687 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    102688 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    102689 exclude=exclude) 
    102690 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102691 File
    102692 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102693 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    102694 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    102695 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102696 File
    102697 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102698 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    102699 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    102700 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102701 File
    102702 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102703 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    102704 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    102705 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102706 File
    102707 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102708 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    102709 p = super().first_intercept(mxyz1, mxyz2) 
    102710 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102711 File
    102712 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102713 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    102714 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    102715 exclude=exclude) 
    102716 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102717 File
    102718 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102719 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    102720 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    102721 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102722 File
    102723 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102724 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    102725 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    102726 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102727 File
    102728 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102729 packages/chimerax/graphics/drawing.py", line 1108, in
    102730 _first_intercept_excluding_children 
    102731 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    102732 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102733 File
    102734 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102735 packages/chimerax/geometry/place.py", line 201, in inverse 
    102736 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    102737 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102738 File
    102739 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102740 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    102741 rinv[:, :] = matrix_inverse(r) 
    102742 ^^^^^^^^^^^^^^^^^ 
    102743 File
    102744 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102745 packages/numpy/linalg/linalg.py", line 561, in inv 
    102746 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    102747 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102748 File
    102749 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102750 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    102751 raise LinAlgError("Singular matrix") 
    102752 numpy.linalg.LinAlgError: Singular matrix 
    102753  
    102754 numpy.linalg.LinAlgError: Singular matrix 
    102755  
    102756 File
    102757 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102758 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    102759 raise LinAlgError("Singular matrix") 
    102760  
    102761 See log for complete Python traceback. 
    102762  
    102763 Traceback (most recent call last): 
    102764 File
    102765 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102766 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    102767 self.session.ui.mouse_modes.mouse_pause_tracking() 
    102768 File
    102769 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102770 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    102771 mouse_pause_tracking 
    102772 self._mouse_pause() 
    102773 File
    102774 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102775 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    102776 m.pause(self._mouse_pause_position) 
    102777 File
    102778 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102779 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    102780 p = self.view.picked_object(x, y) 
    102781 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102782 File
    102783 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102784 packages/chimerax/graphics/view.py", line 838, in picked_object 
    102785 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    102786 beyond, 
    102787 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102788 File
    102789 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102790 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    102791 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    102792 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102793 File
    102794 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102795 packages/chimerax/core/models.py", line 143, in first_intercept 
    102796 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    102797 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102798 File
    102799 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102800 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    102801 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    102802 exclude=exclude) 
    102803 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102804 File
    102805 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102806 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    102807 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    102808 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102809 File
    102810 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102811 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    102812 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    102813 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102814 File
    102815 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102816 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    102817 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    102818 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102819 File
    102820 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102821 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    102822 p = super().first_intercept(mxyz1, mxyz2) 
    102823 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102824 File
    102825 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102826 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    102827 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    102828 exclude=exclude) 
    102829 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102830 File
    102831 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102832 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    102833 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    102834 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102835 File
    102836 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102837 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    102838 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    102839 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102840 File
    102841 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102842 packages/chimerax/graphics/drawing.py", line 1108, in
    102843 _first_intercept_excluding_children 
    102844 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    102845 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102846 File
    102847 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102848 packages/chimerax/geometry/place.py", line 201, in inverse 
    102849 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    102850 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102851 File
    102852 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102853 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    102854 rinv[:, :] = matrix_inverse(r) 
    102855 ^^^^^^^^^^^^^^^^^ 
    102856 File
    102857 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102858 packages/numpy/linalg/linalg.py", line 561, in inv 
    102859 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    102860 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102861 File
    102862 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102863 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    102864 raise LinAlgError("Singular matrix") 
    102865 numpy.linalg.LinAlgError: Singular matrix 
    102866  
    102867 numpy.linalg.LinAlgError: Singular matrix 
    102868  
    102869 File
    102870 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102871 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    102872 raise LinAlgError("Singular matrix") 
    102873  
    102874 See log for complete Python traceback. 
    102875  
    102876 Traceback (most recent call last): 
    102877 File
    102878 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102879 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    102880 self.session.ui.mouse_modes.mouse_pause_tracking() 
    102881 File
    102882 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102883 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    102884 mouse_pause_tracking 
    102885 self._mouse_pause() 
    102886 File
    102887 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102888 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    102889 m.pause(self._mouse_pause_position) 
    102890 File
    102891 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102892 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    102893 p = self.view.picked_object(x, y) 
    102894 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102895 File
    102896 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102897 packages/chimerax/graphics/view.py", line 838, in picked_object 
    102898 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    102899 beyond, 
    102900 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102901 File
    102902 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102903 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    102904 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    102905 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102906 File
    102907 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102908 packages/chimerax/core/models.py", line 143, in first_intercept 
    102909 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    102910 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102911 File
    102912 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102913 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    102914 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    102915 exclude=exclude) 
    102916 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102917 File
    102918 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102919 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    102920 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    102921 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102922 File
    102923 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102924 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    102925 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    102926 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102927 File
    102928 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102929 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    102930 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    102931 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102932 File
    102933 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102934 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    102935 p = super().first_intercept(mxyz1, mxyz2) 
    102936 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102937 File
    102938 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102939 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    102940 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    102941 exclude=exclude) 
    102942 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102943 File
    102944 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102945 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    102946 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    102947 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102948 File
    102949 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102950 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    102951 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    102952 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102953 File
    102954 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102955 packages/chimerax/graphics/drawing.py", line 1108, in
    102956 _first_intercept_excluding_children 
    102957 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    102958 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102959 File
    102960 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102961 packages/chimerax/geometry/place.py", line 201, in inverse 
    102962 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    102963 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102964 File
    102965 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102966 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    102967 rinv[:, :] = matrix_inverse(r) 
    102968 ^^^^^^^^^^^^^^^^^ 
    102969 File
    102970 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102971 packages/numpy/linalg/linalg.py", line 561, in inv 
    102972 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    102973 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    102974 File
    102975 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102976 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    102977 raise LinAlgError("Singular matrix") 
    102978 numpy.linalg.LinAlgError: Singular matrix 
    102979  
    102980 numpy.linalg.LinAlgError: Singular matrix 
    102981  
    102982 File
    102983 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102984 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    102985 raise LinAlgError("Singular matrix") 
    102986  
    102987 See log for complete Python traceback. 
    102988  
    102989 Traceback (most recent call last): 
    102990 File
    102991 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102992 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    102993 self.session.ui.mouse_modes.mouse_pause_tracking() 
    102994 File
    102995 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    102996 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    102997 mouse_pause_tracking 
    102998 self._mouse_pause() 
    102999 File
    103000 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103001 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    103002 m.pause(self._mouse_pause_position) 
    103003 File
    103004 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103005 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    103006 p = self.view.picked_object(x, y) 
    103007 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103008 File
    103009 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103010 packages/chimerax/graphics/view.py", line 838, in picked_object 
    103011 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    103012 beyond, 
    103013 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103014 File
    103015 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103016 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    103017 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    103018 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103019 File
    103020 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103021 packages/chimerax/core/models.py", line 143, in first_intercept 
    103022 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    103023 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103024 File
    103025 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103026 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    103027 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    103028 exclude=exclude) 
    103029 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103030 File
    103031 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103032 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    103033 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    103034 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103035 File
    103036 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103037 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    103038 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    103039 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103040 File
    103041 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103042 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    103043 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    103044 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103045 File
    103046 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103047 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    103048 p = super().first_intercept(mxyz1, mxyz2) 
    103049 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103050 File
    103051 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103052 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    103053 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    103054 exclude=exclude) 
    103055 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103056 File
    103057 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103058 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    103059 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    103060 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103061 File
    103062 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103063 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    103064 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    103065 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103066 File
    103067 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103068 packages/chimerax/graphics/drawing.py", line 1108, in
    103069 _first_intercept_excluding_children 
    103070 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    103071 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103072 File
    103073 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103074 packages/chimerax/geometry/place.py", line 201, in inverse 
    103075 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    103076 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103077 File
    103078 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103079 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    103080 rinv[:, :] = matrix_inverse(r) 
    103081 ^^^^^^^^^^^^^^^^^ 
    103082 File
    103083 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103084 packages/numpy/linalg/linalg.py", line 561, in inv 
    103085 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    103086 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103087 File
    103088 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103089 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    103090 raise LinAlgError("Singular matrix") 
    103091 numpy.linalg.LinAlgError: Singular matrix 
    103092  
    103093 numpy.linalg.LinAlgError: Singular matrix 
    103094  
    103095 File
    103096 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103097 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    103098 raise LinAlgError("Singular matrix") 
    103099  
    103100 See log for complete Python traceback. 
    103101  
    103102 Traceback (most recent call last): 
    103103 File
    103104 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103105 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    103106 self.session.ui.mouse_modes.mouse_pause_tracking() 
    103107 File
    103108 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103109 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    103110 mouse_pause_tracking 
    103111 self._mouse_pause() 
    103112 File
    103113 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103114 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    103115 m.pause(self._mouse_pause_position) 
    103116 File
    103117 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103118 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    103119 p = self.view.picked_object(x, y) 
    103120 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103121 File
    103122 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103123 packages/chimerax/graphics/view.py", line 838, in picked_object 
    103124 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    103125 beyond, 
    103126 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103127 File
    103128 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103129 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    103130 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    103131 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103132 File
    103133 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103134 packages/chimerax/core/models.py", line 143, in first_intercept 
    103135 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    103136 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103137 File
    103138 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103139 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    103140 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    103141 exclude=exclude) 
    103142 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103143 File
    103144 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103145 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    103146 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    103147 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103148 File
    103149 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103150 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    103151 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    103152 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103153 File
    103154 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103155 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    103156 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    103157 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103158 File
    103159 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103160 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    103161 p = super().first_intercept(mxyz1, mxyz2) 
    103162 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103163 File
    103164 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103165 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    103166 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    103167 exclude=exclude) 
    103168 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103169 File
    103170 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103171 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    103172 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    103173 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103174 File
    103175 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103176 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    103177 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    103178 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103179 File
    103180 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103181 packages/chimerax/graphics/drawing.py", line 1108, in
    103182 _first_intercept_excluding_children 
    103183 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    103184 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103185 File
    103186 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103187 packages/chimerax/geometry/place.py", line 201, in inverse 
    103188 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    103189 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103190 File
    103191 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103192 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    103193 rinv[:, :] = matrix_inverse(r) 
    103194 ^^^^^^^^^^^^^^^^^ 
    103195 File
    103196 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103197 packages/numpy/linalg/linalg.py", line 561, in inv 
    103198 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    103199 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103200 File
    103201 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103202 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    103203 raise LinAlgError("Singular matrix") 
    103204 numpy.linalg.LinAlgError: Singular matrix 
    103205  
    103206 numpy.linalg.LinAlgError: Singular matrix 
    103207  
    103208 File
    103209 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103210 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    103211 raise LinAlgError("Singular matrix") 
    103212  
    103213 See log for complete Python traceback. 
    103214  
    103215 Traceback (most recent call last): 
    103216 File
    103217 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103218 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    103219 self.session.ui.mouse_modes.mouse_pause_tracking() 
    103220 File
    103221 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103222 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    103223 mouse_pause_tracking 
    103224 self._mouse_pause() 
    103225 File
    103226 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103227 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    103228 m.pause(self._mouse_pause_position) 
    103229 File
    103230 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103231 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    103232 p = self.view.picked_object(x, y) 
    103233 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103234 File
    103235 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103236 packages/chimerax/graphics/view.py", line 838, in picked_object 
    103237 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    103238 beyond, 
    103239 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103240 File
    103241 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103242 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    103243 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    103244 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103245 File
    103246 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103247 packages/chimerax/core/models.py", line 143, in first_intercept 
    103248 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    103249 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103250 File
    103251 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103252 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    103253 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    103254 exclude=exclude) 
    103255 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103256 File
    103257 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103258 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    103259 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    103260 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103261 File
    103262 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103263 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    103264 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    103265 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103266 File
    103267 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103268 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    103269 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    103270 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103271 File
    103272 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103273 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    103274 p = super().first_intercept(mxyz1, mxyz2) 
    103275 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103276 File
    103277 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103278 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    103279 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    103280 exclude=exclude) 
    103281 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103282 File
    103283 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103284 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    103285 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    103286 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103287 File
    103288 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103289 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    103290 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    103291 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103292 File
    103293 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103294 packages/chimerax/graphics/drawing.py", line 1108, in
    103295 _first_intercept_excluding_children 
    103296 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    103297 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103298 File
    103299 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103300 packages/chimerax/geometry/place.py", line 201, in inverse 
    103301 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    103302 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103303 File
    103304 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103305 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    103306 rinv[:, :] = matrix_inverse(r) 
    103307 ^^^^^^^^^^^^^^^^^ 
    103308 File
    103309 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103310 packages/numpy/linalg/linalg.py", line 561, in inv 
    103311 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    103312 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103313 File
    103314 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103315 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    103316 raise LinAlgError("Singular matrix") 
    103317 numpy.linalg.LinAlgError: Singular matrix 
    103318  
    103319 numpy.linalg.LinAlgError: Singular matrix 
    103320  
    103321 File
    103322 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103323 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    103324 raise LinAlgError("Singular matrix") 
    103325  
    103326 See log for complete Python traceback. 
    103327  
    103328 Traceback (most recent call last): 
    103329 File
    103330 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103331 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    103332 self.session.ui.mouse_modes.mouse_pause_tracking() 
    103333 File
    103334 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103335 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    103336 mouse_pause_tracking 
    103337 self._mouse_pause() 
    103338 File
    103339 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103340 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    103341 m.pause(self._mouse_pause_position) 
    103342 File
    103343 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103344 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    103345 p = self.view.picked_object(x, y) 
    103346 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103347 File
    103348 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103349 packages/chimerax/graphics/view.py", line 838, in picked_object 
    103350 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    103351 beyond, 
    103352 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103353 File
    103354 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103355 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    103356 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    103357 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103358 File
    103359 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103360 packages/chimerax/core/models.py", line 143, in first_intercept 
    103361 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    103362 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103363 File
    103364 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103365 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    103366 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    103367 exclude=exclude) 
    103368 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103369 File
    103370 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103371 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    103372 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    103373 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103374 File
    103375 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103376 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    103377 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    103378 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103379 File
    103380 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103381 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    103382 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    103383 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103384 File
    103385 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103386 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    103387 p = super().first_intercept(mxyz1, mxyz2) 
    103388 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103389 File
    103390 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103391 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    103392 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    103393 exclude=exclude) 
    103394 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103395 File
    103396 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103397 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    103398 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    103399 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103400 File
    103401 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103402 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    103403 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    103404 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103405 File
    103406 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103407 packages/chimerax/graphics/drawing.py", line 1108, in
    103408 _first_intercept_excluding_children 
    103409 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    103410 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103411 File
    103412 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103413 packages/chimerax/geometry/place.py", line 201, in inverse 
    103414 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    103415 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103416 File
    103417 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103418 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    103419 rinv[:, :] = matrix_inverse(r) 
    103420 ^^^^^^^^^^^^^^^^^ 
    103421 File
    103422 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103423 packages/numpy/linalg/linalg.py", line 561, in inv 
    103424 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    103425 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103426 File
    103427 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103428 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    103429 raise LinAlgError("Singular matrix") 
    103430 numpy.linalg.LinAlgError: Singular matrix 
    103431  
    103432 numpy.linalg.LinAlgError: Singular matrix 
    103433  
    103434 File
    103435 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103436 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    103437 raise LinAlgError("Singular matrix") 
    103438  
    103439 See log for complete Python traceback. 
    103440  
    103441 Traceback (most recent call last): 
    103442 File
    103443 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103444 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    103445 self.session.ui.mouse_modes.mouse_pause_tracking() 
    103446 File
    103447 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103448 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    103449 mouse_pause_tracking 
    103450 self._mouse_pause() 
    103451 File
    103452 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103453 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    103454 m.pause(self._mouse_pause_position) 
    103455 File
    103456 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103457 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    103458 p = self.view.picked_object(x, y) 
    103459 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103460 File
    103461 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103462 packages/chimerax/graphics/view.py", line 838, in picked_object 
    103463 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    103464 beyond, 
    103465 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103466 File
    103467 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103468 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    103469 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    103470 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103471 File
    103472 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103473 packages/chimerax/core/models.py", line 143, in first_intercept 
    103474 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    103475 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103476 File
    103477 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103478 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    103479 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    103480 exclude=exclude) 
    103481 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103482 File
    103483 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103484 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    103485 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    103486 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103487 File
    103488 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103489 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    103490 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    103491 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103492 File
    103493 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103494 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    103495 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    103496 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103497 File
    103498 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103499 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    103500 p = super().first_intercept(mxyz1, mxyz2) 
    103501 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103502 File
    103503 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103504 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    103505 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    103506 exclude=exclude) 
    103507 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103508 File
    103509 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103510 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    103511 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    103512 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103513 File
    103514 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103515 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    103516 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    103517 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103518 File
    103519 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103520 packages/chimerax/graphics/drawing.py", line 1108, in
    103521 _first_intercept_excluding_children 
    103522 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    103523 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103524 File
    103525 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103526 packages/chimerax/geometry/place.py", line 201, in inverse 
    103527 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    103528 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103529 File
    103530 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103531 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    103532 rinv[:, :] = matrix_inverse(r) 
    103533 ^^^^^^^^^^^^^^^^^ 
    103534 File
    103535 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103536 packages/numpy/linalg/linalg.py", line 561, in inv 
    103537 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    103538 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103539 File
    103540 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103541 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    103542 raise LinAlgError("Singular matrix") 
    103543 numpy.linalg.LinAlgError: Singular matrix 
    103544  
    103545 numpy.linalg.LinAlgError: Singular matrix 
    103546  
    103547 File
    103548 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103549 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    103550 raise LinAlgError("Singular matrix") 
    103551  
    103552 See log for complete Python traceback. 
    103553  
    103554 Traceback (most recent call last): 
    103555 File
    103556 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103557 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    103558 self.session.ui.mouse_modes.mouse_pause_tracking() 
    103559 File
    103560 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103561 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    103562 mouse_pause_tracking 
    103563 self._mouse_pause() 
    103564 File
    103565 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103566 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    103567 m.pause(self._mouse_pause_position) 
    103568 File
    103569 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103570 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    103571 p = self.view.picked_object(x, y) 
    103572 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103573 File
    103574 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103575 packages/chimerax/graphics/view.py", line 838, in picked_object 
    103576 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    103577 beyond, 
    103578 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103579 File
    103580 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103581 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    103582 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    103583 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103584 File
    103585 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103586 packages/chimerax/core/models.py", line 143, in first_intercept 
    103587 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    103588 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103589 File
    103590 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103591 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    103592 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    103593 exclude=exclude) 
    103594 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103595 File
    103596 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103597 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    103598 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    103599 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103600 File
    103601 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103602 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    103603 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    103604 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103605 File
    103606 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103607 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    103608 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    103609 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103610 File
    103611 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103612 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    103613 p = super().first_intercept(mxyz1, mxyz2) 
    103614 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103615 File
    103616 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103617 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    103618 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    103619 exclude=exclude) 
    103620 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103621 File
    103622 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103623 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    103624 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    103625 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103626 File
    103627 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103628 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    103629 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    103630 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103631 File
    103632 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103633 packages/chimerax/graphics/drawing.py", line 1108, in
    103634 _first_intercept_excluding_children 
    103635 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    103636 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103637 File
    103638 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103639 packages/chimerax/geometry/place.py", line 201, in inverse 
    103640 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    103641 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103642 File
    103643 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103644 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    103645 rinv[:, :] = matrix_inverse(r) 
    103646 ^^^^^^^^^^^^^^^^^ 
    103647 File
    103648 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103649 packages/numpy/linalg/linalg.py", line 561, in inv 
    103650 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    103651 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103652 File
    103653 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103654 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    103655 raise LinAlgError("Singular matrix") 
    103656 numpy.linalg.LinAlgError: Singular matrix 
    103657  
    103658 numpy.linalg.LinAlgError: Singular matrix 
    103659  
    103660 File
    103661 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103662 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    103663 raise LinAlgError("Singular matrix") 
    103664  
    103665 See log for complete Python traceback. 
    103666  
    103667 Traceback (most recent call last): 
    103668 File
    103669 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103670 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    103671 self.session.ui.mouse_modes.mouse_pause_tracking() 
    103672 File
    103673 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103674 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    103675 mouse_pause_tracking 
    103676 self._mouse_pause() 
    103677 File
    103678 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103679 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    103680 m.pause(self._mouse_pause_position) 
    103681 File
    103682 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103683 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    103684 p = self.view.picked_object(x, y) 
    103685 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103686 File
    103687 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103688 packages/chimerax/graphics/view.py", line 838, in picked_object 
    103689 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    103690 beyond, 
    103691 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103692 File
    103693 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103694 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    103695 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    103696 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103697 File
    103698 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103699 packages/chimerax/core/models.py", line 143, in first_intercept 
    103700 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    103701 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103702 File
    103703 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103704 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    103705 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    103706 exclude=exclude) 
    103707 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103708 File
    103709 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103710 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    103711 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    103712 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103713 File
    103714 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103715 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    103716 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    103717 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103718 File
    103719 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103720 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    103721 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    103722 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103723 File
    103724 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103725 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    103726 p = super().first_intercept(mxyz1, mxyz2) 
    103727 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103728 File
    103729 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103730 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    103731 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    103732 exclude=exclude) 
    103733 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103734 File
    103735 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103736 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    103737 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    103738 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103739 File
    103740 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103741 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    103742 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    103743 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103744 File
    103745 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103746 packages/chimerax/graphics/drawing.py", line 1108, in
    103747 _first_intercept_excluding_children 
    103748 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    103749 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103750 File
    103751 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103752 packages/chimerax/geometry/place.py", line 201, in inverse 
    103753 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    103754 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103755 File
    103756 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103757 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    103758 rinv[:, :] = matrix_inverse(r) 
    103759 ^^^^^^^^^^^^^^^^^ 
    103760 File
    103761 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103762 packages/numpy/linalg/linalg.py", line 561, in inv 
    103763 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    103764 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103765 File
    103766 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103767 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    103768 raise LinAlgError("Singular matrix") 
    103769 numpy.linalg.LinAlgError: Singular matrix 
    103770  
    103771 numpy.linalg.LinAlgError: Singular matrix 
    103772  
    103773 File
    103774 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103775 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    103776 raise LinAlgError("Singular matrix") 
    103777  
    103778 See log for complete Python traceback. 
    103779  
    103780 Traceback (most recent call last): 
    103781 File
    103782 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103783 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    103784 self.session.ui.mouse_modes.mouse_pause_tracking() 
    103785 File
    103786 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103787 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    103788 mouse_pause_tracking 
    103789 self._mouse_pause() 
    103790 File
    103791 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103792 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    103793 m.pause(self._mouse_pause_position) 
    103794 File
    103795 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103796 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    103797 p = self.view.picked_object(x, y) 
    103798 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103799 File
    103800 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103801 packages/chimerax/graphics/view.py", line 838, in picked_object 
    103802 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    103803 beyond, 
    103804 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103805 File
    103806 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103807 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    103808 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    103809 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103810 File
    103811 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103812 packages/chimerax/core/models.py", line 143, in first_intercept 
    103813 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    103814 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103815 File
    103816 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103817 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    103818 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    103819 exclude=exclude) 
    103820 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103821 File
    103822 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103823 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    103824 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    103825 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103826 File
    103827 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103828 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    103829 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    103830 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103831 File
    103832 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103833 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    103834 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    103835 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103836 File
    103837 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103838 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    103839 p = super().first_intercept(mxyz1, mxyz2) 
    103840 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103841 File
    103842 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103843 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    103844 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    103845 exclude=exclude) 
    103846 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103847 File
    103848 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103849 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    103850 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    103851 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103852 File
    103853 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103854 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    103855 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    103856 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103857 File
    103858 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103859 packages/chimerax/graphics/drawing.py", line 1108, in
    103860 _first_intercept_excluding_children 
    103861 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    103862 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103863 File
    103864 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103865 packages/chimerax/geometry/place.py", line 201, in inverse 
    103866 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    103867 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103868 File
    103869 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103870 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    103871 rinv[:, :] = matrix_inverse(r) 
    103872 ^^^^^^^^^^^^^^^^^ 
    103873 File
    103874 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103875 packages/numpy/linalg/linalg.py", line 561, in inv 
    103876 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    103877 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103878 File
    103879 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103880 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    103881 raise LinAlgError("Singular matrix") 
    103882 numpy.linalg.LinAlgError: Singular matrix 
    103883  
    103884 numpy.linalg.LinAlgError: Singular matrix 
    103885  
    103886 File
    103887 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103888 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    103889 raise LinAlgError("Singular matrix") 
    103890  
    103891 See log for complete Python traceback. 
    103892  
    103893 Traceback (most recent call last): 
    103894 File
    103895 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103896 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    103897 self.session.ui.mouse_modes.mouse_pause_tracking() 
    103898 File
    103899 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103900 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    103901 mouse_pause_tracking 
    103902 self._mouse_pause() 
    103903 File
    103904 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103905 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    103906 m.pause(self._mouse_pause_position) 
    103907 File
    103908 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103909 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    103910 p = self.view.picked_object(x, y) 
    103911 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103912 File
    103913 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103914 packages/chimerax/graphics/view.py", line 838, in picked_object 
    103915 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    103916 beyond, 
    103917 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103918 File
    103919 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103920 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    103921 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    103922 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103923 File
    103924 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103925 packages/chimerax/core/models.py", line 143, in first_intercept 
    103926 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    103927 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103928 File
    103929 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103930 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    103931 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    103932 exclude=exclude) 
    103933 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103934 File
    103935 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103936 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    103937 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    103938 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103939 File
    103940 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103941 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    103942 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    103943 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103944 File
    103945 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103946 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    103947 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    103948 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103949 File
    103950 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103951 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    103952 p = super().first_intercept(mxyz1, mxyz2) 
    103953 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103954 File
    103955 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103956 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    103957 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    103958 exclude=exclude) 
    103959 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103960 File
    103961 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103962 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    103963 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    103964 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103965 File
    103966 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103967 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    103968 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    103969 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103970 File
    103971 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103972 packages/chimerax/graphics/drawing.py", line 1108, in
    103973 _first_intercept_excluding_children 
    103974 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    103975 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103976 File
    103977 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103978 packages/chimerax/geometry/place.py", line 201, in inverse 
    103979 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    103980 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103981 File
    103982 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103983 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    103984 rinv[:, :] = matrix_inverse(r) 
    103985 ^^^^^^^^^^^^^^^^^ 
    103986 File
    103987 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103988 packages/numpy/linalg/linalg.py", line 561, in inv 
    103989 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    103990 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    103991 File
    103992 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    103993 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    103994 raise LinAlgError("Singular matrix") 
    103995 numpy.linalg.LinAlgError: Singular matrix 
    103996  
    103997 numpy.linalg.LinAlgError: Singular matrix 
    103998  
    103999 File
    104000 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104001 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    104002 raise LinAlgError("Singular matrix") 
    104003  
    104004 See log for complete Python traceback. 
    104005  
    104006 Traceback (most recent call last): 
    104007 File
    104008 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104009 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    104010 self.session.ui.mouse_modes.mouse_pause_tracking() 
    104011 File
    104012 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104013 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    104014 mouse_pause_tracking 
    104015 self._mouse_pause() 
    104016 File
    104017 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104018 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    104019 m.pause(self._mouse_pause_position) 
    104020 File
    104021 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104022 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    104023 p = self.view.picked_object(x, y) 
    104024 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104025 File
    104026 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104027 packages/chimerax/graphics/view.py", line 838, in picked_object 
    104028 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    104029 beyond, 
    104030 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104031 File
    104032 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104033 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    104034 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    104035 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104036 File
    104037 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104038 packages/chimerax/core/models.py", line 143, in first_intercept 
    104039 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    104040 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104041 File
    104042 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104043 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    104044 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    104045 exclude=exclude) 
    104046 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104047 File
    104048 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104049 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    104050 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    104051 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104052 File
    104053 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104054 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    104055 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    104056 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104057 File
    104058 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104059 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    104060 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    104061 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104062 File
    104063 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104064 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    104065 p = super().first_intercept(mxyz1, mxyz2) 
    104066 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104067 File
    104068 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104069 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    104070 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    104071 exclude=exclude) 
    104072 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104073 File
    104074 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104075 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    104076 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    104077 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104078 File
    104079 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104080 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    104081 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    104082 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104083 File
    104084 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104085 packages/chimerax/graphics/drawing.py", line 1108, in
    104086 _first_intercept_excluding_children 
    104087 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    104088 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104089 File
    104090 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104091 packages/chimerax/geometry/place.py", line 201, in inverse 
    104092 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    104093 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104094 File
    104095 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104096 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    104097 rinv[:, :] = matrix_inverse(r) 
    104098 ^^^^^^^^^^^^^^^^^ 
    104099 File
    104100 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104101 packages/numpy/linalg/linalg.py", line 561, in inv 
    104102 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    104103 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104104 File
    104105 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104106 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    104107 raise LinAlgError("Singular matrix") 
    104108 numpy.linalg.LinAlgError: Singular matrix 
    104109  
    104110 numpy.linalg.LinAlgError: Singular matrix 
    104111  
    104112 File
    104113 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104114 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    104115 raise LinAlgError("Singular matrix") 
    104116  
    104117 See log for complete Python traceback. 
    104118  
    104119 Traceback (most recent call last): 
    104120 File
    104121 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104122 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    104123 self.session.ui.mouse_modes.mouse_pause_tracking() 
    104124 File
    104125 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104126 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    104127 mouse_pause_tracking 
    104128 self._mouse_pause() 
    104129 File
    104130 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104131 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    104132 m.pause(self._mouse_pause_position) 
    104133 File
    104134 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104135 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    104136 p = self.view.picked_object(x, y) 
    104137 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104138 File
    104139 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104140 packages/chimerax/graphics/view.py", line 838, in picked_object 
    104141 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    104142 beyond, 
    104143 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104144 File
    104145 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104146 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    104147 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    104148 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104149 File
    104150 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104151 packages/chimerax/core/models.py", line 143, in first_intercept 
    104152 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    104153 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104154 File
    104155 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104156 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    104157 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    104158 exclude=exclude) 
    104159 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104160 File
    104161 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104162 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    104163 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    104164 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104165 File
    104166 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104167 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    104168 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    104169 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104170 File
    104171 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104172 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    104173 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    104174 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104175 File
    104176 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104177 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    104178 p = super().first_intercept(mxyz1, mxyz2) 
    104179 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104180 File
    104181 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104182 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    104183 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    104184 exclude=exclude) 
    104185 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104186 File
    104187 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104188 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    104189 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    104190 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104191 File
    104192 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104193 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    104194 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    104195 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104196 File
    104197 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104198 packages/chimerax/graphics/drawing.py", line 1108, in
    104199 _first_intercept_excluding_children 
    104200 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    104201 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104202 File
    104203 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104204 packages/chimerax/geometry/place.py", line 201, in inverse 
    104205 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    104206 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104207 File
    104208 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104209 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    104210 rinv[:, :] = matrix_inverse(r) 
    104211 ^^^^^^^^^^^^^^^^^ 
    104212 File
    104213 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104214 packages/numpy/linalg/linalg.py", line 561, in inv 
    104215 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    104216 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104217 File
    104218 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104219 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    104220 raise LinAlgError("Singular matrix") 
    104221 numpy.linalg.LinAlgError: Singular matrix 
    104222  
    104223 numpy.linalg.LinAlgError: Singular matrix 
    104224  
    104225 File
    104226 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104227 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    104228 raise LinAlgError("Singular matrix") 
    104229  
    104230 See log for complete Python traceback. 
    104231  
    104232 Traceback (most recent call last): 
    104233 File
    104234 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104235 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    104236 self.session.ui.mouse_modes.mouse_pause_tracking() 
    104237 File
    104238 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104239 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    104240 mouse_pause_tracking 
    104241 self._mouse_pause() 
    104242 File
    104243 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104244 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    104245 m.pause(self._mouse_pause_position) 
    104246 File
    104247 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104248 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    104249 p = self.view.picked_object(x, y) 
    104250 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104251 File
    104252 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104253 packages/chimerax/graphics/view.py", line 838, in picked_object 
    104254 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    104255 beyond, 
    104256 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104257 File
    104258 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104259 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    104260 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    104261 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104262 File
    104263 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104264 packages/chimerax/core/models.py", line 143, in first_intercept 
    104265 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    104266 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104267 File
    104268 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104269 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    104270 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    104271 exclude=exclude) 
    104272 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104273 File
    104274 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104275 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    104276 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    104277 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104278 File
    104279 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104280 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    104281 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    104282 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104283 File
    104284 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104285 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    104286 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    104287 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104288 File
    104289 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104290 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    104291 p = super().first_intercept(mxyz1, mxyz2) 
    104292 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104293 File
    104294 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104295 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    104296 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    104297 exclude=exclude) 
    104298 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104299 File
    104300 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104301 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    104302 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    104303 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104304 File
    104305 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104306 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    104307 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    104308 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104309 File
    104310 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104311 packages/chimerax/graphics/drawing.py", line 1108, in
    104312 _first_intercept_excluding_children 
    104313 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    104314 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104315 File
    104316 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104317 packages/chimerax/geometry/place.py", line 201, in inverse 
    104318 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    104319 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104320 File
    104321 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104322 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    104323 rinv[:, :] = matrix_inverse(r) 
    104324 ^^^^^^^^^^^^^^^^^ 
    104325 File
    104326 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104327 packages/numpy/linalg/linalg.py", line 561, in inv 
    104328 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    104329 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104330 File
    104331 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104332 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    104333 raise LinAlgError("Singular matrix") 
    104334 numpy.linalg.LinAlgError: Singular matrix 
    104335  
    104336 numpy.linalg.LinAlgError: Singular matrix 
    104337  
    104338 File
    104339 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104340 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    104341 raise LinAlgError("Singular matrix") 
    104342  
    104343 See log for complete Python traceback. 
    104344  
    104345 Traceback (most recent call last): 
    104346 File
    104347 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104348 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    104349 self.session.ui.mouse_modes.mouse_pause_tracking() 
    104350 File
    104351 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104352 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    104353 mouse_pause_tracking 
    104354 self._mouse_pause() 
    104355 File
    104356 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104357 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    104358 m.pause(self._mouse_pause_position) 
    104359 File
    104360 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104361 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    104362 p = self.view.picked_object(x, y) 
    104363 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104364 File
    104365 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104366 packages/chimerax/graphics/view.py", line 838, in picked_object 
    104367 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    104368 beyond, 
    104369 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104370 File
    104371 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104372 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    104373 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    104374 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104375 File
    104376 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104377 packages/chimerax/core/models.py", line 143, in first_intercept 
    104378 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    104379 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104380 File
    104381 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104382 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    104383 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    104384 exclude=exclude) 
    104385 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104386 File
    104387 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104388 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    104389 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    104390 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104391 File
    104392 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104393 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    104394 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    104395 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104396 File
    104397 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104398 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    104399 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    104400 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104401 File
    104402 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104403 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    104404 p = super().first_intercept(mxyz1, mxyz2) 
    104405 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104406 File
    104407 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104408 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    104409 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    104410 exclude=exclude) 
    104411 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104412 File
    104413 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104414 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    104415 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    104416 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104417 File
    104418 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104419 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    104420 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    104421 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104422 File
    104423 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104424 packages/chimerax/graphics/drawing.py", line 1108, in
    104425 _first_intercept_excluding_children 
    104426 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    104427 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104428 File
    104429 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104430 packages/chimerax/geometry/place.py", line 201, in inverse 
    104431 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    104432 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104433 File
    104434 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104435 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    104436 rinv[:, :] = matrix_inverse(r) 
    104437 ^^^^^^^^^^^^^^^^^ 
    104438 File
    104439 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104440 packages/numpy/linalg/linalg.py", line 561, in inv 
    104441 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    104442 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104443 File
    104444 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104445 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    104446 raise LinAlgError("Singular matrix") 
    104447 numpy.linalg.LinAlgError: Singular matrix 
    104448  
    104449 numpy.linalg.LinAlgError: Singular matrix 
    104450  
    104451 File
    104452 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104453 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    104454 raise LinAlgError("Singular matrix") 
    104455  
    104456 See log for complete Python traceback. 
    104457  
    104458 Traceback (most recent call last): 
    104459 File
    104460 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104461 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    104462 self.session.ui.mouse_modes.mouse_pause_tracking() 
    104463 File
    104464 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104465 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    104466 mouse_pause_tracking 
    104467 self._mouse_pause() 
    104468 File
    104469 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104470 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    104471 m.pause(self._mouse_pause_position) 
    104472 File
    104473 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104474 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    104475 p = self.view.picked_object(x, y) 
    104476 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104477 File
    104478 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104479 packages/chimerax/graphics/view.py", line 838, in picked_object 
    104480 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    104481 beyond, 
    104482 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104483 File
    104484 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104485 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    104486 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    104487 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104488 File
    104489 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104490 packages/chimerax/core/models.py", line 143, in first_intercept 
    104491 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    104492 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104493 File
    104494 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104495 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    104496 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    104497 exclude=exclude) 
    104498 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104499 File
    104500 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104501 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    104502 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    104503 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104504 File
    104505 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104506 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    104507 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    104508 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104509 File
    104510 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104511 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    104512 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    104513 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104514 File
    104515 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104516 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    104517 p = super().first_intercept(mxyz1, mxyz2) 
    104518 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104519 File
    104520 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104521 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    104522 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    104523 exclude=exclude) 
    104524 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104525 File
    104526 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104527 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    104528 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    104529 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104530 File
    104531 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104532 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    104533 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    104534 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104535 File
    104536 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104537 packages/chimerax/graphics/drawing.py", line 1108, in
    104538 _first_intercept_excluding_children 
    104539 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    104540 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104541 File
    104542 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104543 packages/chimerax/geometry/place.py", line 201, in inverse 
    104544 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    104545 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104546 File
    104547 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104548 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    104549 rinv[:, :] = matrix_inverse(r) 
    104550 ^^^^^^^^^^^^^^^^^ 
    104551 File
    104552 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104553 packages/numpy/linalg/linalg.py", line 561, in inv 
    104554 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    104555 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104556 File
    104557 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104558 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    104559 raise LinAlgError("Singular matrix") 
    104560 numpy.linalg.LinAlgError: Singular matrix 
    104561  
    104562 numpy.linalg.LinAlgError: Singular matrix 
    104563  
    104564 File
    104565 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104566 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    104567 raise LinAlgError("Singular matrix") 
    104568  
    104569 See log for complete Python traceback. 
    104570  
    104571 Traceback (most recent call last): 
    104572 File
    104573 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104574 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    104575 self.session.ui.mouse_modes.mouse_pause_tracking() 
    104576 File
    104577 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104578 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    104579 mouse_pause_tracking 
    104580 self._mouse_pause() 
    104581 File
    104582 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104583 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    104584 m.pause(self._mouse_pause_position) 
    104585 File
    104586 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104587 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    104588 p = self.view.picked_object(x, y) 
    104589 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104590 File
    104591 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104592 packages/chimerax/graphics/view.py", line 838, in picked_object 
    104593 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    104594 beyond, 
    104595 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104596 File
    104597 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104598 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    104599 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    104600 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104601 File
    104602 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104603 packages/chimerax/core/models.py", line 143, in first_intercept 
    104604 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    104605 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104606 File
    104607 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104608 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    104609 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    104610 exclude=exclude) 
    104611 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104612 File
    104613 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104614 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    104615 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    104616 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104617 File
    104618 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104619 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    104620 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    104621 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104622 File
    104623 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104624 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    104625 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    104626 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104627 File
    104628 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104629 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    104630 p = super().first_intercept(mxyz1, mxyz2) 
    104631 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104632 File
    104633 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104634 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    104635 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    104636 exclude=exclude) 
    104637 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104638 File
    104639 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104640 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    104641 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    104642 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104643 File
    104644 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104645 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    104646 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    104647 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104648 File
    104649 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104650 packages/chimerax/graphics/drawing.py", line 1108, in
    104651 _first_intercept_excluding_children 
    104652 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    104653 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104654 File
    104655 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104656 packages/chimerax/geometry/place.py", line 201, in inverse 
    104657 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    104658 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104659 File
    104660 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104661 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    104662 rinv[:, :] = matrix_inverse(r) 
    104663 ^^^^^^^^^^^^^^^^^ 
    104664 File
    104665 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104666 packages/numpy/linalg/linalg.py", line 561, in inv 
    104667 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    104668 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104669 File
    104670 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104671 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    104672 raise LinAlgError("Singular matrix") 
    104673 numpy.linalg.LinAlgError: Singular matrix 
    104674  
    104675 numpy.linalg.LinAlgError: Singular matrix 
    104676  
    104677 File
    104678 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104679 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    104680 raise LinAlgError("Singular matrix") 
    104681  
    104682 See log for complete Python traceback. 
    104683  
    104684 Traceback (most recent call last): 
    104685 File
    104686 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104687 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    104688 self.session.ui.mouse_modes.mouse_pause_tracking() 
    104689 File
    104690 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104691 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    104692 mouse_pause_tracking 
    104693 self._mouse_pause() 
    104694 File
    104695 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104696 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    104697 m.pause(self._mouse_pause_position) 
    104698 File
    104699 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104700 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    104701 p = self.view.picked_object(x, y) 
    104702 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104703 File
    104704 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104705 packages/chimerax/graphics/view.py", line 838, in picked_object 
    104706 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    104707 beyond, 
    104708 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104709 File
    104710 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104711 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    104712 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    104713 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104714 File
    104715 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104716 packages/chimerax/core/models.py", line 143, in first_intercept 
    104717 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    104718 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104719 File
    104720 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104721 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    104722 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    104723 exclude=exclude) 
    104724 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104725 File
    104726 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104727 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    104728 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    104729 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104730 File
    104731 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104732 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    104733 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    104734 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104735 File
    104736 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104737 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    104738 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    104739 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104740 File
    104741 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104742 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    104743 p = super().first_intercept(mxyz1, mxyz2) 
    104744 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104745 File
    104746 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104747 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    104748 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    104749 exclude=exclude) 
    104750 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104751 File
    104752 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104753 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    104754 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    104755 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104756 File
    104757 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104758 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    104759 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    104760 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104761 File
    104762 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104763 packages/chimerax/graphics/drawing.py", line 1108, in
    104764 _first_intercept_excluding_children 
    104765 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    104766 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104767 File
    104768 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104769 packages/chimerax/geometry/place.py", line 201, in inverse 
    104770 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    104771 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104772 File
    104773 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104774 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    104775 rinv[:, :] = matrix_inverse(r) 
    104776 ^^^^^^^^^^^^^^^^^ 
    104777 File
    104778 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104779 packages/numpy/linalg/linalg.py", line 561, in inv 
    104780 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    104781 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104782 File
    104783 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104784 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    104785 raise LinAlgError("Singular matrix") 
    104786 numpy.linalg.LinAlgError: Singular matrix 
    104787  
    104788 numpy.linalg.LinAlgError: Singular matrix 
    104789  
    104790 File
    104791 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104792 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    104793 raise LinAlgError("Singular matrix") 
    104794  
    104795 See log for complete Python traceback. 
    104796  
    104797 Traceback (most recent call last): 
    104798 File
    104799 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104800 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    104801 self.session.ui.mouse_modes.mouse_pause_tracking() 
    104802 File
    104803 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104804 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    104805 mouse_pause_tracking 
    104806 self._mouse_pause() 
    104807 File
    104808 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104809 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    104810 m.pause(self._mouse_pause_position) 
    104811 File
    104812 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104813 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    104814 p = self.view.picked_object(x, y) 
    104815 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104816 File
    104817 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104818 packages/chimerax/graphics/view.py", line 838, in picked_object 
    104819 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    104820 beyond, 
    104821 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104822 File
    104823 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104824 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    104825 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    104826 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104827 File
    104828 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104829 packages/chimerax/core/models.py", line 143, in first_intercept 
    104830 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    104831 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104832 File
    104833 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104834 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    104835 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    104836 exclude=exclude) 
    104837 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104838 File
    104839 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104840 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    104841 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    104842 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104843 File
    104844 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104845 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    104846 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    104847 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104848 File
    104849 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104850 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    104851 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    104852 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104853 File
    104854 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104855 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    104856 p = super().first_intercept(mxyz1, mxyz2) 
    104857 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104858 File
    104859 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104860 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    104861 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    104862 exclude=exclude) 
    104863 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104864 File
    104865 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104866 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    104867 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    104868 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104869 File
    104870 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104871 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    104872 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    104873 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104874 File
    104875 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104876 packages/chimerax/graphics/drawing.py", line 1108, in
    104877 _first_intercept_excluding_children 
    104878 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    104879 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104880 File
    104881 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104882 packages/chimerax/geometry/place.py", line 201, in inverse 
    104883 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    104884 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104885 File
    104886 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104887 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    104888 rinv[:, :] = matrix_inverse(r) 
    104889 ^^^^^^^^^^^^^^^^^ 
    104890 File
    104891 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104892 packages/numpy/linalg/linalg.py", line 561, in inv 
    104893 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    104894 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104895 File
    104896 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104897 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    104898 raise LinAlgError("Singular matrix") 
    104899 numpy.linalg.LinAlgError: Singular matrix 
    104900  
    104901 numpy.linalg.LinAlgError: Singular matrix 
    104902  
    104903 File
    104904 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104905 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    104906 raise LinAlgError("Singular matrix") 
    104907  
    104908 See log for complete Python traceback. 
    104909  
    104910 Traceback (most recent call last): 
    104911 File
    104912 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104913 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    104914 self.session.ui.mouse_modes.mouse_pause_tracking() 
    104915 File
    104916 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104917 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    104918 mouse_pause_tracking 
    104919 self._mouse_pause() 
    104920 File
    104921 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104922 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    104923 m.pause(self._mouse_pause_position) 
    104924 File
    104925 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104926 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    104927 p = self.view.picked_object(x, y) 
    104928 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104929 File
    104930 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104931 packages/chimerax/graphics/view.py", line 838, in picked_object 
    104932 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    104933 beyond, 
    104934 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104935 File
    104936 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104937 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    104938 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    104939 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104940 File
    104941 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104942 packages/chimerax/core/models.py", line 143, in first_intercept 
    104943 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    104944 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104945 File
    104946 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104947 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    104948 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    104949 exclude=exclude) 
    104950 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104951 File
    104952 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104953 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    104954 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    104955 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104956 File
    104957 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104958 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    104959 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    104960 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104961 File
    104962 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104963 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    104964 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    104965 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104966 File
    104967 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104968 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    104969 p = super().first_intercept(mxyz1, mxyz2) 
    104970 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104971 File
    104972 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104973 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    104974 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    104975 exclude=exclude) 
    104976 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104977 File
    104978 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104979 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    104980 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    104981 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104982 File
    104983 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104984 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    104985 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    104986 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104987 File
    104988 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104989 packages/chimerax/graphics/drawing.py", line 1108, in
    104990 _first_intercept_excluding_children 
    104991 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    104992 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104993 File
    104994 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    104995 packages/chimerax/geometry/place.py", line 201, in inverse 
    104996 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    104997 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    104998 File
    104999 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105000 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    105001 rinv[:, :] = matrix_inverse(r) 
    105002 ^^^^^^^^^^^^^^^^^ 
    105003 File
    105004 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105005 packages/numpy/linalg/linalg.py", line 561, in inv 
    105006 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    105007 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105008 File
    105009 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105010 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    105011 raise LinAlgError("Singular matrix") 
    105012 numpy.linalg.LinAlgError: Singular matrix 
    105013  
    105014 numpy.linalg.LinAlgError: Singular matrix 
    105015  
    105016 File
    105017 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105018 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    105019 raise LinAlgError("Singular matrix") 
    105020  
    105021 See log for complete Python traceback. 
    105022  
    105023 Traceback (most recent call last): 
    105024 File
    105025 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105026 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    105027 self.session.ui.mouse_modes.mouse_pause_tracking() 
    105028 File
    105029 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105030 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    105031 mouse_pause_tracking 
    105032 self._mouse_pause() 
    105033 File
    105034 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105035 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    105036 m.pause(self._mouse_pause_position) 
    105037 File
    105038 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105039 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    105040 p = self.view.picked_object(x, y) 
    105041 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105042 File
    105043 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105044 packages/chimerax/graphics/view.py", line 838, in picked_object 
    105045 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    105046 beyond, 
    105047 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105048 File
    105049 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105050 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    105051 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    105052 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105053 File
    105054 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105055 packages/chimerax/core/models.py", line 143, in first_intercept 
    105056 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    105057 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105058 File
    105059 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105060 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    105061 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    105062 exclude=exclude) 
    105063 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105064 File
    105065 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105066 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    105067 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    105068 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105069 File
    105070 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105071 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    105072 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    105073 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105074 File
    105075 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105076 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    105077 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    105078 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105079 File
    105080 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105081 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    105082 p = super().first_intercept(mxyz1, mxyz2) 
    105083 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105084 File
    105085 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105086 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    105087 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    105088 exclude=exclude) 
    105089 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105090 File
    105091 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105092 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    105093 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    105094 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105095 File
    105096 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105097 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    105098 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    105099 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105100 File
    105101 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105102 packages/chimerax/graphics/drawing.py", line 1108, in
    105103 _first_intercept_excluding_children 
    105104 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    105105 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105106 File
    105107 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105108 packages/chimerax/geometry/place.py", line 201, in inverse 
    105109 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    105110 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105111 File
    105112 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105113 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    105114 rinv[:, :] = matrix_inverse(r) 
    105115 ^^^^^^^^^^^^^^^^^ 
    105116 File
    105117 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105118 packages/numpy/linalg/linalg.py", line 561, in inv 
    105119 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    105120 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105121 File
    105122 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105123 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    105124 raise LinAlgError("Singular matrix") 
    105125 numpy.linalg.LinAlgError: Singular matrix 
    105126  
    105127 numpy.linalg.LinAlgError: Singular matrix 
    105128  
    105129 File
    105130 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105131 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    105132 raise LinAlgError("Singular matrix") 
    105133  
    105134 See log for complete Python traceback. 
    105135  
    105136 Traceback (most recent call last): 
    105137 File
    105138 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105139 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    105140 self.session.ui.mouse_modes.mouse_pause_tracking() 
    105141 File
    105142 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105143 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    105144 mouse_pause_tracking 
    105145 self._mouse_pause() 
    105146 File
    105147 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105148 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    105149 m.pause(self._mouse_pause_position) 
    105150 File
    105151 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105152 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    105153 p = self.view.picked_object(x, y) 
    105154 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105155 File
    105156 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105157 packages/chimerax/graphics/view.py", line 838, in picked_object 
    105158 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    105159 beyond, 
    105160 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105161 File
    105162 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105163 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    105164 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    105165 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105166 File
    105167 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105168 packages/chimerax/core/models.py", line 143, in first_intercept 
    105169 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    105170 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105171 File
    105172 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105173 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    105174 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    105175 exclude=exclude) 
    105176 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105177 File
    105178 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105179 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    105180 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    105181 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105182 File
    105183 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105184 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    105185 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    105186 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105187 File
    105188 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105189 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    105190 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    105191 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105192 File
    105193 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105194 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    105195 p = super().first_intercept(mxyz1, mxyz2) 
    105196 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105197 File
    105198 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105199 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    105200 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    105201 exclude=exclude) 
    105202 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105203 File
    105204 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105205 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    105206 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    105207 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105208 File
    105209 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105210 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    105211 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    105212 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105213 File
    105214 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105215 packages/chimerax/graphics/drawing.py", line 1108, in
    105216 _first_intercept_excluding_children 
    105217 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    105218 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105219 File
    105220 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105221 packages/chimerax/geometry/place.py", line 201, in inverse 
    105222 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    105223 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105224 File
    105225 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105226 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    105227 rinv[:, :] = matrix_inverse(r) 
    105228 ^^^^^^^^^^^^^^^^^ 
    105229 File
    105230 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105231 packages/numpy/linalg/linalg.py", line 561, in inv 
    105232 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    105233 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105234 File
    105235 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105236 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    105237 raise LinAlgError("Singular matrix") 
    105238 numpy.linalg.LinAlgError: Singular matrix 
    105239  
    105240 numpy.linalg.LinAlgError: Singular matrix 
    105241  
    105242 File
    105243 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105244 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    105245 raise LinAlgError("Singular matrix") 
    105246  
    105247 See log for complete Python traceback. 
    105248  
    105249 Traceback (most recent call last): 
    105250 File
    105251 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105252 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    105253 self.session.ui.mouse_modes.mouse_pause_tracking() 
    105254 File
    105255 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105256 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    105257 mouse_pause_tracking 
    105258 self._mouse_pause() 
    105259 File
    105260 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105261 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    105262 m.pause(self._mouse_pause_position) 
    105263 File
    105264 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105265 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    105266 p = self.view.picked_object(x, y) 
    105267 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105268 File
    105269 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105270 packages/chimerax/graphics/view.py", line 838, in picked_object 
    105271 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    105272 beyond, 
    105273 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105274 File
    105275 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105276 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    105277 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    105278 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105279 File
    105280 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105281 packages/chimerax/core/models.py", line 143, in first_intercept 
    105282 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    105283 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105284 File
    105285 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105286 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    105287 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    105288 exclude=exclude) 
    105289 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105290 File
    105291 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105292 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    105293 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    105294 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105295 File
    105296 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105297 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    105298 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    105299 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105300 File
    105301 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105302 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    105303 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    105304 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105305 File
    105306 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105307 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    105308 p = super().first_intercept(mxyz1, mxyz2) 
    105309 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105310 File
    105311 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105312 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    105313 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    105314 exclude=exclude) 
    105315 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105316 File
    105317 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105318 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    105319 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    105320 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105321 File
    105322 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105323 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    105324 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    105325 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105326 File
    105327 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105328 packages/chimerax/graphics/drawing.py", line 1108, in
    105329 _first_intercept_excluding_children 
    105330 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    105331 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105332 File
    105333 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105334 packages/chimerax/geometry/place.py", line 201, in inverse 
    105335 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    105336 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105337 File
    105338 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105339 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    105340 rinv[:, :] = matrix_inverse(r) 
    105341 ^^^^^^^^^^^^^^^^^ 
    105342 File
    105343 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105344 packages/numpy/linalg/linalg.py", line 561, in inv 
    105345 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    105346 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105347 File
    105348 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105349 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    105350 raise LinAlgError("Singular matrix") 
    105351 numpy.linalg.LinAlgError: Singular matrix 
    105352  
    105353 numpy.linalg.LinAlgError: Singular matrix 
    105354  
    105355 File
    105356 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105357 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    105358 raise LinAlgError("Singular matrix") 
    105359  
    105360 See log for complete Python traceback. 
    105361  
    105362 Traceback (most recent call last): 
    105363 File
    105364 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105365 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    105366 self.session.ui.mouse_modes.mouse_pause_tracking() 
    105367 File
    105368 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105369 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    105370 mouse_pause_tracking 
    105371 self._mouse_pause() 
    105372 File
    105373 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105374 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    105375 m.pause(self._mouse_pause_position) 
    105376 File
    105377 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105378 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    105379 p = self.view.picked_object(x, y) 
    105380 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105381 File
    105382 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105383 packages/chimerax/graphics/view.py", line 838, in picked_object 
    105384 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    105385 beyond, 
    105386 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105387 File
    105388 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105389 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    105390 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    105391 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105392 File
    105393 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105394 packages/chimerax/core/models.py", line 143, in first_intercept 
    105395 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    105396 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105397 File
    105398 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105399 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    105400 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    105401 exclude=exclude) 
    105402 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105403 File
    105404 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105405 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    105406 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    105407 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105408 File
    105409 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105410 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    105411 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    105412 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105413 File
    105414 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105415 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    105416 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    105417 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105418 File
    105419 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105420 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    105421 p = super().first_intercept(mxyz1, mxyz2) 
    105422 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105423 File
    105424 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105425 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    105426 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    105427 exclude=exclude) 
    105428 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105429 File
    105430 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105431 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    105432 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    105433 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105434 File
    105435 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105436 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    105437 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    105438 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105439 File
    105440 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105441 packages/chimerax/graphics/drawing.py", line 1108, in
    105442 _first_intercept_excluding_children 
    105443 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    105444 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105445 File
    105446 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105447 packages/chimerax/geometry/place.py", line 201, in inverse 
    105448 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    105449 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105450 File
    105451 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105452 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    105453 rinv[:, :] = matrix_inverse(r) 
    105454 ^^^^^^^^^^^^^^^^^ 
    105455 File
    105456 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105457 packages/numpy/linalg/linalg.py", line 561, in inv 
    105458 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    105459 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105460 File
    105461 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105462 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    105463 raise LinAlgError("Singular matrix") 
    105464 numpy.linalg.LinAlgError: Singular matrix 
    105465  
    105466 numpy.linalg.LinAlgError: Singular matrix 
    105467  
    105468 File
    105469 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105470 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    105471 raise LinAlgError("Singular matrix") 
    105472  
    105473 See log for complete Python traceback. 
    105474  
    105475 Traceback (most recent call last): 
    105476 File
    105477 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105478 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    105479 self.session.ui.mouse_modes.mouse_pause_tracking() 
    105480 File
    105481 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105482 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    105483 mouse_pause_tracking 
    105484 self._mouse_pause() 
    105485 File
    105486 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105487 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    105488 m.pause(self._mouse_pause_position) 
    105489 File
    105490 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105491 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    105492 p = self.view.picked_object(x, y) 
    105493 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105494 File
    105495 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105496 packages/chimerax/graphics/view.py", line 838, in picked_object 
    105497 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    105498 beyond, 
    105499 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105500 File
    105501 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105502 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    105503 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    105504 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105505 File
    105506 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105507 packages/chimerax/core/models.py", line 143, in first_intercept 
    105508 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    105509 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105510 File
    105511 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105512 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    105513 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    105514 exclude=exclude) 
    105515 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105516 File
    105517 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105518 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    105519 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    105520 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105521 File
    105522 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105523 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    105524 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    105525 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105526 File
    105527 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105528 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    105529 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    105530 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105531 File
    105532 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105533 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    105534 p = super().first_intercept(mxyz1, mxyz2) 
    105535 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105536 File
    105537 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105538 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    105539 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    105540 exclude=exclude) 
    105541 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105542 File
    105543 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105544 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    105545 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    105546 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105547 File
    105548 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105549 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    105550 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    105551 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105552 File
    105553 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105554 packages/chimerax/graphics/drawing.py", line 1108, in
    105555 _first_intercept_excluding_children 
    105556 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    105557 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105558 File
    105559 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105560 packages/chimerax/geometry/place.py", line 201, in inverse 
    105561 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    105562 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105563 File
    105564 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105565 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    105566 rinv[:, :] = matrix_inverse(r) 
    105567 ^^^^^^^^^^^^^^^^^ 
    105568 File
    105569 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105570 packages/numpy/linalg/linalg.py", line 561, in inv 
    105571 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    105572 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105573 File
    105574 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105575 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    105576 raise LinAlgError("Singular matrix") 
    105577 numpy.linalg.LinAlgError: Singular matrix 
    105578  
    105579 numpy.linalg.LinAlgError: Singular matrix 
    105580  
    105581 File
    105582 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105583 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    105584 raise LinAlgError("Singular matrix") 
    105585  
    105586 See log for complete Python traceback. 
    105587  
    105588 Traceback (most recent call last): 
    105589 File
    105590 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105591 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    105592 self.session.ui.mouse_modes.mouse_pause_tracking() 
    105593 File
    105594 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105595 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    105596 mouse_pause_tracking 
    105597 self._mouse_pause() 
    105598 File
    105599 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105600 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    105601 m.pause(self._mouse_pause_position) 
    105602 File
    105603 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105604 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    105605 p = self.view.picked_object(x, y) 
    105606 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105607 File
    105608 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105609 packages/chimerax/graphics/view.py", line 838, in picked_object 
    105610 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    105611 beyond, 
    105612 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105613 File
    105614 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105615 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    105616 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    105617 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105618 File
    105619 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105620 packages/chimerax/core/models.py", line 143, in first_intercept 
    105621 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    105622 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105623 File
    105624 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105625 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    105626 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    105627 exclude=exclude) 
    105628 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105629 File
    105630 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105631 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    105632 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    105633 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105634 File
    105635 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105636 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    105637 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    105638 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105639 File
    105640 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105641 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    105642 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    105643 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105644 File
    105645 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105646 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    105647 p = super().first_intercept(mxyz1, mxyz2) 
    105648 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105649 File
    105650 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105651 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    105652 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    105653 exclude=exclude) 
    105654 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105655 File
    105656 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105657 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    105658 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    105659 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105660 File
    105661 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105662 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    105663 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    105664 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105665 File
    105666 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105667 packages/chimerax/graphics/drawing.py", line 1108, in
    105668 _first_intercept_excluding_children 
    105669 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    105670 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105671 File
    105672 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105673 packages/chimerax/geometry/place.py", line 201, in inverse 
    105674 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    105675 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105676 File
    105677 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105678 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    105679 rinv[:, :] = matrix_inverse(r) 
    105680 ^^^^^^^^^^^^^^^^^ 
    105681 File
    105682 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105683 packages/numpy/linalg/linalg.py", line 561, in inv 
    105684 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    105685 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105686 File
    105687 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105688 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    105689 raise LinAlgError("Singular matrix") 
    105690 numpy.linalg.LinAlgError: Singular matrix 
    105691  
    105692 numpy.linalg.LinAlgError: Singular matrix 
    105693  
    105694 File
    105695 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105696 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    105697 raise LinAlgError("Singular matrix") 
    105698  
    105699 See log for complete Python traceback. 
    105700  
    105701 Traceback (most recent call last): 
    105702 File
    105703 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105704 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    105705 self.session.ui.mouse_modes.mouse_pause_tracking() 
    105706 File
    105707 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105708 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    105709 mouse_pause_tracking 
    105710 self._mouse_pause() 
    105711 File
    105712 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105713 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    105714 m.pause(self._mouse_pause_position) 
    105715 File
    105716 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105717 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    105718 p = self.view.picked_object(x, y) 
    105719 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105720 File
    105721 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105722 packages/chimerax/graphics/view.py", line 838, in picked_object 
    105723 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    105724 beyond, 
    105725 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105726 File
    105727 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105728 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    105729 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    105730 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105731 File
    105732 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105733 packages/chimerax/core/models.py", line 143, in first_intercept 
    105734 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    105735 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105736 File
    105737 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105738 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    105739 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    105740 exclude=exclude) 
    105741 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105742 File
    105743 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105744 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    105745 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    105746 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105747 File
    105748 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105749 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    105750 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    105751 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105752 File
    105753 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105754 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    105755 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    105756 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105757 File
    105758 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105759 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    105760 p = super().first_intercept(mxyz1, mxyz2) 
    105761 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105762 File
    105763 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105764 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    105765 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    105766 exclude=exclude) 
    105767 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105768 File
    105769 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105770 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    105771 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    105772 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105773 File
    105774 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105775 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    105776 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    105777 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105778 File
    105779 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105780 packages/chimerax/graphics/drawing.py", line 1108, in
    105781 _first_intercept_excluding_children 
    105782 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    105783 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105784 File
    105785 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105786 packages/chimerax/geometry/place.py", line 201, in inverse 
    105787 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    105788 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105789 File
    105790 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105791 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    105792 rinv[:, :] = matrix_inverse(r) 
    105793 ^^^^^^^^^^^^^^^^^ 
    105794 File
    105795 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105796 packages/numpy/linalg/linalg.py", line 561, in inv 
    105797 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    105798 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105799 File
    105800 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105801 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    105802 raise LinAlgError("Singular matrix") 
    105803 numpy.linalg.LinAlgError: Singular matrix 
    105804  
    105805 numpy.linalg.LinAlgError: Singular matrix 
    105806  
    105807 File
    105808 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105809 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    105810 raise LinAlgError("Singular matrix") 
    105811  
    105812 See log for complete Python traceback. 
    105813  
    105814 Traceback (most recent call last): 
    105815 File
    105816 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105817 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    105818 self.session.ui.mouse_modes.mouse_pause_tracking() 
    105819 File
    105820 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105821 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    105822 mouse_pause_tracking 
    105823 self._mouse_pause() 
    105824 File
    105825 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105826 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    105827 m.pause(self._mouse_pause_position) 
    105828 File
    105829 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105830 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    105831 p = self.view.picked_object(x, y) 
    105832 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105833 File
    105834 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105835 packages/chimerax/graphics/view.py", line 838, in picked_object 
    105836 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    105837 beyond, 
    105838 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105839 File
    105840 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105841 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    105842 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    105843 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105844 File
    105845 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105846 packages/chimerax/core/models.py", line 143, in first_intercept 
    105847 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    105848 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105849 File
    105850 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105851 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    105852 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    105853 exclude=exclude) 
    105854 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105855 File
    105856 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105857 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    105858 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    105859 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105860 File
    105861 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105862 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    105863 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    105864 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105865 File
    105866 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105867 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    105868 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    105869 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105870 File
    105871 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105872 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    105873 p = super().first_intercept(mxyz1, mxyz2) 
    105874 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105875 File
    105876 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105877 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    105878 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    105879 exclude=exclude) 
    105880 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105881 File
    105882 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105883 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    105884 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    105885 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105886 File
    105887 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105888 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    105889 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    105890 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105891 File
    105892 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105893 packages/chimerax/graphics/drawing.py", line 1108, in
    105894 _first_intercept_excluding_children 
    105895 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    105896 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105897 File
    105898 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105899 packages/chimerax/geometry/place.py", line 201, in inverse 
    105900 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    105901 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105902 File
    105903 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105904 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    105905 rinv[:, :] = matrix_inverse(r) 
    105906 ^^^^^^^^^^^^^^^^^ 
    105907 File
    105908 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105909 packages/numpy/linalg/linalg.py", line 561, in inv 
    105910 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    105911 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105912 File
    105913 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105914 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    105915 raise LinAlgError("Singular matrix") 
    105916 numpy.linalg.LinAlgError: Singular matrix 
    105917  
    105918 numpy.linalg.LinAlgError: Singular matrix 
    105919  
    105920 File
    105921 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105922 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    105923 raise LinAlgError("Singular matrix") 
    105924  
    105925 See log for complete Python traceback. 
    105926  
    105927 Traceback (most recent call last): 
    105928 File
    105929 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105930 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    105931 self.session.ui.mouse_modes.mouse_pause_tracking() 
    105932 File
    105933 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105934 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    105935 mouse_pause_tracking 
    105936 self._mouse_pause() 
    105937 File
    105938 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105939 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    105940 m.pause(self._mouse_pause_position) 
    105941 File
    105942 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105943 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    105944 p = self.view.picked_object(x, y) 
    105945 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105946 File
    105947 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105948 packages/chimerax/graphics/view.py", line 838, in picked_object 
    105949 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    105950 beyond, 
    105951 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105952 File
    105953 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105954 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    105955 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    105956 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105957 File
    105958 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105959 packages/chimerax/core/models.py", line 143, in first_intercept 
    105960 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    105961 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105962 File
    105963 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105964 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    105965 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    105966 exclude=exclude) 
    105967 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105968 File
    105969 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105970 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    105971 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    105972 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105973 File
    105974 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105975 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    105976 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    105977 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105978 File
    105979 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105980 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    105981 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    105982 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105983 File
    105984 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105985 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    105986 p = super().first_intercept(mxyz1, mxyz2) 
    105987 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105988 File
    105989 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105990 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    105991 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    105992 exclude=exclude) 
    105993 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105994 File
    105995 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    105996 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    105997 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    105998 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    105999 File
    106000 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106001 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    106002 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    106003 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106004 File
    106005 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106006 packages/chimerax/graphics/drawing.py", line 1108, in
    106007 _first_intercept_excluding_children 
    106008 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    106009 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106010 File
    106011 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106012 packages/chimerax/geometry/place.py", line 201, in inverse 
    106013 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    106014 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106015 File
    106016 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106017 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    106018 rinv[:, :] = matrix_inverse(r) 
    106019 ^^^^^^^^^^^^^^^^^ 
    106020 File
    106021 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106022 packages/numpy/linalg/linalg.py", line 561, in inv 
    106023 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    106024 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106025 File
    106026 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106027 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    106028 raise LinAlgError("Singular matrix") 
    106029 numpy.linalg.LinAlgError: Singular matrix 
    106030  
    106031 numpy.linalg.LinAlgError: Singular matrix 
    106032  
    106033 File
    106034 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106035 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    106036 raise LinAlgError("Singular matrix") 
    106037  
    106038 See log for complete Python traceback. 
    106039  
    106040 Traceback (most recent call last): 
    106041 File
    106042 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106043 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    106044 self.session.ui.mouse_modes.mouse_pause_tracking() 
    106045 File
    106046 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106047 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    106048 mouse_pause_tracking 
    106049 self._mouse_pause() 
    106050 File
    106051 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106052 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    106053 m.pause(self._mouse_pause_position) 
    106054 File
    106055 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106056 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    106057 p = self.view.picked_object(x, y) 
    106058 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106059 File
    106060 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106061 packages/chimerax/graphics/view.py", line 838, in picked_object 
    106062 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    106063 beyond, 
    106064 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106065 File
    106066 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106067 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    106068 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    106069 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106070 File
    106071 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106072 packages/chimerax/core/models.py", line 143, in first_intercept 
    106073 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    106074 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106075 File
    106076 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106077 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    106078 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    106079 exclude=exclude) 
    106080 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106081 File
    106082 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106083 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    106084 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    106085 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106086 File
    106087 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106088 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    106089 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    106090 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106091 File
    106092 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106093 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    106094 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    106095 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106096 File
    106097 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106098 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    106099 p = super().first_intercept(mxyz1, mxyz2) 
    106100 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106101 File
    106102 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106103 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    106104 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    106105 exclude=exclude) 
    106106 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106107 File
    106108 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106109 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    106110 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    106111 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106112 File
    106113 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106114 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    106115 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    106116 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106117 File
    106118 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106119 packages/chimerax/graphics/drawing.py", line 1108, in
    106120 _first_intercept_excluding_children 
    106121 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    106122 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106123 File
    106124 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106125 packages/chimerax/geometry/place.py", line 201, in inverse 
    106126 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    106127 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106128 File
    106129 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106130 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    106131 rinv[:, :] = matrix_inverse(r) 
    106132 ^^^^^^^^^^^^^^^^^ 
    106133 File
    106134 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106135 packages/numpy/linalg/linalg.py", line 561, in inv 
    106136 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    106137 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106138 File
    106139 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106140 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    106141 raise LinAlgError("Singular matrix") 
    106142 numpy.linalg.LinAlgError: Singular matrix 
    106143  
    106144 numpy.linalg.LinAlgError: Singular matrix 
    106145  
    106146 File
    106147 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106148 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    106149 raise LinAlgError("Singular matrix") 
    106150  
    106151 See log for complete Python traceback. 
    106152  
    106153 Traceback (most recent call last): 
    106154 File
    106155 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106156 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    106157 self.session.ui.mouse_modes.mouse_pause_tracking() 
    106158 File
    106159 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106160 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    106161 mouse_pause_tracking 
    106162 self._mouse_pause() 
    106163 File
    106164 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106165 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    106166 m.pause(self._mouse_pause_position) 
    106167 File
    106168 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106169 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    106170 p = self.view.picked_object(x, y) 
    106171 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106172 File
    106173 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106174 packages/chimerax/graphics/view.py", line 838, in picked_object 
    106175 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    106176 beyond, 
    106177 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106178 File
    106179 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106180 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    106181 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    106182 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106183 File
    106184 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106185 packages/chimerax/core/models.py", line 143, in first_intercept 
    106186 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    106187 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106188 File
    106189 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106190 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    106191 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    106192 exclude=exclude) 
    106193 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106194 File
    106195 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106196 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    106197 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    106198 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106199 File
    106200 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106201 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    106202 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    106203 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106204 File
    106205 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106206 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    106207 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    106208 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106209 File
    106210 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106211 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    106212 p = super().first_intercept(mxyz1, mxyz2) 
    106213 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106214 File
    106215 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106216 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    106217 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    106218 exclude=exclude) 
    106219 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106220 File
    106221 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106222 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    106223 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    106224 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106225 File
    106226 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106227 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    106228 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    106229 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106230 File
    106231 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106232 packages/chimerax/graphics/drawing.py", line 1108, in
    106233 _first_intercept_excluding_children 
    106234 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    106235 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106236 File
    106237 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106238 packages/chimerax/geometry/place.py", line 201, in inverse 
    106239 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    106240 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106241 File
    106242 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106243 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    106244 rinv[:, :] = matrix_inverse(r) 
    106245 ^^^^^^^^^^^^^^^^^ 
    106246 File
    106247 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106248 packages/numpy/linalg/linalg.py", line 561, in inv 
    106249 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    106250 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106251 File
    106252 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106253 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    106254 raise LinAlgError("Singular matrix") 
    106255 numpy.linalg.LinAlgError: Singular matrix 
    106256  
    106257 numpy.linalg.LinAlgError: Singular matrix 
    106258  
    106259 File
    106260 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106261 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    106262 raise LinAlgError("Singular matrix") 
    106263  
    106264 See log for complete Python traceback. 
    106265  
    106266 Traceback (most recent call last): 
    106267 File
    106268 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106269 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    106270 self.session.ui.mouse_modes.mouse_pause_tracking() 
    106271 File
    106272 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106273 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    106274 mouse_pause_tracking 
    106275 self._mouse_pause() 
    106276 File
    106277 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106278 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    106279 m.pause(self._mouse_pause_position) 
    106280 File
    106281 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106282 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    106283 p = self.view.picked_object(x, y) 
    106284 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106285 File
    106286 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106287 packages/chimerax/graphics/view.py", line 838, in picked_object 
    106288 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    106289 beyond, 
    106290 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106291 File
    106292 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106293 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    106294 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    106295 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106296 File
    106297 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106298 packages/chimerax/core/models.py", line 143, in first_intercept 
    106299 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    106300 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106301 File
    106302 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106303 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    106304 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    106305 exclude=exclude) 
    106306 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106307 File
    106308 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106309 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    106310 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    106311 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106312 File
    106313 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106314 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    106315 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    106316 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106317 File
    106318 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106319 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    106320 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    106321 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106322 File
    106323 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106324 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    106325 p = super().first_intercept(mxyz1, mxyz2) 
    106326 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106327 File
    106328 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106329 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    106330 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    106331 exclude=exclude) 
    106332 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106333 File
    106334 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106335 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    106336 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    106337 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106338 File
    106339 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106340 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    106341 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    106342 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106343 File
    106344 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106345 packages/chimerax/graphics/drawing.py", line 1108, in
    106346 _first_intercept_excluding_children 
    106347 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    106348 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106349 File
    106350 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106351 packages/chimerax/geometry/place.py", line 201, in inverse 
    106352 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    106353 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106354 File
    106355 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106356 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    106357 rinv[:, :] = matrix_inverse(r) 
    106358 ^^^^^^^^^^^^^^^^^ 
    106359 File
    106360 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106361 packages/numpy/linalg/linalg.py", line 561, in inv 
    106362 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    106363 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106364 File
    106365 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106366 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    106367 raise LinAlgError("Singular matrix") 
    106368 numpy.linalg.LinAlgError: Singular matrix 
    106369  
    106370 numpy.linalg.LinAlgError: Singular matrix 
    106371  
    106372 File
    106373 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106374 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    106375 raise LinAlgError("Singular matrix") 
    106376  
    106377 See log for complete Python traceback. 
    106378  
    106379 Traceback (most recent call last): 
    106380 File
    106381 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106382 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    106383 self.session.ui.mouse_modes.mouse_pause_tracking() 
    106384 File
    106385 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106386 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    106387 mouse_pause_tracking 
    106388 self._mouse_pause() 
    106389 File
    106390 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106391 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    106392 m.pause(self._mouse_pause_position) 
    106393 File
    106394 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106395 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    106396 p = self.view.picked_object(x, y) 
    106397 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106398 File
    106399 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106400 packages/chimerax/graphics/view.py", line 838, in picked_object 
    106401 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    106402 beyond, 
    106403 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106404 File
    106405 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106406 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    106407 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    106408 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106409 File
    106410 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106411 packages/chimerax/core/models.py", line 143, in first_intercept 
    106412 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    106413 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106414 File
    106415 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106416 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    106417 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    106418 exclude=exclude) 
    106419 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106420 File
    106421 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106422 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    106423 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    106424 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106425 File
    106426 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106427 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    106428 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    106429 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106430 File
    106431 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106432 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    106433 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    106434 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106435 File
    106436 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106437 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    106438 p = super().first_intercept(mxyz1, mxyz2) 
    106439 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106440 File
    106441 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106442 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    106443 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    106444 exclude=exclude) 
    106445 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106446 File
    106447 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106448 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    106449 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    106450 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106451 File
    106452 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106453 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    106454 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    106455 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106456 File
    106457 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106458 packages/chimerax/graphics/drawing.py", line 1108, in
    106459 _first_intercept_excluding_children 
    106460 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    106461 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106462 File
    106463 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106464 packages/chimerax/geometry/place.py", line 201, in inverse 
    106465 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    106466 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106467 File
    106468 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106469 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    106470 rinv[:, :] = matrix_inverse(r) 
    106471 ^^^^^^^^^^^^^^^^^ 
    106472 File
    106473 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106474 packages/numpy/linalg/linalg.py", line 561, in inv 
    106475 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    106476 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106477 File
    106478 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106479 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    106480 raise LinAlgError("Singular matrix") 
    106481 numpy.linalg.LinAlgError: Singular matrix 
    106482  
    106483 numpy.linalg.LinAlgError: Singular matrix 
    106484  
    106485 File
    106486 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106487 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    106488 raise LinAlgError("Singular matrix") 
    106489  
    106490 See log for complete Python traceback. 
    106491  
    106492 Traceback (most recent call last): 
    106493 File
    106494 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106495 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    106496 self.session.ui.mouse_modes.mouse_pause_tracking() 
    106497 File
    106498 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106499 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    106500 mouse_pause_tracking 
    106501 self._mouse_pause() 
    106502 File
    106503 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106504 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    106505 m.pause(self._mouse_pause_position) 
    106506 File
    106507 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106508 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    106509 p = self.view.picked_object(x, y) 
    106510 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106511 File
    106512 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106513 packages/chimerax/graphics/view.py", line 838, in picked_object 
    106514 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    106515 beyond, 
    106516 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106517 File
    106518 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106519 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    106520 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    106521 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106522 File
    106523 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106524 packages/chimerax/core/models.py", line 143, in first_intercept 
    106525 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    106526 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106527 File
    106528 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106529 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    106530 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    106531 exclude=exclude) 
    106532 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106533 File
    106534 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106535 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    106536 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    106537 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106538 File
    106539 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106540 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    106541 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    106542 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106543 File
    106544 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106545 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    106546 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    106547 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106548 File
    106549 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106550 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    106551 p = super().first_intercept(mxyz1, mxyz2) 
    106552 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106553 File
    106554 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106555 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    106556 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    106557 exclude=exclude) 
    106558 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106559 File
    106560 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106561 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    106562 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    106563 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106564 File
    106565 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106566 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    106567 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    106568 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106569 File
    106570 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106571 packages/chimerax/graphics/drawing.py", line 1108, in
    106572 _first_intercept_excluding_children 
    106573 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    106574 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106575 File
    106576 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106577 packages/chimerax/geometry/place.py", line 201, in inverse 
    106578 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    106579 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106580 File
    106581 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106582 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    106583 rinv[:, :] = matrix_inverse(r) 
    106584 ^^^^^^^^^^^^^^^^^ 
    106585 File
    106586 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106587 packages/numpy/linalg/linalg.py", line 561, in inv 
    106588 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    106589 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106590 File
    106591 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106592 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    106593 raise LinAlgError("Singular matrix") 
    106594 numpy.linalg.LinAlgError: Singular matrix 
    106595  
    106596 numpy.linalg.LinAlgError: Singular matrix 
    106597  
    106598 File
    106599 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106600 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    106601 raise LinAlgError("Singular matrix") 
    106602  
    106603 See log for complete Python traceback. 
    106604  
    106605 Traceback (most recent call last): 
    106606 File
    106607 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106608 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    106609 self.session.ui.mouse_modes.mouse_pause_tracking() 
    106610 File
    106611 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106612 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    106613 mouse_pause_tracking 
    106614 self._mouse_pause() 
    106615 File
    106616 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106617 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    106618 m.pause(self._mouse_pause_position) 
    106619 File
    106620 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106621 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    106622 p = self.view.picked_object(x, y) 
    106623 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106624 File
    106625 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106626 packages/chimerax/graphics/view.py", line 838, in picked_object 
    106627 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    106628 beyond, 
    106629 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106630 File
    106631 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106632 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    106633 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    106634 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106635 File
    106636 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106637 packages/chimerax/core/models.py", line 143, in first_intercept 
    106638 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    106639 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106640 File
    106641 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106642 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    106643 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    106644 exclude=exclude) 
    106645 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106646 File
    106647 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106648 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    106649 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    106650 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106651 File
    106652 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106653 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    106654 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    106655 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106656 File
    106657 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106658 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    106659 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    106660 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106661 File
    106662 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106663 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    106664 p = super().first_intercept(mxyz1, mxyz2) 
    106665 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106666 File
    106667 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106668 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    106669 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    106670 exclude=exclude) 
    106671 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106672 File
    106673 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106674 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    106675 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    106676 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106677 File
    106678 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106679 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    106680 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    106681 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106682 File
    106683 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106684 packages/chimerax/graphics/drawing.py", line 1108, in
    106685 _first_intercept_excluding_children 
    106686 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    106687 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106688 File
    106689 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106690 packages/chimerax/geometry/place.py", line 201, in inverse 
    106691 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    106692 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106693 File
    106694 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106695 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    106696 rinv[:, :] = matrix_inverse(r) 
    106697 ^^^^^^^^^^^^^^^^^ 
    106698 File
    106699 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106700 packages/numpy/linalg/linalg.py", line 561, in inv 
    106701 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    106702 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106703 File
    106704 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106705 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    106706 raise LinAlgError("Singular matrix") 
    106707 numpy.linalg.LinAlgError: Singular matrix 
    106708  
    106709 numpy.linalg.LinAlgError: Singular matrix 
    106710  
    106711 File
    106712 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106713 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    106714 raise LinAlgError("Singular matrix") 
    106715  
    106716 See log for complete Python traceback. 
    106717  
    106718 Traceback (most recent call last): 
    106719 File
    106720 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106721 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    106722 self.session.ui.mouse_modes.mouse_pause_tracking() 
    106723 File
    106724 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106725 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    106726 mouse_pause_tracking 
    106727 self._mouse_pause() 
    106728 File
    106729 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106730 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    106731 m.pause(self._mouse_pause_position) 
    106732 File
    106733 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106734 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    106735 p = self.view.picked_object(x, y) 
    106736 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106737 File
    106738 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106739 packages/chimerax/graphics/view.py", line 838, in picked_object 
    106740 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    106741 beyond, 
    106742 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106743 File
    106744 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106745 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    106746 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    106747 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106748 File
    106749 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106750 packages/chimerax/core/models.py", line 143, in first_intercept 
    106751 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    106752 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106753 File
    106754 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106755 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    106756 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    106757 exclude=exclude) 
    106758 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106759 File
    106760 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106761 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    106762 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    106763 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106764 File
    106765 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106766 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    106767 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    106768 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106769 File
    106770 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106771 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    106772 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    106773 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106774 File
    106775 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106776 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    106777 p = super().first_intercept(mxyz1, mxyz2) 
    106778 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106779 File
    106780 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106781 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    106782 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    106783 exclude=exclude) 
    106784 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106785 File
    106786 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106787 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    106788 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    106789 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106790 File
    106791 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106792 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    106793 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    106794 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106795 File
    106796 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106797 packages/chimerax/graphics/drawing.py", line 1108, in
    106798 _first_intercept_excluding_children 
    106799 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    106800 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106801 File
    106802 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106803 packages/chimerax/geometry/place.py", line 201, in inverse 
    106804 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    106805 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106806 File
    106807 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106808 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    106809 rinv[:, :] = matrix_inverse(r) 
    106810 ^^^^^^^^^^^^^^^^^ 
    106811 File
    106812 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106813 packages/numpy/linalg/linalg.py", line 561, in inv 
    106814 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    106815 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106816 File
    106817 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106818 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    106819 raise LinAlgError("Singular matrix") 
    106820 numpy.linalg.LinAlgError: Singular matrix 
    106821  
    106822 numpy.linalg.LinAlgError: Singular matrix 
    106823  
    106824 File
    106825 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106826 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    106827 raise LinAlgError("Singular matrix") 
    106828  
    106829 See log for complete Python traceback. 
    106830  
    106831 Traceback (most recent call last): 
    106832 File
    106833 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106834 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    106835 self.session.ui.mouse_modes.mouse_pause_tracking() 
    106836 File
    106837 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106838 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    106839 mouse_pause_tracking 
    106840 self._mouse_pause() 
    106841 File
    106842 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106843 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    106844 m.pause(self._mouse_pause_position) 
    106845 File
    106846 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106847 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    106848 p = self.view.picked_object(x, y) 
    106849 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106850 File
    106851 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106852 packages/chimerax/graphics/view.py", line 838, in picked_object 
    106853 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    106854 beyond, 
    106855 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106856 File
    106857 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106858 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    106859 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    106860 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106861 File
    106862 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106863 packages/chimerax/core/models.py", line 143, in first_intercept 
    106864 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    106865 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106866 File
    106867 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106868 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    106869 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    106870 exclude=exclude) 
    106871 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106872 File
    106873 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106874 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    106875 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    106876 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106877 File
    106878 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106879 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    106880 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    106881 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106882 File
    106883 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106884 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    106885 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    106886 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106887 File
    106888 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106889 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    106890 p = super().first_intercept(mxyz1, mxyz2) 
    106891 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106892 File
    106893 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106894 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    106895 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    106896 exclude=exclude) 
    106897 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106898 File
    106899 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106900 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    106901 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    106902 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106903 File
    106904 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106905 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    106906 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    106907 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106908 File
    106909 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106910 packages/chimerax/graphics/drawing.py", line 1108, in
    106911 _first_intercept_excluding_children 
    106912 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    106913 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106914 File
    106915 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106916 packages/chimerax/geometry/place.py", line 201, in inverse 
    106917 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    106918 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106919 File
    106920 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106921 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    106922 rinv[:, :] = matrix_inverse(r) 
    106923 ^^^^^^^^^^^^^^^^^ 
    106924 File
    106925 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106926 packages/numpy/linalg/linalg.py", line 561, in inv 
    106927 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    106928 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106929 File
    106930 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106931 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    106932 raise LinAlgError("Singular matrix") 
    106933 numpy.linalg.LinAlgError: Singular matrix 
    106934  
    106935 numpy.linalg.LinAlgError: Singular matrix 
    106936  
    106937 File
    106938 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106939 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    106940 raise LinAlgError("Singular matrix") 
    106941  
    106942 See log for complete Python traceback. 
    106943  
    106944 Traceback (most recent call last): 
    106945 File
    106946 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106947 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    106948 self.session.ui.mouse_modes.mouse_pause_tracking() 
    106949 File
    106950 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106951 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    106952 mouse_pause_tracking 
    106953 self._mouse_pause() 
    106954 File
    106955 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106956 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    106957 m.pause(self._mouse_pause_position) 
    106958 File
    106959 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106960 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    106961 p = self.view.picked_object(x, y) 
    106962 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106963 File
    106964 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106965 packages/chimerax/graphics/view.py", line 838, in picked_object 
    106966 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    106967 beyond, 
    106968 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106969 File
    106970 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106971 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    106972 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    106973 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106974 File
    106975 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106976 packages/chimerax/core/models.py", line 143, in first_intercept 
    106977 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    106978 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106979 File
    106980 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106981 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    106982 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    106983 exclude=exclude) 
    106984 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106985 File
    106986 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106987 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    106988 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    106989 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106990 File
    106991 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106992 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    106993 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    106994 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    106995 File
    106996 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    106997 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    106998 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    106999 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107000 File
    107001 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107002 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    107003 p = super().first_intercept(mxyz1, mxyz2) 
    107004 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107005 File
    107006 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107007 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    107008 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    107009 exclude=exclude) 
    107010 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107011 File
    107012 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107013 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    107014 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    107015 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107016 File
    107017 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107018 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    107019 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    107020 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107021 File
    107022 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107023 packages/chimerax/graphics/drawing.py", line 1108, in
    107024 _first_intercept_excluding_children 
    107025 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    107026 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107027 File
    107028 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107029 packages/chimerax/geometry/place.py", line 201, in inverse 
    107030 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    107031 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107032 File
    107033 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107034 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    107035 rinv[:, :] = matrix_inverse(r) 
    107036 ^^^^^^^^^^^^^^^^^ 
    107037 File
    107038 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107039 packages/numpy/linalg/linalg.py", line 561, in inv 
    107040 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    107041 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107042 File
    107043 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107044 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    107045 raise LinAlgError("Singular matrix") 
    107046 numpy.linalg.LinAlgError: Singular matrix 
    107047  
    107048 numpy.linalg.LinAlgError: Singular matrix 
    107049  
    107050 File
    107051 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107052 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    107053 raise LinAlgError("Singular matrix") 
    107054  
    107055 See log for complete Python traceback. 
    107056  
    107057 Traceback (most recent call last): 
    107058 File
    107059 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107060 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    107061 self.session.ui.mouse_modes.mouse_pause_tracking() 
    107062 File
    107063 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107064 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    107065 mouse_pause_tracking 
    107066 self._mouse_pause() 
    107067 File
    107068 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107069 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    107070 m.pause(self._mouse_pause_position) 
    107071 File
    107072 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107073 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    107074 p = self.view.picked_object(x, y) 
    107075 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107076 File
    107077 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107078 packages/chimerax/graphics/view.py", line 838, in picked_object 
    107079 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    107080 beyond, 
    107081 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107082 File
    107083 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107084 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    107085 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    107086 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107087 File
    107088 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107089 packages/chimerax/core/models.py", line 143, in first_intercept 
    107090 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    107091 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107092 File
    107093 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107094 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    107095 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    107096 exclude=exclude) 
    107097 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107098 File
    107099 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107100 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    107101 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    107102 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107103 File
    107104 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107105 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    107106 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    107107 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107108 File
    107109 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107110 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    107111 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    107112 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107113 File
    107114 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107115 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    107116 p = super().first_intercept(mxyz1, mxyz2) 
    107117 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107118 File
    107119 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107120 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    107121 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    107122 exclude=exclude) 
    107123 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107124 File
    107125 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107126 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    107127 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    107128 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107129 File
    107130 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107131 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    107132 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    107133 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107134 File
    107135 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107136 packages/chimerax/graphics/drawing.py", line 1108, in
    107137 _first_intercept_excluding_children 
    107138 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    107139 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107140 File
    107141 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107142 packages/chimerax/geometry/place.py", line 201, in inverse 
    107143 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    107144 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107145 File
    107146 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107147 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    107148 rinv[:, :] = matrix_inverse(r) 
    107149 ^^^^^^^^^^^^^^^^^ 
    107150 File
    107151 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107152 packages/numpy/linalg/linalg.py", line 561, in inv 
    107153 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    107154 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107155 File
    107156 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107157 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    107158 raise LinAlgError("Singular matrix") 
    107159 numpy.linalg.LinAlgError: Singular matrix 
    107160  
    107161 numpy.linalg.LinAlgError: Singular matrix 
    107162  
    107163 File
    107164 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107165 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    107166 raise LinAlgError("Singular matrix") 
    107167  
    107168 See log for complete Python traceback. 
    107169  
    107170 Traceback (most recent call last): 
    107171 File
    107172 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107173 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    107174 self.session.ui.mouse_modes.mouse_pause_tracking() 
    107175 File
    107176 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107177 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    107178 mouse_pause_tracking 
    107179 self._mouse_pause() 
    107180 File
    107181 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107182 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    107183 m.pause(self._mouse_pause_position) 
    107184 File
    107185 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107186 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    107187 p = self.view.picked_object(x, y) 
    107188 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107189 File
    107190 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107191 packages/chimerax/graphics/view.py", line 838, in picked_object 
    107192 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    107193 beyond, 
    107194 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107195 File
    107196 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107197 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    107198 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    107199 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107200 File
    107201 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107202 packages/chimerax/core/models.py", line 143, in first_intercept 
    107203 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    107204 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107205 File
    107206 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107207 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    107208 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    107209 exclude=exclude) 
    107210 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107211 File
    107212 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107213 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    107214 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    107215 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107216 File
    107217 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107218 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    107219 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    107220 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107221 File
    107222 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107223 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    107224 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    107225 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107226 File
    107227 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107228 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    107229 p = super().first_intercept(mxyz1, mxyz2) 
    107230 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107231 File
    107232 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107233 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    107234 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    107235 exclude=exclude) 
    107236 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107237 File
    107238 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107239 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    107240 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    107241 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107242 File
    107243 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107244 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    107245 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    107246 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107247 File
    107248 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107249 packages/chimerax/graphics/drawing.py", line 1108, in
    107250 _first_intercept_excluding_children 
    107251 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    107252 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107253 File
    107254 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107255 packages/chimerax/geometry/place.py", line 201, in inverse 
    107256 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    107257 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107258 File
    107259 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107260 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    107261 rinv[:, :] = matrix_inverse(r) 
    107262 ^^^^^^^^^^^^^^^^^ 
    107263 File
    107264 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107265 packages/numpy/linalg/linalg.py", line 561, in inv 
    107266 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    107267 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107268 File
    107269 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107270 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    107271 raise LinAlgError("Singular matrix") 
    107272 numpy.linalg.LinAlgError: Singular matrix 
    107273  
    107274 numpy.linalg.LinAlgError: Singular matrix 
    107275  
    107276 File
    107277 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107278 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    107279 raise LinAlgError("Singular matrix") 
    107280  
    107281 See log for complete Python traceback. 
    107282  
    107283 Traceback (most recent call last): 
    107284 File
    107285 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107286 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    107287 self.session.ui.mouse_modes.mouse_pause_tracking() 
    107288 File
    107289 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107290 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    107291 mouse_pause_tracking 
    107292 self._mouse_pause() 
    107293 File
    107294 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107295 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    107296 m.pause(self._mouse_pause_position) 
    107297 File
    107298 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107299 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    107300 p = self.view.picked_object(x, y) 
    107301 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107302 File
    107303 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107304 packages/chimerax/graphics/view.py", line 838, in picked_object 
    107305 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    107306 beyond, 
    107307 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107308 File
    107309 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107310 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    107311 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    107312 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107313 File
    107314 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107315 packages/chimerax/core/models.py", line 143, in first_intercept 
    107316 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    107317 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107318 File
    107319 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107320 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    107321 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    107322 exclude=exclude) 
    107323 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107324 File
    107325 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107326 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    107327 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    107328 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107329 File
    107330 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107331 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    107332 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    107333 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107334 File
    107335 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107336 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    107337 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    107338 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107339 File
    107340 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107341 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    107342 p = super().first_intercept(mxyz1, mxyz2) 
    107343 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107344 File
    107345 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107346 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    107347 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    107348 exclude=exclude) 
    107349 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107350 File
    107351 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107352 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    107353 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    107354 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107355 File
    107356 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107357 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    107358 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    107359 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107360 File
    107361 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107362 packages/chimerax/graphics/drawing.py", line 1108, in
    107363 _first_intercept_excluding_children 
    107364 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    107365 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107366 File
    107367 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107368 packages/chimerax/geometry/place.py", line 201, in inverse 
    107369 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    107370 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107371 File
    107372 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107373 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    107374 rinv[:, :] = matrix_inverse(r) 
    107375 ^^^^^^^^^^^^^^^^^ 
    107376 File
    107377 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107378 packages/numpy/linalg/linalg.py", line 561, in inv 
    107379 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    107380 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107381 File
    107382 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107383 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    107384 raise LinAlgError("Singular matrix") 
    107385 numpy.linalg.LinAlgError: Singular matrix 
    107386  
    107387 numpy.linalg.LinAlgError: Singular matrix 
    107388  
    107389 File
    107390 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107391 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    107392 raise LinAlgError("Singular matrix") 
    107393  
    107394 See log for complete Python traceback. 
    107395  
    107396 Traceback (most recent call last): 
    107397 File
    107398 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107399 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    107400 self.session.ui.mouse_modes.mouse_pause_tracking() 
    107401 File
    107402 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107403 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    107404 mouse_pause_tracking 
    107405 self._mouse_pause() 
    107406 File
    107407 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107408 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    107409 m.pause(self._mouse_pause_position) 
    107410 File
    107411 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107412 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    107413 p = self.view.picked_object(x, y) 
    107414 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107415 File
    107416 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107417 packages/chimerax/graphics/view.py", line 838, in picked_object 
    107418 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    107419 beyond, 
    107420 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107421 File
    107422 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107423 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    107424 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    107425 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107426 File
    107427 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107428 packages/chimerax/core/models.py", line 143, in first_intercept 
    107429 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    107430 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107431 File
    107432 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107433 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    107434 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    107435 exclude=exclude) 
    107436 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107437 File
    107438 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107439 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    107440 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    107441 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107442 File
    107443 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107444 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    107445 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    107446 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107447 File
    107448 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107449 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    107450 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    107451 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107452 File
    107453 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107454 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    107455 p = super().first_intercept(mxyz1, mxyz2) 
    107456 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107457 File
    107458 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107459 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    107460 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    107461 exclude=exclude) 
    107462 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107463 File
    107464 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107465 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    107466 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    107467 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107468 File
    107469 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107470 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    107471 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    107472 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107473 File
    107474 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107475 packages/chimerax/graphics/drawing.py", line 1108, in
    107476 _first_intercept_excluding_children 
    107477 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    107478 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107479 File
    107480 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107481 packages/chimerax/geometry/place.py", line 201, in inverse 
    107482 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    107483 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107484 File
    107485 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107486 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    107487 rinv[:, :] = matrix_inverse(r) 
    107488 ^^^^^^^^^^^^^^^^^ 
    107489 File
    107490 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107491 packages/numpy/linalg/linalg.py", line 561, in inv 
    107492 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    107493 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107494 File
    107495 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107496 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    107497 raise LinAlgError("Singular matrix") 
    107498 numpy.linalg.LinAlgError: Singular matrix 
    107499  
    107500 numpy.linalg.LinAlgError: Singular matrix 
    107501  
    107502 File
    107503 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107504 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    107505 raise LinAlgError("Singular matrix") 
    107506  
    107507 See log for complete Python traceback. 
    107508  
    107509 Traceback (most recent call last): 
    107510 File
    107511 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107512 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    107513 self.session.ui.mouse_modes.mouse_pause_tracking() 
    107514 File
    107515 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107516 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    107517 mouse_pause_tracking 
    107518 self._mouse_pause() 
    107519 File
    107520 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107521 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    107522 m.pause(self._mouse_pause_position) 
    107523 File
    107524 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107525 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    107526 p = self.view.picked_object(x, y) 
    107527 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107528 File
    107529 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107530 packages/chimerax/graphics/view.py", line 838, in picked_object 
    107531 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    107532 beyond, 
    107533 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107534 File
    107535 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107536 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    107537 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    107538 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107539 File
    107540 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107541 packages/chimerax/core/models.py", line 143, in first_intercept 
    107542 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    107543 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107544 File
    107545 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107546 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    107547 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    107548 exclude=exclude) 
    107549 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107550 File
    107551 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107552 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    107553 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    107554 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107555 File
    107556 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107557 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    107558 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    107559 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107560 File
    107561 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107562 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    107563 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    107564 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107565 File
    107566 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107567 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    107568 p = super().first_intercept(mxyz1, mxyz2) 
    107569 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107570 File
    107571 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107572 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    107573 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    107574 exclude=exclude) 
    107575 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107576 File
    107577 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107578 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    107579 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    107580 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107581 File
    107582 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107583 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    107584 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    107585 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107586 File
    107587 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107588 packages/chimerax/graphics/drawing.py", line 1108, in
    107589 _first_intercept_excluding_children 
    107590 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    107591 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107592 File
    107593 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107594 packages/chimerax/geometry/place.py", line 201, in inverse 
    107595 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    107596 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107597 File
    107598 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107599 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    107600 rinv[:, :] = matrix_inverse(r) 
    107601 ^^^^^^^^^^^^^^^^^ 
    107602 File
    107603 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107604 packages/numpy/linalg/linalg.py", line 561, in inv 
    107605 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    107606 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107607 File
    107608 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107609 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    107610 raise LinAlgError("Singular matrix") 
    107611 numpy.linalg.LinAlgError: Singular matrix 
    107612  
    107613 numpy.linalg.LinAlgError: Singular matrix 
    107614  
    107615 File
    107616 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107617 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    107618 raise LinAlgError("Singular matrix") 
    107619  
    107620 See log for complete Python traceback. 
    107621  
    107622 Traceback (most recent call last): 
    107623 File
    107624 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107625 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    107626 self.session.ui.mouse_modes.mouse_pause_tracking() 
    107627 File
    107628 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107629 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    107630 mouse_pause_tracking 
    107631 self._mouse_pause() 
    107632 File
    107633 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107634 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    107635 m.pause(self._mouse_pause_position) 
    107636 File
    107637 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107638 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    107639 p = self.view.picked_object(x, y) 
    107640 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107641 File
    107642 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107643 packages/chimerax/graphics/view.py", line 838, in picked_object 
    107644 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    107645 beyond, 
    107646 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107647 File
    107648 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107649 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    107650 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    107651 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107652 File
    107653 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107654 packages/chimerax/core/models.py", line 143, in first_intercept 
    107655 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    107656 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107657 File
    107658 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107659 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    107660 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    107661 exclude=exclude) 
    107662 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107663 File
    107664 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107665 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    107666 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    107667 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107668 File
    107669 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107670 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    107671 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    107672 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107673 File
    107674 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107675 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    107676 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    107677 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107678 File
    107679 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107680 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    107681 p = super().first_intercept(mxyz1, mxyz2) 
    107682 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107683 File
    107684 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107685 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    107686 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    107687 exclude=exclude) 
    107688 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107689 File
    107690 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107691 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    107692 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    107693 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107694 File
    107695 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107696 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    107697 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    107698 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107699 File
    107700 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107701 packages/chimerax/graphics/drawing.py", line 1108, in
    107702 _first_intercept_excluding_children 
    107703 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    107704 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107705 File
    107706 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107707 packages/chimerax/geometry/place.py", line 201, in inverse 
    107708 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    107709 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107710 File
    107711 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107712 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    107713 rinv[:, :] = matrix_inverse(r) 
    107714 ^^^^^^^^^^^^^^^^^ 
    107715 File
    107716 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107717 packages/numpy/linalg/linalg.py", line 561, in inv 
    107718 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    107719 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107720 File
    107721 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107722 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    107723 raise LinAlgError("Singular matrix") 
    107724 numpy.linalg.LinAlgError: Singular matrix 
    107725  
    107726 numpy.linalg.LinAlgError: Singular matrix 
    107727  
    107728 File
    107729 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107730 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    107731 raise LinAlgError("Singular matrix") 
    107732  
    107733 See log for complete Python traceback. 
    107734  
    107735 Traceback (most recent call last): 
    107736 File
    107737 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107738 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    107739 self.session.ui.mouse_modes.mouse_pause_tracking() 
    107740 File
    107741 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107742 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    107743 mouse_pause_tracking 
    107744 self._mouse_pause() 
    107745 File
    107746 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107747 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    107748 m.pause(self._mouse_pause_position) 
    107749 File
    107750 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107751 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    107752 p = self.view.picked_object(x, y) 
    107753 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107754 File
    107755 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107756 packages/chimerax/graphics/view.py", line 838, in picked_object 
    107757 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    107758 beyond, 
    107759 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107760 File
    107761 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107762 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    107763 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    107764 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107765 File
    107766 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107767 packages/chimerax/core/models.py", line 143, in first_intercept 
    107768 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    107769 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107770 File
    107771 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107772 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    107773 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    107774 exclude=exclude) 
    107775 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107776 File
    107777 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107778 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    107779 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    107780 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107781 File
    107782 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107783 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    107784 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    107785 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107786 File
    107787 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107788 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    107789 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    107790 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107791 File
    107792 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107793 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    107794 p = super().first_intercept(mxyz1, mxyz2) 
    107795 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107796 File
    107797 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107798 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    107799 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    107800 exclude=exclude) 
    107801 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107802 File
    107803 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107804 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    107805 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    107806 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107807 File
    107808 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107809 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    107810 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    107811 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107812 File
    107813 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107814 packages/chimerax/graphics/drawing.py", line 1108, in
    107815 _first_intercept_excluding_children 
    107816 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    107817 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107818 File
    107819 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107820 packages/chimerax/geometry/place.py", line 201, in inverse 
    107821 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    107822 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107823 File
    107824 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107825 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    107826 rinv[:, :] = matrix_inverse(r) 
    107827 ^^^^^^^^^^^^^^^^^ 
    107828 File
    107829 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107830 packages/numpy/linalg/linalg.py", line 561, in inv 
    107831 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    107832 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107833 File
    107834 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107835 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    107836 raise LinAlgError("Singular matrix") 
    107837 numpy.linalg.LinAlgError: Singular matrix 
    107838  
    107839 numpy.linalg.LinAlgError: Singular matrix 
    107840  
    107841 File
    107842 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107843 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    107844 raise LinAlgError("Singular matrix") 
    107845  
    107846 See log for complete Python traceback. 
    107847  
    107848 Traceback (most recent call last): 
    107849 File
    107850 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107851 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    107852 self.session.ui.mouse_modes.mouse_pause_tracking() 
    107853 File
    107854 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107855 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    107856 mouse_pause_tracking 
    107857 self._mouse_pause() 
    107858 File
    107859 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107860 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    107861 m.pause(self._mouse_pause_position) 
    107862 File
    107863 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107864 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    107865 p = self.view.picked_object(x, y) 
    107866 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107867 File
    107868 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107869 packages/chimerax/graphics/view.py", line 838, in picked_object 
    107870 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    107871 beyond, 
    107872 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107873 File
    107874 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107875 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    107876 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    107877 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107878 File
    107879 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107880 packages/chimerax/core/models.py", line 143, in first_intercept 
    107881 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    107882 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107883 File
    107884 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107885 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    107886 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    107887 exclude=exclude) 
    107888 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107889 File
    107890 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107891 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    107892 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    107893 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107894 File
    107895 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107896 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    107897 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    107898 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107899 File
    107900 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107901 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    107902 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    107903 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107904 File
    107905 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107906 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    107907 p = super().first_intercept(mxyz1, mxyz2) 
    107908 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107909 File
    107910 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107911 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    107912 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    107913 exclude=exclude) 
    107914 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107915 File
    107916 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107917 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    107918 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    107919 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107920 File
    107921 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107922 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    107923 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    107924 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107925 File
    107926 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107927 packages/chimerax/graphics/drawing.py", line 1108, in
    107928 _first_intercept_excluding_children 
    107929 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    107930 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107931 File
    107932 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107933 packages/chimerax/geometry/place.py", line 201, in inverse 
    107934 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    107935 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107936 File
    107937 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107938 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    107939 rinv[:, :] = matrix_inverse(r) 
    107940 ^^^^^^^^^^^^^^^^^ 
    107941 File
    107942 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107943 packages/numpy/linalg/linalg.py", line 561, in inv 
    107944 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    107945 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107946 File
    107947 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107948 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    107949 raise LinAlgError("Singular matrix") 
    107950 numpy.linalg.LinAlgError: Singular matrix 
    107951  
    107952 numpy.linalg.LinAlgError: Singular matrix 
    107953  
    107954 File
    107955 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107956 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    107957 raise LinAlgError("Singular matrix") 
    107958  
    107959 See log for complete Python traceback. 
    107960  
    107961 Traceback (most recent call last): 
    107962 File
    107963 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107964 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    107965 self.session.ui.mouse_modes.mouse_pause_tracking() 
    107966 File
    107967 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107968 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    107969 mouse_pause_tracking 
    107970 self._mouse_pause() 
    107971 File
    107972 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107973 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    107974 m.pause(self._mouse_pause_position) 
    107975 File
    107976 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107977 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    107978 p = self.view.picked_object(x, y) 
    107979 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107980 File
    107981 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107982 packages/chimerax/graphics/view.py", line 838, in picked_object 
    107983 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    107984 beyond, 
    107985 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107986 File
    107987 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107988 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    107989 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    107990 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107991 File
    107992 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107993 packages/chimerax/core/models.py", line 143, in first_intercept 
    107994 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    107995 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    107996 File
    107997 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    107998 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    107999 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    108000 exclude=exclude) 
    108001 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108002 File
    108003 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108004 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    108005 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    108006 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108007 File
    108008 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108009 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    108010 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    108011 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108012 File
    108013 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108014 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    108015 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    108016 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108017 File
    108018 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108019 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    108020 p = super().first_intercept(mxyz1, mxyz2) 
    108021 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108022 File
    108023 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108024 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    108025 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    108026 exclude=exclude) 
    108027 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108028 File
    108029 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108030 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    108031 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    108032 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108033 File
    108034 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108035 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    108036 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    108037 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108038 File
    108039 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108040 packages/chimerax/graphics/drawing.py", line 1108, in
    108041 _first_intercept_excluding_children 
    108042 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    108043 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108044 File
    108045 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108046 packages/chimerax/geometry/place.py", line 201, in inverse 
    108047 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    108048 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108049 File
    108050 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108051 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    108052 rinv[:, :] = matrix_inverse(r) 
    108053 ^^^^^^^^^^^^^^^^^ 
    108054 File
    108055 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108056 packages/numpy/linalg/linalg.py", line 561, in inv 
    108057 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    108058 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108059 File
    108060 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108061 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    108062 raise LinAlgError("Singular matrix") 
    108063 numpy.linalg.LinAlgError: Singular matrix 
    108064  
    108065 numpy.linalg.LinAlgError: Singular matrix 
    108066  
    108067 File
    108068 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108069 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    108070 raise LinAlgError("Singular matrix") 
    108071  
    108072 See log for complete Python traceback. 
    108073  
    108074 Traceback (most recent call last): 
    108075 File
    108076 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108077 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    108078 self.session.ui.mouse_modes.mouse_pause_tracking() 
    108079 File
    108080 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108081 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    108082 mouse_pause_tracking 
    108083 self._mouse_pause() 
    108084 File
    108085 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108086 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    108087 m.pause(self._mouse_pause_position) 
    108088 File
    108089 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108090 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    108091 p = self.view.picked_object(x, y) 
    108092 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108093 File
    108094 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108095 packages/chimerax/graphics/view.py", line 838, in picked_object 
    108096 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    108097 beyond, 
    108098 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108099 File
    108100 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108101 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    108102 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    108103 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108104 File
    108105 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108106 packages/chimerax/core/models.py", line 143, in first_intercept 
    108107 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    108108 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108109 File
    108110 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108111 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    108112 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    108113 exclude=exclude) 
    108114 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108115 File
    108116 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108117 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    108118 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    108119 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108120 File
    108121 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108122 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    108123 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    108124 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108125 File
    108126 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108127 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    108128 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    108129 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108130 File
    108131 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108132 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    108133 p = super().first_intercept(mxyz1, mxyz2) 
    108134 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108135 File
    108136 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108137 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    108138 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    108139 exclude=exclude) 
    108140 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108141 File
    108142 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108143 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    108144 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    108145 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108146 File
    108147 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108148 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    108149 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    108150 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108151 File
    108152 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108153 packages/chimerax/graphics/drawing.py", line 1108, in
    108154 _first_intercept_excluding_children 
    108155 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    108156 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108157 File
    108158 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108159 packages/chimerax/geometry/place.py", line 201, in inverse 
    108160 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    108161 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108162 File
    108163 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108164 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    108165 rinv[:, :] = matrix_inverse(r) 
    108166 ^^^^^^^^^^^^^^^^^ 
    108167 File
    108168 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108169 packages/numpy/linalg/linalg.py", line 561, in inv 
    108170 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    108171 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108172 File
    108173 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108174 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    108175 raise LinAlgError("Singular matrix") 
    108176 numpy.linalg.LinAlgError: Singular matrix 
    108177  
    108178 numpy.linalg.LinAlgError: Singular matrix 
    108179  
    108180 File
    108181 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108182 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    108183 raise LinAlgError("Singular matrix") 
    108184  
    108185 See log for complete Python traceback. 
    108186  
    108187 Traceback (most recent call last): 
    108188 File
    108189 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108190 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    108191 self.session.ui.mouse_modes.mouse_pause_tracking() 
    108192 File
    108193 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108194 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    108195 mouse_pause_tracking 
    108196 self._mouse_pause() 
    108197 File
    108198 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108199 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    108200 m.pause(self._mouse_pause_position) 
    108201 File
    108202 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108203 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    108204 p = self.view.picked_object(x, y) 
    108205 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108206 File
    108207 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108208 packages/chimerax/graphics/view.py", line 838, in picked_object 
    108209 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    108210 beyond, 
    108211 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108212 File
    108213 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108214 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    108215 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    108216 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108217 File
    108218 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108219 packages/chimerax/core/models.py", line 143, in first_intercept 
    108220 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    108221 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108222 File
    108223 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108224 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    108225 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    108226 exclude=exclude) 
    108227 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108228 File
    108229 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108230 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    108231 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    108232 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108233 File
    108234 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108235 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    108236 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    108237 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108238 File
    108239 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108240 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    108241 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    108242 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108243 File
    108244 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108245 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    108246 p = super().first_intercept(mxyz1, mxyz2) 
    108247 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108248 File
    108249 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108250 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    108251 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    108252 exclude=exclude) 
    108253 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108254 File
    108255 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108256 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    108257 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    108258 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108259 File
    108260 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108261 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    108262 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    108263 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108264 File
    108265 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108266 packages/chimerax/graphics/drawing.py", line 1108, in
    108267 _first_intercept_excluding_children 
    108268 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    108269 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108270 File
    108271 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108272 packages/chimerax/geometry/place.py", line 201, in inverse 
    108273 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    108274 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108275 File
    108276 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108277 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    108278 rinv[:, :] = matrix_inverse(r) 
    108279 ^^^^^^^^^^^^^^^^^ 
    108280 File
    108281 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108282 packages/numpy/linalg/linalg.py", line 561, in inv 
    108283 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    108284 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108285 File
    108286 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108287 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    108288 raise LinAlgError("Singular matrix") 
    108289 numpy.linalg.LinAlgError: Singular matrix 
    108290  
    108291 numpy.linalg.LinAlgError: Singular matrix 
    108292  
    108293 File
    108294 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108295 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    108296 raise LinAlgError("Singular matrix") 
    108297  
    108298 See log for complete Python traceback. 
    108299  
    108300 Traceback (most recent call last): 
    108301 File
    108302 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108303 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    108304 self.session.ui.mouse_modes.mouse_pause_tracking() 
    108305 File
    108306 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108307 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    108308 mouse_pause_tracking 
    108309 self._mouse_pause() 
    108310 File
    108311 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108312 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    108313 m.pause(self._mouse_pause_position) 
    108314 File
    108315 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108316 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    108317 p = self.view.picked_object(x, y) 
    108318 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108319 File
    108320 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108321 packages/chimerax/graphics/view.py", line 838, in picked_object 
    108322 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    108323 beyond, 
    108324 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108325 File
    108326 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108327 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    108328 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    108329 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108330 File
    108331 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108332 packages/chimerax/core/models.py", line 143, in first_intercept 
    108333 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    108334 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108335 File
    108336 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108337 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    108338 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    108339 exclude=exclude) 
    108340 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108341 File
    108342 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108343 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    108344 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    108345 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108346 File
    108347 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108348 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    108349 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    108350 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108351 File
    108352 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108353 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    108354 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    108355 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108356 File
    108357 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108358 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    108359 p = super().first_intercept(mxyz1, mxyz2) 
    108360 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108361 File
    108362 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108363 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    108364 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    108365 exclude=exclude) 
    108366 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108367 File
    108368 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108369 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    108370 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    108371 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108372 File
    108373 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108374 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    108375 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    108376 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108377 File
    108378 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108379 packages/chimerax/graphics/drawing.py", line 1108, in
    108380 _first_intercept_excluding_children 
    108381 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    108382 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108383 File
    108384 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108385 packages/chimerax/geometry/place.py", line 201, in inverse 
    108386 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    108387 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108388 File
    108389 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108390 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    108391 rinv[:, :] = matrix_inverse(r) 
    108392 ^^^^^^^^^^^^^^^^^ 
    108393 File
    108394 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108395 packages/numpy/linalg/linalg.py", line 561, in inv 
    108396 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    108397 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108398 File
    108399 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108400 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    108401 raise LinAlgError("Singular matrix") 
    108402 numpy.linalg.LinAlgError: Singular matrix 
    108403  
    108404 numpy.linalg.LinAlgError: Singular matrix 
    108405  
    108406 File
    108407 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108408 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    108409 raise LinAlgError("Singular matrix") 
    108410  
    108411 See log for complete Python traceback. 
    108412  
    108413 Traceback (most recent call last): 
    108414 File
    108415 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108416 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    108417 self.session.ui.mouse_modes.mouse_pause_tracking() 
    108418 File
    108419 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108420 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    108421 mouse_pause_tracking 
    108422 self._mouse_pause() 
    108423 File
    108424 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108425 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    108426 m.pause(self._mouse_pause_position) 
    108427 File
    108428 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108429 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    108430 p = self.view.picked_object(x, y) 
    108431 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108432 File
    108433 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108434 packages/chimerax/graphics/view.py", line 838, in picked_object 
    108435 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    108436 beyond, 
    108437 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108438 File
    108439 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108440 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    108441 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    108442 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108443 File
    108444 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108445 packages/chimerax/core/models.py", line 143, in first_intercept 
    108446 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    108447 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108448 File
    108449 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108450 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    108451 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    108452 exclude=exclude) 
    108453 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108454 File
    108455 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108456 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    108457 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    108458 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108459 File
    108460 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108461 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    108462 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    108463 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108464 File
    108465 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108466 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    108467 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    108468 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108469 File
    108470 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108471 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    108472 p = super().first_intercept(mxyz1, mxyz2) 
    108473 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108474 File
    108475 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108476 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    108477 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    108478 exclude=exclude) 
    108479 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108480 File
    108481 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108482 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    108483 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    108484 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108485 File
    108486 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108487 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    108488 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    108489 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108490 File
    108491 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108492 packages/chimerax/graphics/drawing.py", line 1108, in
    108493 _first_intercept_excluding_children 
    108494 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    108495 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108496 File
    108497 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108498 packages/chimerax/geometry/place.py", line 201, in inverse 
    108499 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    108500 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108501 File
    108502 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108503 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    108504 rinv[:, :] = matrix_inverse(r) 
    108505 ^^^^^^^^^^^^^^^^^ 
    108506 File
    108507 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108508 packages/numpy/linalg/linalg.py", line 561, in inv 
    108509 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    108510 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108511 File
    108512 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108513 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    108514 raise LinAlgError("Singular matrix") 
    108515 numpy.linalg.LinAlgError: Singular matrix 
    108516  
    108517 numpy.linalg.LinAlgError: Singular matrix 
    108518  
    108519 File
    108520 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108521 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    108522 raise LinAlgError("Singular matrix") 
    108523  
    108524 See log for complete Python traceback. 
    108525  
    108526 Traceback (most recent call last): 
    108527 File
    108528 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108529 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    108530 self.session.ui.mouse_modes.mouse_pause_tracking() 
    108531 File
    108532 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108533 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    108534 mouse_pause_tracking 
    108535 self._mouse_pause() 
    108536 File
    108537 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108538 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    108539 m.pause(self._mouse_pause_position) 
    108540 File
    108541 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108542 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    108543 p = self.view.picked_object(x, y) 
    108544 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108545 File
    108546 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108547 packages/chimerax/graphics/view.py", line 838, in picked_object 
    108548 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    108549 beyond, 
    108550 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108551 File
    108552 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108553 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    108554 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    108555 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108556 File
    108557 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108558 packages/chimerax/core/models.py", line 143, in first_intercept 
    108559 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    108560 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108561 File
    108562 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108563 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    108564 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    108565 exclude=exclude) 
    108566 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108567 File
    108568 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108569 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    108570 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    108571 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108572 File
    108573 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108574 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    108575 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    108576 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108577 File
    108578 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108579 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    108580 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    108581 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108582 File
    108583 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108584 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    108585 p = super().first_intercept(mxyz1, mxyz2) 
    108586 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108587 File
    108588 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108589 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    108590 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    108591 exclude=exclude) 
    108592 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108593 File
    108594 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108595 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    108596 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    108597 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108598 File
    108599 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108600 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    108601 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    108602 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108603 File
    108604 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108605 packages/chimerax/graphics/drawing.py", line 1108, in
    108606 _first_intercept_excluding_children 
    108607 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    108608 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108609 File
    108610 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108611 packages/chimerax/geometry/place.py", line 201, in inverse 
    108612 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    108613 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108614 File
    108615 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108616 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    108617 rinv[:, :] = matrix_inverse(r) 
    108618 ^^^^^^^^^^^^^^^^^ 
    108619 File
    108620 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108621 packages/numpy/linalg/linalg.py", line 561, in inv 
    108622 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    108623 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108624 File
    108625 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108626 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    108627 raise LinAlgError("Singular matrix") 
    108628 numpy.linalg.LinAlgError: Singular matrix 
    108629  
    108630 numpy.linalg.LinAlgError: Singular matrix 
    108631  
    108632 File
    108633 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108634 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    108635 raise LinAlgError("Singular matrix") 
    108636  
    108637 See log for complete Python traceback. 
    108638  
    108639 Traceback (most recent call last): 
    108640 File
    108641 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108642 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    108643 self.session.ui.mouse_modes.mouse_pause_tracking() 
    108644 File
    108645 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108646 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    108647 mouse_pause_tracking 
    108648 self._mouse_pause() 
    108649 File
    108650 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108651 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    108652 m.pause(self._mouse_pause_position) 
    108653 File
    108654 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108655 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    108656 p = self.view.picked_object(x, y) 
    108657 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108658 File
    108659 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108660 packages/chimerax/graphics/view.py", line 838, in picked_object 
    108661 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    108662 beyond, 
    108663 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108664 File
    108665 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108666 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    108667 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    108668 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108669 File
    108670 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108671 packages/chimerax/core/models.py", line 143, in first_intercept 
    108672 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    108673 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108674 File
    108675 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108676 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    108677 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    108678 exclude=exclude) 
    108679 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108680 File
    108681 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108682 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    108683 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    108684 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108685 File
    108686 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108687 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    108688 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    108689 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108690 File
    108691 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108692 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    108693 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    108694 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108695 File
    108696 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108697 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    108698 p = super().first_intercept(mxyz1, mxyz2) 
    108699 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108700 File
    108701 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108702 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    108703 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    108704 exclude=exclude) 
    108705 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108706 File
    108707 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108708 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    108709 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    108710 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108711 File
    108712 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108713 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    108714 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    108715 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108716 File
    108717 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108718 packages/chimerax/graphics/drawing.py", line 1108, in
    108719 _first_intercept_excluding_children 
    108720 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    108721 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108722 File
    108723 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108724 packages/chimerax/geometry/place.py", line 201, in inverse 
    108725 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    108726 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108727 File
    108728 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108729 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    108730 rinv[:, :] = matrix_inverse(r) 
    108731 ^^^^^^^^^^^^^^^^^ 
    108732 File
    108733 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108734 packages/numpy/linalg/linalg.py", line 561, in inv 
    108735 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    108736 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108737 File
    108738 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108739 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    108740 raise LinAlgError("Singular matrix") 
    108741 numpy.linalg.LinAlgError: Singular matrix 
    108742  
    108743 numpy.linalg.LinAlgError: Singular matrix 
    108744  
    108745 File
    108746 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108747 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    108748 raise LinAlgError("Singular matrix") 
    108749  
    108750 See log for complete Python traceback. 
    108751  
    108752 Traceback (most recent call last): 
    108753 File
    108754 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108755 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    108756 self.session.ui.mouse_modes.mouse_pause_tracking() 
    108757 File
    108758 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108759 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    108760 mouse_pause_tracking 
    108761 self._mouse_pause() 
    108762 File
    108763 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108764 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    108765 m.pause(self._mouse_pause_position) 
    108766 File
    108767 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108768 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    108769 p = self.view.picked_object(x, y) 
    108770 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108771 File
    108772 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108773 packages/chimerax/graphics/view.py", line 838, in picked_object 
    108774 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    108775 beyond, 
    108776 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108777 File
    108778 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108779 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    108780 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    108781 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108782 File
    108783 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108784 packages/chimerax/core/models.py", line 143, in first_intercept 
    108785 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    108786 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108787 File
    108788 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108789 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    108790 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    108791 exclude=exclude) 
    108792 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108793 File
    108794 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108795 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    108796 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    108797 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108798 File
    108799 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108800 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    108801 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    108802 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108803 File
    108804 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108805 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    108806 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    108807 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108808 File
    108809 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108810 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    108811 p = super().first_intercept(mxyz1, mxyz2) 
    108812 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108813 File
    108814 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108815 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    108816 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    108817 exclude=exclude) 
    108818 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108819 File
    108820 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108821 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    108822 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    108823 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108824 File
    108825 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108826 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    108827 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    108828 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108829 File
    108830 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108831 packages/chimerax/graphics/drawing.py", line 1108, in
    108832 _first_intercept_excluding_children 
    108833 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    108834 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108835 File
    108836 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108837 packages/chimerax/geometry/place.py", line 201, in inverse 
    108838 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    108839 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108840 File
    108841 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108842 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    108843 rinv[:, :] = matrix_inverse(r) 
    108844 ^^^^^^^^^^^^^^^^^ 
    108845 File
    108846 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108847 packages/numpy/linalg/linalg.py", line 561, in inv 
    108848 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    108849 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108850 File
    108851 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108852 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    108853 raise LinAlgError("Singular matrix") 
    108854 numpy.linalg.LinAlgError: Singular matrix 
    108855  
    108856 numpy.linalg.LinAlgError: Singular matrix 
    108857  
    108858 File
    108859 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108860 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    108861 raise LinAlgError("Singular matrix") 
    108862  
    108863 See log for complete Python traceback. 
    108864  
    108865 Traceback (most recent call last): 
    108866 File
    108867 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108868 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    108869 self.session.ui.mouse_modes.mouse_pause_tracking() 
    108870 File
    108871 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108872 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    108873 mouse_pause_tracking 
    108874 self._mouse_pause() 
    108875 File
    108876 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108877 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    108878 m.pause(self._mouse_pause_position) 
    108879 File
    108880 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108881 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    108882 p = self.view.picked_object(x, y) 
    108883 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108884 File
    108885 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108886 packages/chimerax/graphics/view.py", line 838, in picked_object 
    108887 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    108888 beyond, 
    108889 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108890 File
    108891 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108892 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    108893 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    108894 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108895 File
    108896 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108897 packages/chimerax/core/models.py", line 143, in first_intercept 
    108898 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    108899 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108900 File
    108901 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108902 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    108903 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    108904 exclude=exclude) 
    108905 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108906 File
    108907 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108908 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    108909 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    108910 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108911 File
    108912 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108913 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    108914 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    108915 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108916 File
    108917 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108918 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    108919 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    108920 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108921 File
    108922 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108923 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    108924 p = super().first_intercept(mxyz1, mxyz2) 
    108925 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108926 File
    108927 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108928 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    108929 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    108930 exclude=exclude) 
    108931 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108932 File
    108933 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108934 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    108935 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    108936 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108937 File
    108938 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108939 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    108940 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    108941 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108942 File
    108943 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108944 packages/chimerax/graphics/drawing.py", line 1108, in
    108945 _first_intercept_excluding_children 
    108946 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    108947 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108948 File
    108949 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108950 packages/chimerax/geometry/place.py", line 201, in inverse 
    108951 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    108952 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108953 File
    108954 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108955 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    108956 rinv[:, :] = matrix_inverse(r) 
    108957 ^^^^^^^^^^^^^^^^^ 
    108958 File
    108959 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108960 packages/numpy/linalg/linalg.py", line 561, in inv 
    108961 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    108962 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108963 File
    108964 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108965 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    108966 raise LinAlgError("Singular matrix") 
    108967 numpy.linalg.LinAlgError: Singular matrix 
    108968  
    108969 numpy.linalg.LinAlgError: Singular matrix 
    108970  
    108971 File
    108972 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108973 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    108974 raise LinAlgError("Singular matrix") 
    108975  
    108976 See log for complete Python traceback. 
    108977  
    108978 Traceback (most recent call last): 
    108979 File
    108980 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108981 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    108982 self.session.ui.mouse_modes.mouse_pause_tracking() 
    108983 File
    108984 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108985 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    108986 mouse_pause_tracking 
    108987 self._mouse_pause() 
    108988 File
    108989 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108990 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    108991 m.pause(self._mouse_pause_position) 
    108992 File
    108993 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108994 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    108995 p = self.view.picked_object(x, y) 
    108996 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    108997 File
    108998 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    108999 packages/chimerax/graphics/view.py", line 838, in picked_object 
    109000 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    109001 beyond, 
    109002 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109003 File
    109004 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109005 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    109006 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    109007 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109008 File
    109009 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109010 packages/chimerax/core/models.py", line 143, in first_intercept 
    109011 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    109012 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109013 File
    109014 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109015 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    109016 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    109017 exclude=exclude) 
    109018 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109019 File
    109020 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109021 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    109022 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    109023 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109024 File
    109025 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109026 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    109027 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    109028 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109029 File
    109030 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109031 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    109032 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    109033 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109034 File
    109035 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109036 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    109037 p = super().first_intercept(mxyz1, mxyz2) 
    109038 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109039 File
    109040 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109041 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    109042 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    109043 exclude=exclude) 
    109044 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109045 File
    109046 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109047 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    109048 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    109049 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109050 File
    109051 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109052 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    109053 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    109054 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109055 File
    109056 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109057 packages/chimerax/graphics/drawing.py", line 1108, in
    109058 _first_intercept_excluding_children 
    109059 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    109060 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109061 File
    109062 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109063 packages/chimerax/geometry/place.py", line 201, in inverse 
    109064 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    109065 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109066 File
    109067 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109068 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    109069 rinv[:, :] = matrix_inverse(r) 
    109070 ^^^^^^^^^^^^^^^^^ 
    109071 File
    109072 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109073 packages/numpy/linalg/linalg.py", line 561, in inv 
    109074 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    109075 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109076 File
    109077 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109078 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    109079 raise LinAlgError("Singular matrix") 
    109080 numpy.linalg.LinAlgError: Singular matrix 
    109081  
    109082 numpy.linalg.LinAlgError: Singular matrix 
    109083  
    109084 File
    109085 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109086 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    109087 raise LinAlgError("Singular matrix") 
    109088  
    109089 See log for complete Python traceback. 
    109090  
    109091 Traceback (most recent call last): 
    109092 File
    109093 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109094 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    109095 self.session.ui.mouse_modes.mouse_pause_tracking() 
    109096 File
    109097 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109098 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    109099 mouse_pause_tracking 
    109100 self._mouse_pause() 
    109101 File
    109102 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109103 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    109104 m.pause(self._mouse_pause_position) 
    109105 File
    109106 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109107 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    109108 p = self.view.picked_object(x, y) 
    109109 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109110 File
    109111 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109112 packages/chimerax/graphics/view.py", line 838, in picked_object 
    109113 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    109114 beyond, 
    109115 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109116 File
    109117 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109118 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    109119 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    109120 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109121 File
    109122 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109123 packages/chimerax/core/models.py", line 143, in first_intercept 
    109124 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    109125 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109126 File
    109127 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109128 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    109129 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    109130 exclude=exclude) 
    109131 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109132 File
    109133 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109134 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    109135 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    109136 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109137 File
    109138 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109139 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    109140 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    109141 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109142 File
    109143 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109144 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    109145 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    109146 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109147 File
    109148 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109149 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    109150 p = super().first_intercept(mxyz1, mxyz2) 
    109151 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109152 File
    109153 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109154 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    109155 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    109156 exclude=exclude) 
    109157 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109158 File
    109159 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109160 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    109161 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    109162 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109163 File
    109164 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109165 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    109166 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    109167 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109168 File
    109169 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109170 packages/chimerax/graphics/drawing.py", line 1108, in
    109171 _first_intercept_excluding_children 
    109172 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    109173 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109174 File
    109175 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109176 packages/chimerax/geometry/place.py", line 201, in inverse 
    109177 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    109178 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109179 File
    109180 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109181 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    109182 rinv[:, :] = matrix_inverse(r) 
    109183 ^^^^^^^^^^^^^^^^^ 
    109184 File
    109185 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109186 packages/numpy/linalg/linalg.py", line 561, in inv 
    109187 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    109188 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109189 File
    109190 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109191 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    109192 raise LinAlgError("Singular matrix") 
    109193 numpy.linalg.LinAlgError: Singular matrix 
    109194  
    109195 numpy.linalg.LinAlgError: Singular matrix 
    109196  
    109197 File
    109198 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109199 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    109200 raise LinAlgError("Singular matrix") 
    109201  
    109202 See log for complete Python traceback. 
    109203  
    109204 Traceback (most recent call last): 
    109205 File
    109206 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109207 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    109208 self.session.ui.mouse_modes.mouse_pause_tracking() 
    109209 File
    109210 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109211 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    109212 mouse_pause_tracking 
    109213 self._mouse_pause() 
    109214 File
    109215 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109216 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    109217 m.pause(self._mouse_pause_position) 
    109218 File
    109219 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109220 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    109221 p = self.view.picked_object(x, y) 
    109222 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109223 File
    109224 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109225 packages/chimerax/graphics/view.py", line 838, in picked_object 
    109226 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    109227 beyond, 
    109228 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109229 File
    109230 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109231 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    109232 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    109233 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109234 File
    109235 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109236 packages/chimerax/core/models.py", line 143, in first_intercept 
    109237 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    109238 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109239 File
    109240 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109241 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    109242 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    109243 exclude=exclude) 
    109244 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109245 File
    109246 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109247 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    109248 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    109249 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109250 File
    109251 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109252 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    109253 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    109254 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109255 File
    109256 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109257 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    109258 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    109259 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109260 File
    109261 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109262 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    109263 p = super().first_intercept(mxyz1, mxyz2) 
    109264 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109265 File
    109266 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109267 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    109268 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    109269 exclude=exclude) 
    109270 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109271 File
    109272 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109273 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    109274 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    109275 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109276 File
    109277 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109278 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    109279 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    109280 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109281 File
    109282 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109283 packages/chimerax/graphics/drawing.py", line 1108, in
    109284 _first_intercept_excluding_children 
    109285 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    109286 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109287 File
    109288 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109289 packages/chimerax/geometry/place.py", line 201, in inverse 
    109290 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    109291 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109292 File
    109293 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109294 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    109295 rinv[:, :] = matrix_inverse(r) 
    109296 ^^^^^^^^^^^^^^^^^ 
    109297 File
    109298 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109299 packages/numpy/linalg/linalg.py", line 561, in inv 
    109300 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    109301 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109302 File
    109303 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109304 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    109305 raise LinAlgError("Singular matrix") 
    109306 numpy.linalg.LinAlgError: Singular matrix 
    109307  
    109308 numpy.linalg.LinAlgError: Singular matrix 
    109309  
    109310 File
    109311 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109312 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    109313 raise LinAlgError("Singular matrix") 
    109314  
    109315 See log for complete Python traceback. 
    109316  
    109317 Traceback (most recent call last): 
    109318 File
    109319 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109320 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    109321 self.session.ui.mouse_modes.mouse_pause_tracking() 
    109322 File
    109323 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109324 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    109325 mouse_pause_tracking 
    109326 self._mouse_pause() 
    109327 File
    109328 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109329 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    109330 m.pause(self._mouse_pause_position) 
    109331 File
    109332 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109333 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    109334 p = self.view.picked_object(x, y) 
    109335 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109336 File
    109337 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109338 packages/chimerax/graphics/view.py", line 838, in picked_object 
    109339 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    109340 beyond, 
    109341 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109342 File
    109343 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109344 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    109345 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    109346 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109347 File
    109348 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109349 packages/chimerax/core/models.py", line 143, in first_intercept 
    109350 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    109351 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109352 File
    109353 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109354 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    109355 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    109356 exclude=exclude) 
    109357 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109358 File
    109359 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109360 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    109361 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    109362 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109363 File
    109364 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109365 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    109366 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    109367 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109368 File
    109369 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109370 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    109371 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    109372 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109373 File
    109374 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109375 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    109376 p = super().first_intercept(mxyz1, mxyz2) 
    109377 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109378 File
    109379 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109380 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    109381 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    109382 exclude=exclude) 
    109383 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109384 File
    109385 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109386 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    109387 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    109388 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109389 File
    109390 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109391 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    109392 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    109393 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109394 File
    109395 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109396 packages/chimerax/graphics/drawing.py", line 1108, in
    109397 _first_intercept_excluding_children 
    109398 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    109399 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109400 File
    109401 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109402 packages/chimerax/geometry/place.py", line 201, in inverse 
    109403 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    109404 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109405 File
    109406 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109407 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    109408 rinv[:, :] = matrix_inverse(r) 
    109409 ^^^^^^^^^^^^^^^^^ 
    109410 File
    109411 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109412 packages/numpy/linalg/linalg.py", line 561, in inv 
    109413 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    109414 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109415 File
    109416 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109417 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    109418 raise LinAlgError("Singular matrix") 
    109419 numpy.linalg.LinAlgError: Singular matrix 
    109420  
    109421 numpy.linalg.LinAlgError: Singular matrix 
    109422  
    109423 File
    109424 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109425 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    109426 raise LinAlgError("Singular matrix") 
    109427  
    109428 See log for complete Python traceback. 
    109429  
    109430 Traceback (most recent call last): 
    109431 File
    109432 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109433 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    109434 self.session.ui.mouse_modes.mouse_pause_tracking() 
    109435 File
    109436 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109437 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    109438 mouse_pause_tracking 
    109439 self._mouse_pause() 
    109440 File
    109441 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109442 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    109443 m.pause(self._mouse_pause_position) 
    109444 File
    109445 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109446 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    109447 p = self.view.picked_object(x, y) 
    109448 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109449 File
    109450 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109451 packages/chimerax/graphics/view.py", line 838, in picked_object 
    109452 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    109453 beyond, 
    109454 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109455 File
    109456 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109457 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    109458 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    109459 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109460 File
    109461 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109462 packages/chimerax/core/models.py", line 143, in first_intercept 
    109463 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    109464 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109465 File
    109466 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109467 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    109468 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    109469 exclude=exclude) 
    109470 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109471 File
    109472 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109473 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    109474 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    109475 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109476 File
    109477 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109478 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    109479 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    109480 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109481 File
    109482 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109483 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    109484 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    109485 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109486 File
    109487 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109488 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    109489 p = super().first_intercept(mxyz1, mxyz2) 
    109490 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109491 File
    109492 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109493 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    109494 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    109495 exclude=exclude) 
    109496 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109497 File
    109498 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109499 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    109500 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    109501 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109502 File
    109503 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109504 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    109505 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    109506 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109507 File
    109508 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109509 packages/chimerax/graphics/drawing.py", line 1108, in
    109510 _first_intercept_excluding_children 
    109511 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    109512 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109513 File
    109514 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109515 packages/chimerax/geometry/place.py", line 201, in inverse 
    109516 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    109517 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109518 File
    109519 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109520 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    109521 rinv[:, :] = matrix_inverse(r) 
    109522 ^^^^^^^^^^^^^^^^^ 
    109523 File
    109524 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109525 packages/numpy/linalg/linalg.py", line 561, in inv 
    109526 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    109527 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109528 File
    109529 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109530 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    109531 raise LinAlgError("Singular matrix") 
    109532 numpy.linalg.LinAlgError: Singular matrix 
    109533  
    109534 numpy.linalg.LinAlgError: Singular matrix 
    109535  
    109536 File
    109537 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109538 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    109539 raise LinAlgError("Singular matrix") 
    109540  
    109541 See log for complete Python traceback. 
    109542  
    109543 Traceback (most recent call last): 
    109544 File
    109545 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109546 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    109547 self.session.ui.mouse_modes.mouse_pause_tracking() 
    109548 File
    109549 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109550 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    109551 mouse_pause_tracking 
    109552 self._mouse_pause() 
    109553 File
    109554 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109555 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    109556 m.pause(self._mouse_pause_position) 
    109557 File
    109558 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109559 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    109560 p = self.view.picked_object(x, y) 
    109561 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109562 File
    109563 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109564 packages/chimerax/graphics/view.py", line 838, in picked_object 
    109565 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    109566 beyond, 
    109567 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109568 File
    109569 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109570 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    109571 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    109572 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109573 File
    109574 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109575 packages/chimerax/core/models.py", line 143, in first_intercept 
    109576 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    109577 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109578 File
    109579 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109580 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    109581 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    109582 exclude=exclude) 
    109583 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109584 File
    109585 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109586 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    109587 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    109588 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109589 File
    109590 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109591 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    109592 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    109593 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109594 File
    109595 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109596 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    109597 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    109598 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109599 File
    109600 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109601 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    109602 p = super().first_intercept(mxyz1, mxyz2) 
    109603 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109604 File
    109605 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109606 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    109607 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    109608 exclude=exclude) 
    109609 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109610 File
    109611 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109612 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    109613 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    109614 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109615 File
    109616 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109617 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    109618 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    109619 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109620 File
    109621 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109622 packages/chimerax/graphics/drawing.py", line 1108, in
    109623 _first_intercept_excluding_children 
    109624 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    109625 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109626 File
    109627 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109628 packages/chimerax/geometry/place.py", line 201, in inverse 
    109629 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    109630 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109631 File
    109632 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109633 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    109634 rinv[:, :] = matrix_inverse(r) 
    109635 ^^^^^^^^^^^^^^^^^ 
    109636 File
    109637 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109638 packages/numpy/linalg/linalg.py", line 561, in inv 
    109639 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    109640 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109641 File
    109642 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109643 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    109644 raise LinAlgError("Singular matrix") 
    109645 numpy.linalg.LinAlgError: Singular matrix 
    109646  
    109647 numpy.linalg.LinAlgError: Singular matrix 
    109648  
    109649 File
    109650 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109651 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    109652 raise LinAlgError("Singular matrix") 
    109653  
    109654 See log for complete Python traceback. 
    109655  
    109656 Traceback (most recent call last): 
    109657 File
    109658 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109659 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    109660 self.session.ui.mouse_modes.mouse_pause_tracking() 
    109661 File
    109662 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109663 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    109664 mouse_pause_tracking 
    109665 self._mouse_pause() 
    109666 File
    109667 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109668 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    109669 m.pause(self._mouse_pause_position) 
    109670 File
    109671 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109672 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    109673 p = self.view.picked_object(x, y) 
    109674 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109675 File
    109676 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109677 packages/chimerax/graphics/view.py", line 838, in picked_object 
    109678 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    109679 beyond, 
    109680 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109681 File
    109682 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109683 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    109684 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    109685 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109686 File
    109687 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109688 packages/chimerax/core/models.py", line 143, in first_intercept 
    109689 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    109690 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109691 File
    109692 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109693 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    109694 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    109695 exclude=exclude) 
    109696 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109697 File
    109698 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109699 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    109700 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    109701 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109702 File
    109703 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109704 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    109705 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    109706 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109707 File
    109708 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109709 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    109710 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    109711 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109712 File
    109713 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109714 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    109715 p = super().first_intercept(mxyz1, mxyz2) 
    109716 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109717 File
    109718 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109719 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    109720 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    109721 exclude=exclude) 
    109722 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109723 File
    109724 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109725 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    109726 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    109727 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109728 File
    109729 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109730 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    109731 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    109732 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109733 File
    109734 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109735 packages/chimerax/graphics/drawing.py", line 1108, in
    109736 _first_intercept_excluding_children 
    109737 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    109738 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109739 File
    109740 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109741 packages/chimerax/geometry/place.py", line 201, in inverse 
    109742 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    109743 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109744 File
    109745 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109746 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    109747 rinv[:, :] = matrix_inverse(r) 
    109748 ^^^^^^^^^^^^^^^^^ 
    109749 File
    109750 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109751 packages/numpy/linalg/linalg.py", line 561, in inv 
    109752 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    109753 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109754 File
    109755 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109756 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    109757 raise LinAlgError("Singular matrix") 
    109758 numpy.linalg.LinAlgError: Singular matrix 
    109759  
    109760 numpy.linalg.LinAlgError: Singular matrix 
    109761  
    109762 File
    109763 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109764 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    109765 raise LinAlgError("Singular matrix") 
    109766  
    109767 See log for complete Python traceback. 
    109768  
    109769 Traceback (most recent call last): 
    109770 File
    109771 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109772 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    109773 self.session.ui.mouse_modes.mouse_pause_tracking() 
    109774 File
    109775 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109776 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    109777 mouse_pause_tracking 
    109778 self._mouse_pause() 
    109779 File
    109780 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109781 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    109782 m.pause(self._mouse_pause_position) 
    109783 File
    109784 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109785 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    109786 p = self.view.picked_object(x, y) 
    109787 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109788 File
    109789 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109790 packages/chimerax/graphics/view.py", line 838, in picked_object 
    109791 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    109792 beyond, 
    109793 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109794 File
    109795 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109796 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    109797 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    109798 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109799 File
    109800 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109801 packages/chimerax/core/models.py", line 143, in first_intercept 
    109802 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    109803 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109804 File
    109805 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109806 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    109807 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    109808 exclude=exclude) 
    109809 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109810 File
    109811 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109812 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    109813 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    109814 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109815 File
    109816 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109817 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    109818 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    109819 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109820 File
    109821 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109822 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    109823 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    109824 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109825 File
    109826 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109827 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    109828 p = super().first_intercept(mxyz1, mxyz2) 
    109829 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109830 File
    109831 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109832 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    109833 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    109834 exclude=exclude) 
    109835 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109836 File
    109837 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109838 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    109839 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    109840 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109841 File
    109842 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109843 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    109844 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    109845 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109846 File
    109847 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109848 packages/chimerax/graphics/drawing.py", line 1108, in
    109849 _first_intercept_excluding_children 
    109850 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    109851 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109852 File
    109853 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109854 packages/chimerax/geometry/place.py", line 201, in inverse 
    109855 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    109856 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109857 File
    109858 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109859 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    109860 rinv[:, :] = matrix_inverse(r) 
    109861 ^^^^^^^^^^^^^^^^^ 
    109862 File
    109863 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109864 packages/numpy/linalg/linalg.py", line 561, in inv 
    109865 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    109866 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109867 File
    109868 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109869 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    109870 raise LinAlgError("Singular matrix") 
    109871 numpy.linalg.LinAlgError: Singular matrix 
    109872  
    109873 numpy.linalg.LinAlgError: Singular matrix 
    109874  
    109875 File
    109876 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109877 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    109878 raise LinAlgError("Singular matrix") 
    109879  
    109880 See log for complete Python traceback. 
    109881  
    109882 Traceback (most recent call last): 
    109883 File
    109884 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109885 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    109886 self.session.ui.mouse_modes.mouse_pause_tracking() 
    109887 File
    109888 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109889 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    109890 mouse_pause_tracking 
    109891 self._mouse_pause() 
    109892 File
    109893 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109894 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    109895 m.pause(self._mouse_pause_position) 
    109896 File
    109897 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109898 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    109899 p = self.view.picked_object(x, y) 
    109900 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109901 File
    109902 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109903 packages/chimerax/graphics/view.py", line 838, in picked_object 
    109904 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    109905 beyond, 
    109906 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109907 File
    109908 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109909 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    109910 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    109911 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109912 File
    109913 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109914 packages/chimerax/core/models.py", line 143, in first_intercept 
    109915 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    109916 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109917 File
    109918 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109919 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    109920 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    109921 exclude=exclude) 
    109922 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109923 File
    109924 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109925 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    109926 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    109927 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109928 File
    109929 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109930 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    109931 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    109932 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109933 File
    109934 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109935 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    109936 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    109937 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109938 File
    109939 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109940 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    109941 p = super().first_intercept(mxyz1, mxyz2) 
    109942 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109943 File
    109944 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109945 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    109946 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    109947 exclude=exclude) 
    109948 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109949 File
    109950 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109951 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    109952 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    109953 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109954 File
    109955 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109956 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    109957 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    109958 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109959 File
    109960 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109961 packages/chimerax/graphics/drawing.py", line 1108, in
    109962 _first_intercept_excluding_children 
    109963 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    109964 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109965 File
    109966 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109967 packages/chimerax/geometry/place.py", line 201, in inverse 
    109968 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    109969 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109970 File
    109971 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109972 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    109973 rinv[:, :] = matrix_inverse(r) 
    109974 ^^^^^^^^^^^^^^^^^ 
    109975 File
    109976 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109977 packages/numpy/linalg/linalg.py", line 561, in inv 
    109978 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    109979 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    109980 File
    109981 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109982 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    109983 raise LinAlgError("Singular matrix") 
    109984 numpy.linalg.LinAlgError: Singular matrix 
    109985  
    109986 numpy.linalg.LinAlgError: Singular matrix 
    109987  
    109988 File
    109989 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109990 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    109991 raise LinAlgError("Singular matrix") 
    109992  
    109993 See log for complete Python traceback. 
    109994  
    109995 Traceback (most recent call last): 
    109996 File
    109997 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    109998 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    109999 self.session.ui.mouse_modes.mouse_pause_tracking() 
    110000 File
    110001 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110002 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    110003 mouse_pause_tracking 
    110004 self._mouse_pause() 
    110005 File
    110006 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110007 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    110008 m.pause(self._mouse_pause_position) 
    110009 File
    110010 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110011 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    110012 p = self.view.picked_object(x, y) 
    110013 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110014 File
    110015 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110016 packages/chimerax/graphics/view.py", line 838, in picked_object 
    110017 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    110018 beyond, 
    110019 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110020 File
    110021 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110022 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    110023 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    110024 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110025 File
    110026 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110027 packages/chimerax/core/models.py", line 143, in first_intercept 
    110028 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    110029 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110030 File
    110031 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110032 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    110033 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    110034 exclude=exclude) 
    110035 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110036 File
    110037 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110038 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    110039 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    110040 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110041 File
    110042 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110043 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    110044 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    110045 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110046 File
    110047 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110048 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    110049 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    110050 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110051 File
    110052 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110053 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    110054 p = super().first_intercept(mxyz1, mxyz2) 
    110055 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110056 File
    110057 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110058 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    110059 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    110060 exclude=exclude) 
    110061 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110062 File
    110063 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110064 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    110065 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    110066 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110067 File
    110068 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110069 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    110070 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    110071 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110072 File
    110073 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110074 packages/chimerax/graphics/drawing.py", line 1108, in
    110075 _first_intercept_excluding_children 
    110076 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    110077 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110078 File
    110079 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110080 packages/chimerax/geometry/place.py", line 201, in inverse 
    110081 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    110082 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110083 File
    110084 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110085 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    110086 rinv[:, :] = matrix_inverse(r) 
    110087 ^^^^^^^^^^^^^^^^^ 
    110088 File
    110089 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110090 packages/numpy/linalg/linalg.py", line 561, in inv 
    110091 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    110092 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110093 File
    110094 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110095 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    110096 raise LinAlgError("Singular matrix") 
    110097 numpy.linalg.LinAlgError: Singular matrix 
    110098  
    110099 numpy.linalg.LinAlgError: Singular matrix 
    110100  
    110101 File
    110102 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110103 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    110104 raise LinAlgError("Singular matrix") 
    110105  
    110106 See log for complete Python traceback. 
    110107  
    110108 Traceback (most recent call last): 
    110109 File
    110110 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110111 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    110112 self.session.ui.mouse_modes.mouse_pause_tracking() 
    110113 File
    110114 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110115 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    110116 mouse_pause_tracking 
    110117 self._mouse_pause() 
    110118 File
    110119 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110120 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    110121 m.pause(self._mouse_pause_position) 
    110122 File
    110123 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110124 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    110125 p = self.view.picked_object(x, y) 
    110126 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110127 File
    110128 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110129 packages/chimerax/graphics/view.py", line 838, in picked_object 
    110130 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    110131 beyond, 
    110132 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110133 File
    110134 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110135 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    110136 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    110137 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110138 File
    110139 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110140 packages/chimerax/core/models.py", line 143, in first_intercept 
    110141 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    110142 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110143 File
    110144 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110145 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    110146 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    110147 exclude=exclude) 
    110148 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110149 File
    110150 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110151 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    110152 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    110153 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110154 File
    110155 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110156 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    110157 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    110158 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110159 File
    110160 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110161 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    110162 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    110163 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110164 File
    110165 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110166 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    110167 p = super().first_intercept(mxyz1, mxyz2) 
    110168 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110169 File
    110170 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110171 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    110172 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    110173 exclude=exclude) 
    110174 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110175 File
    110176 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110177 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    110178 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    110179 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110180 File
    110181 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110182 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    110183 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    110184 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110185 File
    110186 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110187 packages/chimerax/graphics/drawing.py", line 1108, in
    110188 _first_intercept_excluding_children 
    110189 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    110190 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110191 File
    110192 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110193 packages/chimerax/geometry/place.py", line 201, in inverse 
    110194 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    110195 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110196 File
    110197 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110198 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    110199 rinv[:, :] = matrix_inverse(r) 
    110200 ^^^^^^^^^^^^^^^^^ 
    110201 File
    110202 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110203 packages/numpy/linalg/linalg.py", line 561, in inv 
    110204 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    110205 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110206 File
    110207 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110208 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    110209 raise LinAlgError("Singular matrix") 
    110210 numpy.linalg.LinAlgError: Singular matrix 
    110211  
    110212 numpy.linalg.LinAlgError: Singular matrix 
    110213  
    110214 File
    110215 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110216 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    110217 raise LinAlgError("Singular matrix") 
    110218  
    110219 See log for complete Python traceback. 
    110220  
    110221 Traceback (most recent call last): 
    110222 File
    110223 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110224 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    110225 self.session.ui.mouse_modes.mouse_pause_tracking() 
    110226 File
    110227 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110228 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    110229 mouse_pause_tracking 
    110230 self._mouse_pause() 
    110231 File
    110232 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110233 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    110234 m.pause(self._mouse_pause_position) 
    110235 File
    110236 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110237 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    110238 p = self.view.picked_object(x, y) 
    110239 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110240 File
    110241 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110242 packages/chimerax/graphics/view.py", line 838, in picked_object 
    110243 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    110244 beyond, 
    110245 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110246 File
    110247 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110248 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    110249 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    110250 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110251 File
    110252 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110253 packages/chimerax/core/models.py", line 143, in first_intercept 
    110254 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    110255 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110256 File
    110257 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110258 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    110259 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    110260 exclude=exclude) 
    110261 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110262 File
    110263 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110264 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    110265 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    110266 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110267 File
    110268 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110269 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    110270 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    110271 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110272 File
    110273 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110274 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    110275 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    110276 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110277 File
    110278 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110279 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    110280 p = super().first_intercept(mxyz1, mxyz2) 
    110281 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110282 File
    110283 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110284 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    110285 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    110286 exclude=exclude) 
    110287 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110288 File
    110289 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110290 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    110291 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    110292 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110293 File
    110294 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110295 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    110296 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    110297 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110298 File
    110299 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110300 packages/chimerax/graphics/drawing.py", line 1108, in
    110301 _first_intercept_excluding_children 
    110302 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    110303 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110304 File
    110305 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110306 packages/chimerax/geometry/place.py", line 201, in inverse 
    110307 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    110308 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110309 File
    110310 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110311 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    110312 rinv[:, :] = matrix_inverse(r) 
    110313 ^^^^^^^^^^^^^^^^^ 
    110314 File
    110315 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110316 packages/numpy/linalg/linalg.py", line 561, in inv 
    110317 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    110318 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110319 File
    110320 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110321 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    110322 raise LinAlgError("Singular matrix") 
    110323 numpy.linalg.LinAlgError: Singular matrix 
    110324  
    110325 numpy.linalg.LinAlgError: Singular matrix 
    110326  
    110327 File
    110328 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110329 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    110330 raise LinAlgError("Singular matrix") 
    110331  
    110332 See log for complete Python traceback. 
    110333  
    110334 Traceback (most recent call last): 
    110335 File
    110336 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110337 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    110338 self.session.ui.mouse_modes.mouse_pause_tracking() 
    110339 File
    110340 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110341 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    110342 mouse_pause_tracking 
    110343 self._mouse_pause() 
    110344 File
    110345 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110346 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    110347 m.pause(self._mouse_pause_position) 
    110348 File
    110349 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110350 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    110351 p = self.view.picked_object(x, y) 
    110352 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110353 File
    110354 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110355 packages/chimerax/graphics/view.py", line 838, in picked_object 
    110356 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    110357 beyond, 
    110358 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110359 File
    110360 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110361 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    110362 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    110363 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110364 File
    110365 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110366 packages/chimerax/core/models.py", line 143, in first_intercept 
    110367 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    110368 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110369 File
    110370 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110371 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    110372 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    110373 exclude=exclude) 
    110374 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110375 File
    110376 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110377 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    110378 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    110379 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110380 File
    110381 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110382 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    110383 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    110384 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110385 File
    110386 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110387 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    110388 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    110389 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110390 File
    110391 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110392 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    110393 p = super().first_intercept(mxyz1, mxyz2) 
    110394 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110395 File
    110396 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110397 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    110398 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    110399 exclude=exclude) 
    110400 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110401 File
    110402 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110403 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    110404 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    110405 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110406 File
    110407 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110408 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    110409 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    110410 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110411 File
    110412 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110413 packages/chimerax/graphics/drawing.py", line 1108, in
    110414 _first_intercept_excluding_children 
    110415 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    110416 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110417 File
    110418 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110419 packages/chimerax/geometry/place.py", line 201, in inverse 
    110420 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    110421 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110422 File
    110423 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110424 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    110425 rinv[:, :] = matrix_inverse(r) 
    110426 ^^^^^^^^^^^^^^^^^ 
    110427 File
    110428 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110429 packages/numpy/linalg/linalg.py", line 561, in inv 
    110430 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    110431 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110432 File
    110433 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110434 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    110435 raise LinAlgError("Singular matrix") 
    110436 numpy.linalg.LinAlgError: Singular matrix 
    110437  
    110438 numpy.linalg.LinAlgError: Singular matrix 
    110439  
    110440 File
    110441 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110442 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    110443 raise LinAlgError("Singular matrix") 
    110444  
    110445 See log for complete Python traceback. 
    110446  
    110447 Traceback (most recent call last): 
    110448 File
    110449 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110450 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    110451 self.session.ui.mouse_modes.mouse_pause_tracking() 
    110452 File
    110453 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110454 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    110455 mouse_pause_tracking 
    110456 self._mouse_pause() 
    110457 File
    110458 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110459 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    110460 m.pause(self._mouse_pause_position) 
    110461 File
    110462 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110463 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    110464 p = self.view.picked_object(x, y) 
    110465 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110466 File
    110467 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110468 packages/chimerax/graphics/view.py", line 838, in picked_object 
    110469 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    110470 beyond, 
    110471 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110472 File
    110473 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110474 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    110475 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    110476 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110477 File
    110478 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110479 packages/chimerax/core/models.py", line 143, in first_intercept 
    110480 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    110481 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110482 File
    110483 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110484 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    110485 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    110486 exclude=exclude) 
    110487 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110488 File
    110489 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110490 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    110491 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    110492 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110493 File
    110494 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110495 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    110496 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    110497 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110498 File
    110499 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110500 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    110501 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    110502 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110503 File
    110504 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110505 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    110506 p = super().first_intercept(mxyz1, mxyz2) 
    110507 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110508 File
    110509 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110510 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    110511 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    110512 exclude=exclude) 
    110513 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110514 File
    110515 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110516 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    110517 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    110518 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110519 File
    110520 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110521 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    110522 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    110523 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110524 File
    110525 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110526 packages/chimerax/graphics/drawing.py", line 1108, in
    110527 _first_intercept_excluding_children 
    110528 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    110529 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110530 File
    110531 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110532 packages/chimerax/geometry/place.py", line 201, in inverse 
    110533 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    110534 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110535 File
    110536 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110537 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    110538 rinv[:, :] = matrix_inverse(r) 
    110539 ^^^^^^^^^^^^^^^^^ 
    110540 File
    110541 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110542 packages/numpy/linalg/linalg.py", line 561, in inv 
    110543 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    110544 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110545 File
    110546 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110547 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    110548 raise LinAlgError("Singular matrix") 
    110549 numpy.linalg.LinAlgError: Singular matrix 
    110550  
    110551 numpy.linalg.LinAlgError: Singular matrix 
    110552  
    110553 File
    110554 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110555 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    110556 raise LinAlgError("Singular matrix") 
    110557  
    110558 See log for complete Python traceback. 
    110559  
    110560 Traceback (most recent call last): 
    110561 File
    110562 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110563 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    110564 self.session.ui.mouse_modes.mouse_pause_tracking() 
    110565 File
    110566 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110567 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    110568 mouse_pause_tracking 
    110569 self._mouse_pause() 
    110570 File
    110571 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110572 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    110573 m.pause(self._mouse_pause_position) 
    110574 File
    110575 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110576 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    110577 p = self.view.picked_object(x, y) 
    110578 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110579 File
    110580 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110581 packages/chimerax/graphics/view.py", line 838, in picked_object 
    110582 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    110583 beyond, 
    110584 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110585 File
    110586 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110587 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    110588 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    110589 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110590 File
    110591 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110592 packages/chimerax/core/models.py", line 143, in first_intercept 
    110593 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    110594 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110595 File
    110596 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110597 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    110598 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    110599 exclude=exclude) 
    110600 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110601 File
    110602 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110603 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    110604 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    110605 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110606 File
    110607 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110608 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    110609 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    110610 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110611 File
    110612 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110613 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    110614 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    110615 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110616 File
    110617 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110618 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    110619 p = super().first_intercept(mxyz1, mxyz2) 
    110620 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110621 File
    110622 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110623 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    110624 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    110625 exclude=exclude) 
    110626 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110627 File
    110628 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110629 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    110630 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    110631 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110632 File
    110633 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110634 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    110635 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    110636 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110637 File
    110638 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110639 packages/chimerax/graphics/drawing.py", line 1108, in
    110640 _first_intercept_excluding_children 
    110641 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    110642 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110643 File
    110644 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110645 packages/chimerax/geometry/place.py", line 201, in inverse 
    110646 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    110647 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110648 File
    110649 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110650 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    110651 rinv[:, :] = matrix_inverse(r) 
    110652 ^^^^^^^^^^^^^^^^^ 
    110653 File
    110654 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110655 packages/numpy/linalg/linalg.py", line 561, in inv 
    110656 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    110657 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110658 File
    110659 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110660 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    110661 raise LinAlgError("Singular matrix") 
    110662 numpy.linalg.LinAlgError: Singular matrix 
    110663  
    110664 numpy.linalg.LinAlgError: Singular matrix 
    110665  
    110666 File
    110667 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110668 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    110669 raise LinAlgError("Singular matrix") 
    110670  
    110671 See log for complete Python traceback. 
    110672  
    110673 Traceback (most recent call last): 
    110674 File
    110675 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110676 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    110677 self.session.ui.mouse_modes.mouse_pause_tracking() 
    110678 File
    110679 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110680 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    110681 mouse_pause_tracking 
    110682 self._mouse_pause() 
    110683 File
    110684 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110685 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    110686 m.pause(self._mouse_pause_position) 
    110687 File
    110688 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110689 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    110690 p = self.view.picked_object(x, y) 
    110691 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110692 File
    110693 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110694 packages/chimerax/graphics/view.py", line 838, in picked_object 
    110695 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    110696 beyond, 
    110697 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110698 File
    110699 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110700 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    110701 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    110702 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110703 File
    110704 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110705 packages/chimerax/core/models.py", line 143, in first_intercept 
    110706 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    110707 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110708 File
    110709 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110710 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    110711 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    110712 exclude=exclude) 
    110713 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110714 File
    110715 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110716 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    110717 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    110718 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110719 File
    110720 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110721 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    110722 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    110723 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110724 File
    110725 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110726 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    110727 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    110728 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110729 File
    110730 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110731 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    110732 p = super().first_intercept(mxyz1, mxyz2) 
    110733 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110734 File
    110735 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110736 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    110737 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    110738 exclude=exclude) 
    110739 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110740 File
    110741 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110742 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    110743 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    110744 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110745 File
    110746 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110747 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    110748 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    110749 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110750 File
    110751 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110752 packages/chimerax/graphics/drawing.py", line 1108, in
    110753 _first_intercept_excluding_children 
    110754 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    110755 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110756 File
    110757 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110758 packages/chimerax/geometry/place.py", line 201, in inverse 
    110759 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    110760 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110761 File
    110762 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110763 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    110764 rinv[:, :] = matrix_inverse(r) 
    110765 ^^^^^^^^^^^^^^^^^ 
    110766 File
    110767 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110768 packages/numpy/linalg/linalg.py", line 561, in inv 
    110769 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    110770 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110771 File
    110772 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110773 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    110774 raise LinAlgError("Singular matrix") 
    110775 numpy.linalg.LinAlgError: Singular matrix 
    110776  
    110777 numpy.linalg.LinAlgError: Singular matrix 
    110778  
    110779 File
    110780 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110781 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    110782 raise LinAlgError("Singular matrix") 
    110783  
    110784 See log for complete Python traceback. 
    110785  
    110786 Traceback (most recent call last): 
    110787 File
    110788 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110789 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    110790 self.session.ui.mouse_modes.mouse_pause_tracking() 
    110791 File
    110792 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110793 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    110794 mouse_pause_tracking 
    110795 self._mouse_pause() 
    110796 File
    110797 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110798 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    110799 m.pause(self._mouse_pause_position) 
    110800 File
    110801 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110802 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    110803 p = self.view.picked_object(x, y) 
    110804 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110805 File
    110806 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110807 packages/chimerax/graphics/view.py", line 838, in picked_object 
    110808 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    110809 beyond, 
    110810 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110811 File
    110812 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110813 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    110814 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    110815 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110816 File
    110817 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110818 packages/chimerax/core/models.py", line 143, in first_intercept 
    110819 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    110820 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110821 File
    110822 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110823 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    110824 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    110825 exclude=exclude) 
    110826 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110827 File
    110828 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110829 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    110830 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    110831 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110832 File
    110833 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110834 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    110835 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    110836 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110837 File
    110838 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110839 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    110840 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    110841 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110842 File
    110843 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110844 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    110845 p = super().first_intercept(mxyz1, mxyz2) 
    110846 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110847 File
    110848 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110849 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    110850 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    110851 exclude=exclude) 
    110852 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110853 File
    110854 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110855 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    110856 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    110857 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110858 File
    110859 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110860 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    110861 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    110862 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110863 File
    110864 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110865 packages/chimerax/graphics/drawing.py", line 1108, in
    110866 _first_intercept_excluding_children 
    110867 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    110868 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110869 File
    110870 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110871 packages/chimerax/geometry/place.py", line 201, in inverse 
    110872 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    110873 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110874 File
    110875 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110876 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    110877 rinv[:, :] = matrix_inverse(r) 
    110878 ^^^^^^^^^^^^^^^^^ 
    110879 File
    110880 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110881 packages/numpy/linalg/linalg.py", line 561, in inv 
    110882 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    110883 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110884 File
    110885 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110886 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    110887 raise LinAlgError("Singular matrix") 
    110888 numpy.linalg.LinAlgError: Singular matrix 
    110889  
    110890 numpy.linalg.LinAlgError: Singular matrix 
    110891  
    110892 File
    110893 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110894 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    110895 raise LinAlgError("Singular matrix") 
    110896  
    110897 See log for complete Python traceback. 
    110898  
    110899 Traceback (most recent call last): 
    110900 File
    110901 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110902 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    110903 self.session.ui.mouse_modes.mouse_pause_tracking() 
    110904 File
    110905 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110906 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    110907 mouse_pause_tracking 
    110908 self._mouse_pause() 
    110909 File
    110910 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110911 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    110912 m.pause(self._mouse_pause_position) 
    110913 File
    110914 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110915 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    110916 p = self.view.picked_object(x, y) 
    110917 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110918 File
    110919 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110920 packages/chimerax/graphics/view.py", line 838, in picked_object 
    110921 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    110922 beyond, 
    110923 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110924 File
    110925 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110926 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    110927 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    110928 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110929 File
    110930 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110931 packages/chimerax/core/models.py", line 143, in first_intercept 
    110932 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    110933 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110934 File
    110935 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110936 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    110937 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    110938 exclude=exclude) 
    110939 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110940 File
    110941 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110942 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    110943 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    110944 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110945 File
    110946 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110947 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    110948 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    110949 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110950 File
    110951 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110952 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    110953 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    110954 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110955 File
    110956 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110957 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    110958 p = super().first_intercept(mxyz1, mxyz2) 
    110959 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110960 File
    110961 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110962 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    110963 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    110964 exclude=exclude) 
    110965 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110966 File
    110967 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110968 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    110969 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    110970 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110971 File
    110972 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110973 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    110974 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    110975 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110976 File
    110977 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110978 packages/chimerax/graphics/drawing.py", line 1108, in
    110979 _first_intercept_excluding_children 
    110980 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    110981 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110982 File
    110983 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110984 packages/chimerax/geometry/place.py", line 201, in inverse 
    110985 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    110986 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110987 File
    110988 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110989 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    110990 rinv[:, :] = matrix_inverse(r) 
    110991 ^^^^^^^^^^^^^^^^^ 
    110992 File
    110993 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110994 packages/numpy/linalg/linalg.py", line 561, in inv 
    110995 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    110996 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    110997 File
    110998 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    110999 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    111000 raise LinAlgError("Singular matrix") 
    111001 numpy.linalg.LinAlgError: Singular matrix 
    111002  
    111003 numpy.linalg.LinAlgError: Singular matrix 
    111004  
    111005 File
    111006 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111007 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    111008 raise LinAlgError("Singular matrix") 
    111009  
    111010 See log for complete Python traceback. 
    111011  
    111012 Traceback (most recent call last): 
    111013 File
    111014 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111015 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    111016 self.session.ui.mouse_modes.mouse_pause_tracking() 
    111017 File
    111018 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111019 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    111020 mouse_pause_tracking 
    111021 self._mouse_pause() 
    111022 File
    111023 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111024 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    111025 m.pause(self._mouse_pause_position) 
    111026 File
    111027 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111028 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    111029 p = self.view.picked_object(x, y) 
    111030 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111031 File
    111032 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111033 packages/chimerax/graphics/view.py", line 838, in picked_object 
    111034 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    111035 beyond, 
    111036 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111037 File
    111038 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111039 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    111040 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    111041 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111042 File
    111043 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111044 packages/chimerax/core/models.py", line 143, in first_intercept 
    111045 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    111046 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111047 File
    111048 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111049 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    111050 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    111051 exclude=exclude) 
    111052 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111053 File
    111054 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111055 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    111056 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    111057 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111058 File
    111059 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111060 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    111061 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    111062 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111063 File
    111064 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111065 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    111066 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    111067 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111068 File
    111069 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111070 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    111071 p = super().first_intercept(mxyz1, mxyz2) 
    111072 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111073 File
    111074 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111075 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    111076 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    111077 exclude=exclude) 
    111078 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111079 File
    111080 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111081 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    111082 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    111083 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111084 File
    111085 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111086 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    111087 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    111088 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111089 File
    111090 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111091 packages/chimerax/graphics/drawing.py", line 1108, in
    111092 _first_intercept_excluding_children 
    111093 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    111094 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111095 File
    111096 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111097 packages/chimerax/geometry/place.py", line 201, in inverse 
    111098 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    111099 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111100 File
    111101 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111102 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    111103 rinv[:, :] = matrix_inverse(r) 
    111104 ^^^^^^^^^^^^^^^^^ 
    111105 File
    111106 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111107 packages/numpy/linalg/linalg.py", line 561, in inv 
    111108 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    111109 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111110 File
    111111 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111112 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    111113 raise LinAlgError("Singular matrix") 
    111114 numpy.linalg.LinAlgError: Singular matrix 
    111115  
    111116 numpy.linalg.LinAlgError: Singular matrix 
    111117  
    111118 File
    111119 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111120 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    111121 raise LinAlgError("Singular matrix") 
    111122  
    111123 See log for complete Python traceback. 
    111124  
    111125 Traceback (most recent call last): 
    111126 File
    111127 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111128 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    111129 self.session.ui.mouse_modes.mouse_pause_tracking() 
    111130 File
    111131 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111132 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    111133 mouse_pause_tracking 
    111134 self._mouse_pause() 
    111135 File
    111136 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111137 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    111138 m.pause(self._mouse_pause_position) 
    111139 File
    111140 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111141 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    111142 p = self.view.picked_object(x, y) 
    111143 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111144 File
    111145 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111146 packages/chimerax/graphics/view.py", line 838, in picked_object 
    111147 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    111148 beyond, 
    111149 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111150 File
    111151 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111152 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    111153 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    111154 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111155 File
    111156 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111157 packages/chimerax/core/models.py", line 143, in first_intercept 
    111158 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    111159 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111160 File
    111161 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111162 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    111163 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    111164 exclude=exclude) 
    111165 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111166 File
    111167 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111168 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    111169 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    111170 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111171 File
    111172 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111173 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    111174 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    111175 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111176 File
    111177 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111178 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    111179 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    111180 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111181 File
    111182 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111183 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    111184 p = super().first_intercept(mxyz1, mxyz2) 
    111185 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111186 File
    111187 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111188 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    111189 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    111190 exclude=exclude) 
    111191 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111192 File
    111193 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111194 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    111195 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    111196 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111197 File
    111198 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111199 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    111200 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    111201 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111202 File
    111203 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111204 packages/chimerax/graphics/drawing.py", line 1108, in
    111205 _first_intercept_excluding_children 
    111206 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    111207 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111208 File
    111209 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111210 packages/chimerax/geometry/place.py", line 201, in inverse 
    111211 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    111212 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111213 File
    111214 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111215 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    111216 rinv[:, :] = matrix_inverse(r) 
    111217 ^^^^^^^^^^^^^^^^^ 
    111218 File
    111219 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111220 packages/numpy/linalg/linalg.py", line 561, in inv 
    111221 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    111222 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111223 File
    111224 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111225 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    111226 raise LinAlgError("Singular matrix") 
    111227 numpy.linalg.LinAlgError: Singular matrix 
    111228  
    111229 numpy.linalg.LinAlgError: Singular matrix 
    111230  
    111231 File
    111232 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111233 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    111234 raise LinAlgError("Singular matrix") 
    111235  
    111236 See log for complete Python traceback. 
    111237  
    111238 Traceback (most recent call last): 
    111239 File
    111240 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111241 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    111242 self.session.ui.mouse_modes.mouse_pause_tracking() 
    111243 File
    111244 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111245 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    111246 mouse_pause_tracking 
    111247 self._mouse_pause() 
    111248 File
    111249 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111250 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    111251 m.pause(self._mouse_pause_position) 
    111252 File
    111253 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111254 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    111255 p = self.view.picked_object(x, y) 
    111256 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111257 File
    111258 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111259 packages/chimerax/graphics/view.py", line 838, in picked_object 
    111260 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    111261 beyond, 
    111262 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111263 File
    111264 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111265 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    111266 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    111267 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111268 File
    111269 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111270 packages/chimerax/core/models.py", line 143, in first_intercept 
    111271 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    111272 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111273 File
    111274 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111275 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    111276 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    111277 exclude=exclude) 
    111278 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111279 File
    111280 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111281 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    111282 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    111283 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111284 File
    111285 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111286 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    111287 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    111288 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111289 File
    111290 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111291 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    111292 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    111293 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111294 File
    111295 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111296 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    111297 p = super().first_intercept(mxyz1, mxyz2) 
    111298 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111299 File
    111300 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111301 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    111302 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    111303 exclude=exclude) 
    111304 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111305 File
    111306 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111307 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    111308 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    111309 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111310 File
    111311 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111312 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    111313 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    111314 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111315 File
    111316 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111317 packages/chimerax/graphics/drawing.py", line 1108, in
    111318 _first_intercept_excluding_children 
    111319 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    111320 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111321 File
    111322 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111323 packages/chimerax/geometry/place.py", line 201, in inverse 
    111324 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    111325 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111326 File
    111327 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111328 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    111329 rinv[:, :] = matrix_inverse(r) 
    111330 ^^^^^^^^^^^^^^^^^ 
    111331 File
    111332 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111333 packages/numpy/linalg/linalg.py", line 561, in inv 
    111334 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    111335 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111336 File
    111337 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111338 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    111339 raise LinAlgError("Singular matrix") 
    111340 numpy.linalg.LinAlgError: Singular matrix 
    111341  
    111342 numpy.linalg.LinAlgError: Singular matrix 
    111343  
    111344 File
    111345 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111346 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    111347 raise LinAlgError("Singular matrix") 
    111348  
    111349 See log for complete Python traceback. 
    111350  
    111351 Traceback (most recent call last): 
    111352 File
    111353 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111354 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    111355 self.session.ui.mouse_modes.mouse_pause_tracking() 
    111356 File
    111357 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111358 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    111359 mouse_pause_tracking 
    111360 self._mouse_pause() 
    111361 File
    111362 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111363 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    111364 m.pause(self._mouse_pause_position) 
    111365 File
    111366 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111367 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    111368 p = self.view.picked_object(x, y) 
    111369 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111370 File
    111371 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111372 packages/chimerax/graphics/view.py", line 838, in picked_object 
    111373 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    111374 beyond, 
    111375 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111376 File
    111377 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111378 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    111379 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    111380 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111381 File
    111382 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111383 packages/chimerax/core/models.py", line 143, in first_intercept 
    111384 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    111385 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111386 File
    111387 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111388 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    111389 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    111390 exclude=exclude) 
    111391 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111392 File
    111393 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111394 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    111395 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    111396 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111397 File
    111398 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111399 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    111400 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    111401 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111402 File
    111403 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111404 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    111405 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    111406 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111407 File
    111408 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111409 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    111410 p = super().first_intercept(mxyz1, mxyz2) 
    111411 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111412 File
    111413 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111414 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    111415 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    111416 exclude=exclude) 
    111417 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111418 File
    111419 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111420 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    111421 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    111422 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111423 File
    111424 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111425 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    111426 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    111427 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111428 File
    111429 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111430 packages/chimerax/graphics/drawing.py", line 1108, in
    111431 _first_intercept_excluding_children 
    111432 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    111433 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111434 File
    111435 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111436 packages/chimerax/geometry/place.py", line 201, in inverse 
    111437 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    111438 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111439 File
    111440 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111441 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    111442 rinv[:, :] = matrix_inverse(r) 
    111443 ^^^^^^^^^^^^^^^^^ 
    111444 File
    111445 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111446 packages/numpy/linalg/linalg.py", line 561, in inv 
    111447 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    111448 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111449 File
    111450 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111451 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    111452 raise LinAlgError("Singular matrix") 
    111453 numpy.linalg.LinAlgError: Singular matrix 
    111454  
    111455 numpy.linalg.LinAlgError: Singular matrix 
    111456  
    111457 File
    111458 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111459 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    111460 raise LinAlgError("Singular matrix") 
    111461  
    111462 See log for complete Python traceback. 
    111463  
    111464 Traceback (most recent call last): 
    111465 File
    111466 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111467 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    111468 self.session.ui.mouse_modes.mouse_pause_tracking() 
    111469 File
    111470 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111471 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    111472 mouse_pause_tracking 
    111473 self._mouse_pause() 
    111474 File
    111475 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111476 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    111477 m.pause(self._mouse_pause_position) 
    111478 File
    111479 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111480 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    111481 p = self.view.picked_object(x, y) 
    111482 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111483 File
    111484 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111485 packages/chimerax/graphics/view.py", line 838, in picked_object 
    111486 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    111487 beyond, 
    111488 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111489 File
    111490 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111491 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    111492 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    111493 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111494 File
    111495 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111496 packages/chimerax/core/models.py", line 143, in first_intercept 
    111497 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    111498 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111499 File
    111500 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111501 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    111502 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    111503 exclude=exclude) 
    111504 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111505 File
    111506 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111507 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    111508 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    111509 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111510 File
    111511 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111512 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    111513 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    111514 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111515 File
    111516 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111517 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    111518 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    111519 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111520 File
    111521 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111522 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    111523 p = super().first_intercept(mxyz1, mxyz2) 
    111524 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111525 File
    111526 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111527 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    111528 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    111529 exclude=exclude) 
    111530 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111531 File
    111532 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111533 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    111534 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    111535 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111536 File
    111537 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111538 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    111539 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    111540 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111541 File
    111542 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111543 packages/chimerax/graphics/drawing.py", line 1108, in
    111544 _first_intercept_excluding_children 
    111545 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    111546 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111547 File
    111548 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111549 packages/chimerax/geometry/place.py", line 201, in inverse 
    111550 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    111551 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111552 File
    111553 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111554 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    111555 rinv[:, :] = matrix_inverse(r) 
    111556 ^^^^^^^^^^^^^^^^^ 
    111557 File
    111558 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111559 packages/numpy/linalg/linalg.py", line 561, in inv 
    111560 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    111561 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111562 File
    111563 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111564 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    111565 raise LinAlgError("Singular matrix") 
    111566 numpy.linalg.LinAlgError: Singular matrix 
    111567  
    111568 numpy.linalg.LinAlgError: Singular matrix 
    111569  
    111570 File
    111571 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111572 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    111573 raise LinAlgError("Singular matrix") 
    111574  
    111575 See log for complete Python traceback. 
    111576  
    111577 Traceback (most recent call last): 
    111578 File
    111579 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111580 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    111581 self.session.ui.mouse_modes.mouse_pause_tracking() 
    111582 File
    111583 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111584 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    111585 mouse_pause_tracking 
    111586 self._mouse_pause() 
    111587 File
    111588 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111589 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    111590 m.pause(self._mouse_pause_position) 
    111591 File
    111592 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111593 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    111594 p = self.view.picked_object(x, y) 
    111595 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111596 File
    111597 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111598 packages/chimerax/graphics/view.py", line 838, in picked_object 
    111599 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    111600 beyond, 
    111601 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111602 File
    111603 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111604 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    111605 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    111606 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111607 File
    111608 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111609 packages/chimerax/core/models.py", line 143, in first_intercept 
    111610 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    111611 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111612 File
    111613 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111614 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    111615 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    111616 exclude=exclude) 
    111617 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111618 File
    111619 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111620 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    111621 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    111622 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111623 File
    111624 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111625 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    111626 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    111627 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111628 File
    111629 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111630 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    111631 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    111632 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111633 File
    111634 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111635 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    111636 p = super().first_intercept(mxyz1, mxyz2) 
    111637 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111638 File
    111639 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111640 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    111641 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    111642 exclude=exclude) 
    111643 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111644 File
    111645 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111646 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    111647 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    111648 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111649 File
    111650 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111651 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    111652 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    111653 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111654 File
    111655 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111656 packages/chimerax/graphics/drawing.py", line 1108, in
    111657 _first_intercept_excluding_children 
    111658 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    111659 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111660 File
    111661 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111662 packages/chimerax/geometry/place.py", line 201, in inverse 
    111663 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    111664 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111665 File
    111666 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111667 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    111668 rinv[:, :] = matrix_inverse(r) 
    111669 ^^^^^^^^^^^^^^^^^ 
    111670 File
    111671 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111672 packages/numpy/linalg/linalg.py", line 561, in inv 
    111673 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    111674 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111675 File
    111676 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111677 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    111678 raise LinAlgError("Singular matrix") 
    111679 numpy.linalg.LinAlgError: Singular matrix 
    111680  
    111681 numpy.linalg.LinAlgError: Singular matrix 
    111682  
    111683 File
    111684 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111685 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    111686 raise LinAlgError("Singular matrix") 
    111687  
    111688 See log for complete Python traceback. 
    111689  
    111690 Traceback (most recent call last): 
    111691 File
    111692 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111693 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    111694 self.session.ui.mouse_modes.mouse_pause_tracking() 
    111695 File
    111696 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111697 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    111698 mouse_pause_tracking 
    111699 self._mouse_pause() 
    111700 File
    111701 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111702 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    111703 m.pause(self._mouse_pause_position) 
    111704 File
    111705 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111706 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    111707 p = self.view.picked_object(x, y) 
    111708 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111709 File
    111710 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111711 packages/chimerax/graphics/view.py", line 838, in picked_object 
    111712 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    111713 beyond, 
    111714 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111715 File
    111716 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111717 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    111718 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    111719 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111720 File
    111721 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111722 packages/chimerax/core/models.py", line 143, in first_intercept 
    111723 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    111724 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111725 File
    111726 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111727 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    111728 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    111729 exclude=exclude) 
    111730 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111731 File
    111732 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111733 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    111734 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    111735 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111736 File
    111737 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111738 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    111739 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    111740 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111741 File
    111742 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111743 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    111744 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    111745 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111746 File
    111747 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111748 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    111749 p = super().first_intercept(mxyz1, mxyz2) 
    111750 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111751 File
    111752 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111753 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    111754 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    111755 exclude=exclude) 
    111756 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111757 File
    111758 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111759 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    111760 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    111761 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111762 File
    111763 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111764 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    111765 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    111766 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111767 File
    111768 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111769 packages/chimerax/graphics/drawing.py", line 1108, in
    111770 _first_intercept_excluding_children 
    111771 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    111772 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111773 File
    111774 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111775 packages/chimerax/geometry/place.py", line 201, in inverse 
    111776 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    111777 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111778 File
    111779 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111780 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    111781 rinv[:, :] = matrix_inverse(r) 
    111782 ^^^^^^^^^^^^^^^^^ 
    111783 File
    111784 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111785 packages/numpy/linalg/linalg.py", line 561, in inv 
    111786 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    111787 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111788 File
    111789 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111790 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    111791 raise LinAlgError("Singular matrix") 
    111792 numpy.linalg.LinAlgError: Singular matrix 
    111793  
    111794 numpy.linalg.LinAlgError: Singular matrix 
    111795  
    111796 File
    111797 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111798 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    111799 raise LinAlgError("Singular matrix") 
    111800  
    111801 See log for complete Python traceback. 
    111802  
    111803 Traceback (most recent call last): 
    111804 File
    111805 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111806 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    111807 self.session.ui.mouse_modes.mouse_pause_tracking() 
    111808 File
    111809 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111810 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    111811 mouse_pause_tracking 
    111812 self._mouse_pause() 
    111813 File
    111814 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111815 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    111816 m.pause(self._mouse_pause_position) 
    111817 File
    111818 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111819 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    111820 p = self.view.picked_object(x, y) 
    111821 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111822 File
    111823 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111824 packages/chimerax/graphics/view.py", line 838, in picked_object 
    111825 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    111826 beyond, 
    111827 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111828 File
    111829 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111830 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    111831 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    111832 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111833 File
    111834 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111835 packages/chimerax/core/models.py", line 143, in first_intercept 
    111836 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    111837 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111838 File
    111839 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111840 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    111841 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    111842 exclude=exclude) 
    111843 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111844 File
    111845 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111846 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    111847 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    111848 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111849 File
    111850 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111851 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    111852 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    111853 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111854 File
    111855 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111856 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    111857 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    111858 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111859 File
    111860 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111861 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    111862 p = super().first_intercept(mxyz1, mxyz2) 
    111863 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111864 File
    111865 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111866 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    111867 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    111868 exclude=exclude) 
    111869 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111870 File
    111871 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111872 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    111873 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    111874 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111875 File
    111876 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111877 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    111878 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    111879 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111880 File
    111881 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111882 packages/chimerax/graphics/drawing.py", line 1108, in
    111883 _first_intercept_excluding_children 
    111884 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    111885 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111886 File
    111887 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111888 packages/chimerax/geometry/place.py", line 201, in inverse 
    111889 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    111890 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111891 File
    111892 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111893 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    111894 rinv[:, :] = matrix_inverse(r) 
    111895 ^^^^^^^^^^^^^^^^^ 
    111896 File
    111897 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111898 packages/numpy/linalg/linalg.py", line 561, in inv 
    111899 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    111900 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111901 File
    111902 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111903 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    111904 raise LinAlgError("Singular matrix") 
    111905 numpy.linalg.LinAlgError: Singular matrix 
    111906  
    111907 numpy.linalg.LinAlgError: Singular matrix 
    111908  
    111909 File
    111910 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111911 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    111912 raise LinAlgError("Singular matrix") 
    111913  
    111914 See log for complete Python traceback. 
    111915  
    111916 Traceback (most recent call last): 
    111917 File
    111918 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111919 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    111920 self.session.ui.mouse_modes.mouse_pause_tracking() 
    111921 File
    111922 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111923 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    111924 mouse_pause_tracking 
    111925 self._mouse_pause() 
    111926 File
    111927 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111928 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    111929 m.pause(self._mouse_pause_position) 
    111930 File
    111931 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111932 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    111933 p = self.view.picked_object(x, y) 
    111934 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111935 File
    111936 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111937 packages/chimerax/graphics/view.py", line 838, in picked_object 
    111938 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    111939 beyond, 
    111940 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111941 File
    111942 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111943 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    111944 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    111945 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111946 File
    111947 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111948 packages/chimerax/core/models.py", line 143, in first_intercept 
    111949 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    111950 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111951 File
    111952 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111953 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    111954 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    111955 exclude=exclude) 
    111956 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111957 File
    111958 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111959 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    111960 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    111961 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111962 File
    111963 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111964 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    111965 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    111966 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111967 File
    111968 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111969 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    111970 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    111971 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111972 File
    111973 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111974 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    111975 p = super().first_intercept(mxyz1, mxyz2) 
    111976 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111977 File
    111978 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111979 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    111980 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    111981 exclude=exclude) 
    111982 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111983 File
    111984 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111985 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    111986 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    111987 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111988 File
    111989 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111990 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    111991 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    111992 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111993 File
    111994 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    111995 packages/chimerax/graphics/drawing.py", line 1108, in
    111996 _first_intercept_excluding_children 
    111997 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    111998 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    111999 File
    112000 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112001 packages/chimerax/geometry/place.py", line 201, in inverse 
    112002 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    112003 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112004 File
    112005 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112006 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    112007 rinv[:, :] = matrix_inverse(r) 
    112008 ^^^^^^^^^^^^^^^^^ 
    112009 File
    112010 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112011 packages/numpy/linalg/linalg.py", line 561, in inv 
    112012 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    112013 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112014 File
    112015 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112016 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    112017 raise LinAlgError("Singular matrix") 
    112018 numpy.linalg.LinAlgError: Singular matrix 
    112019  
    112020 numpy.linalg.LinAlgError: Singular matrix 
    112021  
    112022 File
    112023 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112024 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    112025 raise LinAlgError("Singular matrix") 
    112026  
    112027 See log for complete Python traceback. 
    112028  
    112029 Traceback (most recent call last): 
    112030 File
    112031 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112032 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    112033 self.session.ui.mouse_modes.mouse_pause_tracking() 
    112034 File
    112035 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112036 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    112037 mouse_pause_tracking 
    112038 self._mouse_pause() 
    112039 File
    112040 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112041 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    112042 m.pause(self._mouse_pause_position) 
    112043 File
    112044 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112045 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    112046 p = self.view.picked_object(x, y) 
    112047 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112048 File
    112049 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112050 packages/chimerax/graphics/view.py", line 838, in picked_object 
    112051 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    112052 beyond, 
    112053 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112054 File
    112055 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112056 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    112057 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    112058 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112059 File
    112060 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112061 packages/chimerax/core/models.py", line 143, in first_intercept 
    112062 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    112063 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112064 File
    112065 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112066 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    112067 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    112068 exclude=exclude) 
    112069 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112070 File
    112071 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112072 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    112073 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    112074 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112075 File
    112076 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112077 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    112078 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    112079 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112080 File
    112081 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112082 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    112083 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    112084 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112085 File
    112086 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112087 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    112088 p = super().first_intercept(mxyz1, mxyz2) 
    112089 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112090 File
    112091 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112092 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    112093 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    112094 exclude=exclude) 
    112095 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112096 File
    112097 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112098 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    112099 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    112100 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112101 File
    112102 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112103 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    112104 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    112105 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112106 File
    112107 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112108 packages/chimerax/graphics/drawing.py", line 1108, in
    112109 _first_intercept_excluding_children 
    112110 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    112111 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112112 File
    112113 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112114 packages/chimerax/geometry/place.py", line 201, in inverse 
    112115 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    112116 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112117 File
    112118 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112119 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    112120 rinv[:, :] = matrix_inverse(r) 
    112121 ^^^^^^^^^^^^^^^^^ 
    112122 File
    112123 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112124 packages/numpy/linalg/linalg.py", line 561, in inv 
    112125 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    112126 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112127 File
    112128 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112129 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    112130 raise LinAlgError("Singular matrix") 
    112131 numpy.linalg.LinAlgError: Singular matrix 
    112132  
    112133 numpy.linalg.LinAlgError: Singular matrix 
    112134  
    112135 File
    112136 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112137 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    112138 raise LinAlgError("Singular matrix") 
    112139  
    112140 See log for complete Python traceback. 
    112141  
    112142 Traceback (most recent call last): 
    112143 File
    112144 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112145 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    112146 self.session.ui.mouse_modes.mouse_pause_tracking() 
    112147 File
    112148 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112149 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    112150 mouse_pause_tracking 
    112151 self._mouse_pause() 
    112152 File
    112153 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112154 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    112155 m.pause(self._mouse_pause_position) 
    112156 File
    112157 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112158 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    112159 p = self.view.picked_object(x, y) 
    112160 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112161 File
    112162 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112163 packages/chimerax/graphics/view.py", line 838, in picked_object 
    112164 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    112165 beyond, 
    112166 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112167 File
    112168 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112169 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    112170 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    112171 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112172 File
    112173 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112174 packages/chimerax/core/models.py", line 143, in first_intercept 
    112175 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    112176 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112177 File
    112178 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112179 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    112180 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    112181 exclude=exclude) 
    112182 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112183 File
    112184 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112185 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    112186 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    112187 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112188 File
    112189 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112190 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    112191 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    112192 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112193 File
    112194 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112195 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    112196 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    112197 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112198 File
    112199 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112200 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    112201 p = super().first_intercept(mxyz1, mxyz2) 
    112202 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112203 File
    112204 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112205 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    112206 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    112207 exclude=exclude) 
    112208 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112209 File
    112210 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112211 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    112212 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    112213 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112214 File
    112215 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112216 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    112217 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    112218 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112219 File
    112220 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112221 packages/chimerax/graphics/drawing.py", line 1108, in
    112222 _first_intercept_excluding_children 
    112223 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    112224 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112225 File
    112226 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112227 packages/chimerax/geometry/place.py", line 201, in inverse 
    112228 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    112229 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112230 File
    112231 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112232 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    112233 rinv[:, :] = matrix_inverse(r) 
    112234 ^^^^^^^^^^^^^^^^^ 
    112235 File
    112236 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112237 packages/numpy/linalg/linalg.py", line 561, in inv 
    112238 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    112239 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112240 File
    112241 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112242 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    112243 raise LinAlgError("Singular matrix") 
    112244 numpy.linalg.LinAlgError: Singular matrix 
    112245  
    112246 numpy.linalg.LinAlgError: Singular matrix 
    112247  
    112248 File
    112249 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112250 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    112251 raise LinAlgError("Singular matrix") 
    112252  
    112253 See log for complete Python traceback. 
    112254  
    112255 Traceback (most recent call last): 
    112256 File
    112257 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112258 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    112259 self.session.ui.mouse_modes.mouse_pause_tracking() 
    112260 File
    112261 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112262 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    112263 mouse_pause_tracking 
    112264 self._mouse_pause() 
    112265 File
    112266 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112267 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    112268 m.pause(self._mouse_pause_position) 
    112269 File
    112270 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112271 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    112272 p = self.view.picked_object(x, y) 
    112273 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112274 File
    112275 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112276 packages/chimerax/graphics/view.py", line 838, in picked_object 
    112277 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    112278 beyond, 
    112279 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112280 File
    112281 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112282 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    112283 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    112284 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112285 File
    112286 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112287 packages/chimerax/core/models.py", line 143, in first_intercept 
    112288 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    112289 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112290 File
    112291 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112292 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    112293 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    112294 exclude=exclude) 
    112295 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112296 File
    112297 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112298 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    112299 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    112300 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112301 File
    112302 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112303 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    112304 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    112305 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112306 File
    112307 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112308 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    112309 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    112310 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112311 File
    112312 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112313 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    112314 p = super().first_intercept(mxyz1, mxyz2) 
    112315 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112316 File
    112317 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112318 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    112319 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    112320 exclude=exclude) 
    112321 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112322 File
    112323 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112324 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    112325 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    112326 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112327 File
    112328 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112329 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    112330 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    112331 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112332 File
    112333 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112334 packages/chimerax/graphics/drawing.py", line 1108, in
    112335 _first_intercept_excluding_children 
    112336 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    112337 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112338 File
    112339 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112340 packages/chimerax/geometry/place.py", line 201, in inverse 
    112341 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    112342 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112343 File
    112344 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112345 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    112346 rinv[:, :] = matrix_inverse(r) 
    112347 ^^^^^^^^^^^^^^^^^ 
    112348 File
    112349 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112350 packages/numpy/linalg/linalg.py", line 561, in inv 
    112351 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    112352 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112353 File
    112354 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112355 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    112356 raise LinAlgError("Singular matrix") 
    112357 numpy.linalg.LinAlgError: Singular matrix 
    112358  
    112359 numpy.linalg.LinAlgError: Singular matrix 
    112360  
    112361 File
    112362 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112363 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    112364 raise LinAlgError("Singular matrix") 
    112365  
    112366 See log for complete Python traceback. 
    112367  
    112368 Traceback (most recent call last): 
    112369 File
    112370 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112371 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    112372 self.session.ui.mouse_modes.mouse_pause_tracking() 
    112373 File
    112374 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112375 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    112376 mouse_pause_tracking 
    112377 self._mouse_pause() 
    112378 File
    112379 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112380 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    112381 m.pause(self._mouse_pause_position) 
    112382 File
    112383 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112384 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    112385 p = self.view.picked_object(x, y) 
    112386 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112387 File
    112388 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112389 packages/chimerax/graphics/view.py", line 838, in picked_object 
    112390 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    112391 beyond, 
    112392 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112393 File
    112394 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112395 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    112396 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    112397 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112398 File
    112399 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112400 packages/chimerax/core/models.py", line 143, in first_intercept 
    112401 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    112402 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112403 File
    112404 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112405 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    112406 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    112407 exclude=exclude) 
    112408 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112409 File
    112410 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112411 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    112412 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    112413 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112414 File
    112415 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112416 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    112417 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    112418 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112419 File
    112420 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112421 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    112422 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    112423 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112424 File
    112425 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112426 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    112427 p = super().first_intercept(mxyz1, mxyz2) 
    112428 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112429 File
    112430 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112431 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    112432 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    112433 exclude=exclude) 
    112434 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112435 File
    112436 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112437 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    112438 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    112439 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112440 File
    112441 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112442 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    112443 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    112444 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112445 File
    112446 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112447 packages/chimerax/graphics/drawing.py", line 1108, in
    112448 _first_intercept_excluding_children 
    112449 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    112450 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112451 File
    112452 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112453 packages/chimerax/geometry/place.py", line 201, in inverse 
    112454 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    112455 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112456 File
    112457 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112458 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    112459 rinv[:, :] = matrix_inverse(r) 
    112460 ^^^^^^^^^^^^^^^^^ 
    112461 File
    112462 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112463 packages/numpy/linalg/linalg.py", line 561, in inv 
    112464 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    112465 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112466 File
    112467 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112468 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    112469 raise LinAlgError("Singular matrix") 
    112470 numpy.linalg.LinAlgError: Singular matrix 
    112471  
    112472 numpy.linalg.LinAlgError: Singular matrix 
    112473  
    112474 File
    112475 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112476 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    112477 raise LinAlgError("Singular matrix") 
    112478  
    112479 See log for complete Python traceback. 
    112480  
    112481 Traceback (most recent call last): 
    112482 File
    112483 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112484 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    112485 self.session.ui.mouse_modes.mouse_pause_tracking() 
    112486 File
    112487 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112488 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    112489 mouse_pause_tracking 
    112490 self._mouse_pause() 
    112491 File
    112492 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112493 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    112494 m.pause(self._mouse_pause_position) 
    112495 File
    112496 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112497 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    112498 p = self.view.picked_object(x, y) 
    112499 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112500 File
    112501 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112502 packages/chimerax/graphics/view.py", line 838, in picked_object 
    112503 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    112504 beyond, 
    112505 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112506 File
    112507 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112508 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    112509 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    112510 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112511 File
    112512 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112513 packages/chimerax/core/models.py", line 143, in first_intercept 
    112514 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    112515 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112516 File
    112517 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112518 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    112519 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    112520 exclude=exclude) 
    112521 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112522 File
    112523 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112524 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    112525 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    112526 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112527 File
    112528 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112529 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    112530 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    112531 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112532 File
    112533 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112534 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    112535 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    112536 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112537 File
    112538 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112539 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    112540 p = super().first_intercept(mxyz1, mxyz2) 
    112541 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112542 File
    112543 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112544 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    112545 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    112546 exclude=exclude) 
    112547 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112548 File
    112549 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112550 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    112551 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    112552 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112553 File
    112554 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112555 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    112556 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    112557 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112558 File
    112559 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112560 packages/chimerax/graphics/drawing.py", line 1108, in
    112561 _first_intercept_excluding_children 
    112562 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    112563 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112564 File
    112565 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112566 packages/chimerax/geometry/place.py", line 201, in inverse 
    112567 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    112568 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112569 File
    112570 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112571 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    112572 rinv[:, :] = matrix_inverse(r) 
    112573 ^^^^^^^^^^^^^^^^^ 
    112574 File
    112575 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112576 packages/numpy/linalg/linalg.py", line 561, in inv 
    112577 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    112578 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112579 File
    112580 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112581 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    112582 raise LinAlgError("Singular matrix") 
    112583 numpy.linalg.LinAlgError: Singular matrix 
    112584  
    112585 numpy.linalg.LinAlgError: Singular matrix 
    112586  
    112587 File
    112588 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112589 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    112590 raise LinAlgError("Singular matrix") 
    112591  
    112592 See log for complete Python traceback. 
    112593  
    112594 Traceback (most recent call last): 
    112595 File
    112596 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112597 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    112598 self.session.ui.mouse_modes.mouse_pause_tracking() 
    112599 File
    112600 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112601 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    112602 mouse_pause_tracking 
    112603 self._mouse_pause() 
    112604 File
    112605 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112606 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    112607 m.pause(self._mouse_pause_position) 
    112608 File
    112609 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112610 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    112611 p = self.view.picked_object(x, y) 
    112612 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112613 File
    112614 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112615 packages/chimerax/graphics/view.py", line 838, in picked_object 
    112616 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    112617 beyond, 
    112618 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112619 File
    112620 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112621 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    112622 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    112623 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112624 File
    112625 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112626 packages/chimerax/core/models.py", line 143, in first_intercept 
    112627 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    112628 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112629 File
    112630 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112631 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    112632 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    112633 exclude=exclude) 
    112634 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112635 File
    112636 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112637 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    112638 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    112639 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112640 File
    112641 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112642 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    112643 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    112644 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112645 File
    112646 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112647 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    112648 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    112649 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112650 File
    112651 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112652 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    112653 p = super().first_intercept(mxyz1, mxyz2) 
    112654 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112655 File
    112656 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112657 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    112658 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    112659 exclude=exclude) 
    112660 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112661 File
    112662 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112663 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    112664 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    112665 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112666 File
    112667 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112668 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    112669 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    112670 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112671 File
    112672 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112673 packages/chimerax/graphics/drawing.py", line 1108, in
    112674 _first_intercept_excluding_children 
    112675 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    112676 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112677 File
    112678 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112679 packages/chimerax/geometry/place.py", line 201, in inverse 
    112680 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    112681 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112682 File
    112683 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112684 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    112685 rinv[:, :] = matrix_inverse(r) 
    112686 ^^^^^^^^^^^^^^^^^ 
    112687 File
    112688 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112689 packages/numpy/linalg/linalg.py", line 561, in inv 
    112690 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    112691 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112692 File
    112693 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112694 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    112695 raise LinAlgError("Singular matrix") 
    112696 numpy.linalg.LinAlgError: Singular matrix 
    112697  
    112698 numpy.linalg.LinAlgError: Singular matrix 
    112699  
    112700 File
    112701 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112702 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    112703 raise LinAlgError("Singular matrix") 
    112704  
    112705 See log for complete Python traceback. 
    112706  
    112707 Traceback (most recent call last): 
    112708 File
    112709 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112710 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    112711 self.session.ui.mouse_modes.mouse_pause_tracking() 
    112712 File
    112713 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112714 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    112715 mouse_pause_tracking 
    112716 self._mouse_pause() 
    112717 File
    112718 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112719 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    112720 m.pause(self._mouse_pause_position) 
    112721 File
    112722 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112723 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    112724 p = self.view.picked_object(x, y) 
    112725 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112726 File
    112727 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112728 packages/chimerax/graphics/view.py", line 838, in picked_object 
    112729 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    112730 beyond, 
    112731 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112732 File
    112733 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112734 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    112735 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    112736 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112737 File
    112738 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112739 packages/chimerax/core/models.py", line 143, in first_intercept 
    112740 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    112741 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112742 File
    112743 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112744 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    112745 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    112746 exclude=exclude) 
    112747 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112748 File
    112749 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112750 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    112751 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    112752 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112753 File
    112754 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112755 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    112756 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    112757 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112758 File
    112759 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112760 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    112761 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    112762 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112763 File
    112764 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112765 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    112766 p = super().first_intercept(mxyz1, mxyz2) 
    112767 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112768 File
    112769 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112770 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    112771 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    112772 exclude=exclude) 
    112773 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112774 File
    112775 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112776 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    112777 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    112778 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112779 File
    112780 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112781 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    112782 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    112783 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112784 File
    112785 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112786 packages/chimerax/graphics/drawing.py", line 1108, in
    112787 _first_intercept_excluding_children 
    112788 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    112789 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112790 File
    112791 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112792 packages/chimerax/geometry/place.py", line 201, in inverse 
    112793 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    112794 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112795 File
    112796 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112797 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    112798 rinv[:, :] = matrix_inverse(r) 
    112799 ^^^^^^^^^^^^^^^^^ 
    112800 File
    112801 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112802 packages/numpy/linalg/linalg.py", line 561, in inv 
    112803 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    112804 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112805 File
    112806 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112807 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    112808 raise LinAlgError("Singular matrix") 
    112809 numpy.linalg.LinAlgError: Singular matrix 
    112810  
    112811 numpy.linalg.LinAlgError: Singular matrix 
    112812  
    112813 File
    112814 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112815 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    112816 raise LinAlgError("Singular matrix") 
    112817  
    112818 See log for complete Python traceback. 
    112819  
    112820 Traceback (most recent call last): 
    112821 File
    112822 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112823 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    112824 self.session.ui.mouse_modes.mouse_pause_tracking() 
    112825 File
    112826 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112827 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    112828 mouse_pause_tracking 
    112829 self._mouse_pause() 
    112830 File
    112831 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112832 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    112833 m.pause(self._mouse_pause_position) 
    112834 File
    112835 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112836 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    112837 p = self.view.picked_object(x, y) 
    112838 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112839 File
    112840 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112841 packages/chimerax/graphics/view.py", line 838, in picked_object 
    112842 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    112843 beyond, 
    112844 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112845 File
    112846 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112847 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    112848 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    112849 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112850 File
    112851 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112852 packages/chimerax/core/models.py", line 143, in first_intercept 
    112853 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    112854 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112855 File
    112856 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112857 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    112858 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    112859 exclude=exclude) 
    112860 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112861 File
    112862 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112863 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    112864 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    112865 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112866 File
    112867 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112868 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    112869 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    112870 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112871 File
    112872 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112873 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    112874 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    112875 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112876 File
    112877 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112878 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    112879 p = super().first_intercept(mxyz1, mxyz2) 
    112880 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112881 File
    112882 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112883 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    112884 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    112885 exclude=exclude) 
    112886 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112887 File
    112888 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112889 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    112890 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    112891 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112892 File
    112893 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112894 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    112895 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    112896 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112897 File
    112898 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112899 packages/chimerax/graphics/drawing.py", line 1108, in
    112900 _first_intercept_excluding_children 
    112901 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    112902 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112903 File
    112904 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112905 packages/chimerax/geometry/place.py", line 201, in inverse 
    112906 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    112907 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112908 File
    112909 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112910 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    112911 rinv[:, :] = matrix_inverse(r) 
    112912 ^^^^^^^^^^^^^^^^^ 
    112913 File
    112914 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112915 packages/numpy/linalg/linalg.py", line 561, in inv 
    112916 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    112917 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112918 File
    112919 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112920 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    112921 raise LinAlgError("Singular matrix") 
    112922 numpy.linalg.LinAlgError: Singular matrix 
    112923  
    112924 numpy.linalg.LinAlgError: Singular matrix 
    112925  
    112926 File
    112927 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112928 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    112929 raise LinAlgError("Singular matrix") 
    112930  
    112931 See log for complete Python traceback. 
    112932  
    112933 Traceback (most recent call last): 
    112934 File
    112935 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112936 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    112937 self.session.ui.mouse_modes.mouse_pause_tracking() 
    112938 File
    112939 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112940 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    112941 mouse_pause_tracking 
    112942 self._mouse_pause() 
    112943 File
    112944 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112945 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    112946 m.pause(self._mouse_pause_position) 
    112947 File
    112948 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112949 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    112950 p = self.view.picked_object(x, y) 
    112951 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112952 File
    112953 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112954 packages/chimerax/graphics/view.py", line 838, in picked_object 
    112955 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    112956 beyond, 
    112957 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112958 File
    112959 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112960 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    112961 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    112962 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112963 File
    112964 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112965 packages/chimerax/core/models.py", line 143, in first_intercept 
    112966 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    112967 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112968 File
    112969 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112970 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    112971 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    112972 exclude=exclude) 
    112973 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112974 File
    112975 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112976 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    112977 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    112978 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112979 File
    112980 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112981 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    112982 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    112983 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112984 File
    112985 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112986 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    112987 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    112988 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112989 File
    112990 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112991 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    112992 p = super().first_intercept(mxyz1, mxyz2) 
    112993 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    112994 File
    112995 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    112996 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    112997 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    112998 exclude=exclude) 
    112999 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113000 File
    113001 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113002 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    113003 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    113004 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113005 File
    113006 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113007 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    113008 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    113009 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113010 File
    113011 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113012 packages/chimerax/graphics/drawing.py", line 1108, in
    113013 _first_intercept_excluding_children 
    113014 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    113015 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113016 File
    113017 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113018 packages/chimerax/geometry/place.py", line 201, in inverse 
    113019 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    113020 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113021 File
    113022 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113023 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    113024 rinv[:, :] = matrix_inverse(r) 
    113025 ^^^^^^^^^^^^^^^^^ 
    113026 File
    113027 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113028 packages/numpy/linalg/linalg.py", line 561, in inv 
    113029 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    113030 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113031 File
    113032 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113033 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    113034 raise LinAlgError("Singular matrix") 
    113035 numpy.linalg.LinAlgError: Singular matrix 
    113036  
    113037 numpy.linalg.LinAlgError: Singular matrix 
    113038  
    113039 File
    113040 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113041 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    113042 raise LinAlgError("Singular matrix") 
    113043  
    113044 See log for complete Python traceback. 
    113045  
    113046 Traceback (most recent call last): 
    113047 File
    113048 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113049 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    113050 self.session.ui.mouse_modes.mouse_pause_tracking() 
    113051 File
    113052 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113053 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    113054 mouse_pause_tracking 
    113055 self._mouse_pause() 
    113056 File
    113057 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113058 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    113059 m.pause(self._mouse_pause_position) 
    113060 File
    113061 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113062 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    113063 p = self.view.picked_object(x, y) 
    113064 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113065 File
    113066 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113067 packages/chimerax/graphics/view.py", line 838, in picked_object 
    113068 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    113069 beyond, 
    113070 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113071 File
    113072 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113073 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    113074 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    113075 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113076 File
    113077 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113078 packages/chimerax/core/models.py", line 143, in first_intercept 
    113079 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    113080 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113081 File
    113082 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113083 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    113084 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    113085 exclude=exclude) 
    113086 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113087 File
    113088 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113089 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    113090 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    113091 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113092 File
    113093 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113094 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    113095 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    113096 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113097 File
    113098 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113099 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    113100 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    113101 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113102 File
    113103 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113104 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    113105 p = super().first_intercept(mxyz1, mxyz2) 
    113106 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113107 File
    113108 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113109 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    113110 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    113111 exclude=exclude) 
    113112 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113113 File
    113114 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113115 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    113116 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    113117 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113118 File
    113119 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113120 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    113121 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    113122 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113123 File
    113124 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113125 packages/chimerax/graphics/drawing.py", line 1108, in
    113126 _first_intercept_excluding_children 
    113127 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    113128 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113129 File
    113130 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113131 packages/chimerax/geometry/place.py", line 201, in inverse 
    113132 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    113133 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113134 File
    113135 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113136 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    113137 rinv[:, :] = matrix_inverse(r) 
    113138 ^^^^^^^^^^^^^^^^^ 
    113139 File
    113140 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113141 packages/numpy/linalg/linalg.py", line 561, in inv 
    113142 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    113143 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113144 File
    113145 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113146 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    113147 raise LinAlgError("Singular matrix") 
    113148 numpy.linalg.LinAlgError: Singular matrix 
    113149  
    113150 numpy.linalg.LinAlgError: Singular matrix 
    113151  
    113152 File
    113153 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113154 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    113155 raise LinAlgError("Singular matrix") 
    113156  
    113157 See log for complete Python traceback. 
    113158  
    113159 Traceback (most recent call last): 
    113160 File
    113161 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113162 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    113163 self.session.ui.mouse_modes.mouse_pause_tracking() 
    113164 File
    113165 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113166 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    113167 mouse_pause_tracking 
    113168 self._mouse_pause() 
    113169 File
    113170 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113171 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    113172 m.pause(self._mouse_pause_position) 
    113173 File
    113174 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113175 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    113176 p = self.view.picked_object(x, y) 
    113177 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113178 File
    113179 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113180 packages/chimerax/graphics/view.py", line 838, in picked_object 
    113181 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    113182 beyond, 
    113183 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113184 File
    113185 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113186 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    113187 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    113188 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113189 File
    113190 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113191 packages/chimerax/core/models.py", line 143, in first_intercept 
    113192 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    113193 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113194 File
    113195 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113196 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    113197 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    113198 exclude=exclude) 
    113199 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113200 File
    113201 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113202 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    113203 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    113204 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113205 File
    113206 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113207 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    113208 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    113209 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113210 File
    113211 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113212 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    113213 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    113214 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113215 File
    113216 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113217 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    113218 p = super().first_intercept(mxyz1, mxyz2) 
    113219 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113220 File
    113221 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113222 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    113223 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    113224 exclude=exclude) 
    113225 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113226 File
    113227 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113228 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    113229 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    113230 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113231 File
    113232 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113233 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    113234 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    113235 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113236 File
    113237 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113238 packages/chimerax/graphics/drawing.py", line 1108, in
    113239 _first_intercept_excluding_children 
    113240 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    113241 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113242 File
    113243 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113244 packages/chimerax/geometry/place.py", line 201, in inverse 
    113245 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    113246 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113247 File
    113248 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113249 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    113250 rinv[:, :] = matrix_inverse(r) 
    113251 ^^^^^^^^^^^^^^^^^ 
    113252 File
    113253 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113254 packages/numpy/linalg/linalg.py", line 561, in inv 
    113255 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    113256 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113257 File
    113258 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113259 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    113260 raise LinAlgError("Singular matrix") 
    113261 numpy.linalg.LinAlgError: Singular matrix 
    113262  
    113263 numpy.linalg.LinAlgError: Singular matrix 
    113264  
    113265 File
    113266 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113267 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    113268 raise LinAlgError("Singular matrix") 
    113269  
    113270 See log for complete Python traceback. 
    113271  
    113272 Traceback (most recent call last): 
    113273 File
    113274 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113275 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    113276 self.session.ui.mouse_modes.mouse_pause_tracking() 
    113277 File
    113278 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113279 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    113280 mouse_pause_tracking 
    113281 self._mouse_pause() 
    113282 File
    113283 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113284 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    113285 m.pause(self._mouse_pause_position) 
    113286 File
    113287 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113288 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    113289 p = self.view.picked_object(x, y) 
    113290 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113291 File
    113292 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113293 packages/chimerax/graphics/view.py", line 838, in picked_object 
    113294 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    113295 beyond, 
    113296 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113297 File
    113298 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113299 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    113300 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    113301 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113302 File
    113303 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113304 packages/chimerax/core/models.py", line 143, in first_intercept 
    113305 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    113306 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113307 File
    113308 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113309 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    113310 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    113311 exclude=exclude) 
    113312 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113313 File
    113314 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113315 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    113316 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    113317 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113318 File
    113319 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113320 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    113321 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    113322 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113323 File
    113324 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113325 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    113326 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    113327 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113328 File
    113329 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113330 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    113331 p = super().first_intercept(mxyz1, mxyz2) 
    113332 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113333 File
    113334 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113335 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    113336 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    113337 exclude=exclude) 
    113338 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113339 File
    113340 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113341 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    113342 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    113343 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113344 File
    113345 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113346 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    113347 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    113348 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113349 File
    113350 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113351 packages/chimerax/graphics/drawing.py", line 1108, in
    113352 _first_intercept_excluding_children 
    113353 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    113354 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113355 File
    113356 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113357 packages/chimerax/geometry/place.py", line 201, in inverse 
    113358 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    113359 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113360 File
    113361 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113362 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    113363 rinv[:, :] = matrix_inverse(r) 
    113364 ^^^^^^^^^^^^^^^^^ 
    113365 File
    113366 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113367 packages/numpy/linalg/linalg.py", line 561, in inv 
    113368 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    113369 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113370 File
    113371 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113372 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    113373 raise LinAlgError("Singular matrix") 
    113374 numpy.linalg.LinAlgError: Singular matrix 
    113375  
    113376 numpy.linalg.LinAlgError: Singular matrix 
    113377  
    113378 File
    113379 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113380 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    113381 raise LinAlgError("Singular matrix") 
    113382  
    113383 See log for complete Python traceback. 
    113384  
    113385 Traceback (most recent call last): 
    113386 File
    113387 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113388 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    113389 self.session.ui.mouse_modes.mouse_pause_tracking() 
    113390 File
    113391 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113392 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    113393 mouse_pause_tracking 
    113394 self._mouse_pause() 
    113395 File
    113396 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113397 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    113398 m.pause(self._mouse_pause_position) 
    113399 File
    113400 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113401 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    113402 p = self.view.picked_object(x, y) 
    113403 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113404 File
    113405 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113406 packages/chimerax/graphics/view.py", line 838, in picked_object 
    113407 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    113408 beyond, 
    113409 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113410 File
    113411 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113412 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    113413 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    113414 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113415 File
    113416 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113417 packages/chimerax/core/models.py", line 143, in first_intercept 
    113418 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    113419 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113420 File
    113421 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113422 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    113423 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    113424 exclude=exclude) 
    113425 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113426 File
    113427 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113428 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    113429 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    113430 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113431 File
    113432 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113433 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    113434 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    113435 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113436 File
    113437 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113438 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    113439 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    113440 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113441 File
    113442 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113443 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    113444 p = super().first_intercept(mxyz1, mxyz2) 
    113445 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113446 File
    113447 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113448 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    113449 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    113450 exclude=exclude) 
    113451 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113452 File
    113453 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113454 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    113455 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    113456 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113457 File
    113458 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113459 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    113460 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    113461 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113462 File
    113463 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113464 packages/chimerax/graphics/drawing.py", line 1108, in
    113465 _first_intercept_excluding_children 
    113466 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    113467 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113468 File
    113469 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113470 packages/chimerax/geometry/place.py", line 201, in inverse 
    113471 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    113472 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113473 File
    113474 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113475 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    113476 rinv[:, :] = matrix_inverse(r) 
    113477 ^^^^^^^^^^^^^^^^^ 
    113478 File
    113479 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113480 packages/numpy/linalg/linalg.py", line 561, in inv 
    113481 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    113482 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113483 File
    113484 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113485 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    113486 raise LinAlgError("Singular matrix") 
    113487 numpy.linalg.LinAlgError: Singular matrix 
    113488  
    113489 numpy.linalg.LinAlgError: Singular matrix 
    113490  
    113491 File
    113492 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113493 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    113494 raise LinAlgError("Singular matrix") 
    113495  
    113496 See log for complete Python traceback. 
    113497  
    113498 Traceback (most recent call last): 
    113499 File
    113500 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113501 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    113502 self.session.ui.mouse_modes.mouse_pause_tracking() 
    113503 File
    113504 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113505 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    113506 mouse_pause_tracking 
    113507 self._mouse_pause() 
    113508 File
    113509 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113510 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    113511 m.pause(self._mouse_pause_position) 
    113512 File
    113513 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113514 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    113515 p = self.view.picked_object(x, y) 
    113516 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113517 File
    113518 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113519 packages/chimerax/graphics/view.py", line 838, in picked_object 
    113520 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    113521 beyond, 
    113522 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113523 File
    113524 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113525 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    113526 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    113527 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113528 File
    113529 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113530 packages/chimerax/core/models.py", line 143, in first_intercept 
    113531 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    113532 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113533 File
    113534 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113535 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    113536 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    113537 exclude=exclude) 
    113538 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113539 File
    113540 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113541 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    113542 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    113543 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113544 File
    113545 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113546 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    113547 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    113548 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113549 File
    113550 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113551 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    113552 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    113553 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113554 File
    113555 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113556 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    113557 p = super().first_intercept(mxyz1, mxyz2) 
    113558 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113559 File
    113560 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113561 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    113562 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    113563 exclude=exclude) 
    113564 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113565 File
    113566 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113567 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    113568 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    113569 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113570 File
    113571 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113572 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    113573 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    113574 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113575 File
    113576 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113577 packages/chimerax/graphics/drawing.py", line 1108, in
    113578 _first_intercept_excluding_children 
    113579 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    113580 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113581 File
    113582 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113583 packages/chimerax/geometry/place.py", line 201, in inverse 
    113584 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    113585 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113586 File
    113587 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113588 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    113589 rinv[:, :] = matrix_inverse(r) 
    113590 ^^^^^^^^^^^^^^^^^ 
    113591 File
    113592 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113593 packages/numpy/linalg/linalg.py", line 561, in inv 
    113594 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    113595 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113596 File
    113597 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113598 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    113599 raise LinAlgError("Singular matrix") 
    113600 numpy.linalg.LinAlgError: Singular matrix 
    113601  
    113602 numpy.linalg.LinAlgError: Singular matrix 
    113603  
    113604 File
    113605 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113606 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    113607 raise LinAlgError("Singular matrix") 
    113608  
    113609 See log for complete Python traceback. 
    113610  
    113611 Traceback (most recent call last): 
    113612 File
    113613 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113614 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    113615 self.session.ui.mouse_modes.mouse_pause_tracking() 
    113616 File
    113617 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113618 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    113619 mouse_pause_tracking 
    113620 self._mouse_pause() 
    113621 File
    113622 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113623 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    113624 m.pause(self._mouse_pause_position) 
    113625 File
    113626 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113627 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    113628 p = self.view.picked_object(x, y) 
    113629 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113630 File
    113631 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113632 packages/chimerax/graphics/view.py", line 838, in picked_object 
    113633 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    113634 beyond, 
    113635 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113636 File
    113637 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113638 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    113639 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    113640 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113641 File
    113642 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113643 packages/chimerax/core/models.py", line 143, in first_intercept 
    113644 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    113645 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113646 File
    113647 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113648 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    113649 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    113650 exclude=exclude) 
    113651 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113652 File
    113653 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113654 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    113655 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    113656 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113657 File
    113658 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113659 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    113660 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    113661 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113662 File
    113663 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113664 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    113665 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    113666 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113667 File
    113668 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113669 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    113670 p = super().first_intercept(mxyz1, mxyz2) 
    113671 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113672 File
    113673 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113674 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    113675 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    113676 exclude=exclude) 
    113677 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113678 File
    113679 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113680 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    113681 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    113682 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113683 File
    113684 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113685 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    113686 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    113687 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113688 File
    113689 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113690 packages/chimerax/graphics/drawing.py", line 1108, in
    113691 _first_intercept_excluding_children 
    113692 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    113693 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113694 File
    113695 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113696 packages/chimerax/geometry/place.py", line 201, in inverse 
    113697 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    113698 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113699 File
    113700 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113701 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    113702 rinv[:, :] = matrix_inverse(r) 
    113703 ^^^^^^^^^^^^^^^^^ 
    113704 File
    113705 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113706 packages/numpy/linalg/linalg.py", line 561, in inv 
    113707 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    113708 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113709 File
    113710 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113711 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    113712 raise LinAlgError("Singular matrix") 
    113713 numpy.linalg.LinAlgError: Singular matrix 
    113714  
    113715 numpy.linalg.LinAlgError: Singular matrix 
    113716  
    113717 File
    113718 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113719 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    113720 raise LinAlgError("Singular matrix") 
    113721  
    113722 See log for complete Python traceback. 
    113723  
    113724 Traceback (most recent call last): 
    113725 File
    113726 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113727 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    113728 self.session.ui.mouse_modes.mouse_pause_tracking() 
    113729 File
    113730 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113731 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    113732 mouse_pause_tracking 
    113733 self._mouse_pause() 
    113734 File
    113735 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113736 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    113737 m.pause(self._mouse_pause_position) 
    113738 File
    113739 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113740 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    113741 p = self.view.picked_object(x, y) 
    113742 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113743 File
    113744 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113745 packages/chimerax/graphics/view.py", line 838, in picked_object 
    113746 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    113747 beyond, 
    113748 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113749 File
    113750 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113751 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    113752 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    113753 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113754 File
    113755 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113756 packages/chimerax/core/models.py", line 143, in first_intercept 
    113757 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    113758 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113759 File
    113760 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113761 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    113762 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    113763 exclude=exclude) 
    113764 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113765 File
    113766 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113767 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    113768 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    113769 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113770 File
    113771 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113772 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    113773 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    113774 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113775 File
    113776 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113777 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    113778 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    113779 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113780 File
    113781 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113782 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    113783 p = super().first_intercept(mxyz1, mxyz2) 
    113784 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113785 File
    113786 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113787 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    113788 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    113789 exclude=exclude) 
    113790 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113791 File
    113792 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113793 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    113794 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    113795 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113796 File
    113797 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113798 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    113799 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    113800 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113801 File
    113802 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113803 packages/chimerax/graphics/drawing.py", line 1108, in
    113804 _first_intercept_excluding_children 
    113805 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    113806 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113807 File
    113808 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113809 packages/chimerax/geometry/place.py", line 201, in inverse 
    113810 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    113811 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113812 File
    113813 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113814 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    113815 rinv[:, :] = matrix_inverse(r) 
    113816 ^^^^^^^^^^^^^^^^^ 
    113817 File
    113818 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113819 packages/numpy/linalg/linalg.py", line 561, in inv 
    113820 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    113821 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113822 File
    113823 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113824 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    113825 raise LinAlgError("Singular matrix") 
    113826 numpy.linalg.LinAlgError: Singular matrix 
    113827  
    113828 numpy.linalg.LinAlgError: Singular matrix 
    113829  
    113830 File
    113831 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113832 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    113833 raise LinAlgError("Singular matrix") 
    113834  
    113835 See log for complete Python traceback. 
    113836  
    113837 Traceback (most recent call last): 
    113838 File
    113839 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113840 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    113841 self.session.ui.mouse_modes.mouse_pause_tracking() 
    113842 File
    113843 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113844 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    113845 mouse_pause_tracking 
    113846 self._mouse_pause() 
    113847 File
    113848 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113849 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    113850 m.pause(self._mouse_pause_position) 
    113851 File
    113852 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113853 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    113854 p = self.view.picked_object(x, y) 
    113855 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113856 File
    113857 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113858 packages/chimerax/graphics/view.py", line 838, in picked_object 
    113859 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    113860 beyond, 
    113861 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113862 File
    113863 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113864 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    113865 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    113866 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113867 File
    113868 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113869 packages/chimerax/core/models.py", line 143, in first_intercept 
    113870 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    113871 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113872 File
    113873 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113874 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    113875 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    113876 exclude=exclude) 
    113877 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113878 File
    113879 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113880 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    113881 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    113882 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113883 File
    113884 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113885 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    113886 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    113887 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113888 File
    113889 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113890 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    113891 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    113892 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113893 File
    113894 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113895 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    113896 p = super().first_intercept(mxyz1, mxyz2) 
    113897 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113898 File
    113899 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113900 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    113901 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    113902 exclude=exclude) 
    113903 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113904 File
    113905 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113906 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    113907 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    113908 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113909 File
    113910 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113911 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    113912 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    113913 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113914 File
    113915 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113916 packages/chimerax/graphics/drawing.py", line 1108, in
    113917 _first_intercept_excluding_children 
    113918 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    113919 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113920 File
    113921 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113922 packages/chimerax/geometry/place.py", line 201, in inverse 
    113923 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    113924 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113925 File
    113926 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113927 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    113928 rinv[:, :] = matrix_inverse(r) 
    113929 ^^^^^^^^^^^^^^^^^ 
    113930 File
    113931 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113932 packages/numpy/linalg/linalg.py", line 561, in inv 
    113933 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    113934 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113935 File
    113936 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113937 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    113938 raise LinAlgError("Singular matrix") 
    113939 numpy.linalg.LinAlgError: Singular matrix 
    113940  
    113941 numpy.linalg.LinAlgError: Singular matrix 
    113942  
    113943 File
    113944 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113945 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    113946 raise LinAlgError("Singular matrix") 
    113947  
    113948 See log for complete Python traceback. 
    113949  
    113950 Traceback (most recent call last): 
    113951 File
    113952 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113953 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    113954 self.session.ui.mouse_modes.mouse_pause_tracking() 
    113955 File
    113956 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113957 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    113958 mouse_pause_tracking 
    113959 self._mouse_pause() 
    113960 File
    113961 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113962 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    113963 m.pause(self._mouse_pause_position) 
    113964 File
    113965 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113966 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    113967 p = self.view.picked_object(x, y) 
    113968 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113969 File
    113970 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113971 packages/chimerax/graphics/view.py", line 838, in picked_object 
    113972 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    113973 beyond, 
    113974 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113975 File
    113976 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113977 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    113978 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    113979 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113980 File
    113981 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113982 packages/chimerax/core/models.py", line 143, in first_intercept 
    113983 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    113984 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113985 File
    113986 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113987 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    113988 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    113989 exclude=exclude) 
    113990 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113991 File
    113992 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113993 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    113994 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    113995 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    113996 File
    113997 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    113998 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    113999 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    114000 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114001 File
    114002 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114003 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    114004 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    114005 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114006 File
    114007 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114008 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    114009 p = super().first_intercept(mxyz1, mxyz2) 
    114010 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114011 File
    114012 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114013 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    114014 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    114015 exclude=exclude) 
    114016 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114017 File
    114018 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114019 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    114020 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    114021 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114022 File
    114023 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114024 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    114025 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    114026 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114027 File
    114028 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114029 packages/chimerax/graphics/drawing.py", line 1108, in
    114030 _first_intercept_excluding_children 
    114031 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    114032 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114033 File
    114034 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114035 packages/chimerax/geometry/place.py", line 201, in inverse 
    114036 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    114037 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114038 File
    114039 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114040 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    114041 rinv[:, :] = matrix_inverse(r) 
    114042 ^^^^^^^^^^^^^^^^^ 
    114043 File
    114044 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114045 packages/numpy/linalg/linalg.py", line 561, in inv 
    114046 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    114047 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114048 File
    114049 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114050 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    114051 raise LinAlgError("Singular matrix") 
    114052 numpy.linalg.LinAlgError: Singular matrix 
    114053  
    114054 numpy.linalg.LinAlgError: Singular matrix 
    114055  
    114056 File
    114057 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114058 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    114059 raise LinAlgError("Singular matrix") 
    114060  
    114061 See log for complete Python traceback. 
    114062  
    114063 Traceback (most recent call last): 
    114064 File
    114065 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114066 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    114067 self.session.ui.mouse_modes.mouse_pause_tracking() 
    114068 File
    114069 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114070 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    114071 mouse_pause_tracking 
    114072 self._mouse_pause() 
    114073 File
    114074 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114075 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    114076 m.pause(self._mouse_pause_position) 
    114077 File
    114078 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114079 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    114080 p = self.view.picked_object(x, y) 
    114081 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114082 File
    114083 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114084 packages/chimerax/graphics/view.py", line 838, in picked_object 
    114085 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    114086 beyond, 
    114087 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114088 File
    114089 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114090 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    114091 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    114092 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114093 File
    114094 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114095 packages/chimerax/core/models.py", line 143, in first_intercept 
    114096 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    114097 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114098 File
    114099 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114100 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    114101 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    114102 exclude=exclude) 
    114103 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114104 File
    114105 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114106 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    114107 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    114108 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114109 File
    114110 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114111 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    114112 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    114113 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114114 File
    114115 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114116 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    114117 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    114118 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114119 File
    114120 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114121 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    114122 p = super().first_intercept(mxyz1, mxyz2) 
    114123 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114124 File
    114125 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114126 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    114127 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    114128 exclude=exclude) 
    114129 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114130 File
    114131 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114132 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    114133 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    114134 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114135 File
    114136 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114137 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    114138 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    114139 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114140 File
    114141 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114142 packages/chimerax/graphics/drawing.py", line 1108, in
    114143 _first_intercept_excluding_children 
    114144 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    114145 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114146 File
    114147 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114148 packages/chimerax/geometry/place.py", line 201, in inverse 
    114149 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    114150 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114151 File
    114152 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114153 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    114154 rinv[:, :] = matrix_inverse(r) 
    114155 ^^^^^^^^^^^^^^^^^ 
    114156 File
    114157 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114158 packages/numpy/linalg/linalg.py", line 561, in inv 
    114159 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    114160 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114161 File
    114162 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114163 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    114164 raise LinAlgError("Singular matrix") 
    114165 numpy.linalg.LinAlgError: Singular matrix 
    114166  
    114167 numpy.linalg.LinAlgError: Singular matrix 
    114168  
    114169 File
    114170 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114171 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    114172 raise LinAlgError("Singular matrix") 
    114173  
    114174 See log for complete Python traceback. 
    114175  
    114176 Traceback (most recent call last): 
    114177 File
    114178 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114179 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    114180 self.session.ui.mouse_modes.mouse_pause_tracking() 
    114181 File
    114182 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114183 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    114184 mouse_pause_tracking 
    114185 self._mouse_pause() 
    114186 File
    114187 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114188 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    114189 m.pause(self._mouse_pause_position) 
    114190 File
    114191 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114192 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    114193 p = self.view.picked_object(x, y) 
    114194 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114195 File
    114196 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114197 packages/chimerax/graphics/view.py", line 838, in picked_object 
    114198 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    114199 beyond, 
    114200 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114201 File
    114202 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114203 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    114204 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    114205 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114206 File
    114207 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114208 packages/chimerax/core/models.py", line 143, in first_intercept 
    114209 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    114210 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114211 File
    114212 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114213 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    114214 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    114215 exclude=exclude) 
    114216 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114217 File
    114218 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114219 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    114220 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    114221 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114222 File
    114223 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114224 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    114225 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    114226 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114227 File
    114228 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114229 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    114230 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    114231 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114232 File
    114233 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114234 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    114235 p = super().first_intercept(mxyz1, mxyz2) 
    114236 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114237 File
    114238 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114239 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    114240 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    114241 exclude=exclude) 
    114242 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114243 File
    114244 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114245 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    114246 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    114247 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114248 File
    114249 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114250 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    114251 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    114252 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114253 File
    114254 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114255 packages/chimerax/graphics/drawing.py", line 1108, in
    114256 _first_intercept_excluding_children 
    114257 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    114258 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114259 File
    114260 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114261 packages/chimerax/geometry/place.py", line 201, in inverse 
    114262 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    114263 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114264 File
    114265 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114266 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    114267 rinv[:, :] = matrix_inverse(r) 
    114268 ^^^^^^^^^^^^^^^^^ 
    114269 File
    114270 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114271 packages/numpy/linalg/linalg.py", line 561, in inv 
    114272 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    114273 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114274 File
    114275 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114276 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    114277 raise LinAlgError("Singular matrix") 
    114278 numpy.linalg.LinAlgError: Singular matrix 
    114279  
    114280 numpy.linalg.LinAlgError: Singular matrix 
    114281  
    114282 File
    114283 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114284 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    114285 raise LinAlgError("Singular matrix") 
    114286  
    114287 See log for complete Python traceback. 
    114288  
    114289 Traceback (most recent call last): 
    114290 File
    114291 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114292 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    114293 self.session.ui.mouse_modes.mouse_pause_tracking() 
    114294 File
    114295 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114296 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    114297 mouse_pause_tracking 
    114298 self._mouse_pause() 
    114299 File
    114300 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114301 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    114302 m.pause(self._mouse_pause_position) 
    114303 File
    114304 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114305 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    114306 p = self.view.picked_object(x, y) 
    114307 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114308 File
    114309 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114310 packages/chimerax/graphics/view.py", line 838, in picked_object 
    114311 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    114312 beyond, 
    114313 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114314 File
    114315 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114316 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    114317 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    114318 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114319 File
    114320 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114321 packages/chimerax/core/models.py", line 143, in first_intercept 
    114322 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    114323 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114324 File
    114325 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114326 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    114327 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    114328 exclude=exclude) 
    114329 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114330 File
    114331 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114332 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    114333 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    114334 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114335 File
    114336 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114337 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    114338 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    114339 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114340 File
    114341 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114342 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    114343 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    114344 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114345 File
    114346 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114347 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    114348 p = super().first_intercept(mxyz1, mxyz2) 
    114349 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114350 File
    114351 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114352 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    114353 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    114354 exclude=exclude) 
    114355 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114356 File
    114357 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114358 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    114359 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    114360 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114361 File
    114362 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114363 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    114364 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    114365 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114366 File
    114367 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114368 packages/chimerax/graphics/drawing.py", line 1108, in
    114369 _first_intercept_excluding_children 
    114370 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    114371 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114372 File
    114373 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114374 packages/chimerax/geometry/place.py", line 201, in inverse 
    114375 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    114376 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114377 File
    114378 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114379 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    114380 rinv[:, :] = matrix_inverse(r) 
    114381 ^^^^^^^^^^^^^^^^^ 
    114382 File
    114383 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114384 packages/numpy/linalg/linalg.py", line 561, in inv 
    114385 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    114386 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114387 File
    114388 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114389 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    114390 raise LinAlgError("Singular matrix") 
    114391 numpy.linalg.LinAlgError: Singular matrix 
    114392  
    114393 numpy.linalg.LinAlgError: Singular matrix 
    114394  
    114395 File
    114396 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114397 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    114398 raise LinAlgError("Singular matrix") 
    114399  
    114400 See log for complete Python traceback. 
    114401  
    114402 Traceback (most recent call last): 
    114403 File
    114404 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114405 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    114406 self.session.ui.mouse_modes.mouse_pause_tracking() 
    114407 File
    114408 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114409 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    114410 mouse_pause_tracking 
    114411 self._mouse_pause() 
    114412 File
    114413 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114414 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    114415 m.pause(self._mouse_pause_position) 
    114416 File
    114417 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114418 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    114419 p = self.view.picked_object(x, y) 
    114420 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114421 File
    114422 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114423 packages/chimerax/graphics/view.py", line 838, in picked_object 
    114424 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    114425 beyond, 
    114426 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114427 File
    114428 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114429 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    114430 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    114431 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114432 File
    114433 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114434 packages/chimerax/core/models.py", line 143, in first_intercept 
    114435 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    114436 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114437 File
    114438 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114439 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    114440 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    114441 exclude=exclude) 
    114442 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114443 File
    114444 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114445 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    114446 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    114447 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114448 File
    114449 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114450 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    114451 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    114452 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114453 File
    114454 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114455 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    114456 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    114457 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114458 File
    114459 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114460 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    114461 p = super().first_intercept(mxyz1, mxyz2) 
    114462 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114463 File
    114464 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114465 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    114466 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    114467 exclude=exclude) 
    114468 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114469 File
    114470 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114471 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    114472 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    114473 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114474 File
    114475 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114476 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    114477 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    114478 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114479 File
    114480 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114481 packages/chimerax/graphics/drawing.py", line 1108, in
    114482 _first_intercept_excluding_children 
    114483 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    114484 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114485 File
    114486 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114487 packages/chimerax/geometry/place.py", line 201, in inverse 
    114488 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    114489 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114490 File
    114491 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114492 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    114493 rinv[:, :] = matrix_inverse(r) 
    114494 ^^^^^^^^^^^^^^^^^ 
    114495 File
    114496 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114497 packages/numpy/linalg/linalg.py", line 561, in inv 
    114498 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    114499 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114500 File
    114501 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114502 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    114503 raise LinAlgError("Singular matrix") 
    114504 numpy.linalg.LinAlgError: Singular matrix 
    114505  
    114506 numpy.linalg.LinAlgError: Singular matrix 
    114507  
    114508 File
    114509 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114510 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    114511 raise LinAlgError("Singular matrix") 
    114512  
    114513 See log for complete Python traceback. 
    114514  
    114515 Traceback (most recent call last): 
    114516 File
    114517 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114518 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    114519 self.session.ui.mouse_modes.mouse_pause_tracking() 
    114520 File
    114521 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114522 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    114523 mouse_pause_tracking 
    114524 self._mouse_pause() 
    114525 File
    114526 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114527 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    114528 m.pause(self._mouse_pause_position) 
    114529 File
    114530 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114531 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    114532 p = self.view.picked_object(x, y) 
    114533 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114534 File
    114535 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114536 packages/chimerax/graphics/view.py", line 838, in picked_object 
    114537 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    114538 beyond, 
    114539 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114540 File
    114541 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114542 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    114543 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    114544 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114545 File
    114546 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114547 packages/chimerax/core/models.py", line 143, in first_intercept 
    114548 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    114549 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114550 File
    114551 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114552 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    114553 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    114554 exclude=exclude) 
    114555 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114556 File
    114557 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114558 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    114559 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    114560 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114561 File
    114562 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114563 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    114564 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    114565 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114566 File
    114567 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114568 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    114569 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    114570 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114571 File
    114572 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114573 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    114574 p = super().first_intercept(mxyz1, mxyz2) 
    114575 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114576 File
    114577 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114578 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    114579 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    114580 exclude=exclude) 
    114581 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114582 File
    114583 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114584 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    114585 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    114586 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114587 File
    114588 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114589 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    114590 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    114591 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114592 File
    114593 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114594 packages/chimerax/graphics/drawing.py", line 1108, in
    114595 _first_intercept_excluding_children 
    114596 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    114597 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114598 File
    114599 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114600 packages/chimerax/geometry/place.py", line 201, in inverse 
    114601 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    114602 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114603 File
    114604 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114605 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    114606 rinv[:, :] = matrix_inverse(r) 
    114607 ^^^^^^^^^^^^^^^^^ 
    114608 File
    114609 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114610 packages/numpy/linalg/linalg.py", line 561, in inv 
    114611 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    114612 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114613 File
    114614 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114615 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    114616 raise LinAlgError("Singular matrix") 
    114617 numpy.linalg.LinAlgError: Singular matrix 
    114618  
    114619 numpy.linalg.LinAlgError: Singular matrix 
    114620  
    114621 File
    114622 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114623 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    114624 raise LinAlgError("Singular matrix") 
    114625  
    114626 See log for complete Python traceback. 
    114627  
    114628 Traceback (most recent call last): 
    114629 File
    114630 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114631 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    114632 self.session.ui.mouse_modes.mouse_pause_tracking() 
    114633 File
    114634 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114635 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    114636 mouse_pause_tracking 
    114637 self._mouse_pause() 
    114638 File
    114639 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114640 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    114641 m.pause(self._mouse_pause_position) 
    114642 File
    114643 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114644 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    114645 p = self.view.picked_object(x, y) 
    114646 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114647 File
    114648 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114649 packages/chimerax/graphics/view.py", line 838, in picked_object 
    114650 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    114651 beyond, 
    114652 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114653 File
    114654 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114655 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    114656 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    114657 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114658 File
    114659 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114660 packages/chimerax/core/models.py", line 143, in first_intercept 
    114661 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    114662 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114663 File
    114664 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114665 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    114666 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    114667 exclude=exclude) 
    114668 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114669 File
    114670 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114671 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    114672 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    114673 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114674 File
    114675 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114676 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    114677 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    114678 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114679 File
    114680 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114681 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    114682 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    114683 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114684 File
    114685 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114686 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    114687 p = super().first_intercept(mxyz1, mxyz2) 
    114688 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114689 File
    114690 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114691 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    114692 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    114693 exclude=exclude) 
    114694 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114695 File
    114696 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114697 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    114698 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    114699 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114700 File
    114701 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114702 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    114703 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    114704 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114705 File
    114706 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114707 packages/chimerax/graphics/drawing.py", line 1108, in
    114708 _first_intercept_excluding_children 
    114709 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    114710 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114711 File
    114712 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114713 packages/chimerax/geometry/place.py", line 201, in inverse 
    114714 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    114715 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114716 File
    114717 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114718 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    114719 rinv[:, :] = matrix_inverse(r) 
    114720 ^^^^^^^^^^^^^^^^^ 
    114721 File
    114722 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114723 packages/numpy/linalg/linalg.py", line 561, in inv 
    114724 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    114725 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114726 File
    114727 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114728 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    114729 raise LinAlgError("Singular matrix") 
    114730 numpy.linalg.LinAlgError: Singular matrix 
    114731  
    114732 numpy.linalg.LinAlgError: Singular matrix 
    114733  
    114734 File
    114735 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114736 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    114737 raise LinAlgError("Singular matrix") 
    114738  
    114739 See log for complete Python traceback. 
    114740  
    114741 Traceback (most recent call last): 
    114742 File
    114743 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114744 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    114745 self.session.ui.mouse_modes.mouse_pause_tracking() 
    114746 File
    114747 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114748 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    114749 mouse_pause_tracking 
    114750 self._mouse_pause() 
    114751 File
    114752 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114753 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    114754 m.pause(self._mouse_pause_position) 
    114755 File
    114756 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114757 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    114758 p = self.view.picked_object(x, y) 
    114759 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114760 File
    114761 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114762 packages/chimerax/graphics/view.py", line 838, in picked_object 
    114763 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    114764 beyond, 
    114765 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114766 File
    114767 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114768 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    114769 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    114770 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114771 File
    114772 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114773 packages/chimerax/core/models.py", line 143, in first_intercept 
    114774 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    114775 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114776 File
    114777 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114778 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    114779 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    114780 exclude=exclude) 
    114781 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114782 File
    114783 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114784 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    114785 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    114786 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114787 File
    114788 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114789 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    114790 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    114791 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114792 File
    114793 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114794 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    114795 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    114796 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114797 File
    114798 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114799 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    114800 p = super().first_intercept(mxyz1, mxyz2) 
    114801 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114802 File
    114803 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114804 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    114805 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    114806 exclude=exclude) 
    114807 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114808 File
    114809 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114810 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    114811 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    114812 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114813 File
    114814 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114815 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    114816 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    114817 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114818 File
    114819 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114820 packages/chimerax/graphics/drawing.py", line 1108, in
    114821 _first_intercept_excluding_children 
    114822 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    114823 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114824 File
    114825 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114826 packages/chimerax/geometry/place.py", line 201, in inverse 
    114827 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    114828 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114829 File
    114830 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114831 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    114832 rinv[:, :] = matrix_inverse(r) 
    114833 ^^^^^^^^^^^^^^^^^ 
    114834 File
    114835 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114836 packages/numpy/linalg/linalg.py", line 561, in inv 
    114837 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    114838 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114839 File
    114840 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114841 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    114842 raise LinAlgError("Singular matrix") 
    114843 numpy.linalg.LinAlgError: Singular matrix 
    114844  
    114845 numpy.linalg.LinAlgError: Singular matrix 
    114846  
    114847 File
    114848 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114849 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    114850 raise LinAlgError("Singular matrix") 
    114851  
    114852 See log for complete Python traceback. 
    114853  
    114854 Traceback (most recent call last): 
    114855 File
    114856 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114857 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    114858 self.session.ui.mouse_modes.mouse_pause_tracking() 
    114859 File
    114860 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114861 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    114862 mouse_pause_tracking 
    114863 self._mouse_pause() 
    114864 File
    114865 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114866 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    114867 m.pause(self._mouse_pause_position) 
    114868 File
    114869 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114870 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    114871 p = self.view.picked_object(x, y) 
    114872 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114873 File
    114874 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114875 packages/chimerax/graphics/view.py", line 838, in picked_object 
    114876 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    114877 beyond, 
    114878 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114879 File
    114880 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114881 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    114882 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    114883 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114884 File
    114885 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114886 packages/chimerax/core/models.py", line 143, in first_intercept 
    114887 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    114888 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114889 File
    114890 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114891 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    114892 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    114893 exclude=exclude) 
    114894 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114895 File
    114896 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114897 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    114898 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    114899 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114900 File
    114901 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114902 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    114903 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    114904 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114905 File
    114906 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114907 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    114908 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    114909 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114910 File
    114911 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114912 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    114913 p = super().first_intercept(mxyz1, mxyz2) 
    114914 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114915 File
    114916 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114917 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    114918 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    114919 exclude=exclude) 
    114920 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114921 File
    114922 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114923 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    114924 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    114925 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114926 File
    114927 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114928 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    114929 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    114930 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114931 File
    114932 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114933 packages/chimerax/graphics/drawing.py", line 1108, in
    114934 _first_intercept_excluding_children 
    114935 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    114936 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114937 File
    114938 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114939 packages/chimerax/geometry/place.py", line 201, in inverse 
    114940 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    114941 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114942 File
    114943 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114944 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    114945 rinv[:, :] = matrix_inverse(r) 
    114946 ^^^^^^^^^^^^^^^^^ 
    114947 File
    114948 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114949 packages/numpy/linalg/linalg.py", line 561, in inv 
    114950 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    114951 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114952 File
    114953 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114954 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    114955 raise LinAlgError("Singular matrix") 
    114956 numpy.linalg.LinAlgError: Singular matrix 
    114957  
    114958 numpy.linalg.LinAlgError: Singular matrix 
    114959  
    114960 File
    114961 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114962 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    114963 raise LinAlgError("Singular matrix") 
    114964  
    114965 See log for complete Python traceback. 
    114966  
    114967 Traceback (most recent call last): 
    114968 File
    114969 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114970 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    114971 self.session.ui.mouse_modes.mouse_pause_tracking() 
    114972 File
    114973 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114974 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    114975 mouse_pause_tracking 
    114976 self._mouse_pause() 
    114977 File
    114978 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114979 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    114980 m.pause(self._mouse_pause_position) 
    114981 File
    114982 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114983 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    114984 p = self.view.picked_object(x, y) 
    114985 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114986 File
    114987 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114988 packages/chimerax/graphics/view.py", line 838, in picked_object 
    114989 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    114990 beyond, 
    114991 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114992 File
    114993 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114994 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    114995 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    114996 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    114997 File
    114998 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    114999 packages/chimerax/core/models.py", line 143, in first_intercept 
    115000 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    115001 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115002 File
    115003 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115004 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    115005 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    115006 exclude=exclude) 
    115007 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115008 File
    115009 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115010 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    115011 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    115012 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115013 File
    115014 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115015 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    115016 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    115017 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115018 File
    115019 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115020 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    115021 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    115022 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115023 File
    115024 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115025 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    115026 p = super().first_intercept(mxyz1, mxyz2) 
    115027 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115028 File
    115029 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115030 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    115031 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    115032 exclude=exclude) 
    115033 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115034 File
    115035 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115036 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    115037 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    115038 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115039 File
    115040 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115041 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    115042 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    115043 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115044 File
    115045 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115046 packages/chimerax/graphics/drawing.py", line 1108, in
    115047 _first_intercept_excluding_children 
    115048 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    115049 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115050 File
    115051 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115052 packages/chimerax/geometry/place.py", line 201, in inverse 
    115053 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    115054 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115055 File
    115056 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115057 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    115058 rinv[:, :] = matrix_inverse(r) 
    115059 ^^^^^^^^^^^^^^^^^ 
    115060 File
    115061 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115062 packages/numpy/linalg/linalg.py", line 561, in inv 
    115063 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    115064 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115065 File
    115066 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115067 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    115068 raise LinAlgError("Singular matrix") 
    115069 numpy.linalg.LinAlgError: Singular matrix 
    115070  
    115071 numpy.linalg.LinAlgError: Singular matrix 
    115072  
    115073 File
    115074 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115075 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    115076 raise LinAlgError("Singular matrix") 
    115077  
    115078 See log for complete Python traceback. 
    115079  
    115080 Traceback (most recent call last): 
    115081 File
    115082 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115083 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    115084 self.session.ui.mouse_modes.mouse_pause_tracking() 
    115085 File
    115086 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115087 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    115088 mouse_pause_tracking 
    115089 self._mouse_pause() 
    115090 File
    115091 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115092 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    115093 m.pause(self._mouse_pause_position) 
    115094 File
    115095 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115096 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    115097 p = self.view.picked_object(x, y) 
    115098 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115099 File
    115100 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115101 packages/chimerax/graphics/view.py", line 838, in picked_object 
    115102 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    115103 beyond, 
    115104 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115105 File
    115106 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115107 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    115108 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    115109 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115110 File
    115111 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115112 packages/chimerax/core/models.py", line 143, in first_intercept 
    115113 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    115114 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115115 File
    115116 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115117 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    115118 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    115119 exclude=exclude) 
    115120 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115121 File
    115122 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115123 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    115124 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    115125 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115126 File
    115127 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115128 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    115129 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    115130 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115131 File
    115132 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115133 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    115134 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    115135 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115136 File
    115137 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115138 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    115139 p = super().first_intercept(mxyz1, mxyz2) 
    115140 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115141 File
    115142 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115143 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    115144 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    115145 exclude=exclude) 
    115146 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115147 File
    115148 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115149 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    115150 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    115151 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115152 File
    115153 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115154 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    115155 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    115156 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115157 File
    115158 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115159 packages/chimerax/graphics/drawing.py", line 1108, in
    115160 _first_intercept_excluding_children 
    115161 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    115162 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115163 File
    115164 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115165 packages/chimerax/geometry/place.py", line 201, in inverse 
    115166 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    115167 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115168 File
    115169 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115170 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    115171 rinv[:, :] = matrix_inverse(r) 
    115172 ^^^^^^^^^^^^^^^^^ 
    115173 File
    115174 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115175 packages/numpy/linalg/linalg.py", line 561, in inv 
    115176 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    115177 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115178 File
    115179 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115180 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    115181 raise LinAlgError("Singular matrix") 
    115182 numpy.linalg.LinAlgError: Singular matrix 
    115183  
    115184 numpy.linalg.LinAlgError: Singular matrix 
    115185  
    115186 File
    115187 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115188 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    115189 raise LinAlgError("Singular matrix") 
    115190  
    115191 See log for complete Python traceback. 
    115192  
    115193 Traceback (most recent call last): 
    115194 File
    115195 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115196 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    115197 self.session.ui.mouse_modes.mouse_pause_tracking() 
    115198 File
    115199 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115200 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    115201 mouse_pause_tracking 
    115202 self._mouse_pause() 
    115203 File
    115204 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115205 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    115206 m.pause(self._mouse_pause_position) 
    115207 File
    115208 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115209 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    115210 p = self.view.picked_object(x, y) 
    115211 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115212 File
    115213 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115214 packages/chimerax/graphics/view.py", line 838, in picked_object 
    115215 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    115216 beyond, 
    115217 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115218 File
    115219 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115220 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    115221 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    115222 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115223 File
    115224 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115225 packages/chimerax/core/models.py", line 143, in first_intercept 
    115226 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    115227 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115228 File
    115229 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115230 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    115231 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    115232 exclude=exclude) 
    115233 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115234 File
    115235 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115236 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    115237 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    115238 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115239 File
    115240 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115241 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    115242 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    115243 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115244 File
    115245 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115246 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    115247 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    115248 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115249 File
    115250 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115251 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    115252 p = super().first_intercept(mxyz1, mxyz2) 
    115253 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115254 File
    115255 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115256 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    115257 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    115258 exclude=exclude) 
    115259 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115260 File
    115261 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115262 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    115263 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    115264 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115265 File
    115266 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115267 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    115268 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    115269 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115270 File
    115271 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115272 packages/chimerax/graphics/drawing.py", line 1108, in
    115273 _first_intercept_excluding_children 
    115274 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    115275 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115276 File
    115277 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115278 packages/chimerax/geometry/place.py", line 201, in inverse 
    115279 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    115280 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115281 File
    115282 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115283 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    115284 rinv[:, :] = matrix_inverse(r) 
    115285 ^^^^^^^^^^^^^^^^^ 
    115286 File
    115287 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115288 packages/numpy/linalg/linalg.py", line 561, in inv 
    115289 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    115290 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115291 File
    115292 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115293 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    115294 raise LinAlgError("Singular matrix") 
    115295 numpy.linalg.LinAlgError: Singular matrix 
    115296  
    115297 numpy.linalg.LinAlgError: Singular matrix 
    115298  
    115299 File
    115300 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115301 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    115302 raise LinAlgError("Singular matrix") 
    115303  
    115304 See log for complete Python traceback. 
    115305  
    115306 Traceback (most recent call last): 
    115307 File
    115308 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115309 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    115310 self.session.ui.mouse_modes.mouse_pause_tracking() 
    115311 File
    115312 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115313 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    115314 mouse_pause_tracking 
    115315 self._mouse_pause() 
    115316 File
    115317 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115318 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    115319 m.pause(self._mouse_pause_position) 
    115320 File
    115321 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115322 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    115323 p = self.view.picked_object(x, y) 
    115324 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115325 File
    115326 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115327 packages/chimerax/graphics/view.py", line 838, in picked_object 
    115328 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    115329 beyond, 
    115330 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115331 File
    115332 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115333 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    115334 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    115335 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115336 File
    115337 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115338 packages/chimerax/core/models.py", line 143, in first_intercept 
    115339 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    115340 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115341 File
    115342 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115343 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    115344 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    115345 exclude=exclude) 
    115346 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115347 File
    115348 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115349 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    115350 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    115351 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115352 File
    115353 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115354 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    115355 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    115356 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115357 File
    115358 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115359 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    115360 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    115361 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115362 File
    115363 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115364 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    115365 p = super().first_intercept(mxyz1, mxyz2) 
    115366 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115367 File
    115368 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115369 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    115370 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    115371 exclude=exclude) 
    115372 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115373 File
    115374 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115375 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    115376 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    115377 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115378 File
    115379 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115380 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    115381 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    115382 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115383 File
    115384 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115385 packages/chimerax/graphics/drawing.py", line 1108, in
    115386 _first_intercept_excluding_children 
    115387 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    115388 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115389 File
    115390 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115391 packages/chimerax/geometry/place.py", line 201, in inverse 
    115392 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    115393 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115394 File
    115395 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115396 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    115397 rinv[:, :] = matrix_inverse(r) 
    115398 ^^^^^^^^^^^^^^^^^ 
    115399 File
    115400 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115401 packages/numpy/linalg/linalg.py", line 561, in inv 
    115402 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    115403 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115404 File
    115405 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115406 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    115407 raise LinAlgError("Singular matrix") 
    115408 numpy.linalg.LinAlgError: Singular matrix 
    115409  
    115410 numpy.linalg.LinAlgError: Singular matrix 
    115411  
    115412 File
    115413 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115414 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    115415 raise LinAlgError("Singular matrix") 
    115416  
    115417 See log for complete Python traceback. 
    115418  
    115419 Traceback (most recent call last): 
    115420 File
    115421 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115422 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    115423 self.session.ui.mouse_modes.mouse_pause_tracking() 
    115424 File
    115425 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115426 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    115427 mouse_pause_tracking 
    115428 self._mouse_pause() 
    115429 File
    115430 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115431 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    115432 m.pause(self._mouse_pause_position) 
    115433 File
    115434 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115435 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    115436 p = self.view.picked_object(x, y) 
    115437 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115438 File
    115439 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115440 packages/chimerax/graphics/view.py", line 838, in picked_object 
    115441 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    115442 beyond, 
    115443 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115444 File
    115445 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115446 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    115447 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    115448 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115449 File
    115450 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115451 packages/chimerax/core/models.py", line 143, in first_intercept 
    115452 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    115453 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115454 File
    115455 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115456 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    115457 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    115458 exclude=exclude) 
    115459 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115460 File
    115461 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115462 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    115463 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    115464 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115465 File
    115466 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115467 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    115468 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    115469 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115470 File
    115471 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115472 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    115473 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    115474 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115475 File
    115476 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115477 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    115478 p = super().first_intercept(mxyz1, mxyz2) 
    115479 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115480 File
    115481 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115482 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    115483 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    115484 exclude=exclude) 
    115485 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115486 File
    115487 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115488 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    115489 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    115490 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115491 File
    115492 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115493 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    115494 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    115495 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115496 File
    115497 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115498 packages/chimerax/graphics/drawing.py", line 1108, in
    115499 _first_intercept_excluding_children 
    115500 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    115501 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115502 File
    115503 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115504 packages/chimerax/geometry/place.py", line 201, in inverse 
    115505 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    115506 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115507 File
    115508 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115509 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    115510 rinv[:, :] = matrix_inverse(r) 
    115511 ^^^^^^^^^^^^^^^^^ 
    115512 File
    115513 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115514 packages/numpy/linalg/linalg.py", line 561, in inv 
    115515 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    115516 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115517 File
    115518 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115519 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    115520 raise LinAlgError("Singular matrix") 
    115521 numpy.linalg.LinAlgError: Singular matrix 
    115522  
    115523 numpy.linalg.LinAlgError: Singular matrix 
    115524  
    115525 File
    115526 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115527 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    115528 raise LinAlgError("Singular matrix") 
    115529  
    115530 See log for complete Python traceback. 
    115531  
    115532 Traceback (most recent call last): 
    115533 File
    115534 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115535 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    115536 self.session.ui.mouse_modes.mouse_pause_tracking() 
    115537 File
    115538 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115539 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    115540 mouse_pause_tracking 
    115541 self._mouse_pause() 
    115542 File
    115543 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115544 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    115545 m.pause(self._mouse_pause_position) 
    115546 File
    115547 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115548 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    115549 p = self.view.picked_object(x, y) 
    115550 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115551 File
    115552 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115553 packages/chimerax/graphics/view.py", line 838, in picked_object 
    115554 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    115555 beyond, 
    115556 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115557 File
    115558 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115559 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    115560 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    115561 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115562 File
    115563 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115564 packages/chimerax/core/models.py", line 143, in first_intercept 
    115565 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    115566 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115567 File
    115568 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115569 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    115570 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    115571 exclude=exclude) 
    115572 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115573 File
    115574 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115575 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    115576 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    115577 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115578 File
    115579 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115580 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    115581 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    115582 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115583 File
    115584 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115585 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    115586 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    115587 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115588 File
    115589 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115590 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    115591 p = super().first_intercept(mxyz1, mxyz2) 
    115592 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115593 File
    115594 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115595 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    115596 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    115597 exclude=exclude) 
    115598 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115599 File
    115600 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115601 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    115602 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    115603 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115604 File
    115605 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115606 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    115607 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    115608 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115609 File
    115610 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115611 packages/chimerax/graphics/drawing.py", line 1108, in
    115612 _first_intercept_excluding_children 
    115613 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    115614 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115615 File
    115616 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115617 packages/chimerax/geometry/place.py", line 201, in inverse 
    115618 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    115619 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115620 File
    115621 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115622 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    115623 rinv[:, :] = matrix_inverse(r) 
    115624 ^^^^^^^^^^^^^^^^^ 
    115625 File
    115626 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115627 packages/numpy/linalg/linalg.py", line 561, in inv 
    115628 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    115629 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115630 File
    115631 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115632 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    115633 raise LinAlgError("Singular matrix") 
    115634 numpy.linalg.LinAlgError: Singular matrix 
    115635  
    115636 numpy.linalg.LinAlgError: Singular matrix 
    115637  
    115638 File
    115639 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115640 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    115641 raise LinAlgError("Singular matrix") 
    115642  
    115643 See log for complete Python traceback. 
    115644  
    115645 Traceback (most recent call last): 
    115646 File
    115647 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115648 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    115649 self.session.ui.mouse_modes.mouse_pause_tracking() 
    115650 File
    115651 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115652 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    115653 mouse_pause_tracking 
    115654 self._mouse_pause() 
    115655 File
    115656 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115657 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    115658 m.pause(self._mouse_pause_position) 
    115659 File
    115660 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115661 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    115662 p = self.view.picked_object(x, y) 
    115663 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115664 File
    115665 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115666 packages/chimerax/graphics/view.py", line 838, in picked_object 
    115667 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    115668 beyond, 
    115669 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115670 File
    115671 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115672 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    115673 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    115674 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115675 File
    115676 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115677 packages/chimerax/core/models.py", line 143, in first_intercept 
    115678 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    115679 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115680 File
    115681 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115682 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    115683 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    115684 exclude=exclude) 
    115685 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115686 File
    115687 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115688 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    115689 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    115690 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115691 File
    115692 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115693 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    115694 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    115695 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115696 File
    115697 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115698 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    115699 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    115700 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115701 File
    115702 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115703 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    115704 p = super().first_intercept(mxyz1, mxyz2) 
    115705 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115706 File
    115707 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115708 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    115709 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    115710 exclude=exclude) 
    115711 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115712 File
    115713 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115714 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    115715 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    115716 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115717 File
    115718 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115719 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    115720 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    115721 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115722 File
    115723 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115724 packages/chimerax/graphics/drawing.py", line 1108, in
    115725 _first_intercept_excluding_children 
    115726 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    115727 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115728 File
    115729 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115730 packages/chimerax/geometry/place.py", line 201, in inverse 
    115731 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    115732 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115733 File
    115734 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115735 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    115736 rinv[:, :] = matrix_inverse(r) 
    115737 ^^^^^^^^^^^^^^^^^ 
    115738 File
    115739 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115740 packages/numpy/linalg/linalg.py", line 561, in inv 
    115741 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    115742 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115743 File
    115744 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115745 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    115746 raise LinAlgError("Singular matrix") 
    115747 numpy.linalg.LinAlgError: Singular matrix 
    115748  
    115749 numpy.linalg.LinAlgError: Singular matrix 
    115750  
    115751 File
    115752 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115753 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    115754 raise LinAlgError("Singular matrix") 
    115755  
    115756 See log for complete Python traceback. 
    115757  
    115758 Traceback (most recent call last): 
    115759 File
    115760 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115761 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    115762 self.session.ui.mouse_modes.mouse_pause_tracking() 
    115763 File
    115764 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115765 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    115766 mouse_pause_tracking 
    115767 self._mouse_pause() 
    115768 File
    115769 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115770 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    115771 m.pause(self._mouse_pause_position) 
    115772 File
    115773 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115774 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    115775 p = self.view.picked_object(x, y) 
    115776 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115777 File
    115778 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115779 packages/chimerax/graphics/view.py", line 838, in picked_object 
    115780 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    115781 beyond, 
    115782 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115783 File
    115784 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115785 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    115786 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    115787 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115788 File
    115789 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115790 packages/chimerax/core/models.py", line 143, in first_intercept 
    115791 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    115792 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115793 File
    115794 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115795 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    115796 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    115797 exclude=exclude) 
    115798 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115799 File
    115800 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115801 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    115802 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    115803 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115804 File
    115805 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115806 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    115807 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    115808 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115809 File
    115810 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115811 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    115812 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    115813 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115814 File
    115815 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115816 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    115817 p = super().first_intercept(mxyz1, mxyz2) 
    115818 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115819 File
    115820 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115821 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    115822 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    115823 exclude=exclude) 
    115824 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115825 File
    115826 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115827 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    115828 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    115829 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115830 File
    115831 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115832 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    115833 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    115834 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115835 File
    115836 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115837 packages/chimerax/graphics/drawing.py", line 1108, in
    115838 _first_intercept_excluding_children 
    115839 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    115840 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115841 File
    115842 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115843 packages/chimerax/geometry/place.py", line 201, in inverse 
    115844 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    115845 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115846 File
    115847 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115848 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    115849 rinv[:, :] = matrix_inverse(r) 
    115850 ^^^^^^^^^^^^^^^^^ 
    115851 File
    115852 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115853 packages/numpy/linalg/linalg.py", line 561, in inv 
    115854 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    115855 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115856 File
    115857 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115858 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    115859 raise LinAlgError("Singular matrix") 
    115860 numpy.linalg.LinAlgError: Singular matrix 
    115861  
    115862 numpy.linalg.LinAlgError: Singular matrix 
    115863  
    115864 File
    115865 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115866 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    115867 raise LinAlgError("Singular matrix") 
    115868  
    115869 See log for complete Python traceback. 
    115870  
    115871 Traceback (most recent call last): 
    115872 File
    115873 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115874 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    115875 self.session.ui.mouse_modes.mouse_pause_tracking() 
    115876 File
    115877 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115878 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    115879 mouse_pause_tracking 
    115880 self._mouse_pause() 
    115881 File
    115882 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115883 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    115884 m.pause(self._mouse_pause_position) 
    115885 File
    115886 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115887 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    115888 p = self.view.picked_object(x, y) 
    115889 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115890 File
    115891 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115892 packages/chimerax/graphics/view.py", line 838, in picked_object 
    115893 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    115894 beyond, 
    115895 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115896 File
    115897 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115898 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    115899 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    115900 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115901 File
    115902 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115903 packages/chimerax/core/models.py", line 143, in first_intercept 
    115904 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    115905 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115906 File
    115907 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115908 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    115909 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    115910 exclude=exclude) 
    115911 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115912 File
    115913 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115914 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    115915 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    115916 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115917 File
    115918 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115919 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    115920 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    115921 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115922 File
    115923 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115924 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    115925 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    115926 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115927 File
    115928 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115929 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    115930 p = super().first_intercept(mxyz1, mxyz2) 
    115931 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115932 File
    115933 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115934 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    115935 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    115936 exclude=exclude) 
    115937 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115938 File
    115939 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115940 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    115941 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    115942 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115943 File
    115944 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115945 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    115946 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    115947 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115948 File
    115949 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115950 packages/chimerax/graphics/drawing.py", line 1108, in
    115951 _first_intercept_excluding_children 
    115952 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    115953 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115954 File
    115955 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115956 packages/chimerax/geometry/place.py", line 201, in inverse 
    115957 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    115958 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115959 File
    115960 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115961 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    115962 rinv[:, :] = matrix_inverse(r) 
    115963 ^^^^^^^^^^^^^^^^^ 
    115964 File
    115965 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115966 packages/numpy/linalg/linalg.py", line 561, in inv 
    115967 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    115968 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    115969 File
    115970 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115971 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    115972 raise LinAlgError("Singular matrix") 
    115973 numpy.linalg.LinAlgError: Singular matrix 
    115974  
    115975 numpy.linalg.LinAlgError: Singular matrix 
    115976  
    115977 File
    115978 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115979 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    115980 raise LinAlgError("Singular matrix") 
    115981  
    115982 See log for complete Python traceback. 
    115983  
    115984 Traceback (most recent call last): 
    115985 File
    115986 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115987 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    115988 self.session.ui.mouse_modes.mouse_pause_tracking() 
    115989 File
    115990 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115991 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    115992 mouse_pause_tracking 
    115993 self._mouse_pause() 
    115994 File
    115995 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    115996 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    115997 m.pause(self._mouse_pause_position) 
    115998 File
    115999 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116000 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    116001 p = self.view.picked_object(x, y) 
    116002 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116003 File
    116004 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116005 packages/chimerax/graphics/view.py", line 838, in picked_object 
    116006 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    116007 beyond, 
    116008 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116009 File
    116010 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116011 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    116012 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    116013 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116014 File
    116015 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116016 packages/chimerax/core/models.py", line 143, in first_intercept 
    116017 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    116018 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116019 File
    116020 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116021 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    116022 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    116023 exclude=exclude) 
    116024 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116025 File
    116026 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116027 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    116028 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    116029 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116030 File
    116031 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116032 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    116033 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    116034 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116035 File
    116036 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116037 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    116038 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    116039 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116040 File
    116041 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116042 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    116043 p = super().first_intercept(mxyz1, mxyz2) 
    116044 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116045 File
    116046 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116047 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    116048 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    116049 exclude=exclude) 
    116050 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116051 File
    116052 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116053 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    116054 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    116055 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116056 File
    116057 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116058 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    116059 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    116060 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116061 File
    116062 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116063 packages/chimerax/graphics/drawing.py", line 1108, in
    116064 _first_intercept_excluding_children 
    116065 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    116066 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116067 File
    116068 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116069 packages/chimerax/geometry/place.py", line 201, in inverse 
    116070 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    116071 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116072 File
    116073 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116074 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    116075 rinv[:, :] = matrix_inverse(r) 
    116076 ^^^^^^^^^^^^^^^^^ 
    116077 File
    116078 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116079 packages/numpy/linalg/linalg.py", line 561, in inv 
    116080 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    116081 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116082 File
    116083 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116084 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    116085 raise LinAlgError("Singular matrix") 
    116086 numpy.linalg.LinAlgError: Singular matrix 
    116087  
    116088 numpy.linalg.LinAlgError: Singular matrix 
    116089  
    116090 File
    116091 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116092 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    116093 raise LinAlgError("Singular matrix") 
    116094  
    116095 See log for complete Python traceback. 
    116096  
    116097 Traceback (most recent call last): 
    116098 File
    116099 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116100 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    116101 self.session.ui.mouse_modes.mouse_pause_tracking() 
    116102 File
    116103 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116104 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    116105 mouse_pause_tracking 
    116106 self._mouse_pause() 
    116107 File
    116108 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116109 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    116110 m.pause(self._mouse_pause_position) 
    116111 File
    116112 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116113 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    116114 p = self.view.picked_object(x, y) 
    116115 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116116 File
    116117 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116118 packages/chimerax/graphics/view.py", line 838, in picked_object 
    116119 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    116120 beyond, 
    116121 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116122 File
    116123 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116124 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    116125 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    116126 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116127 File
    116128 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116129 packages/chimerax/core/models.py", line 143, in first_intercept 
    116130 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    116131 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116132 File
    116133 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116134 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    116135 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    116136 exclude=exclude) 
    116137 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116138 File
    116139 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116140 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    116141 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    116142 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116143 File
    116144 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116145 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    116146 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    116147 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116148 File
    116149 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116150 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    116151 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    116152 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116153 File
    116154 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116155 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    116156 p = super().first_intercept(mxyz1, mxyz2) 
    116157 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116158 File
    116159 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116160 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    116161 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    116162 exclude=exclude) 
    116163 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116164 File
    116165 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116166 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    116167 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    116168 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116169 File
    116170 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116171 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    116172 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    116173 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116174 File
    116175 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116176 packages/chimerax/graphics/drawing.py", line 1108, in
    116177 _first_intercept_excluding_children 
    116178 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    116179 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116180 File
    116181 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116182 packages/chimerax/geometry/place.py", line 201, in inverse 
    116183 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    116184 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116185 File
    116186 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116187 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    116188 rinv[:, :] = matrix_inverse(r) 
    116189 ^^^^^^^^^^^^^^^^^ 
    116190 File
    116191 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116192 packages/numpy/linalg/linalg.py", line 561, in inv 
    116193 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    116194 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116195 File
    116196 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116197 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    116198 raise LinAlgError("Singular matrix") 
    116199 numpy.linalg.LinAlgError: Singular matrix 
    116200  
    116201 numpy.linalg.LinAlgError: Singular matrix 
    116202  
    116203 File
    116204 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116205 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    116206 raise LinAlgError("Singular matrix") 
    116207  
    116208 See log for complete Python traceback. 
    116209  
    116210 Traceback (most recent call last): 
    116211 File
    116212 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116213 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    116214 self.session.ui.mouse_modes.mouse_pause_tracking() 
    116215 File
    116216 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116217 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    116218 mouse_pause_tracking 
    116219 self._mouse_pause() 
    116220 File
    116221 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116222 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    116223 m.pause(self._mouse_pause_position) 
    116224 File
    116225 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116226 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    116227 p = self.view.picked_object(x, y) 
    116228 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116229 File
    116230 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116231 packages/chimerax/graphics/view.py", line 838, in picked_object 
    116232 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    116233 beyond, 
    116234 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116235 File
    116236 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116237 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    116238 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    116239 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116240 File
    116241 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116242 packages/chimerax/core/models.py", line 143, in first_intercept 
    116243 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    116244 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116245 File
    116246 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116247 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    116248 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    116249 exclude=exclude) 
    116250 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116251 File
    116252 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116253 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    116254 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    116255 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116256 File
    116257 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116258 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    116259 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    116260 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116261 File
    116262 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116263 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    116264 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    116265 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116266 File
    116267 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116268 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    116269 p = super().first_intercept(mxyz1, mxyz2) 
    116270 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116271 File
    116272 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116273 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    116274 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    116275 exclude=exclude) 
    116276 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116277 File
    116278 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116279 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    116280 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    116281 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116282 File
    116283 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116284 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    116285 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    116286 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116287 File
    116288 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116289 packages/chimerax/graphics/drawing.py", line 1108, in
    116290 _first_intercept_excluding_children 
    116291 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    116292 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116293 File
    116294 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116295 packages/chimerax/geometry/place.py", line 201, in inverse 
    116296 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    116297 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116298 File
    116299 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116300 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    116301 rinv[:, :] = matrix_inverse(r) 
    116302 ^^^^^^^^^^^^^^^^^ 
    116303 File
    116304 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116305 packages/numpy/linalg/linalg.py", line 561, in inv 
    116306 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    116307 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116308 File
    116309 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116310 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    116311 raise LinAlgError("Singular matrix") 
    116312 numpy.linalg.LinAlgError: Singular matrix 
    116313  
    116314 numpy.linalg.LinAlgError: Singular matrix 
    116315  
    116316 File
    116317 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116318 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    116319 raise LinAlgError("Singular matrix") 
    116320  
    116321 See log for complete Python traceback. 
    116322  
    116323 Traceback (most recent call last): 
    116324 File
    116325 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116326 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    116327 self.session.ui.mouse_modes.mouse_pause_tracking() 
    116328 File
    116329 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116330 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    116331 mouse_pause_tracking 
    116332 self._mouse_pause() 
    116333 File
    116334 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116335 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    116336 m.pause(self._mouse_pause_position) 
    116337 File
    116338 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116339 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    116340 p = self.view.picked_object(x, y) 
    116341 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116342 File
    116343 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116344 packages/chimerax/graphics/view.py", line 838, in picked_object 
    116345 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    116346 beyond, 
    116347 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116348 File
    116349 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116350 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    116351 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    116352 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116353 File
    116354 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116355 packages/chimerax/core/models.py", line 143, in first_intercept 
    116356 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    116357 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116358 File
    116359 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116360 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    116361 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    116362 exclude=exclude) 
    116363 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116364 File
    116365 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116366 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    116367 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    116368 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116369 File
    116370 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116371 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    116372 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    116373 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116374 File
    116375 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116376 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    116377 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    116378 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116379 File
    116380 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116381 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    116382 p = super().first_intercept(mxyz1, mxyz2) 
    116383 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116384 File
    116385 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116386 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    116387 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    116388 exclude=exclude) 
    116389 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116390 File
    116391 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116392 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    116393 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    116394 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116395 File
    116396 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116397 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    116398 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    116399 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116400 File
    116401 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116402 packages/chimerax/graphics/drawing.py", line 1108, in
    116403 _first_intercept_excluding_children 
    116404 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    116405 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116406 File
    116407 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116408 packages/chimerax/geometry/place.py", line 201, in inverse 
    116409 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    116410 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116411 File
    116412 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116413 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    116414 rinv[:, :] = matrix_inverse(r) 
    116415 ^^^^^^^^^^^^^^^^^ 
    116416 File
    116417 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116418 packages/numpy/linalg/linalg.py", line 561, in inv 
    116419 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    116420 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116421 File
    116422 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116423 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    116424 raise LinAlgError("Singular matrix") 
    116425 numpy.linalg.LinAlgError: Singular matrix 
    116426  
    116427 numpy.linalg.LinAlgError: Singular matrix 
    116428  
    116429 File
    116430 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116431 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    116432 raise LinAlgError("Singular matrix") 
    116433  
    116434 See log for complete Python traceback. 
    116435  
    116436 Traceback (most recent call last): 
    116437 File
    116438 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116439 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    116440 self.session.ui.mouse_modes.mouse_pause_tracking() 
    116441 File
    116442 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116443 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    116444 mouse_pause_tracking 
    116445 self._mouse_pause() 
    116446 File
    116447 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116448 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    116449 m.pause(self._mouse_pause_position) 
    116450 File
    116451 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116452 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    116453 p = self.view.picked_object(x, y) 
    116454 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116455 File
    116456 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116457 packages/chimerax/graphics/view.py", line 838, in picked_object 
    116458 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    116459 beyond, 
    116460 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116461 File
    116462 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116463 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    116464 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    116465 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116466 File
    116467 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116468 packages/chimerax/core/models.py", line 143, in first_intercept 
    116469 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    116470 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116471 File
    116472 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116473 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    116474 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    116475 exclude=exclude) 
    116476 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116477 File
    116478 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116479 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    116480 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    116481 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116482 File
    116483 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116484 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    116485 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    116486 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116487 File
    116488 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116489 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    116490 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    116491 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116492 File
    116493 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116494 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    116495 p = super().first_intercept(mxyz1, mxyz2) 
    116496 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116497 File
    116498 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116499 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    116500 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    116501 exclude=exclude) 
    116502 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116503 File
    116504 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116505 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    116506 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    116507 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116508 File
    116509 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116510 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    116511 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    116512 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116513 File
    116514 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116515 packages/chimerax/graphics/drawing.py", line 1108, in
    116516 _first_intercept_excluding_children 
    116517 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    116518 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116519 File
    116520 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116521 packages/chimerax/geometry/place.py", line 201, in inverse 
    116522 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    116523 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116524 File
    116525 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116526 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    116527 rinv[:, :] = matrix_inverse(r) 
    116528 ^^^^^^^^^^^^^^^^^ 
    116529 File
    116530 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116531 packages/numpy/linalg/linalg.py", line 561, in inv 
    116532 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    116533 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116534 File
    116535 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116536 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    116537 raise LinAlgError("Singular matrix") 
    116538 numpy.linalg.LinAlgError: Singular matrix 
    116539  
    116540 numpy.linalg.LinAlgError: Singular matrix 
    116541  
    116542 File
    116543 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116544 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    116545 raise LinAlgError("Singular matrix") 
    116546  
    116547 See log for complete Python traceback. 
    116548  
    116549 Traceback (most recent call last): 
    116550 File
    116551 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116552 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    116553 self.session.ui.mouse_modes.mouse_pause_tracking() 
    116554 File
    116555 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116556 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    116557 mouse_pause_tracking 
    116558 self._mouse_pause() 
    116559 File
    116560 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116561 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    116562 m.pause(self._mouse_pause_position) 
    116563 File
    116564 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116565 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    116566 p = self.view.picked_object(x, y) 
    116567 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116568 File
    116569 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116570 packages/chimerax/graphics/view.py", line 838, in picked_object 
    116571 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    116572 beyond, 
    116573 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116574 File
    116575 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116576 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    116577 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    116578 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116579 File
    116580 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116581 packages/chimerax/core/models.py", line 143, in first_intercept 
    116582 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    116583 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116584 File
    116585 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116586 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    116587 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    116588 exclude=exclude) 
    116589 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116590 File
    116591 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116592 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    116593 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    116594 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116595 File
    116596 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116597 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    116598 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    116599 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116600 File
    116601 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116602 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    116603 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    116604 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116605 File
    116606 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116607 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    116608 p = super().first_intercept(mxyz1, mxyz2) 
    116609 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116610 File
    116611 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116612 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    116613 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    116614 exclude=exclude) 
    116615 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116616 File
    116617 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116618 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    116619 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    116620 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116621 File
    116622 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116623 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    116624 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    116625 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116626 File
    116627 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116628 packages/chimerax/graphics/drawing.py", line 1108, in
    116629 _first_intercept_excluding_children 
    116630 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    116631 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116632 File
    116633 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116634 packages/chimerax/geometry/place.py", line 201, in inverse 
    116635 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    116636 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116637 File
    116638 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116639 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    116640 rinv[:, :] = matrix_inverse(r) 
    116641 ^^^^^^^^^^^^^^^^^ 
    116642 File
    116643 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116644 packages/numpy/linalg/linalg.py", line 561, in inv 
    116645 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    116646 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116647 File
    116648 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116649 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    116650 raise LinAlgError("Singular matrix") 
    116651 numpy.linalg.LinAlgError: Singular matrix 
    116652  
    116653 numpy.linalg.LinAlgError: Singular matrix 
    116654  
    116655 File
    116656 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116657 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    116658 raise LinAlgError("Singular matrix") 
    116659  
    116660 See log for complete Python traceback. 
    116661  
    116662 Traceback (most recent call last): 
    116663 File
    116664 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116665 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    116666 self.session.ui.mouse_modes.mouse_pause_tracking() 
    116667 File
    116668 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116669 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    116670 mouse_pause_tracking 
    116671 self._mouse_pause() 
    116672 File
    116673 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116674 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    116675 m.pause(self._mouse_pause_position) 
    116676 File
    116677 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116678 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    116679 p = self.view.picked_object(x, y) 
    116680 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116681 File
    116682 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116683 packages/chimerax/graphics/view.py", line 838, in picked_object 
    116684 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    116685 beyond, 
    116686 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116687 File
    116688 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116689 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    116690 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    116691 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116692 File
    116693 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116694 packages/chimerax/core/models.py", line 143, in first_intercept 
    116695 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    116696 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116697 File
    116698 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116699 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    116700 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    116701 exclude=exclude) 
    116702 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116703 File
    116704 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116705 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    116706 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    116707 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116708 File
    116709 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116710 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    116711 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    116712 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116713 File
    116714 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116715 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    116716 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    116717 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116718 File
    116719 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116720 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    116721 p = super().first_intercept(mxyz1, mxyz2) 
    116722 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116723 File
    116724 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116725 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    116726 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    116727 exclude=exclude) 
    116728 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116729 File
    116730 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116731 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    116732 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    116733 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116734 File
    116735 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116736 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    116737 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    116738 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116739 File
    116740 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116741 packages/chimerax/graphics/drawing.py", line 1108, in
    116742 _first_intercept_excluding_children 
    116743 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    116744 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116745 File
    116746 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116747 packages/chimerax/geometry/place.py", line 201, in inverse 
    116748 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    116749 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116750 File
    116751 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116752 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    116753 rinv[:, :] = matrix_inverse(r) 
    116754 ^^^^^^^^^^^^^^^^^ 
    116755 File
    116756 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116757 packages/numpy/linalg/linalg.py", line 561, in inv 
    116758 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    116759 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116760 File
    116761 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116762 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    116763 raise LinAlgError("Singular matrix") 
    116764 numpy.linalg.LinAlgError: Singular matrix 
    116765  
    116766 numpy.linalg.LinAlgError: Singular matrix 
    116767  
    116768 File
    116769 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116770 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    116771 raise LinAlgError("Singular matrix") 
    116772  
    116773 See log for complete Python traceback. 
    116774  
    116775 Traceback (most recent call last): 
    116776 File
    116777 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116778 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    116779 self.session.ui.mouse_modes.mouse_pause_tracking() 
    116780 File
    116781 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116782 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    116783 mouse_pause_tracking 
    116784 self._mouse_pause() 
    116785 File
    116786 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116787 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    116788 m.pause(self._mouse_pause_position) 
    116789 File
    116790 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116791 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    116792 p = self.view.picked_object(x, y) 
    116793 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116794 File
    116795 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116796 packages/chimerax/graphics/view.py", line 838, in picked_object 
    116797 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    116798 beyond, 
    116799 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116800 File
    116801 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116802 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    116803 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    116804 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116805 File
    116806 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116807 packages/chimerax/core/models.py", line 143, in first_intercept 
    116808 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    116809 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116810 File
    116811 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116812 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    116813 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    116814 exclude=exclude) 
    116815 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116816 File
    116817 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116818 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    116819 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    116820 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116821 File
    116822 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116823 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    116824 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    116825 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116826 File
    116827 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116828 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    116829 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    116830 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116831 File
    116832 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116833 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    116834 p = super().first_intercept(mxyz1, mxyz2) 
    116835 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116836 File
    116837 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116838 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    116839 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    116840 exclude=exclude) 
    116841 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116842 File
    116843 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116844 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    116845 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    116846 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116847 File
    116848 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116849 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    116850 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    116851 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116852 File
    116853 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116854 packages/chimerax/graphics/drawing.py", line 1108, in
    116855 _first_intercept_excluding_children 
    116856 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    116857 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116858 File
    116859 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116860 packages/chimerax/geometry/place.py", line 201, in inverse 
    116861 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    116862 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116863 File
    116864 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116865 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    116866 rinv[:, :] = matrix_inverse(r) 
    116867 ^^^^^^^^^^^^^^^^^ 
    116868 File
    116869 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116870 packages/numpy/linalg/linalg.py", line 561, in inv 
    116871 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    116872 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116873 File
    116874 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116875 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    116876 raise LinAlgError("Singular matrix") 
    116877 numpy.linalg.LinAlgError: Singular matrix 
    116878  
    116879 numpy.linalg.LinAlgError: Singular matrix 
    116880  
    116881 File
    116882 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116883 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    116884 raise LinAlgError("Singular matrix") 
    116885  
    116886 See log for complete Python traceback. 
    116887  
    116888 Traceback (most recent call last): 
    116889 File
    116890 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116891 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    116892 self.session.ui.mouse_modes.mouse_pause_tracking() 
    116893 File
    116894 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116895 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    116896 mouse_pause_tracking 
    116897 self._mouse_pause() 
    116898 File
    116899 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116900 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    116901 m.pause(self._mouse_pause_position) 
    116902 File
    116903 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116904 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    116905 p = self.view.picked_object(x, y) 
    116906 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116907 File
    116908 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116909 packages/chimerax/graphics/view.py", line 838, in picked_object 
    116910 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    116911 beyond, 
    116912 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116913 File
    116914 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116915 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    116916 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    116917 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116918 File
    116919 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116920 packages/chimerax/core/models.py", line 143, in first_intercept 
    116921 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    116922 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116923 File
    116924 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116925 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    116926 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    116927 exclude=exclude) 
    116928 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116929 File
    116930 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116931 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    116932 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    116933 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116934 File
    116935 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116936 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    116937 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    116938 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116939 File
    116940 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116941 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    116942 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    116943 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116944 File
    116945 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116946 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    116947 p = super().first_intercept(mxyz1, mxyz2) 
    116948 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116949 File
    116950 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116951 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    116952 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    116953 exclude=exclude) 
    116954 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116955 File
    116956 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116957 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    116958 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    116959 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116960 File
    116961 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116962 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    116963 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    116964 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116965 File
    116966 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116967 packages/chimerax/graphics/drawing.py", line 1108, in
    116968 _first_intercept_excluding_children 
    116969 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    116970 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116971 File
    116972 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116973 packages/chimerax/geometry/place.py", line 201, in inverse 
    116974 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    116975 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116976 File
    116977 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116978 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    116979 rinv[:, :] = matrix_inverse(r) 
    116980 ^^^^^^^^^^^^^^^^^ 
    116981 File
    116982 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116983 packages/numpy/linalg/linalg.py", line 561, in inv 
    116984 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    116985 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    116986 File
    116987 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116988 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    116989 raise LinAlgError("Singular matrix") 
    116990 numpy.linalg.LinAlgError: Singular matrix 
    116991  
    116992 numpy.linalg.LinAlgError: Singular matrix 
    116993  
    116994 File
    116995 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    116996 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    116997 raise LinAlgError("Singular matrix") 
    116998  
    116999 See log for complete Python traceback. 
    117000  
    117001 Traceback (most recent call last): 
    117002 File
    117003 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117004 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    117005 self.session.ui.mouse_modes.mouse_pause_tracking() 
    117006 File
    117007 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117008 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    117009 mouse_pause_tracking 
    117010 self._mouse_pause() 
    117011 File
    117012 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117013 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    117014 m.pause(self._mouse_pause_position) 
    117015 File
    117016 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117017 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    117018 p = self.view.picked_object(x, y) 
    117019 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117020 File
    117021 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117022 packages/chimerax/graphics/view.py", line 838, in picked_object 
    117023 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    117024 beyond, 
    117025 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117026 File
    117027 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117028 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    117029 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    117030 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117031 File
    117032 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117033 packages/chimerax/core/models.py", line 143, in first_intercept 
    117034 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    117035 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117036 File
    117037 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117038 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    117039 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    117040 exclude=exclude) 
    117041 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117042 File
    117043 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117044 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    117045 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    117046 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117047 File
    117048 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117049 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    117050 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    117051 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117052 File
    117053 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117054 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    117055 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    117056 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117057 File
    117058 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117059 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    117060 p = super().first_intercept(mxyz1, mxyz2) 
    117061 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117062 File
    117063 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117064 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    117065 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    117066 exclude=exclude) 
    117067 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117068 File
    117069 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117070 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    117071 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    117072 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117073 File
    117074 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117075 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    117076 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    117077 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117078 File
    117079 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117080 packages/chimerax/graphics/drawing.py", line 1108, in
    117081 _first_intercept_excluding_children 
    117082 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    117083 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117084 File
    117085 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117086 packages/chimerax/geometry/place.py", line 201, in inverse 
    117087 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    117088 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117089 File
    117090 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117091 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    117092 rinv[:, :] = matrix_inverse(r) 
    117093 ^^^^^^^^^^^^^^^^^ 
    117094 File
    117095 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117096 packages/numpy/linalg/linalg.py", line 561, in inv 
    117097 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    117098 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117099 File
    117100 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117101 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    117102 raise LinAlgError("Singular matrix") 
    117103 numpy.linalg.LinAlgError: Singular matrix 
    117104  
    117105 numpy.linalg.LinAlgError: Singular matrix 
    117106  
    117107 File
    117108 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117109 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    117110 raise LinAlgError("Singular matrix") 
    117111  
    117112 See log for complete Python traceback. 
    117113  
    117114 Traceback (most recent call last): 
    117115 File
    117116 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117117 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    117118 self.session.ui.mouse_modes.mouse_pause_tracking() 
    117119 File
    117120 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117121 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    117122 mouse_pause_tracking 
    117123 self._mouse_pause() 
    117124 File
    117125 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117126 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    117127 m.pause(self._mouse_pause_position) 
    117128 File
    117129 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117130 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    117131 p = self.view.picked_object(x, y) 
    117132 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117133 File
    117134 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117135 packages/chimerax/graphics/view.py", line 838, in picked_object 
    117136 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    117137 beyond, 
    117138 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117139 File
    117140 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117141 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    117142 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    117143 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117144 File
    117145 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117146 packages/chimerax/core/models.py", line 143, in first_intercept 
    117147 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    117148 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117149 File
    117150 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117151 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    117152 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    117153 exclude=exclude) 
    117154 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117155 File
    117156 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117157 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    117158 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    117159 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117160 File
    117161 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117162 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    117163 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    117164 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117165 File
    117166 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117167 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    117168 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    117169 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117170 File
    117171 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117172 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    117173 p = super().first_intercept(mxyz1, mxyz2) 
    117174 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117175 File
    117176 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117177 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    117178 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    117179 exclude=exclude) 
    117180 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117181 File
    117182 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117183 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    117184 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    117185 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117186 File
    117187 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117188 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    117189 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    117190 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117191 File
    117192 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117193 packages/chimerax/graphics/drawing.py", line 1108, in
    117194 _first_intercept_excluding_children 
    117195 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    117196 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117197 File
    117198 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117199 packages/chimerax/geometry/place.py", line 201, in inverse 
    117200 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    117201 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117202 File
    117203 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117204 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    117205 rinv[:, :] = matrix_inverse(r) 
    117206 ^^^^^^^^^^^^^^^^^ 
    117207 File
    117208 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117209 packages/numpy/linalg/linalg.py", line 561, in inv 
    117210 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    117211 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117212 File
    117213 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117214 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    117215 raise LinAlgError("Singular matrix") 
    117216 numpy.linalg.LinAlgError: Singular matrix 
    117217  
    117218 numpy.linalg.LinAlgError: Singular matrix 
    117219  
    117220 File
    117221 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117222 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    117223 raise LinAlgError("Singular matrix") 
    117224  
    117225 See log for complete Python traceback. 
    117226  
    117227 Traceback (most recent call last): 
    117228 File
    117229 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117230 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    117231 self.session.ui.mouse_modes.mouse_pause_tracking() 
    117232 File
    117233 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117234 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    117235 mouse_pause_tracking 
    117236 self._mouse_pause() 
    117237 File
    117238 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117239 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    117240 m.pause(self._mouse_pause_position) 
    117241 File
    117242 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117243 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    117244 p = self.view.picked_object(x, y) 
    117245 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117246 File
    117247 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117248 packages/chimerax/graphics/view.py", line 838, in picked_object 
    117249 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    117250 beyond, 
    117251 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117252 File
    117253 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117254 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    117255 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    117256 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117257 File
    117258 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117259 packages/chimerax/core/models.py", line 143, in first_intercept 
    117260 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    117261 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117262 File
    117263 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117264 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    117265 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    117266 exclude=exclude) 
    117267 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117268 File
    117269 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117270 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    117271 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    117272 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117273 File
    117274 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117275 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    117276 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    117277 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117278 File
    117279 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117280 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    117281 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    117282 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117283 File
    117284 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117285 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    117286 p = super().first_intercept(mxyz1, mxyz2) 
    117287 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117288 File
    117289 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117290 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    117291 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    117292 exclude=exclude) 
    117293 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117294 File
    117295 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117296 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    117297 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    117298 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117299 File
    117300 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117301 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    117302 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    117303 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117304 File
    117305 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117306 packages/chimerax/graphics/drawing.py", line 1108, in
    117307 _first_intercept_excluding_children 
    117308 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    117309 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117310 File
    117311 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117312 packages/chimerax/geometry/place.py", line 201, in inverse 
    117313 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    117314 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117315 File
    117316 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117317 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    117318 rinv[:, :] = matrix_inverse(r) 
    117319 ^^^^^^^^^^^^^^^^^ 
    117320 File
    117321 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117322 packages/numpy/linalg/linalg.py", line 561, in inv 
    117323 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    117324 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117325 File
    117326 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117327 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    117328 raise LinAlgError("Singular matrix") 
    117329 numpy.linalg.LinAlgError: Singular matrix 
    117330  
    117331 numpy.linalg.LinAlgError: Singular matrix 
    117332  
    117333 File
    117334 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117335 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    117336 raise LinAlgError("Singular matrix") 
    117337  
    117338 See log for complete Python traceback. 
    117339  
    117340 Traceback (most recent call last): 
    117341 File
    117342 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117343 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    117344 self.session.ui.mouse_modes.mouse_pause_tracking() 
    117345 File
    117346 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117347 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    117348 mouse_pause_tracking 
    117349 self._mouse_pause() 
    117350 File
    117351 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117352 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    117353 m.pause(self._mouse_pause_position) 
    117354 File
    117355 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117356 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    117357 p = self.view.picked_object(x, y) 
    117358 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117359 File
    117360 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117361 packages/chimerax/graphics/view.py", line 838, in picked_object 
    117362 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    117363 beyond, 
    117364 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117365 File
    117366 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117367 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    117368 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    117369 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117370 File
    117371 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117372 packages/chimerax/core/models.py", line 143, in first_intercept 
    117373 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    117374 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117375 File
    117376 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117377 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    117378 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    117379 exclude=exclude) 
    117380 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117381 File
    117382 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117383 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    117384 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    117385 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117386 File
    117387 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117388 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    117389 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    117390 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117391 File
    117392 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117393 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    117394 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    117395 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117396 File
    117397 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117398 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    117399 p = super().first_intercept(mxyz1, mxyz2) 
    117400 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117401 File
    117402 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117403 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    117404 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    117405 exclude=exclude) 
    117406 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117407 File
    117408 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117409 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    117410 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    117411 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117412 File
    117413 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117414 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    117415 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    117416 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117417 File
    117418 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117419 packages/chimerax/graphics/drawing.py", line 1108, in
    117420 _first_intercept_excluding_children 
    117421 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    117422 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117423 File
    117424 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117425 packages/chimerax/geometry/place.py", line 201, in inverse 
    117426 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    117427 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117428 File
    117429 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117430 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    117431 rinv[:, :] = matrix_inverse(r) 
    117432 ^^^^^^^^^^^^^^^^^ 
    117433 File
    117434 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117435 packages/numpy/linalg/linalg.py", line 561, in inv 
    117436 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    117437 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117438 File
    117439 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117440 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    117441 raise LinAlgError("Singular matrix") 
    117442 numpy.linalg.LinAlgError: Singular matrix 
    117443  
    117444 numpy.linalg.LinAlgError: Singular matrix 
    117445  
    117446 File
    117447 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117448 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    117449 raise LinAlgError("Singular matrix") 
    117450  
    117451 See log for complete Python traceback. 
    117452  
    117453 Traceback (most recent call last): 
    117454 File
    117455 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117456 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    117457 self.session.ui.mouse_modes.mouse_pause_tracking() 
    117458 File
    117459 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117460 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    117461 mouse_pause_tracking 
    117462 self._mouse_pause() 
    117463 File
    117464 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117465 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    117466 m.pause(self._mouse_pause_position) 
    117467 File
    117468 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117469 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    117470 p = self.view.picked_object(x, y) 
    117471 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117472 File
    117473 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117474 packages/chimerax/graphics/view.py", line 838, in picked_object 
    117475 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    117476 beyond, 
    117477 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117478 File
    117479 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117480 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    117481 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    117482 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117483 File
    117484 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117485 packages/chimerax/core/models.py", line 143, in first_intercept 
    117486 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    117487 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117488 File
    117489 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117490 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    117491 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    117492 exclude=exclude) 
    117493 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117494 File
    117495 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117496 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    117497 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    117498 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117499 File
    117500 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117501 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    117502 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    117503 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117504 File
    117505 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117506 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    117507 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    117508 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117509 File
    117510 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117511 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    117512 p = super().first_intercept(mxyz1, mxyz2) 
    117513 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117514 File
    117515 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117516 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    117517 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    117518 exclude=exclude) 
    117519 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117520 File
    117521 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117522 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    117523 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    117524 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117525 File
    117526 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117527 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    117528 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    117529 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117530 File
    117531 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117532 packages/chimerax/graphics/drawing.py", line 1108, in
    117533 _first_intercept_excluding_children 
    117534 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    117535 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117536 File
    117537 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117538 packages/chimerax/geometry/place.py", line 201, in inverse 
    117539 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    117540 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117541 File
    117542 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117543 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    117544 rinv[:, :] = matrix_inverse(r) 
    117545 ^^^^^^^^^^^^^^^^^ 
    117546 File
    117547 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117548 packages/numpy/linalg/linalg.py", line 561, in inv 
    117549 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    117550 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117551 File
    117552 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117553 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    117554 raise LinAlgError("Singular matrix") 
    117555 numpy.linalg.LinAlgError: Singular matrix 
    117556  
    117557 numpy.linalg.LinAlgError: Singular matrix 
    117558  
    117559 File
    117560 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117561 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    117562 raise LinAlgError("Singular matrix") 
    117563  
    117564 See log for complete Python traceback. 
    117565  
    117566 Traceback (most recent call last): 
    117567 File
    117568 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117569 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    117570 self.session.ui.mouse_modes.mouse_pause_tracking() 
    117571 File
    117572 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117573 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    117574 mouse_pause_tracking 
    117575 self._mouse_pause() 
    117576 File
    117577 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117578 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    117579 m.pause(self._mouse_pause_position) 
    117580 File
    117581 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117582 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    117583 p = self.view.picked_object(x, y) 
    117584 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117585 File
    117586 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117587 packages/chimerax/graphics/view.py", line 838, in picked_object 
    117588 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    117589 beyond, 
    117590 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117591 File
    117592 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117593 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    117594 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    117595 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117596 File
    117597 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117598 packages/chimerax/core/models.py", line 143, in first_intercept 
    117599 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    117600 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117601 File
    117602 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117603 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    117604 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    117605 exclude=exclude) 
    117606 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117607 File
    117608 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117609 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    117610 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    117611 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117612 File
    117613 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117614 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    117615 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    117616 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117617 File
    117618 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117619 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    117620 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    117621 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117622 File
    117623 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117624 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    117625 p = super().first_intercept(mxyz1, mxyz2) 
    117626 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117627 File
    117628 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117629 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    117630 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    117631 exclude=exclude) 
    117632 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117633 File
    117634 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117635 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    117636 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    117637 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117638 File
    117639 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117640 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    117641 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    117642 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117643 File
    117644 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117645 packages/chimerax/graphics/drawing.py", line 1108, in
    117646 _first_intercept_excluding_children 
    117647 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    117648 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117649 File
    117650 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117651 packages/chimerax/geometry/place.py", line 201, in inverse 
    117652 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    117653 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117654 File
    117655 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117656 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    117657 rinv[:, :] = matrix_inverse(r) 
    117658 ^^^^^^^^^^^^^^^^^ 
    117659 File
    117660 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117661 packages/numpy/linalg/linalg.py", line 561, in inv 
    117662 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    117663 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117664 File
    117665 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117666 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    117667 raise LinAlgError("Singular matrix") 
    117668 numpy.linalg.LinAlgError: Singular matrix 
    117669  
    117670 numpy.linalg.LinAlgError: Singular matrix 
    117671  
    117672 File
    117673 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117674 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    117675 raise LinAlgError("Singular matrix") 
    117676  
    117677 See log for complete Python traceback. 
    117678  
    117679 Traceback (most recent call last): 
    117680 File
    117681 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117682 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    117683 self.session.ui.mouse_modes.mouse_pause_tracking() 
    117684 File
    117685 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117686 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    117687 mouse_pause_tracking 
    117688 self._mouse_pause() 
    117689 File
    117690 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117691 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    117692 m.pause(self._mouse_pause_position) 
    117693 File
    117694 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117695 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    117696 p = self.view.picked_object(x, y) 
    117697 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117698 File
    117699 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117700 packages/chimerax/graphics/view.py", line 838, in picked_object 
    117701 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    117702 beyond, 
    117703 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117704 File
    117705 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117706 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    117707 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    117708 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117709 File
    117710 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117711 packages/chimerax/core/models.py", line 143, in first_intercept 
    117712 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    117713 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117714 File
    117715 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117716 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    117717 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    117718 exclude=exclude) 
    117719 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117720 File
    117721 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117722 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    117723 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    117724 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117725 File
    117726 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117727 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    117728 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    117729 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117730 File
    117731 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117732 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    117733 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    117734 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117735 File
    117736 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117737 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    117738 p = super().first_intercept(mxyz1, mxyz2) 
    117739 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117740 File
    117741 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117742 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    117743 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    117744 exclude=exclude) 
    117745 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117746 File
    117747 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117748 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    117749 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    117750 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117751 File
    117752 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117753 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    117754 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    117755 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117756 File
    117757 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117758 packages/chimerax/graphics/drawing.py", line 1108, in
    117759 _first_intercept_excluding_children 
    117760 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    117761 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117762 File
    117763 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117764 packages/chimerax/geometry/place.py", line 201, in inverse 
    117765 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    117766 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117767 File
    117768 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117769 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    117770 rinv[:, :] = matrix_inverse(r) 
    117771 ^^^^^^^^^^^^^^^^^ 
    117772 File
    117773 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117774 packages/numpy/linalg/linalg.py", line 561, in inv 
    117775 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    117776 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117777 File
    117778 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117779 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    117780 raise LinAlgError("Singular matrix") 
    117781 numpy.linalg.LinAlgError: Singular matrix 
    117782  
    117783 numpy.linalg.LinAlgError: Singular matrix 
    117784  
    117785 File
    117786 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117787 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    117788 raise LinAlgError("Singular matrix") 
    117789  
    117790 See log for complete Python traceback. 
    117791  
    117792 Traceback (most recent call last): 
    117793 File
    117794 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117795 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    117796 self.session.ui.mouse_modes.mouse_pause_tracking() 
    117797 File
    117798 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117799 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    117800 mouse_pause_tracking 
    117801 self._mouse_pause() 
    117802 File
    117803 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117804 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    117805 m.pause(self._mouse_pause_position) 
    117806 File
    117807 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117808 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    117809 p = self.view.picked_object(x, y) 
    117810 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117811 File
    117812 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117813 packages/chimerax/graphics/view.py", line 838, in picked_object 
    117814 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    117815 beyond, 
    117816 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117817 File
    117818 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117819 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    117820 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    117821 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117822 File
    117823 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117824 packages/chimerax/core/models.py", line 143, in first_intercept 
    117825 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    117826 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117827 File
    117828 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117829 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    117830 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    117831 exclude=exclude) 
    117832 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117833 File
    117834 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117835 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    117836 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    117837 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117838 File
    117839 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117840 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    117841 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    117842 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117843 File
    117844 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117845 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    117846 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    117847 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117848 File
    117849 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117850 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    117851 p = super().first_intercept(mxyz1, mxyz2) 
    117852 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117853 File
    117854 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117855 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    117856 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    117857 exclude=exclude) 
    117858 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117859 File
    117860 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117861 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    117862 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    117863 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117864 File
    117865 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117866 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    117867 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    117868 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117869 File
    117870 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117871 packages/chimerax/graphics/drawing.py", line 1108, in
    117872 _first_intercept_excluding_children 
    117873 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    117874 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117875 File
    117876 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117877 packages/chimerax/geometry/place.py", line 201, in inverse 
    117878 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    117879 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117880 File
    117881 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117882 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    117883 rinv[:, :] = matrix_inverse(r) 
    117884 ^^^^^^^^^^^^^^^^^ 
    117885 File
    117886 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117887 packages/numpy/linalg/linalg.py", line 561, in inv 
    117888 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    117889 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117890 File
    117891 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117892 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    117893 raise LinAlgError("Singular matrix") 
    117894 numpy.linalg.LinAlgError: Singular matrix 
    117895  
    117896 numpy.linalg.LinAlgError: Singular matrix 
    117897  
    117898 File
    117899 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117900 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    117901 raise LinAlgError("Singular matrix") 
    117902  
    117903 See log for complete Python traceback. 
    117904  
    117905 Traceback (most recent call last): 
    117906 File
    117907 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117908 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    117909 self.session.ui.mouse_modes.mouse_pause_tracking() 
    117910 File
    117911 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117912 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    117913 mouse_pause_tracking 
    117914 self._mouse_pause() 
    117915 File
    117916 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117917 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    117918 m.pause(self._mouse_pause_position) 
    117919 File
    117920 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117921 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    117922 p = self.view.picked_object(x, y) 
    117923 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117924 File
    117925 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117926 packages/chimerax/graphics/view.py", line 838, in picked_object 
    117927 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    117928 beyond, 
    117929 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117930 File
    117931 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117932 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    117933 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    117934 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117935 File
    117936 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117937 packages/chimerax/core/models.py", line 143, in first_intercept 
    117938 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    117939 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117940 File
    117941 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117942 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    117943 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    117944 exclude=exclude) 
    117945 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117946 File
    117947 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117948 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    117949 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    117950 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117951 File
    117952 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117953 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    117954 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    117955 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117956 File
    117957 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117958 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    117959 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    117960 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117961 File
    117962 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117963 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    117964 p = super().first_intercept(mxyz1, mxyz2) 
    117965 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117966 File
    117967 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117968 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    117969 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    117970 exclude=exclude) 
    117971 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117972 File
    117973 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117974 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    117975 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    117976 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117977 File
    117978 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117979 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    117980 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    117981 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117982 File
    117983 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117984 packages/chimerax/graphics/drawing.py", line 1108, in
    117985 _first_intercept_excluding_children 
    117986 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    117987 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117988 File
    117989 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117990 packages/chimerax/geometry/place.py", line 201, in inverse 
    117991 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    117992 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    117993 File
    117994 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    117995 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    117996 rinv[:, :] = matrix_inverse(r) 
    117997 ^^^^^^^^^^^^^^^^^ 
    117998 File
    117999 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118000 packages/numpy/linalg/linalg.py", line 561, in inv 
    118001 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    118002 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118003 File
    118004 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118005 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    118006 raise LinAlgError("Singular matrix") 
    118007 numpy.linalg.LinAlgError: Singular matrix 
    118008  
    118009 numpy.linalg.LinAlgError: Singular matrix 
    118010  
    118011 File
    118012 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118013 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    118014 raise LinAlgError("Singular matrix") 
    118015  
    118016 See log for complete Python traceback. 
    118017  
    118018 Traceback (most recent call last): 
    118019 File
    118020 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118021 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    118022 self.session.ui.mouse_modes.mouse_pause_tracking() 
    118023 File
    118024 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118025 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    118026 mouse_pause_tracking 
    118027 self._mouse_pause() 
    118028 File
    118029 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118030 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    118031 m.pause(self._mouse_pause_position) 
    118032 File
    118033 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118034 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    118035 p = self.view.picked_object(x, y) 
    118036 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118037 File
    118038 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118039 packages/chimerax/graphics/view.py", line 838, in picked_object 
    118040 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    118041 beyond, 
    118042 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118043 File
    118044 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118045 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    118046 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    118047 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118048 File
    118049 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118050 packages/chimerax/core/models.py", line 143, in first_intercept 
    118051 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    118052 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118053 File
    118054 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118055 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    118056 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    118057 exclude=exclude) 
    118058 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118059 File
    118060 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118061 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    118062 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    118063 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118064 File
    118065 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118066 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    118067 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    118068 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118069 File
    118070 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118071 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    118072 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    118073 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118074 File
    118075 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118076 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    118077 p = super().first_intercept(mxyz1, mxyz2) 
    118078 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118079 File
    118080 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118081 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    118082 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    118083 exclude=exclude) 
    118084 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118085 File
    118086 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118087 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    118088 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    118089 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118090 File
    118091 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118092 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    118093 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    118094 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118095 File
    118096 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118097 packages/chimerax/graphics/drawing.py", line 1108, in
    118098 _first_intercept_excluding_children 
    118099 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    118100 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118101 File
    118102 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118103 packages/chimerax/geometry/place.py", line 201, in inverse 
    118104 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    118105 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118106 File
    118107 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118108 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    118109 rinv[:, :] = matrix_inverse(r) 
    118110 ^^^^^^^^^^^^^^^^^ 
    118111 File
    118112 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118113 packages/numpy/linalg/linalg.py", line 561, in inv 
    118114 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    118115 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118116 File
    118117 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118118 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    118119 raise LinAlgError("Singular matrix") 
    118120 numpy.linalg.LinAlgError: Singular matrix 
    118121  
    118122 numpy.linalg.LinAlgError: Singular matrix 
    118123  
    118124 File
    118125 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118126 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    118127 raise LinAlgError("Singular matrix") 
    118128  
    118129 See log for complete Python traceback. 
    118130  
    118131 Traceback (most recent call last): 
    118132 File
    118133 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118134 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    118135 self.session.ui.mouse_modes.mouse_pause_tracking() 
    118136 File
    118137 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118138 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    118139 mouse_pause_tracking 
    118140 self._mouse_pause() 
    118141 File
    118142 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118143 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    118144 m.pause(self._mouse_pause_position) 
    118145 File
    118146 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118147 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    118148 p = self.view.picked_object(x, y) 
    118149 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118150 File
    118151 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118152 packages/chimerax/graphics/view.py", line 838, in picked_object 
    118153 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    118154 beyond, 
    118155 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118156 File
    118157 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118158 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    118159 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    118160 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118161 File
    118162 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118163 packages/chimerax/core/models.py", line 143, in first_intercept 
    118164 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    118165 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118166 File
    118167 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118168 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    118169 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    118170 exclude=exclude) 
    118171 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118172 File
    118173 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118174 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    118175 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    118176 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118177 File
    118178 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118179 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    118180 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    118181 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118182 File
    118183 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118184 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    118185 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    118186 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118187 File
    118188 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118189 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    118190 p = super().first_intercept(mxyz1, mxyz2) 
    118191 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118192 File
    118193 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118194 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    118195 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    118196 exclude=exclude) 
    118197 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118198 File
    118199 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118200 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    118201 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    118202 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118203 File
    118204 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118205 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    118206 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    118207 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118208 File
    118209 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118210 packages/chimerax/graphics/drawing.py", line 1108, in
    118211 _first_intercept_excluding_children 
    118212 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    118213 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118214 File
    118215 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118216 packages/chimerax/geometry/place.py", line 201, in inverse 
    118217 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    118218 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118219 File
    118220 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118221 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    118222 rinv[:, :] = matrix_inverse(r) 
    118223 ^^^^^^^^^^^^^^^^^ 
    118224 File
    118225 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118226 packages/numpy/linalg/linalg.py", line 561, in inv 
    118227 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    118228 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118229 File
    118230 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118231 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    118232 raise LinAlgError("Singular matrix") 
    118233 numpy.linalg.LinAlgError: Singular matrix 
    118234  
    118235 numpy.linalg.LinAlgError: Singular matrix 
    118236  
    118237 File
    118238 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118239 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    118240 raise LinAlgError("Singular matrix") 
    118241  
    118242 See log for complete Python traceback. 
    118243  
    118244 Traceback (most recent call last): 
    118245 File
    118246 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118247 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    118248 self.session.ui.mouse_modes.mouse_pause_tracking() 
    118249 File
    118250 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118251 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    118252 mouse_pause_tracking 
    118253 self._mouse_pause() 
    118254 File
    118255 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118256 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    118257 m.pause(self._mouse_pause_position) 
    118258 File
    118259 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118260 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    118261 p = self.view.picked_object(x, y) 
    118262 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118263 File
    118264 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118265 packages/chimerax/graphics/view.py", line 838, in picked_object 
    118266 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    118267 beyond, 
    118268 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118269 File
    118270 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118271 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    118272 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    118273 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118274 File
    118275 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118276 packages/chimerax/core/models.py", line 143, in first_intercept 
    118277 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    118278 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118279 File
    118280 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118281 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    118282 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    118283 exclude=exclude) 
    118284 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118285 File
    118286 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118287 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    118288 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    118289 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118290 File
    118291 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118292 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    118293 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    118294 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118295 File
    118296 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118297 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    118298 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    118299 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118300 File
    118301 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118302 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    118303 p = super().first_intercept(mxyz1, mxyz2) 
    118304 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118305 File
    118306 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118307 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    118308 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    118309 exclude=exclude) 
    118310 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118311 File
    118312 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118313 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    118314 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    118315 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118316 File
    118317 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118318 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    118319 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    118320 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118321 File
    118322 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118323 packages/chimerax/graphics/drawing.py", line 1108, in
    118324 _first_intercept_excluding_children 
    118325 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    118326 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118327 File
    118328 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118329 packages/chimerax/geometry/place.py", line 201, in inverse 
    118330 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    118331 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118332 File
    118333 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118334 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    118335 rinv[:, :] = matrix_inverse(r) 
    118336 ^^^^^^^^^^^^^^^^^ 
    118337 File
    118338 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118339 packages/numpy/linalg/linalg.py", line 561, in inv 
    118340 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    118341 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118342 File
    118343 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118344 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    118345 raise LinAlgError("Singular matrix") 
    118346 numpy.linalg.LinAlgError: Singular matrix 
    118347  
    118348 numpy.linalg.LinAlgError: Singular matrix 
    118349  
    118350 File
    118351 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118352 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    118353 raise LinAlgError("Singular matrix") 
    118354  
    118355 See log for complete Python traceback. 
    118356  
    118357 Traceback (most recent call last): 
    118358 File
    118359 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118360 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    118361 self.session.ui.mouse_modes.mouse_pause_tracking() 
    118362 File
    118363 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118364 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    118365 mouse_pause_tracking 
    118366 self._mouse_pause() 
    118367 File
    118368 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118369 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    118370 m.pause(self._mouse_pause_position) 
    118371 File
    118372 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118373 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    118374 p = self.view.picked_object(x, y) 
    118375 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118376 File
    118377 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118378 packages/chimerax/graphics/view.py", line 838, in picked_object 
    118379 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    118380 beyond, 
    118381 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118382 File
    118383 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118384 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    118385 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    118386 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118387 File
    118388 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118389 packages/chimerax/core/models.py", line 143, in first_intercept 
    118390 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    118391 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118392 File
    118393 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118394 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    118395 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    118396 exclude=exclude) 
    118397 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118398 File
    118399 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118400 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    118401 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    118402 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118403 File
    118404 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118405 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    118406 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    118407 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118408 File
    118409 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118410 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    118411 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    118412 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118413 File
    118414 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118415 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    118416 p = super().first_intercept(mxyz1, mxyz2) 
    118417 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118418 File
    118419 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118420 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    118421 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    118422 exclude=exclude) 
    118423 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118424 File
    118425 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118426 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    118427 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    118428 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118429 File
    118430 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118431 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    118432 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    118433 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118434 File
    118435 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118436 packages/chimerax/graphics/drawing.py", line 1108, in
    118437 _first_intercept_excluding_children 
    118438 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    118439 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118440 File
    118441 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118442 packages/chimerax/geometry/place.py", line 201, in inverse 
    118443 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    118444 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118445 File
    118446 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118447 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    118448 rinv[:, :] = matrix_inverse(r) 
    118449 ^^^^^^^^^^^^^^^^^ 
    118450 File
    118451 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118452 packages/numpy/linalg/linalg.py", line 561, in inv 
    118453 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    118454 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118455 File
    118456 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118457 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    118458 raise LinAlgError("Singular matrix") 
    118459 numpy.linalg.LinAlgError: Singular matrix 
    118460  
    118461 numpy.linalg.LinAlgError: Singular matrix 
    118462  
    118463 File
    118464 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118465 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    118466 raise LinAlgError("Singular matrix") 
    118467  
    118468 See log for complete Python traceback. 
    118469  
    118470 Traceback (most recent call last): 
    118471 File
    118472 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118473 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    118474 self.session.ui.mouse_modes.mouse_pause_tracking() 
    118475 File
    118476 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118477 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    118478 mouse_pause_tracking 
    118479 self._mouse_pause() 
    118480 File
    118481 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118482 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    118483 m.pause(self._mouse_pause_position) 
    118484 File
    118485 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118486 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    118487 p = self.view.picked_object(x, y) 
    118488 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118489 File
    118490 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118491 packages/chimerax/graphics/view.py", line 838, in picked_object 
    118492 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    118493 beyond, 
    118494 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118495 File
    118496 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118497 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    118498 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    118499 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118500 File
    118501 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118502 packages/chimerax/core/models.py", line 143, in first_intercept 
    118503 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    118504 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118505 File
    118506 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118507 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    118508 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    118509 exclude=exclude) 
    118510 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118511 File
    118512 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118513 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    118514 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    118515 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118516 File
    118517 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118518 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    118519 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    118520 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118521 File
    118522 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118523 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    118524 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    118525 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118526 File
    118527 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118528 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    118529 p = super().first_intercept(mxyz1, mxyz2) 
    118530 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118531 File
    118532 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118533 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    118534 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    118535 exclude=exclude) 
    118536 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118537 File
    118538 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118539 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    118540 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    118541 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118542 File
    118543 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118544 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    118545 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    118546 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118547 File
    118548 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118549 packages/chimerax/graphics/drawing.py", line 1108, in
    118550 _first_intercept_excluding_children 
    118551 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    118552 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118553 File
    118554 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118555 packages/chimerax/geometry/place.py", line 201, in inverse 
    118556 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    118557 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118558 File
    118559 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118560 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    118561 rinv[:, :] = matrix_inverse(r) 
    118562 ^^^^^^^^^^^^^^^^^ 
    118563 File
    118564 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118565 packages/numpy/linalg/linalg.py", line 561, in inv 
    118566 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    118567 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118568 File
    118569 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118570 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    118571 raise LinAlgError("Singular matrix") 
    118572 numpy.linalg.LinAlgError: Singular matrix 
    118573  
    118574 numpy.linalg.LinAlgError: Singular matrix 
    118575  
    118576 File
    118577 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118578 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    118579 raise LinAlgError("Singular matrix") 
    118580  
    118581 See log for complete Python traceback. 
    118582  
    118583 Traceback (most recent call last): 
    118584 File
    118585 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118586 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    118587 self.session.ui.mouse_modes.mouse_pause_tracking() 
    118588 File
    118589 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118590 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    118591 mouse_pause_tracking 
    118592 self._mouse_pause() 
    118593 File
    118594 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118595 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    118596 m.pause(self._mouse_pause_position) 
    118597 File
    118598 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118599 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    118600 p = self.view.picked_object(x, y) 
    118601 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118602 File
    118603 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118604 packages/chimerax/graphics/view.py", line 838, in picked_object 
    118605 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    118606 beyond, 
    118607 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118608 File
    118609 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118610 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    118611 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    118612 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118613 File
    118614 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118615 packages/chimerax/core/models.py", line 143, in first_intercept 
    118616 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    118617 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118618 File
    118619 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118620 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    118621 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    118622 exclude=exclude) 
    118623 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118624 File
    118625 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118626 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    118627 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    118628 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118629 File
    118630 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118631 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    118632 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    118633 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118634 File
    118635 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118636 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    118637 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    118638 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118639 File
    118640 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118641 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    118642 p = super().first_intercept(mxyz1, mxyz2) 
    118643 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118644 File
    118645 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118646 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    118647 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    118648 exclude=exclude) 
    118649 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118650 File
    118651 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118652 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    118653 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    118654 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118655 File
    118656 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118657 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    118658 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    118659 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118660 File
    118661 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118662 packages/chimerax/graphics/drawing.py", line 1108, in
    118663 _first_intercept_excluding_children 
    118664 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    118665 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118666 File
    118667 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118668 packages/chimerax/geometry/place.py", line 201, in inverse 
    118669 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    118670 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118671 File
    118672 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118673 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    118674 rinv[:, :] = matrix_inverse(r) 
    118675 ^^^^^^^^^^^^^^^^^ 
    118676 File
    118677 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118678 packages/numpy/linalg/linalg.py", line 561, in inv 
    118679 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    118680 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118681 File
    118682 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118683 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    118684 raise LinAlgError("Singular matrix") 
    118685 numpy.linalg.LinAlgError: Singular matrix 
    118686  
    118687 numpy.linalg.LinAlgError: Singular matrix 
    118688  
    118689 File
    118690 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118691 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    118692 raise LinAlgError("Singular matrix") 
    118693  
    118694 See log for complete Python traceback. 
    118695  
    118696 Traceback (most recent call last): 
    118697 File
    118698 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118699 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    118700 self.session.ui.mouse_modes.mouse_pause_tracking() 
    118701 File
    118702 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118703 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    118704 mouse_pause_tracking 
    118705 self._mouse_pause() 
    118706 File
    118707 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118708 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    118709 m.pause(self._mouse_pause_position) 
    118710 File
    118711 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118712 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    118713 p = self.view.picked_object(x, y) 
    118714 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118715 File
    118716 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118717 packages/chimerax/graphics/view.py", line 838, in picked_object 
    118718 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    118719 beyond, 
    118720 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118721 File
    118722 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118723 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    118724 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    118725 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118726 File
    118727 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118728 packages/chimerax/core/models.py", line 143, in first_intercept 
    118729 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    118730 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118731 File
    118732 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118733 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    118734 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    118735 exclude=exclude) 
    118736 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118737 File
    118738 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118739 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    118740 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    118741 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118742 File
    118743 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118744 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    118745 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    118746 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118747 File
    118748 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118749 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    118750 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    118751 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118752 File
    118753 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118754 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    118755 p = super().first_intercept(mxyz1, mxyz2) 
    118756 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118757 File
    118758 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118759 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    118760 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    118761 exclude=exclude) 
    118762 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118763 File
    118764 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118765 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    118766 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    118767 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118768 File
    118769 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118770 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    118771 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    118772 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118773 File
    118774 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118775 packages/chimerax/graphics/drawing.py", line 1108, in
    118776 _first_intercept_excluding_children 
    118777 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    118778 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118779 File
    118780 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118781 packages/chimerax/geometry/place.py", line 201, in inverse 
    118782 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    118783 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118784 File
    118785 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118786 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    118787 rinv[:, :] = matrix_inverse(r) 
    118788 ^^^^^^^^^^^^^^^^^ 
    118789 File
    118790 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118791 packages/numpy/linalg/linalg.py", line 561, in inv 
    118792 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    118793 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118794 File
    118795 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118796 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    118797 raise LinAlgError("Singular matrix") 
    118798 numpy.linalg.LinAlgError: Singular matrix 
    118799  
    118800 numpy.linalg.LinAlgError: Singular matrix 
    118801  
    118802 File
    118803 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118804 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    118805 raise LinAlgError("Singular matrix") 
    118806  
    118807 See log for complete Python traceback. 
    118808  
    118809 Traceback (most recent call last): 
    118810 File
    118811 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118812 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    118813 self.session.ui.mouse_modes.mouse_pause_tracking() 
    118814 File
    118815 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118816 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    118817 mouse_pause_tracking 
    118818 self._mouse_pause() 
    118819 File
    118820 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118821 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    118822 m.pause(self._mouse_pause_position) 
    118823 File
    118824 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118825 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    118826 p = self.view.picked_object(x, y) 
    118827 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118828 File
    118829 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118830 packages/chimerax/graphics/view.py", line 838, in picked_object 
    118831 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    118832 beyond, 
    118833 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118834 File
    118835 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118836 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    118837 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    118838 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118839 File
    118840 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118841 packages/chimerax/core/models.py", line 143, in first_intercept 
    118842 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    118843 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118844 File
    118845 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118846 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    118847 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    118848 exclude=exclude) 
    118849 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118850 File
    118851 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118852 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    118853 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    118854 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118855 File
    118856 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118857 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    118858 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    118859 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118860 File
    118861 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118862 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    118863 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    118864 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118865 File
    118866 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118867 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    118868 p = super().first_intercept(mxyz1, mxyz2) 
    118869 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118870 File
    118871 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118872 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    118873 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    118874 exclude=exclude) 
    118875 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118876 File
    118877 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118878 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    118879 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    118880 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118881 File
    118882 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118883 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    118884 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    118885 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118886 File
    118887 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118888 packages/chimerax/graphics/drawing.py", line 1108, in
    118889 _first_intercept_excluding_children 
    118890 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    118891 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118892 File
    118893 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118894 packages/chimerax/geometry/place.py", line 201, in inverse 
    118895 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    118896 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118897 File
    118898 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118899 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    118900 rinv[:, :] = matrix_inverse(r) 
    118901 ^^^^^^^^^^^^^^^^^ 
    118902 File
    118903 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118904 packages/numpy/linalg/linalg.py", line 561, in inv 
    118905 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    118906 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118907 File
    118908 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118909 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    118910 raise LinAlgError("Singular matrix") 
    118911 numpy.linalg.LinAlgError: Singular matrix 
    118912  
    118913 numpy.linalg.LinAlgError: Singular matrix 
    118914  
    118915 File
    118916 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118917 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    118918 raise LinAlgError("Singular matrix") 
    118919  
    118920 See log for complete Python traceback. 
    118921  
    118922 Traceback (most recent call last): 
    118923 File
    118924 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118925 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    118926 self.session.ui.mouse_modes.mouse_pause_tracking() 
    118927 File
    118928 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118929 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    118930 mouse_pause_tracking 
    118931 self._mouse_pause() 
    118932 File
    118933 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118934 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    118935 m.pause(self._mouse_pause_position) 
    118936 File
    118937 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118938 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    118939 p = self.view.picked_object(x, y) 
    118940 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118941 File
    118942 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118943 packages/chimerax/graphics/view.py", line 838, in picked_object 
    118944 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    118945 beyond, 
    118946 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118947 File
    118948 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118949 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    118950 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    118951 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118952 File
    118953 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118954 packages/chimerax/core/models.py", line 143, in first_intercept 
    118955 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    118956 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118957 File
    118958 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118959 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    118960 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    118961 exclude=exclude) 
    118962 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118963 File
    118964 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118965 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    118966 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    118967 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118968 File
    118969 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118970 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    118971 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    118972 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118973 File
    118974 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118975 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    118976 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    118977 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118978 File
    118979 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118980 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    118981 p = super().first_intercept(mxyz1, mxyz2) 
    118982 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118983 File
    118984 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118985 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    118986 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    118987 exclude=exclude) 
    118988 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118989 File
    118990 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118991 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    118992 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    118993 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118994 File
    118995 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    118996 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    118997 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    118998 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    118999 File
    119000 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119001 packages/chimerax/graphics/drawing.py", line 1108, in
    119002 _first_intercept_excluding_children 
    119003 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    119004 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119005 File
    119006 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119007 packages/chimerax/geometry/place.py", line 201, in inverse 
    119008 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    119009 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119010 File
    119011 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119012 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    119013 rinv[:, :] = matrix_inverse(r) 
    119014 ^^^^^^^^^^^^^^^^^ 
    119015 File
    119016 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119017 packages/numpy/linalg/linalg.py", line 561, in inv 
    119018 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    119019 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119020 File
    119021 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119022 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    119023 raise LinAlgError("Singular matrix") 
    119024 numpy.linalg.LinAlgError: Singular matrix 
    119025  
    119026 numpy.linalg.LinAlgError: Singular matrix 
    119027  
    119028 File
    119029 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119030 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    119031 raise LinAlgError("Singular matrix") 
    119032  
    119033 See log for complete Python traceback. 
    119034  
    119035 Traceback (most recent call last): 
    119036 File
    119037 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119038 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    119039 self.session.ui.mouse_modes.mouse_pause_tracking() 
    119040 File
    119041 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119042 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    119043 mouse_pause_tracking 
    119044 self._mouse_pause() 
    119045 File
    119046 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119047 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    119048 m.pause(self._mouse_pause_position) 
    119049 File
    119050 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119051 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    119052 p = self.view.picked_object(x, y) 
    119053 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119054 File
    119055 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119056 packages/chimerax/graphics/view.py", line 838, in picked_object 
    119057 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    119058 beyond, 
    119059 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119060 File
    119061 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119062 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    119063 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    119064 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119065 File
    119066 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119067 packages/chimerax/core/models.py", line 143, in first_intercept 
    119068 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    119069 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119070 File
    119071 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119072 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    119073 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    119074 exclude=exclude) 
    119075 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119076 File
    119077 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119078 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    119079 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    119080 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119081 File
    119082 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119083 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    119084 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    119085 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119086 File
    119087 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119088 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    119089 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    119090 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119091 File
    119092 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119093 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    119094 p = super().first_intercept(mxyz1, mxyz2) 
    119095 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119096 File
    119097 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119098 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    119099 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    119100 exclude=exclude) 
    119101 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119102 File
    119103 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119104 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    119105 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    119106 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119107 File
    119108 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119109 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    119110 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    119111 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119112 File
    119113 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119114 packages/chimerax/graphics/drawing.py", line 1108, in
    119115 _first_intercept_excluding_children 
    119116 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    119117 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119118 File
    119119 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119120 packages/chimerax/geometry/place.py", line 201, in inverse 
    119121 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    119122 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119123 File
    119124 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119125 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    119126 rinv[:, :] = matrix_inverse(r) 
    119127 ^^^^^^^^^^^^^^^^^ 
    119128 File
    119129 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119130 packages/numpy/linalg/linalg.py", line 561, in inv 
    119131 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    119132 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119133 File
    119134 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119135 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    119136 raise LinAlgError("Singular matrix") 
    119137 numpy.linalg.LinAlgError: Singular matrix 
    119138  
    119139 numpy.linalg.LinAlgError: Singular matrix 
    119140  
    119141 File
    119142 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119143 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    119144 raise LinAlgError("Singular matrix") 
    119145  
    119146 See log for complete Python traceback. 
    119147  
    119148 Traceback (most recent call last): 
    119149 File
    119150 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119151 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    119152 self.session.ui.mouse_modes.mouse_pause_tracking() 
    119153 File
    119154 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119155 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    119156 mouse_pause_tracking 
    119157 self._mouse_pause() 
    119158 File
    119159 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119160 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    119161 m.pause(self._mouse_pause_position) 
    119162 File
    119163 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119164 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    119165 p = self.view.picked_object(x, y) 
    119166 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119167 File
    119168 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119169 packages/chimerax/graphics/view.py", line 838, in picked_object 
    119170 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    119171 beyond, 
    119172 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119173 File
    119174 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119175 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    119176 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    119177 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119178 File
    119179 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119180 packages/chimerax/core/models.py", line 143, in first_intercept 
    119181 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    119182 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119183 File
    119184 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119185 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    119186 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    119187 exclude=exclude) 
    119188 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119189 File
    119190 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119191 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    119192 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    119193 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119194 File
    119195 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119196 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    119197 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    119198 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119199 File
    119200 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119201 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    119202 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    119203 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119204 File
    119205 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119206 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    119207 p = super().first_intercept(mxyz1, mxyz2) 
    119208 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119209 File
    119210 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119211 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    119212 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    119213 exclude=exclude) 
    119214 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119215 File
    119216 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119217 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    119218 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    119219 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119220 File
    119221 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119222 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    119223 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    119224 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119225 File
    119226 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119227 packages/chimerax/graphics/drawing.py", line 1108, in
    119228 _first_intercept_excluding_children 
    119229 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    119230 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119231 File
    119232 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119233 packages/chimerax/geometry/place.py", line 201, in inverse 
    119234 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    119235 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119236 File
    119237 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119238 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    119239 rinv[:, :] = matrix_inverse(r) 
    119240 ^^^^^^^^^^^^^^^^^ 
    119241 File
    119242 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119243 packages/numpy/linalg/linalg.py", line 561, in inv 
    119244 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    119245 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119246 File
    119247 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119248 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    119249 raise LinAlgError("Singular matrix") 
    119250 numpy.linalg.LinAlgError: Singular matrix 
    119251  
    119252 numpy.linalg.LinAlgError: Singular matrix 
    119253  
    119254 File
    119255 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119256 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    119257 raise LinAlgError("Singular matrix") 
    119258  
    119259 See log for complete Python traceback. 
    119260  
    119261 Traceback (most recent call last): 
    119262 File
    119263 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119264 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    119265 self.session.ui.mouse_modes.mouse_pause_tracking() 
    119266 File
    119267 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119268 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    119269 mouse_pause_tracking 
    119270 self._mouse_pause() 
    119271 File
    119272 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119273 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    119274 m.pause(self._mouse_pause_position) 
    119275 File
    119276 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119277 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    119278 p = self.view.picked_object(x, y) 
    119279 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119280 File
    119281 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119282 packages/chimerax/graphics/view.py", line 838, in picked_object 
    119283 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    119284 beyond, 
    119285 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119286 File
    119287 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119288 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    119289 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    119290 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119291 File
    119292 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119293 packages/chimerax/core/models.py", line 143, in first_intercept 
    119294 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    119295 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119296 File
    119297 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119298 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    119299 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    119300 exclude=exclude) 
    119301 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119302 File
    119303 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119304 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    119305 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    119306 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119307 File
    119308 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119309 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    119310 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    119311 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119312 File
    119313 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119314 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    119315 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    119316 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119317 File
    119318 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119319 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    119320 p = super().first_intercept(mxyz1, mxyz2) 
    119321 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119322 File
    119323 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119324 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    119325 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    119326 exclude=exclude) 
    119327 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119328 File
    119329 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119330 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    119331 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    119332 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119333 File
    119334 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119335 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    119336 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    119337 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119338 File
    119339 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119340 packages/chimerax/graphics/drawing.py", line 1108, in
    119341 _first_intercept_excluding_children 
    119342 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    119343 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119344 File
    119345 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119346 packages/chimerax/geometry/place.py", line 201, in inverse 
    119347 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    119348 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119349 File
    119350 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119351 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    119352 rinv[:, :] = matrix_inverse(r) 
    119353 ^^^^^^^^^^^^^^^^^ 
    119354 File
    119355 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119356 packages/numpy/linalg/linalg.py", line 561, in inv 
    119357 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    119358 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119359 File
    119360 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119361 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    119362 raise LinAlgError("Singular matrix") 
    119363 numpy.linalg.LinAlgError: Singular matrix 
    119364  
    119365 numpy.linalg.LinAlgError: Singular matrix 
    119366  
    119367 File
    119368 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119369 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    119370 raise LinAlgError("Singular matrix") 
    119371  
    119372 See log for complete Python traceback. 
    119373  
    119374 Traceback (most recent call last): 
    119375 File
    119376 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119377 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    119378 self.session.ui.mouse_modes.mouse_pause_tracking() 
    119379 File
    119380 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119381 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    119382 mouse_pause_tracking 
    119383 self._mouse_pause() 
    119384 File
    119385 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119386 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    119387 m.pause(self._mouse_pause_position) 
    119388 File
    119389 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119390 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    119391 p = self.view.picked_object(x, y) 
    119392 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119393 File
    119394 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119395 packages/chimerax/graphics/view.py", line 838, in picked_object 
    119396 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    119397 beyond, 
    119398 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119399 File
    119400 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119401 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    119402 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    119403 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119404 File
    119405 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119406 packages/chimerax/core/models.py", line 143, in first_intercept 
    119407 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    119408 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119409 File
    119410 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119411 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    119412 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    119413 exclude=exclude) 
    119414 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119415 File
    119416 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119417 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    119418 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    119419 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119420 File
    119421 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119422 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    119423 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    119424 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119425 File
    119426 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119427 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    119428 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    119429 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119430 File
    119431 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119432 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    119433 p = super().first_intercept(mxyz1, mxyz2) 
    119434 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119435 File
    119436 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119437 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    119438 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    119439 exclude=exclude) 
    119440 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119441 File
    119442 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119443 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    119444 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    119445 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119446 File
    119447 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119448 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    119449 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    119450 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119451 File
    119452 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119453 packages/chimerax/graphics/drawing.py", line 1108, in
    119454 _first_intercept_excluding_children 
    119455 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    119456 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119457 File
    119458 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119459 packages/chimerax/geometry/place.py", line 201, in inverse 
    119460 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    119461 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119462 File
    119463 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119464 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    119465 rinv[:, :] = matrix_inverse(r) 
    119466 ^^^^^^^^^^^^^^^^^ 
    119467 File
    119468 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119469 packages/numpy/linalg/linalg.py", line 561, in inv 
    119470 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    119471 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119472 File
    119473 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119474 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    119475 raise LinAlgError("Singular matrix") 
    119476 numpy.linalg.LinAlgError: Singular matrix 
    119477  
    119478 numpy.linalg.LinAlgError: Singular matrix 
    119479  
    119480 File
    119481 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119482 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    119483 raise LinAlgError("Singular matrix") 
    119484  
    119485 See log for complete Python traceback. 
    119486  
    119487 Traceback (most recent call last): 
    119488 File
    119489 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119490 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    119491 self.session.ui.mouse_modes.mouse_pause_tracking() 
    119492 File
    119493 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119494 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    119495 mouse_pause_tracking 
    119496 self._mouse_pause() 
    119497 File
    119498 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119499 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    119500 m.pause(self._mouse_pause_position) 
    119501 File
    119502 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119503 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    119504 p = self.view.picked_object(x, y) 
    119505 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119506 File
    119507 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119508 packages/chimerax/graphics/view.py", line 838, in picked_object 
    119509 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    119510 beyond, 
    119511 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119512 File
    119513 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119514 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    119515 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    119516 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119517 File
    119518 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119519 packages/chimerax/core/models.py", line 143, in first_intercept 
    119520 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    119521 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119522 File
    119523 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119524 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    119525 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    119526 exclude=exclude) 
    119527 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119528 File
    119529 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119530 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    119531 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    119532 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119533 File
    119534 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119535 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    119536 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    119537 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119538 File
    119539 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119540 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    119541 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    119542 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119543 File
    119544 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119545 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    119546 p = super().first_intercept(mxyz1, mxyz2) 
    119547 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119548 File
    119549 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119550 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    119551 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    119552 exclude=exclude) 
    119553 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119554 File
    119555 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119556 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    119557 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    119558 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119559 File
    119560 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119561 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    119562 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    119563 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119564 File
    119565 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119566 packages/chimerax/graphics/drawing.py", line 1108, in
    119567 _first_intercept_excluding_children 
    119568 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    119569 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119570 File
    119571 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119572 packages/chimerax/geometry/place.py", line 201, in inverse 
    119573 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    119574 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119575 File
    119576 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119577 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    119578 rinv[:, :] = matrix_inverse(r) 
    119579 ^^^^^^^^^^^^^^^^^ 
    119580 File
    119581 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119582 packages/numpy/linalg/linalg.py", line 561, in inv 
    119583 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    119584 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119585 File
    119586 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119587 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    119588 raise LinAlgError("Singular matrix") 
    119589 numpy.linalg.LinAlgError: Singular matrix 
    119590  
    119591 numpy.linalg.LinAlgError: Singular matrix 
    119592  
    119593 File
    119594 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119595 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    119596 raise LinAlgError("Singular matrix") 
    119597  
    119598 See log for complete Python traceback. 
    119599  
    119600 Traceback (most recent call last): 
    119601 File
    119602 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119603 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    119604 self.session.ui.mouse_modes.mouse_pause_tracking() 
    119605 File
    119606 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119607 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    119608 mouse_pause_tracking 
    119609 self._mouse_pause() 
    119610 File
    119611 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119612 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    119613 m.pause(self._mouse_pause_position) 
    119614 File
    119615 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119616 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    119617 p = self.view.picked_object(x, y) 
    119618 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119619 File
    119620 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119621 packages/chimerax/graphics/view.py", line 838, in picked_object 
    119622 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    119623 beyond, 
    119624 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119625 File
    119626 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119627 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    119628 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    119629 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119630 File
    119631 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119632 packages/chimerax/core/models.py", line 143, in first_intercept 
    119633 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    119634 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119635 File
    119636 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119637 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    119638 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    119639 exclude=exclude) 
    119640 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119641 File
    119642 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119643 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    119644 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    119645 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119646 File
    119647 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119648 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    119649 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    119650 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119651 File
    119652 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119653 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    119654 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    119655 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119656 File
    119657 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119658 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    119659 p = super().first_intercept(mxyz1, mxyz2) 
    119660 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119661 File
    119662 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119663 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    119664 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    119665 exclude=exclude) 
    119666 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119667 File
    119668 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119669 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    119670 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    119671 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119672 File
    119673 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119674 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    119675 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    119676 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119677 File
    119678 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119679 packages/chimerax/graphics/drawing.py", line 1108, in
    119680 _first_intercept_excluding_children 
    119681 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    119682 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119683 File
    119684 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119685 packages/chimerax/geometry/place.py", line 201, in inverse 
    119686 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    119687 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119688 File
    119689 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119690 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    119691 rinv[:, :] = matrix_inverse(r) 
    119692 ^^^^^^^^^^^^^^^^^ 
    119693 File
    119694 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119695 packages/numpy/linalg/linalg.py", line 561, in inv 
    119696 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    119697 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119698 File
    119699 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119700 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    119701 raise LinAlgError("Singular matrix") 
    119702 numpy.linalg.LinAlgError: Singular matrix 
    119703  
    119704 numpy.linalg.LinAlgError: Singular matrix 
    119705  
    119706 File
    119707 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119708 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    119709 raise LinAlgError("Singular matrix") 
    119710  
    119711 See log for complete Python traceback. 
    119712  
    119713 Traceback (most recent call last): 
    119714 File
    119715 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119716 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    119717 self.session.ui.mouse_modes.mouse_pause_tracking() 
    119718 File
    119719 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119720 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    119721 mouse_pause_tracking 
    119722 self._mouse_pause() 
    119723 File
    119724 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119725 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    119726 m.pause(self._mouse_pause_position) 
    119727 File
    119728 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119729 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    119730 p = self.view.picked_object(x, y) 
    119731 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119732 File
    119733 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119734 packages/chimerax/graphics/view.py", line 838, in picked_object 
    119735 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    119736 beyond, 
    119737 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119738 File
    119739 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119740 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    119741 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    119742 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119743 File
    119744 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119745 packages/chimerax/core/models.py", line 143, in first_intercept 
    119746 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    119747 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119748 File
    119749 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119750 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    119751 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    119752 exclude=exclude) 
    119753 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119754 File
    119755 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119756 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    119757 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    119758 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119759 File
    119760 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119761 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    119762 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    119763 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119764 File
    119765 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119766 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    119767 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    119768 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119769 File
    119770 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119771 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    119772 p = super().first_intercept(mxyz1, mxyz2) 
    119773 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119774 File
    119775 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119776 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    119777 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    119778 exclude=exclude) 
    119779 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119780 File
    119781 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119782 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    119783 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    119784 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119785 File
    119786 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119787 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    119788 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    119789 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119790 File
    119791 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119792 packages/chimerax/graphics/drawing.py", line 1108, in
    119793 _first_intercept_excluding_children 
    119794 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    119795 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119796 File
    119797 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119798 packages/chimerax/geometry/place.py", line 201, in inverse 
    119799 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    119800 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119801 File
    119802 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119803 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    119804 rinv[:, :] = matrix_inverse(r) 
    119805 ^^^^^^^^^^^^^^^^^ 
    119806 File
    119807 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119808 packages/numpy/linalg/linalg.py", line 561, in inv 
    119809 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    119810 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119811 File
    119812 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119813 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    119814 raise LinAlgError("Singular matrix") 
    119815 numpy.linalg.LinAlgError: Singular matrix 
    119816  
    119817 numpy.linalg.LinAlgError: Singular matrix 
    119818  
    119819 File
    119820 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119821 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    119822 raise LinAlgError("Singular matrix") 
    119823  
    119824 See log for complete Python traceback. 
    119825  
    119826 Traceback (most recent call last): 
    119827 File
    119828 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119829 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    119830 self.session.ui.mouse_modes.mouse_pause_tracking() 
    119831 File
    119832 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119833 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    119834 mouse_pause_tracking 
    119835 self._mouse_pause() 
    119836 File
    119837 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119838 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    119839 m.pause(self._mouse_pause_position) 
    119840 File
    119841 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119842 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    119843 p = self.view.picked_object(x, y) 
    119844 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119845 File
    119846 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119847 packages/chimerax/graphics/view.py", line 838, in picked_object 
    119848 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    119849 beyond, 
    119850 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119851 File
    119852 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119853 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    119854 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    119855 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119856 File
    119857 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119858 packages/chimerax/core/models.py", line 143, in first_intercept 
    119859 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    119860 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119861 File
    119862 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119863 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    119864 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    119865 exclude=exclude) 
    119866 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119867 File
    119868 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119869 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    119870 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    119871 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119872 File
    119873 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119874 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    119875 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    119876 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119877 File
    119878 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119879 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    119880 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    119881 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119882 File
    119883 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119884 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    119885 p = super().first_intercept(mxyz1, mxyz2) 
    119886 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119887 File
    119888 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119889 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    119890 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    119891 exclude=exclude) 
    119892 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119893 File
    119894 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119895 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    119896 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    119897 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119898 File
    119899 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119900 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    119901 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    119902 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119903 File
    119904 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119905 packages/chimerax/graphics/drawing.py", line 1108, in
    119906 _first_intercept_excluding_children 
    119907 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    119908 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119909 File
    119910 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119911 packages/chimerax/geometry/place.py", line 201, in inverse 
    119912 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    119913 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119914 File
    119915 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119916 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    119917 rinv[:, :] = matrix_inverse(r) 
    119918 ^^^^^^^^^^^^^^^^^ 
    119919 File
    119920 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119921 packages/numpy/linalg/linalg.py", line 561, in inv 
    119922 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    119923 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119924 File
    119925 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119926 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    119927 raise LinAlgError("Singular matrix") 
    119928 numpy.linalg.LinAlgError: Singular matrix 
    119929  
    119930 numpy.linalg.LinAlgError: Singular matrix 
    119931  
    119932 File
    119933 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119934 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    119935 raise LinAlgError("Singular matrix") 
    119936  
    119937 See log for complete Python traceback. 
    119938  
    119939 Traceback (most recent call last): 
    119940 File
    119941 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119942 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    119943 self.session.ui.mouse_modes.mouse_pause_tracking() 
    119944 File
    119945 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119946 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    119947 mouse_pause_tracking 
    119948 self._mouse_pause() 
    119949 File
    119950 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119951 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    119952 m.pause(self._mouse_pause_position) 
    119953 File
    119954 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119955 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    119956 p = self.view.picked_object(x, y) 
    119957 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119958 File
    119959 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119960 packages/chimerax/graphics/view.py", line 838, in picked_object 
    119961 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    119962 beyond, 
    119963 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119964 File
    119965 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119966 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    119967 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    119968 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119969 File
    119970 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119971 packages/chimerax/core/models.py", line 143, in first_intercept 
    119972 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    119973 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119974 File
    119975 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119976 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    119977 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    119978 exclude=exclude) 
    119979 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119980 File
    119981 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119982 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    119983 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    119984 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119985 File
    119986 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119987 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    119988 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    119989 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119990 File
    119991 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119992 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    119993 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    119994 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    119995 File
    119996 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    119997 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    119998 p = super().first_intercept(mxyz1, mxyz2) 
    119999 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120000 File
    120001 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120002 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    120003 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    120004 exclude=exclude) 
    120005 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120006 File
    120007 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120008 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    120009 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    120010 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120011 File
    120012 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120013 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    120014 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    120015 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120016 File
    120017 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120018 packages/chimerax/graphics/drawing.py", line 1108, in
    120019 _first_intercept_excluding_children 
    120020 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    120021 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120022 File
    120023 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120024 packages/chimerax/geometry/place.py", line 201, in inverse 
    120025 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    120026 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120027 File
    120028 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120029 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    120030 rinv[:, :] = matrix_inverse(r) 
    120031 ^^^^^^^^^^^^^^^^^ 
    120032 File
    120033 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120034 packages/numpy/linalg/linalg.py", line 561, in inv 
    120035 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    120036 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120037 File
    120038 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120039 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    120040 raise LinAlgError("Singular matrix") 
    120041 numpy.linalg.LinAlgError: Singular matrix 
    120042  
    120043 numpy.linalg.LinAlgError: Singular matrix 
    120044  
    120045 File
    120046 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120047 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    120048 raise LinAlgError("Singular matrix") 
    120049  
    120050 See log for complete Python traceback. 
    120051  
    120052 Traceback (most recent call last): 
    120053 File
    120054 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120055 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    120056 self.session.ui.mouse_modes.mouse_pause_tracking() 
    120057 File
    120058 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120059 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    120060 mouse_pause_tracking 
    120061 self._mouse_pause() 
    120062 File
    120063 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120064 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    120065 m.pause(self._mouse_pause_position) 
    120066 File
    120067 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120068 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    120069 p = self.view.picked_object(x, y) 
    120070 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120071 File
    120072 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120073 packages/chimerax/graphics/view.py", line 838, in picked_object 
    120074 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    120075 beyond, 
    120076 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120077 File
    120078 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120079 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    120080 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    120081 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120082 File
    120083 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120084 packages/chimerax/core/models.py", line 143, in first_intercept 
    120085 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    120086 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120087 File
    120088 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120089 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    120090 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    120091 exclude=exclude) 
    120092 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120093 File
    120094 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120095 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    120096 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    120097 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120098 File
    120099 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120100 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    120101 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    120102 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120103 File
    120104 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120105 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    120106 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    120107 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120108 File
    120109 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120110 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    120111 p = super().first_intercept(mxyz1, mxyz2) 
    120112 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120113 File
    120114 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120115 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    120116 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    120117 exclude=exclude) 
    120118 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120119 File
    120120 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120121 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    120122 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    120123 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120124 File
    120125 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120126 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    120127 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    120128 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120129 File
    120130 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120131 packages/chimerax/graphics/drawing.py", line 1108, in
    120132 _first_intercept_excluding_children 
    120133 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    120134 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120135 File
    120136 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120137 packages/chimerax/geometry/place.py", line 201, in inverse 
    120138 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    120139 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120140 File
    120141 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120142 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    120143 rinv[:, :] = matrix_inverse(r) 
    120144 ^^^^^^^^^^^^^^^^^ 
    120145 File
    120146 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120147 packages/numpy/linalg/linalg.py", line 561, in inv 
    120148 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    120149 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120150 File
    120151 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120152 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    120153 raise LinAlgError("Singular matrix") 
    120154 numpy.linalg.LinAlgError: Singular matrix 
    120155  
    120156 numpy.linalg.LinAlgError: Singular matrix 
    120157  
    120158 File
    120159 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120160 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    120161 raise LinAlgError("Singular matrix") 
    120162  
    120163 See log for complete Python traceback. 
    120164  
    120165 Traceback (most recent call last): 
    120166 File
    120167 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120168 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    120169 self.session.ui.mouse_modes.mouse_pause_tracking() 
    120170 File
    120171 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120172 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    120173 mouse_pause_tracking 
    120174 self._mouse_pause() 
    120175 File
    120176 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120177 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    120178 m.pause(self._mouse_pause_position) 
    120179 File
    120180 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120181 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    120182 p = self.view.picked_object(x, y) 
    120183 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120184 File
    120185 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120186 packages/chimerax/graphics/view.py", line 838, in picked_object 
    120187 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    120188 beyond, 
    120189 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120190 File
    120191 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120192 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    120193 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    120194 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120195 File
    120196 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120197 packages/chimerax/core/models.py", line 143, in first_intercept 
    120198 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    120199 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120200 File
    120201 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120202 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    120203 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    120204 exclude=exclude) 
    120205 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120206 File
    120207 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120208 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    120209 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    120210 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120211 File
    120212 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120213 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    120214 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    120215 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120216 File
    120217 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120218 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    120219 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    120220 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120221 File
    120222 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120223 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    120224 p = super().first_intercept(mxyz1, mxyz2) 
    120225 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120226 File
    120227 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120228 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    120229 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    120230 exclude=exclude) 
    120231 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120232 File
    120233 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120234 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    120235 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    120236 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120237 File
    120238 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120239 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    120240 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    120241 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120242 File
    120243 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120244 packages/chimerax/graphics/drawing.py", line 1108, in
    120245 _first_intercept_excluding_children 
    120246 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    120247 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120248 File
    120249 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120250 packages/chimerax/geometry/place.py", line 201, in inverse 
    120251 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    120252 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120253 File
    120254 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120255 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    120256 rinv[:, :] = matrix_inverse(r) 
    120257 ^^^^^^^^^^^^^^^^^ 
    120258 File
    120259 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120260 packages/numpy/linalg/linalg.py", line 561, in inv 
    120261 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    120262 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120263 File
    120264 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120265 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    120266 raise LinAlgError("Singular matrix") 
    120267 numpy.linalg.LinAlgError: Singular matrix 
    120268  
    120269 numpy.linalg.LinAlgError: Singular matrix 
    120270  
    120271 File
    120272 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120273 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    120274 raise LinAlgError("Singular matrix") 
    120275  
    120276 See log for complete Python traceback. 
    120277  
    120278 Traceback (most recent call last): 
    120279 File
    120280 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120281 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    120282 self.session.ui.mouse_modes.mouse_pause_tracking() 
    120283 File
    120284 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120285 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    120286 mouse_pause_tracking 
    120287 self._mouse_pause() 
    120288 File
    120289 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120290 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    120291 m.pause(self._mouse_pause_position) 
    120292 File
    120293 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120294 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    120295 p = self.view.picked_object(x, y) 
    120296 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120297 File
    120298 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120299 packages/chimerax/graphics/view.py", line 838, in picked_object 
    120300 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    120301 beyond, 
    120302 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120303 File
    120304 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120305 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    120306 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    120307 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120308 File
    120309 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120310 packages/chimerax/core/models.py", line 143, in first_intercept 
    120311 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    120312 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120313 File
    120314 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120315 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    120316 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    120317 exclude=exclude) 
    120318 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120319 File
    120320 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120321 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    120322 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    120323 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120324 File
    120325 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120326 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    120327 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    120328 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120329 File
    120330 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120331 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    120332 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    120333 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120334 File
    120335 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120336 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    120337 p = super().first_intercept(mxyz1, mxyz2) 
    120338 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120339 File
    120340 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120341 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    120342 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    120343 exclude=exclude) 
    120344 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120345 File
    120346 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120347 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    120348 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    120349 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120350 File
    120351 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120352 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    120353 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    120354 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120355 File
    120356 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120357 packages/chimerax/graphics/drawing.py", line 1108, in
    120358 _first_intercept_excluding_children 
    120359 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    120360 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120361 File
    120362 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120363 packages/chimerax/geometry/place.py", line 201, in inverse 
    120364 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    120365 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120366 File
    120367 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120368 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    120369 rinv[:, :] = matrix_inverse(r) 
    120370 ^^^^^^^^^^^^^^^^^ 
    120371 File
    120372 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120373 packages/numpy/linalg/linalg.py", line 561, in inv 
    120374 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    120375 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120376 File
    120377 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120378 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    120379 raise LinAlgError("Singular matrix") 
    120380 numpy.linalg.LinAlgError: Singular matrix 
    120381  
    120382 numpy.linalg.LinAlgError: Singular matrix 
    120383  
    120384 File
    120385 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120386 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    120387 raise LinAlgError("Singular matrix") 
    120388  
    120389 See log for complete Python traceback. 
    120390  
    120391 Traceback (most recent call last): 
    120392 File
    120393 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120394 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    120395 self.session.ui.mouse_modes.mouse_pause_tracking() 
    120396 File
    120397 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120398 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    120399 mouse_pause_tracking 
    120400 self._mouse_pause() 
    120401 File
    120402 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120403 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    120404 m.pause(self._mouse_pause_position) 
    120405 File
    120406 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120407 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    120408 p = self.view.picked_object(x, y) 
    120409 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120410 File
    120411 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120412 packages/chimerax/graphics/view.py", line 838, in picked_object 
    120413 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    120414 beyond, 
    120415 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120416 File
    120417 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120418 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    120419 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    120420 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120421 File
    120422 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120423 packages/chimerax/core/models.py", line 143, in first_intercept 
    120424 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    120425 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120426 File
    120427 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120428 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    120429 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    120430 exclude=exclude) 
    120431 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120432 File
    120433 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120434 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    120435 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    120436 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120437 File
    120438 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120439 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    120440 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    120441 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120442 File
    120443 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120444 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    120445 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    120446 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120447 File
    120448 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120449 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    120450 p = super().first_intercept(mxyz1, mxyz2) 
    120451 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120452 File
    120453 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120454 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    120455 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    120456 exclude=exclude) 
    120457 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120458 File
    120459 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120460 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    120461 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    120462 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120463 File
    120464 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120465 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    120466 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    120467 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120468 File
    120469 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120470 packages/chimerax/graphics/drawing.py", line 1108, in
    120471 _first_intercept_excluding_children 
    120472 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    120473 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120474 File
    120475 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120476 packages/chimerax/geometry/place.py", line 201, in inverse 
    120477 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    120478 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120479 File
    120480 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120481 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    120482 rinv[:, :] = matrix_inverse(r) 
    120483 ^^^^^^^^^^^^^^^^^ 
    120484 File
    120485 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120486 packages/numpy/linalg/linalg.py", line 561, in inv 
    120487 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    120488 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120489 File
    120490 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120491 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    120492 raise LinAlgError("Singular matrix") 
    120493 numpy.linalg.LinAlgError: Singular matrix 
    120494  
    120495 numpy.linalg.LinAlgError: Singular matrix 
    120496  
    120497 File
    120498 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120499 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    120500 raise LinAlgError("Singular matrix") 
    120501  
    120502 See log for complete Python traceback. 
    120503  
    120504 Traceback (most recent call last): 
    120505 File
    120506 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120507 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    120508 self.session.ui.mouse_modes.mouse_pause_tracking() 
    120509 File
    120510 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120511 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    120512 mouse_pause_tracking 
    120513 self._mouse_pause() 
    120514 File
    120515 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120516 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    120517 m.pause(self._mouse_pause_position) 
    120518 File
    120519 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120520 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    120521 p = self.view.picked_object(x, y) 
    120522 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120523 File
    120524 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120525 packages/chimerax/graphics/view.py", line 838, in picked_object 
    120526 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    120527 beyond, 
    120528 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120529 File
    120530 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120531 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    120532 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    120533 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120534 File
    120535 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120536 packages/chimerax/core/models.py", line 143, in first_intercept 
    120537 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    120538 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120539 File
    120540 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120541 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    120542 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    120543 exclude=exclude) 
    120544 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120545 File
    120546 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120547 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    120548 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    120549 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120550 File
    120551 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120552 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    120553 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    120554 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120555 File
    120556 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120557 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    120558 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    120559 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120560 File
    120561 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120562 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    120563 p = super().first_intercept(mxyz1, mxyz2) 
    120564 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120565 File
    120566 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120567 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    120568 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    120569 exclude=exclude) 
    120570 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120571 File
    120572 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120573 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    120574 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    120575 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120576 File
    120577 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120578 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    120579 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    120580 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120581 File
    120582 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120583 packages/chimerax/graphics/drawing.py", line 1108, in
    120584 _first_intercept_excluding_children 
    120585 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    120586 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120587 File
    120588 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120589 packages/chimerax/geometry/place.py", line 201, in inverse 
    120590 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    120591 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120592 File
    120593 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120594 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    120595 rinv[:, :] = matrix_inverse(r) 
    120596 ^^^^^^^^^^^^^^^^^ 
    120597 File
    120598 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120599 packages/numpy/linalg/linalg.py", line 561, in inv 
    120600 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    120601 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120602 File
    120603 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120604 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    120605 raise LinAlgError("Singular matrix") 
    120606 numpy.linalg.LinAlgError: Singular matrix 
    120607  
    120608 numpy.linalg.LinAlgError: Singular matrix 
    120609  
    120610 File
    120611 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120612 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    120613 raise LinAlgError("Singular matrix") 
    120614  
    120615 See log for complete Python traceback. 
    120616  
    120617 Traceback (most recent call last): 
    120618 File
    120619 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120620 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    120621 self.session.ui.mouse_modes.mouse_pause_tracking() 
    120622 File
    120623 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120624 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    120625 mouse_pause_tracking 
    120626 self._mouse_pause() 
    120627 File
    120628 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120629 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    120630 m.pause(self._mouse_pause_position) 
    120631 File
    120632 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120633 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    120634 p = self.view.picked_object(x, y) 
    120635 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120636 File
    120637 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120638 packages/chimerax/graphics/view.py", line 838, in picked_object 
    120639 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    120640 beyond, 
    120641 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120642 File
    120643 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120644 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    120645 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    120646 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120647 File
    120648 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120649 packages/chimerax/core/models.py", line 143, in first_intercept 
    120650 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    120651 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120652 File
    120653 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120654 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    120655 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    120656 exclude=exclude) 
    120657 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120658 File
    120659 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120660 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    120661 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    120662 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120663 File
    120664 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120665 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    120666 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    120667 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120668 File
    120669 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120670 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    120671 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    120672 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120673 File
    120674 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120675 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    120676 p = super().first_intercept(mxyz1, mxyz2) 
    120677 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120678 File
    120679 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120680 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    120681 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    120682 exclude=exclude) 
    120683 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120684 File
    120685 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120686 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    120687 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    120688 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120689 File
    120690 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120691 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    120692 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    120693 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120694 File
    120695 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120696 packages/chimerax/graphics/drawing.py", line 1108, in
    120697 _first_intercept_excluding_children 
    120698 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    120699 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120700 File
    120701 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120702 packages/chimerax/geometry/place.py", line 201, in inverse 
    120703 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    120704 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120705 File
    120706 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120707 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    120708 rinv[:, :] = matrix_inverse(r) 
    120709 ^^^^^^^^^^^^^^^^^ 
    120710 File
    120711 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120712 packages/numpy/linalg/linalg.py", line 561, in inv 
    120713 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    120714 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120715 File
    120716 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120717 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    120718 raise LinAlgError("Singular matrix") 
    120719 numpy.linalg.LinAlgError: Singular matrix 
    120720  
    120721 numpy.linalg.LinAlgError: Singular matrix 
    120722  
    120723 File
    120724 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120725 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    120726 raise LinAlgError("Singular matrix") 
    120727  
    120728 See log for complete Python traceback. 
    120729  
    120730 Traceback (most recent call last): 
    120731 File
    120732 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120733 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    120734 self.session.ui.mouse_modes.mouse_pause_tracking() 
    120735 File
    120736 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120737 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    120738 mouse_pause_tracking 
    120739 self._mouse_pause() 
    120740 File
    120741 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120742 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    120743 m.pause(self._mouse_pause_position) 
    120744 File
    120745 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120746 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    120747 p = self.view.picked_object(x, y) 
    120748 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120749 File
    120750 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120751 packages/chimerax/graphics/view.py", line 838, in picked_object 
    120752 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    120753 beyond, 
    120754 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120755 File
    120756 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120757 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    120758 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    120759 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120760 File
    120761 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120762 packages/chimerax/core/models.py", line 143, in first_intercept 
    120763 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    120764 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120765 File
    120766 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120767 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    120768 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    120769 exclude=exclude) 
    120770 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120771 File
    120772 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120773 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    120774 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    120775 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120776 File
    120777 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120778 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    120779 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    120780 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120781 File
    120782 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120783 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    120784 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    120785 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120786 File
    120787 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120788 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    120789 p = super().first_intercept(mxyz1, mxyz2) 
    120790 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120791 File
    120792 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120793 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    120794 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    120795 exclude=exclude) 
    120796 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120797 File
    120798 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120799 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    120800 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    120801 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120802 File
    120803 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120804 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    120805 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    120806 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120807 File
    120808 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120809 packages/chimerax/graphics/drawing.py", line 1108, in
    120810 _first_intercept_excluding_children 
    120811 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    120812 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120813 File
    120814 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120815 packages/chimerax/geometry/place.py", line 201, in inverse 
    120816 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    120817 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120818 File
    120819 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120820 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    120821 rinv[:, :] = matrix_inverse(r) 
    120822 ^^^^^^^^^^^^^^^^^ 
    120823 File
    120824 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120825 packages/numpy/linalg/linalg.py", line 561, in inv 
    120826 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    120827 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120828 File
    120829 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120830 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    120831 raise LinAlgError("Singular matrix") 
    120832 numpy.linalg.LinAlgError: Singular matrix 
    120833  
    120834 numpy.linalg.LinAlgError: Singular matrix 
    120835  
    120836 File
    120837 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120838 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    120839 raise LinAlgError("Singular matrix") 
    120840  
    120841 See log for complete Python traceback. 
    120842  
    120843 Traceback (most recent call last): 
    120844 File
    120845 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120846 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    120847 self.session.ui.mouse_modes.mouse_pause_tracking() 
    120848 File
    120849 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120850 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    120851 mouse_pause_tracking 
    120852 self._mouse_pause() 
    120853 File
    120854 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120855 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    120856 m.pause(self._mouse_pause_position) 
    120857 File
    120858 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120859 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    120860 p = self.view.picked_object(x, y) 
    120861 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120862 File
    120863 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120864 packages/chimerax/graphics/view.py", line 838, in picked_object 
    120865 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    120866 beyond, 
    120867 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120868 File
    120869 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120870 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    120871 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    120872 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120873 File
    120874 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120875 packages/chimerax/core/models.py", line 143, in first_intercept 
    120876 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    120877 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120878 File
    120879 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120880 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    120881 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    120882 exclude=exclude) 
    120883 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120884 File
    120885 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120886 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    120887 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    120888 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120889 File
    120890 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120891 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    120892 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    120893 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120894 File
    120895 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120896 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    120897 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    120898 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120899 File
    120900 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120901 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    120902 p = super().first_intercept(mxyz1, mxyz2) 
    120903 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120904 File
    120905 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120906 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    120907 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    120908 exclude=exclude) 
    120909 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120910 File
    120911 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120912 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    120913 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    120914 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120915 File
    120916 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120917 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    120918 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    120919 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120920 File
    120921 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120922 packages/chimerax/graphics/drawing.py", line 1108, in
    120923 _first_intercept_excluding_children 
    120924 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    120925 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120926 File
    120927 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120928 packages/chimerax/geometry/place.py", line 201, in inverse 
    120929 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    120930 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120931 File
    120932 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120933 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    120934 rinv[:, :] = matrix_inverse(r) 
    120935 ^^^^^^^^^^^^^^^^^ 
    120936 File
    120937 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120938 packages/numpy/linalg/linalg.py", line 561, in inv 
    120939 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    120940 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120941 File
    120942 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120943 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    120944 raise LinAlgError("Singular matrix") 
    120945 numpy.linalg.LinAlgError: Singular matrix 
    120946  
    120947 numpy.linalg.LinAlgError: Singular matrix 
    120948  
    120949 File
    120950 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120951 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    120952 raise LinAlgError("Singular matrix") 
    120953  
    120954 See log for complete Python traceback. 
    120955  
    120956 Traceback (most recent call last): 
    120957 File
    120958 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120959 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    120960 self.session.ui.mouse_modes.mouse_pause_tracking() 
    120961 File
    120962 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120963 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    120964 mouse_pause_tracking 
    120965 self._mouse_pause() 
    120966 File
    120967 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120968 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    120969 m.pause(self._mouse_pause_position) 
    120970 File
    120971 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120972 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    120973 p = self.view.picked_object(x, y) 
    120974 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120975 File
    120976 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120977 packages/chimerax/graphics/view.py", line 838, in picked_object 
    120978 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    120979 beyond, 
    120980 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120981 File
    120982 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120983 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    120984 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    120985 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120986 File
    120987 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120988 packages/chimerax/core/models.py", line 143, in first_intercept 
    120989 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    120990 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120991 File
    120992 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120993 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    120994 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    120995 exclude=exclude) 
    120996 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    120997 File
    120998 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    120999 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    121000 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    121001 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121002 File
    121003 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121004 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    121005 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    121006 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121007 File
    121008 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121009 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    121010 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    121011 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121012 File
    121013 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121014 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    121015 p = super().first_intercept(mxyz1, mxyz2) 
    121016 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121017 File
    121018 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121019 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    121020 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    121021 exclude=exclude) 
    121022 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121023 File
    121024 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121025 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    121026 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    121027 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121028 File
    121029 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121030 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    121031 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    121032 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121033 File
    121034 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121035 packages/chimerax/graphics/drawing.py", line 1108, in
    121036 _first_intercept_excluding_children 
    121037 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    121038 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121039 File
    121040 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121041 packages/chimerax/geometry/place.py", line 201, in inverse 
    121042 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    121043 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121044 File
    121045 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121046 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    121047 rinv[:, :] = matrix_inverse(r) 
    121048 ^^^^^^^^^^^^^^^^^ 
    121049 File
    121050 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121051 packages/numpy/linalg/linalg.py", line 561, in inv 
    121052 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    121053 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121054 File
    121055 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121056 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    121057 raise LinAlgError("Singular matrix") 
    121058 numpy.linalg.LinAlgError: Singular matrix 
    121059  
    121060 numpy.linalg.LinAlgError: Singular matrix 
    121061  
    121062 File
    121063 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121064 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    121065 raise LinAlgError("Singular matrix") 
    121066  
    121067 See log for complete Python traceback. 
    121068  
    121069 Traceback (most recent call last): 
    121070 File
    121071 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121072 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    121073 self.session.ui.mouse_modes.mouse_pause_tracking() 
    121074 File
    121075 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121076 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    121077 mouse_pause_tracking 
    121078 self._mouse_pause() 
    121079 File
    121080 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121081 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    121082 m.pause(self._mouse_pause_position) 
    121083 File
    121084 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121085 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    121086 p = self.view.picked_object(x, y) 
    121087 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121088 File
    121089 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121090 packages/chimerax/graphics/view.py", line 838, in picked_object 
    121091 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    121092 beyond, 
    121093 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121094 File
    121095 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121096 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    121097 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    121098 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121099 File
    121100 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121101 packages/chimerax/core/models.py", line 143, in first_intercept 
    121102 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    121103 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121104 File
    121105 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121106 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    121107 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    121108 exclude=exclude) 
    121109 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121110 File
    121111 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121112 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    121113 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    121114 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121115 File
    121116 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121117 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    121118 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    121119 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121120 File
    121121 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121122 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    121123 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    121124 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121125 File
    121126 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121127 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    121128 p = super().first_intercept(mxyz1, mxyz2) 
    121129 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121130 File
    121131 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121132 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    121133 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    121134 exclude=exclude) 
    121135 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121136 File
    121137 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121138 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    121139 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    121140 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121141 File
    121142 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121143 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    121144 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    121145 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121146 File
    121147 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121148 packages/chimerax/graphics/drawing.py", line 1108, in
    121149 _first_intercept_excluding_children 
    121150 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    121151 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121152 File
    121153 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121154 packages/chimerax/geometry/place.py", line 201, in inverse 
    121155 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    121156 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121157 File
    121158 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121159 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    121160 rinv[:, :] = matrix_inverse(r) 
    121161 ^^^^^^^^^^^^^^^^^ 
    121162 File
    121163 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121164 packages/numpy/linalg/linalg.py", line 561, in inv 
    121165 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    121166 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121167 File
    121168 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121169 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    121170 raise LinAlgError("Singular matrix") 
    121171 numpy.linalg.LinAlgError: Singular matrix 
    121172  
    121173 numpy.linalg.LinAlgError: Singular matrix 
    121174  
    121175 File
    121176 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121177 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    121178 raise LinAlgError("Singular matrix") 
    121179  
    121180 See log for complete Python traceback. 
    121181  
    121182 Traceback (most recent call last): 
    121183 File
    121184 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121185 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    121186 self.session.ui.mouse_modes.mouse_pause_tracking() 
    121187 File
    121188 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121189 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    121190 mouse_pause_tracking 
    121191 self._mouse_pause() 
    121192 File
    121193 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121194 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    121195 m.pause(self._mouse_pause_position) 
    121196 File
    121197 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121198 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    121199 p = self.view.picked_object(x, y) 
    121200 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121201 File
    121202 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121203 packages/chimerax/graphics/view.py", line 838, in picked_object 
    121204 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    121205 beyond, 
    121206 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121207 File
    121208 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121209 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    121210 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    121211 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121212 File
    121213 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121214 packages/chimerax/core/models.py", line 143, in first_intercept 
    121215 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    121216 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121217 File
    121218 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121219 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    121220 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    121221 exclude=exclude) 
    121222 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121223 File
    121224 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121225 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    121226 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    121227 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121228 File
    121229 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121230 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    121231 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    121232 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121233 File
    121234 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121235 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    121236 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    121237 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121238 File
    121239 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121240 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    121241 p = super().first_intercept(mxyz1, mxyz2) 
    121242 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121243 File
    121244 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121245 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    121246 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    121247 exclude=exclude) 
    121248 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121249 File
    121250 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121251 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    121252 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    121253 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121254 File
    121255 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121256 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    121257 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    121258 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121259 File
    121260 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121261 packages/chimerax/graphics/drawing.py", line 1108, in
    121262 _first_intercept_excluding_children 
    121263 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    121264 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121265 File
    121266 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121267 packages/chimerax/geometry/place.py", line 201, in inverse 
    121268 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    121269 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121270 File
    121271 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121272 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    121273 rinv[:, :] = matrix_inverse(r) 
    121274 ^^^^^^^^^^^^^^^^^ 
    121275 File
    121276 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121277 packages/numpy/linalg/linalg.py", line 561, in inv 
    121278 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    121279 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121280 File
    121281 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121282 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    121283 raise LinAlgError("Singular matrix") 
    121284 numpy.linalg.LinAlgError: Singular matrix 
    121285  
    121286 numpy.linalg.LinAlgError: Singular matrix 
    121287  
    121288 File
    121289 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121290 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    121291 raise LinAlgError("Singular matrix") 
    121292  
    121293 See log for complete Python traceback. 
    121294  
    121295 Traceback (most recent call last): 
    121296 File
    121297 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121298 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    121299 self.session.ui.mouse_modes.mouse_pause_tracking() 
    121300 File
    121301 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121302 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    121303 mouse_pause_tracking 
    121304 self._mouse_pause() 
    121305 File
    121306 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121307 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    121308 m.pause(self._mouse_pause_position) 
    121309 File
    121310 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121311 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    121312 p = self.view.picked_object(x, y) 
    121313 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121314 File
    121315 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121316 packages/chimerax/graphics/view.py", line 838, in picked_object 
    121317 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    121318 beyond, 
    121319 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121320 File
    121321 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121322 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    121323 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    121324 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121325 File
    121326 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121327 packages/chimerax/core/models.py", line 143, in first_intercept 
    121328 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    121329 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121330 File
    121331 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121332 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    121333 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    121334 exclude=exclude) 
    121335 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121336 File
    121337 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121338 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    121339 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    121340 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121341 File
    121342 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121343 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    121344 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    121345 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121346 File
    121347 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121348 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    121349 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    121350 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121351 File
    121352 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121353 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    121354 p = super().first_intercept(mxyz1, mxyz2) 
    121355 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121356 File
    121357 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121358 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    121359 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    121360 exclude=exclude) 
    121361 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121362 File
    121363 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121364 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    121365 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    121366 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121367 File
    121368 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121369 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    121370 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    121371 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121372 File
    121373 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121374 packages/chimerax/graphics/drawing.py", line 1108, in
    121375 _first_intercept_excluding_children 
    121376 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    121377 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121378 File
    121379 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121380 packages/chimerax/geometry/place.py", line 201, in inverse 
    121381 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    121382 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121383 File
    121384 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121385 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    121386 rinv[:, :] = matrix_inverse(r) 
    121387 ^^^^^^^^^^^^^^^^^ 
    121388 File
    121389 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121390 packages/numpy/linalg/linalg.py", line 561, in inv 
    121391 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    121392 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121393 File
    121394 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121395 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    121396 raise LinAlgError("Singular matrix") 
    121397 numpy.linalg.LinAlgError: Singular matrix 
    121398  
    121399 numpy.linalg.LinAlgError: Singular matrix 
    121400  
    121401 File
    121402 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121403 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    121404 raise LinAlgError("Singular matrix") 
    121405  
    121406 See log for complete Python traceback. 
    121407  
    121408 Traceback (most recent call last): 
    121409 File
    121410 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121411 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    121412 self.session.ui.mouse_modes.mouse_pause_tracking() 
    121413 File
    121414 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121415 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    121416 mouse_pause_tracking 
    121417 self._mouse_pause() 
    121418 File
    121419 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121420 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    121421 m.pause(self._mouse_pause_position) 
    121422 File
    121423 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121424 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    121425 p = self.view.picked_object(x, y) 
    121426 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121427 File
    121428 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121429 packages/chimerax/graphics/view.py", line 838, in picked_object 
    121430 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    121431 beyond, 
    121432 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121433 File
    121434 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121435 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    121436 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    121437 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121438 File
    121439 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121440 packages/chimerax/core/models.py", line 143, in first_intercept 
    121441 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    121442 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121443 File
    121444 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121445 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    121446 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    121447 exclude=exclude) 
    121448 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121449 File
    121450 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121451 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    121452 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    121453 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121454 File
    121455 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121456 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    121457 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    121458 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121459 File
    121460 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121461 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    121462 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    121463 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121464 File
    121465 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121466 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    121467 p = super().first_intercept(mxyz1, mxyz2) 
    121468 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121469 File
    121470 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121471 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    121472 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    121473 exclude=exclude) 
    121474 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121475 File
    121476 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121477 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    121478 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    121479 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121480 File
    121481 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121482 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    121483 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    121484 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121485 File
    121486 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121487 packages/chimerax/graphics/drawing.py", line 1108, in
    121488 _first_intercept_excluding_children 
    121489 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    121490 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121491 File
    121492 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121493 packages/chimerax/geometry/place.py", line 201, in inverse 
    121494 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    121495 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121496 File
    121497 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121498 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    121499 rinv[:, :] = matrix_inverse(r) 
    121500 ^^^^^^^^^^^^^^^^^ 
    121501 File
    121502 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121503 packages/numpy/linalg/linalg.py", line 561, in inv 
    121504 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    121505 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121506 File
    121507 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121508 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    121509 raise LinAlgError("Singular matrix") 
    121510 numpy.linalg.LinAlgError: Singular matrix 
    121511  
    121512 numpy.linalg.LinAlgError: Singular matrix 
    121513  
    121514 File
    121515 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121516 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    121517 raise LinAlgError("Singular matrix") 
    121518  
    121519 See log for complete Python traceback. 
    121520  
    121521 Traceback (most recent call last): 
    121522 File
    121523 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121524 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    121525 self.session.ui.mouse_modes.mouse_pause_tracking() 
    121526 File
    121527 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121528 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    121529 mouse_pause_tracking 
    121530 self._mouse_pause() 
    121531 File
    121532 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121533 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    121534 m.pause(self._mouse_pause_position) 
    121535 File
    121536 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121537 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    121538 p = self.view.picked_object(x, y) 
    121539 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121540 File
    121541 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121542 packages/chimerax/graphics/view.py", line 838, in picked_object 
    121543 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    121544 beyond, 
    121545 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121546 File
    121547 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121548 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    121549 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    121550 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121551 File
    121552 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121553 packages/chimerax/core/models.py", line 143, in first_intercept 
    121554 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    121555 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121556 File
    121557 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121558 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    121559 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    121560 exclude=exclude) 
    121561 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121562 File
    121563 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121564 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    121565 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    121566 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121567 File
    121568 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121569 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    121570 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    121571 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121572 File
    121573 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121574 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    121575 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    121576 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121577 File
    121578 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121579 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    121580 p = super().first_intercept(mxyz1, mxyz2) 
    121581 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121582 File
    121583 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121584 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    121585 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    121586 exclude=exclude) 
    121587 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121588 File
    121589 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121590 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    121591 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    121592 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121593 File
    121594 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121595 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    121596 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    121597 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121598 File
    121599 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121600 packages/chimerax/graphics/drawing.py", line 1108, in
    121601 _first_intercept_excluding_children 
    121602 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    121603 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121604 File
    121605 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121606 packages/chimerax/geometry/place.py", line 201, in inverse 
    121607 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    121608 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121609 File
    121610 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121611 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    121612 rinv[:, :] = matrix_inverse(r) 
    121613 ^^^^^^^^^^^^^^^^^ 
    121614 File
    121615 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121616 packages/numpy/linalg/linalg.py", line 561, in inv 
    121617 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    121618 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121619 File
    121620 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121621 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    121622 raise LinAlgError("Singular matrix") 
    121623 numpy.linalg.LinAlgError: Singular matrix 
    121624  
    121625 numpy.linalg.LinAlgError: Singular matrix 
    121626  
    121627 File
    121628 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121629 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    121630 raise LinAlgError("Singular matrix") 
    121631  
    121632 See log for complete Python traceback. 
    121633  
    121634 Traceback (most recent call last): 
    121635 File
    121636 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121637 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    121638 self.session.ui.mouse_modes.mouse_pause_tracking() 
    121639 File
    121640 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121641 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    121642 mouse_pause_tracking 
    121643 self._mouse_pause() 
    121644 File
    121645 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121646 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    121647 m.pause(self._mouse_pause_position) 
    121648 File
    121649 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121650 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    121651 p = self.view.picked_object(x, y) 
    121652 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121653 File
    121654 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121655 packages/chimerax/graphics/view.py", line 838, in picked_object 
    121656 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    121657 beyond, 
    121658 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121659 File
    121660 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121661 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    121662 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    121663 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121664 File
    121665 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121666 packages/chimerax/core/models.py", line 143, in first_intercept 
    121667 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    121668 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121669 File
    121670 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121671 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    121672 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    121673 exclude=exclude) 
    121674 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121675 File
    121676 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121677 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    121678 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    121679 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121680 File
    121681 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121682 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    121683 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    121684 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121685 File
    121686 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121687 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    121688 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    121689 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121690 File
    121691 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121692 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    121693 p = super().first_intercept(mxyz1, mxyz2) 
    121694 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121695 File
    121696 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121697 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    121698 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    121699 exclude=exclude) 
    121700 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121701 File
    121702 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121703 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    121704 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    121705 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121706 File
    121707 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121708 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    121709 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    121710 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121711 File
    121712 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121713 packages/chimerax/graphics/drawing.py", line 1108, in
    121714 _first_intercept_excluding_children 
    121715 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    121716 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121717 File
    121718 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121719 packages/chimerax/geometry/place.py", line 201, in inverse 
    121720 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    121721 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121722 File
    121723 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121724 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    121725 rinv[:, :] = matrix_inverse(r) 
    121726 ^^^^^^^^^^^^^^^^^ 
    121727 File
    121728 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121729 packages/numpy/linalg/linalg.py", line 561, in inv 
    121730 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    121731 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121732 File
    121733 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121734 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    121735 raise LinAlgError("Singular matrix") 
    121736 numpy.linalg.LinAlgError: Singular matrix 
    121737  
    121738 numpy.linalg.LinAlgError: Singular matrix 
    121739  
    121740 File
    121741 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121742 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    121743 raise LinAlgError("Singular matrix") 
    121744  
    121745 See log for complete Python traceback. 
    121746  
    121747 Traceback (most recent call last): 
    121748 File
    121749 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121750 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    121751 self.session.ui.mouse_modes.mouse_pause_tracking() 
    121752 File
    121753 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121754 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    121755 mouse_pause_tracking 
    121756 self._mouse_pause() 
    121757 File
    121758 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121759 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    121760 m.pause(self._mouse_pause_position) 
    121761 File
    121762 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121763 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    121764 p = self.view.picked_object(x, y) 
    121765 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121766 File
    121767 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121768 packages/chimerax/graphics/view.py", line 838, in picked_object 
    121769 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    121770 beyond, 
    121771 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121772 File
    121773 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121774 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    121775 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    121776 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121777 File
    121778 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121779 packages/chimerax/core/models.py", line 143, in first_intercept 
    121780 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    121781 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121782 File
    121783 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121784 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    121785 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    121786 exclude=exclude) 
    121787 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121788 File
    121789 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121790 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    121791 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    121792 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121793 File
    121794 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121795 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    121796 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    121797 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121798 File
    121799 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121800 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    121801 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    121802 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121803 File
    121804 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121805 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    121806 p = super().first_intercept(mxyz1, mxyz2) 
    121807 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121808 File
    121809 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121810 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    121811 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    121812 exclude=exclude) 
    121813 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121814 File
    121815 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121816 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    121817 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    121818 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121819 File
    121820 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121821 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    121822 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    121823 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121824 File
    121825 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121826 packages/chimerax/graphics/drawing.py", line 1108, in
    121827 _first_intercept_excluding_children 
    121828 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    121829 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121830 File
    121831 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121832 packages/chimerax/geometry/place.py", line 201, in inverse 
    121833 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    121834 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121835 File
    121836 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121837 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    121838 rinv[:, :] = matrix_inverse(r) 
    121839 ^^^^^^^^^^^^^^^^^ 
    121840 File
    121841 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121842 packages/numpy/linalg/linalg.py", line 561, in inv 
    121843 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    121844 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121845 File
    121846 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121847 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    121848 raise LinAlgError("Singular matrix") 
    121849 numpy.linalg.LinAlgError: Singular matrix 
    121850  
    121851 numpy.linalg.LinAlgError: Singular matrix 
    121852  
    121853 File
    121854 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121855 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    121856 raise LinAlgError("Singular matrix") 
    121857  
    121858 See log for complete Python traceback. 
    121859  
    121860 Traceback (most recent call last): 
    121861 File
    121862 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121863 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    121864 self.session.ui.mouse_modes.mouse_pause_tracking() 
    121865 File
    121866 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121867 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    121868 mouse_pause_tracking 
    121869 self._mouse_pause() 
    121870 File
    121871 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121872 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    121873 m.pause(self._mouse_pause_position) 
    121874 File
    121875 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121876 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    121877 p = self.view.picked_object(x, y) 
    121878 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121879 File
    121880 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121881 packages/chimerax/graphics/view.py", line 838, in picked_object 
    121882 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    121883 beyond, 
    121884 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121885 File
    121886 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121887 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    121888 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    121889 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121890 File
    121891 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121892 packages/chimerax/core/models.py", line 143, in first_intercept 
    121893 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    121894 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121895 File
    121896 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121897 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    121898 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    121899 exclude=exclude) 
    121900 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121901 File
    121902 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121903 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    121904 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    121905 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121906 File
    121907 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121908 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    121909 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    121910 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121911 File
    121912 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121913 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    121914 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    121915 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121916 File
    121917 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121918 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    121919 p = super().first_intercept(mxyz1, mxyz2) 
    121920 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121921 File
    121922 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121923 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    121924 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    121925 exclude=exclude) 
    121926 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121927 File
    121928 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121929 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    121930 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    121931 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121932 File
    121933 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121934 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    121935 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    121936 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121937 File
    121938 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121939 packages/chimerax/graphics/drawing.py", line 1108, in
    121940 _first_intercept_excluding_children 
    121941 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    121942 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121943 File
    121944 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121945 packages/chimerax/geometry/place.py", line 201, in inverse 
    121946 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    121947 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121948 File
    121949 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121950 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    121951 rinv[:, :] = matrix_inverse(r) 
    121952 ^^^^^^^^^^^^^^^^^ 
    121953 File
    121954 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121955 packages/numpy/linalg/linalg.py", line 561, in inv 
    121956 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    121957 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121958 File
    121959 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121960 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    121961 raise LinAlgError("Singular matrix") 
    121962 numpy.linalg.LinAlgError: Singular matrix 
    121963  
    121964 numpy.linalg.LinAlgError: Singular matrix 
    121965  
    121966 File
    121967 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121968 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    121969 raise LinAlgError("Singular matrix") 
    121970  
    121971 See log for complete Python traceback. 
    121972  
    121973 Traceback (most recent call last): 
    121974 File
    121975 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121976 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    121977 self.session.ui.mouse_modes.mouse_pause_tracking() 
    121978 File
    121979 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121980 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    121981 mouse_pause_tracking 
    121982 self._mouse_pause() 
    121983 File
    121984 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121985 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    121986 m.pause(self._mouse_pause_position) 
    121987 File
    121988 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121989 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    121990 p = self.view.picked_object(x, y) 
    121991 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121992 File
    121993 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    121994 packages/chimerax/graphics/view.py", line 838, in picked_object 
    121995 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    121996 beyond, 
    121997 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    121998 File
    121999 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122000 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    122001 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    122002 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122003 File
    122004 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122005 packages/chimerax/core/models.py", line 143, in first_intercept 
    122006 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    122007 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122008 File
    122009 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122010 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    122011 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    122012 exclude=exclude) 
    122013 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122014 File
    122015 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122016 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    122017 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    122018 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122019 File
    122020 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122021 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    122022 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    122023 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122024 File
    122025 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122026 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    122027 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    122028 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122029 File
    122030 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122031 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    122032 p = super().first_intercept(mxyz1, mxyz2) 
    122033 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122034 File
    122035 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122036 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    122037 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    122038 exclude=exclude) 
    122039 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122040 File
    122041 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122042 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    122043 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    122044 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122045 File
    122046 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122047 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    122048 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    122049 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122050 File
    122051 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122052 packages/chimerax/graphics/drawing.py", line 1108, in
    122053 _first_intercept_excluding_children 
    122054 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    122055 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122056 File
    122057 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122058 packages/chimerax/geometry/place.py", line 201, in inverse 
    122059 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    122060 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122061 File
    122062 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122063 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    122064 rinv[:, :] = matrix_inverse(r) 
    122065 ^^^^^^^^^^^^^^^^^ 
    122066 File
    122067 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122068 packages/numpy/linalg/linalg.py", line 561, in inv 
    122069 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    122070 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122071 File
    122072 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122073 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    122074 raise LinAlgError("Singular matrix") 
    122075 numpy.linalg.LinAlgError: Singular matrix 
    122076  
    122077 numpy.linalg.LinAlgError: Singular matrix 
    122078  
    122079 File
    122080 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122081 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    122082 raise LinAlgError("Singular matrix") 
    122083  
    122084 See log for complete Python traceback. 
    122085  
    122086 Traceback (most recent call last): 
    122087 File
    122088 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122089 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    122090 self.session.ui.mouse_modes.mouse_pause_tracking() 
    122091 File
    122092 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122093 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    122094 mouse_pause_tracking 
    122095 self._mouse_pause() 
    122096 File
    122097 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122098 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    122099 m.pause(self._mouse_pause_position) 
    122100 File
    122101 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122102 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    122103 p = self.view.picked_object(x, y) 
    122104 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122105 File
    122106 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122107 packages/chimerax/graphics/view.py", line 838, in picked_object 
    122108 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    122109 beyond, 
    122110 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122111 File
    122112 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122113 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    122114 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    122115 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122116 File
    122117 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122118 packages/chimerax/core/models.py", line 143, in first_intercept 
    122119 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    122120 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122121 File
    122122 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122123 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    122124 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    122125 exclude=exclude) 
    122126 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122127 File
    122128 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122129 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    122130 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    122131 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122132 File
    122133 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122134 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    122135 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    122136 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122137 File
    122138 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122139 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    122140 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    122141 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122142 File
    122143 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122144 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    122145 p = super().first_intercept(mxyz1, mxyz2) 
    122146 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122147 File
    122148 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122149 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    122150 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    122151 exclude=exclude) 
    122152 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122153 File
    122154 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122155 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    122156 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    122157 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122158 File
    122159 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122160 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    122161 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    122162 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122163 File
    122164 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122165 packages/chimerax/graphics/drawing.py", line 1108, in
    122166 _first_intercept_excluding_children 
    122167 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    122168 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122169 File
    122170 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122171 packages/chimerax/geometry/place.py", line 201, in inverse 
    122172 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    122173 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122174 File
    122175 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122176 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    122177 rinv[:, :] = matrix_inverse(r) 
    122178 ^^^^^^^^^^^^^^^^^ 
    122179 File
    122180 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122181 packages/numpy/linalg/linalg.py", line 561, in inv 
    122182 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    122183 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122184 File
    122185 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122186 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    122187 raise LinAlgError("Singular matrix") 
    122188 numpy.linalg.LinAlgError: Singular matrix 
    122189  
    122190 numpy.linalg.LinAlgError: Singular matrix 
    122191  
    122192 File
    122193 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122194 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    122195 raise LinAlgError("Singular matrix") 
    122196  
    122197 See log for complete Python traceback. 
    122198  
    122199 Traceback (most recent call last): 
    122200 File
    122201 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122202 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    122203 self.session.ui.mouse_modes.mouse_pause_tracking() 
    122204 File
    122205 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122206 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    122207 mouse_pause_tracking 
    122208 self._mouse_pause() 
    122209 File
    122210 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122211 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    122212 m.pause(self._mouse_pause_position) 
    122213 File
    122214 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122215 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    122216 p = self.view.picked_object(x, y) 
    122217 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122218 File
    122219 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122220 packages/chimerax/graphics/view.py", line 838, in picked_object 
    122221 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    122222 beyond, 
    122223 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122224 File
    122225 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122226 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    122227 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    122228 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122229 File
    122230 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122231 packages/chimerax/core/models.py", line 143, in first_intercept 
    122232 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    122233 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122234 File
    122235 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122236 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    122237 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    122238 exclude=exclude) 
    122239 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122240 File
    122241 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122242 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    122243 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    122244 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122245 File
    122246 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122247 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    122248 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    122249 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122250 File
    122251 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122252 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    122253 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    122254 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122255 File
    122256 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122257 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    122258 p = super().first_intercept(mxyz1, mxyz2) 
    122259 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122260 File
    122261 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122262 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    122263 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    122264 exclude=exclude) 
    122265 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122266 File
    122267 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122268 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    122269 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    122270 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122271 File
    122272 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122273 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    122274 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    122275 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122276 File
    122277 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122278 packages/chimerax/graphics/drawing.py", line 1108, in
    122279 _first_intercept_excluding_children 
    122280 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    122281 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122282 File
    122283 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122284 packages/chimerax/geometry/place.py", line 201, in inverse 
    122285 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    122286 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122287 File
    122288 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122289 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    122290 rinv[:, :] = matrix_inverse(r) 
    122291 ^^^^^^^^^^^^^^^^^ 
    122292 File
    122293 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122294 packages/numpy/linalg/linalg.py", line 561, in inv 
    122295 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    122296 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122297 File
    122298 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122299 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    122300 raise LinAlgError("Singular matrix") 
    122301 numpy.linalg.LinAlgError: Singular matrix 
    122302  
    122303 numpy.linalg.LinAlgError: Singular matrix 
    122304  
    122305 File
    122306 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122307 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    122308 raise LinAlgError("Singular matrix") 
    122309  
    122310 See log for complete Python traceback. 
    122311  
    122312 Traceback (most recent call last): 
    122313 File
    122314 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122315 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    122316 self.session.ui.mouse_modes.mouse_pause_tracking() 
    122317 File
    122318 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122319 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    122320 mouse_pause_tracking 
    122321 self._mouse_pause() 
    122322 File
    122323 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122324 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    122325 m.pause(self._mouse_pause_position) 
    122326 File
    122327 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122328 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    122329 p = self.view.picked_object(x, y) 
    122330 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122331 File
    122332 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122333 packages/chimerax/graphics/view.py", line 838, in picked_object 
    122334 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    122335 beyond, 
    122336 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122337 File
    122338 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122339 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    122340 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    122341 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122342 File
    122343 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122344 packages/chimerax/core/models.py", line 143, in first_intercept 
    122345 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    122346 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122347 File
    122348 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122349 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    122350 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    122351 exclude=exclude) 
    122352 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122353 File
    122354 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122355 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    122356 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    122357 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122358 File
    122359 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122360 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    122361 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    122362 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122363 File
    122364 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122365 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    122366 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    122367 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122368 File
    122369 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122370 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    122371 p = super().first_intercept(mxyz1, mxyz2) 
    122372 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122373 File
    122374 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122375 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    122376 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    122377 exclude=exclude) 
    122378 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122379 File
    122380 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122381 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    122382 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    122383 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122384 File
    122385 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122386 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    122387 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    122388 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122389 File
    122390 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122391 packages/chimerax/graphics/drawing.py", line 1108, in
    122392 _first_intercept_excluding_children 
    122393 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    122394 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122395 File
    122396 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122397 packages/chimerax/geometry/place.py", line 201, in inverse 
    122398 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    122399 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122400 File
    122401 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122402 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    122403 rinv[:, :] = matrix_inverse(r) 
    122404 ^^^^^^^^^^^^^^^^^ 
    122405 File
    122406 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122407 packages/numpy/linalg/linalg.py", line 561, in inv 
    122408 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    122409 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122410 File
    122411 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122412 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    122413 raise LinAlgError("Singular matrix") 
    122414 numpy.linalg.LinAlgError: Singular matrix 
    122415  
    122416 numpy.linalg.LinAlgError: Singular matrix 
    122417  
    122418 File
    122419 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122420 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    122421 raise LinAlgError("Singular matrix") 
    122422  
    122423 See log for complete Python traceback. 
    122424  
    122425 Traceback (most recent call last): 
    122426 File
    122427 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122428 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    122429 self.session.ui.mouse_modes.mouse_pause_tracking() 
    122430 File
    122431 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122432 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    122433 mouse_pause_tracking 
    122434 self._mouse_pause() 
    122435 File
    122436 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122437 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    122438 m.pause(self._mouse_pause_position) 
    122439 File
    122440 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122441 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    122442 p = self.view.picked_object(x, y) 
    122443 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122444 File
    122445 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122446 packages/chimerax/graphics/view.py", line 838, in picked_object 
    122447 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    122448 beyond, 
    122449 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122450 File
    122451 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122452 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    122453 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    122454 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122455 File
    122456 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122457 packages/chimerax/core/models.py", line 143, in first_intercept 
    122458 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    122459 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122460 File
    122461 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122462 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    122463 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    122464 exclude=exclude) 
    122465 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122466 File
    122467 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122468 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    122469 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    122470 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122471 File
    122472 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122473 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    122474 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    122475 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122476 File
    122477 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122478 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    122479 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    122480 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122481 File
    122482 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122483 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    122484 p = super().first_intercept(mxyz1, mxyz2) 
    122485 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122486 File
    122487 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122488 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    122489 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    122490 exclude=exclude) 
    122491 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122492 File
    122493 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122494 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    122495 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    122496 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122497 File
    122498 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122499 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    122500 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    122501 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122502 File
    122503 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122504 packages/chimerax/graphics/drawing.py", line 1108, in
    122505 _first_intercept_excluding_children 
    122506 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    122507 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122508 File
    122509 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122510 packages/chimerax/geometry/place.py", line 201, in inverse 
    122511 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    122512 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122513 File
    122514 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122515 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    122516 rinv[:, :] = matrix_inverse(r) 
    122517 ^^^^^^^^^^^^^^^^^ 
    122518 File
    122519 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122520 packages/numpy/linalg/linalg.py", line 561, in inv 
    122521 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    122522 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122523 File
    122524 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122525 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    122526 raise LinAlgError("Singular matrix") 
    122527 numpy.linalg.LinAlgError: Singular matrix 
    122528  
    122529 numpy.linalg.LinAlgError: Singular matrix 
    122530  
    122531 File
    122532 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122533 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    122534 raise LinAlgError("Singular matrix") 
    122535  
    122536 See log for complete Python traceback. 
    122537  
    122538 Traceback (most recent call last): 
    122539 File
    122540 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122541 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    122542 self.session.ui.mouse_modes.mouse_pause_tracking() 
    122543 File
    122544 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122545 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    122546 mouse_pause_tracking 
    122547 self._mouse_pause() 
    122548 File
    122549 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122550 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    122551 m.pause(self._mouse_pause_position) 
    122552 File
    122553 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122554 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    122555 p = self.view.picked_object(x, y) 
    122556 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122557 File
    122558 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122559 packages/chimerax/graphics/view.py", line 838, in picked_object 
    122560 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    122561 beyond, 
    122562 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122563 File
    122564 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122565 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    122566 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    122567 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122568 File
    122569 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122570 packages/chimerax/core/models.py", line 143, in first_intercept 
    122571 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    122572 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122573 File
    122574 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122575 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    122576 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    122577 exclude=exclude) 
    122578 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122579 File
    122580 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122581 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    122582 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    122583 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122584 File
    122585 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122586 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    122587 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    122588 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122589 File
    122590 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122591 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    122592 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    122593 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122594 File
    122595 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122596 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    122597 p = super().first_intercept(mxyz1, mxyz2) 
    122598 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122599 File
    122600 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122601 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    122602 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    122603 exclude=exclude) 
    122604 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122605 File
    122606 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122607 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    122608 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    122609 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122610 File
    122611 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122612 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    122613 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    122614 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122615 File
    122616 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122617 packages/chimerax/graphics/drawing.py", line 1108, in
    122618 _first_intercept_excluding_children 
    122619 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    122620 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122621 File
    122622 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122623 packages/chimerax/geometry/place.py", line 201, in inverse 
    122624 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    122625 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122626 File
    122627 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122628 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    122629 rinv[:, :] = matrix_inverse(r) 
    122630 ^^^^^^^^^^^^^^^^^ 
    122631 File
    122632 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122633 packages/numpy/linalg/linalg.py", line 561, in inv 
    122634 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    122635 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122636 File
    122637 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122638 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    122639 raise LinAlgError("Singular matrix") 
    122640 numpy.linalg.LinAlgError: Singular matrix 
    122641  
    122642 numpy.linalg.LinAlgError: Singular matrix 
    122643  
    122644 File
    122645 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122646 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    122647 raise LinAlgError("Singular matrix") 
    122648  
    122649 See log for complete Python traceback. 
    122650  
    122651 Traceback (most recent call last): 
    122652 File
    122653 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122654 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    122655 self.session.ui.mouse_modes.mouse_pause_tracking() 
    122656 File
    122657 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122658 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    122659 mouse_pause_tracking 
    122660 self._mouse_pause() 
    122661 File
    122662 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122663 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    122664 m.pause(self._mouse_pause_position) 
    122665 File
    122666 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122667 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    122668 p = self.view.picked_object(x, y) 
    122669 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122670 File
    122671 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122672 packages/chimerax/graphics/view.py", line 838, in picked_object 
    122673 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    122674 beyond, 
    122675 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122676 File
    122677 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122678 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    122679 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    122680 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122681 File
    122682 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122683 packages/chimerax/core/models.py", line 143, in first_intercept 
    122684 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    122685 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122686 File
    122687 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122688 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    122689 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    122690 exclude=exclude) 
    122691 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122692 File
    122693 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122694 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    122695 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    122696 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122697 File
    122698 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122699 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    122700 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    122701 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122702 File
    122703 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122704 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    122705 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    122706 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122707 File
    122708 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122709 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    122710 p = super().first_intercept(mxyz1, mxyz2) 
    122711 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122712 File
    122713 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122714 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    122715 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    122716 exclude=exclude) 
    122717 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122718 File
    122719 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122720 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    122721 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    122722 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122723 File
    122724 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122725 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    122726 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    122727 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122728 File
    122729 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122730 packages/chimerax/graphics/drawing.py", line 1108, in
    122731 _first_intercept_excluding_children 
    122732 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    122733 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122734 File
    122735 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122736 packages/chimerax/geometry/place.py", line 201, in inverse 
    122737 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    122738 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122739 File
    122740 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122741 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    122742 rinv[:, :] = matrix_inverse(r) 
    122743 ^^^^^^^^^^^^^^^^^ 
    122744 File
    122745 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122746 packages/numpy/linalg/linalg.py", line 561, in inv 
    122747 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    122748 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122749 File
    122750 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122751 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    122752 raise LinAlgError("Singular matrix") 
    122753 numpy.linalg.LinAlgError: Singular matrix 
    122754  
    122755 numpy.linalg.LinAlgError: Singular matrix 
    122756  
    122757 File
    122758 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122759 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    122760 raise LinAlgError("Singular matrix") 
    122761  
    122762 See log for complete Python traceback. 
    122763  
    122764 Traceback (most recent call last): 
    122765 File
    122766 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122767 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    122768 self.session.ui.mouse_modes.mouse_pause_tracking() 
    122769 File
    122770 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122771 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    122772 mouse_pause_tracking 
    122773 self._mouse_pause() 
    122774 File
    122775 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122776 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    122777 m.pause(self._mouse_pause_position) 
    122778 File
    122779 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122780 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    122781 p = self.view.picked_object(x, y) 
    122782 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122783 File
    122784 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122785 packages/chimerax/graphics/view.py", line 838, in picked_object 
    122786 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    122787 beyond, 
    122788 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122789 File
    122790 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122791 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    122792 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    122793 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122794 File
    122795 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122796 packages/chimerax/core/models.py", line 143, in first_intercept 
    122797 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    122798 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122799 File
    122800 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122801 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    122802 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    122803 exclude=exclude) 
    122804 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122805 File
    122806 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122807 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    122808 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    122809 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122810 File
    122811 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122812 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    122813 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    122814 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122815 File
    122816 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122817 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    122818 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    122819 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122820 File
    122821 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122822 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    122823 p = super().first_intercept(mxyz1, mxyz2) 
    122824 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122825 File
    122826 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122827 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    122828 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    122829 exclude=exclude) 
    122830 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122831 File
    122832 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122833 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    122834 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    122835 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122836 File
    122837 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122838 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    122839 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    122840 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122841 File
    122842 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122843 packages/chimerax/graphics/drawing.py", line 1108, in
    122844 _first_intercept_excluding_children 
    122845 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    122846 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122847 File
    122848 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122849 packages/chimerax/geometry/place.py", line 201, in inverse 
    122850 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    122851 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122852 File
    122853 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122854 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    122855 rinv[:, :] = matrix_inverse(r) 
    122856 ^^^^^^^^^^^^^^^^^ 
    122857 File
    122858 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122859 packages/numpy/linalg/linalg.py", line 561, in inv 
    122860 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    122861 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122862 File
    122863 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122864 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    122865 raise LinAlgError("Singular matrix") 
    122866 numpy.linalg.LinAlgError: Singular matrix 
    122867  
    122868 numpy.linalg.LinAlgError: Singular matrix 
    122869  
    122870 File
    122871 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122872 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    122873 raise LinAlgError("Singular matrix") 
    122874  
    122875 See log for complete Python traceback. 
    122876  
    122877 Traceback (most recent call last): 
    122878 File
    122879 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122880 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    122881 self.session.ui.mouse_modes.mouse_pause_tracking() 
    122882 File
    122883 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122884 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    122885 mouse_pause_tracking 
    122886 self._mouse_pause() 
    122887 File
    122888 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122889 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    122890 m.pause(self._mouse_pause_position) 
    122891 File
    122892 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122893 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    122894 p = self.view.picked_object(x, y) 
    122895 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122896 File
    122897 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122898 packages/chimerax/graphics/view.py", line 838, in picked_object 
    122899 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    122900 beyond, 
    122901 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122902 File
    122903 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122904 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    122905 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    122906 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122907 File
    122908 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122909 packages/chimerax/core/models.py", line 143, in first_intercept 
    122910 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    122911 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122912 File
    122913 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122914 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    122915 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    122916 exclude=exclude) 
    122917 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122918 File
    122919 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122920 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    122921 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    122922 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122923 File
    122924 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122925 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    122926 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    122927 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122928 File
    122929 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122930 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    122931 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    122932 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122933 File
    122934 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122935 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    122936 p = super().first_intercept(mxyz1, mxyz2) 
    122937 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122938 File
    122939 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122940 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    122941 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    122942 exclude=exclude) 
    122943 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122944 File
    122945 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122946 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    122947 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    122948 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122949 File
    122950 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122951 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    122952 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    122953 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122954 File
    122955 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122956 packages/chimerax/graphics/drawing.py", line 1108, in
    122957 _first_intercept_excluding_children 
    122958 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    122959 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122960 File
    122961 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122962 packages/chimerax/geometry/place.py", line 201, in inverse 
    122963 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    122964 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122965 File
    122966 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122967 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    122968 rinv[:, :] = matrix_inverse(r) 
    122969 ^^^^^^^^^^^^^^^^^ 
    122970 File
    122971 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122972 packages/numpy/linalg/linalg.py", line 561, in inv 
    122973 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    122974 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    122975 File
    122976 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122977 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    122978 raise LinAlgError("Singular matrix") 
    122979 numpy.linalg.LinAlgError: Singular matrix 
    122980  
    122981 numpy.linalg.LinAlgError: Singular matrix 
    122982  
    122983 File
    122984 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122985 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    122986 raise LinAlgError("Singular matrix") 
    122987  
    122988 See log for complete Python traceback. 
    122989  
    122990 Traceback (most recent call last): 
    122991 File
    122992 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122993 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    122994 self.session.ui.mouse_modes.mouse_pause_tracking() 
    122995 File
    122996 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    122997 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    122998 mouse_pause_tracking 
    122999 self._mouse_pause() 
    123000 File
    123001 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123002 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    123003 m.pause(self._mouse_pause_position) 
    123004 File
    123005 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123006 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    123007 p = self.view.picked_object(x, y) 
    123008 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123009 File
    123010 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123011 packages/chimerax/graphics/view.py", line 838, in picked_object 
    123012 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    123013 beyond, 
    123014 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123015 File
    123016 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123017 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    123018 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    123019 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123020 File
    123021 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123022 packages/chimerax/core/models.py", line 143, in first_intercept 
    123023 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    123024 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123025 File
    123026 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123027 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    123028 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    123029 exclude=exclude) 
    123030 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123031 File
    123032 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123033 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    123034 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    123035 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123036 File
    123037 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123038 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    123039 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    123040 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123041 File
    123042 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123043 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    123044 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    123045 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123046 File
    123047 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123048 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    123049 p = super().first_intercept(mxyz1, mxyz2) 
    123050 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123051 File
    123052 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123053 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    123054 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    123055 exclude=exclude) 
    123056 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123057 File
    123058 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123059 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    123060 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    123061 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123062 File
    123063 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123064 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    123065 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    123066 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123067 File
    123068 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123069 packages/chimerax/graphics/drawing.py", line 1108, in
    123070 _first_intercept_excluding_children 
    123071 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    123072 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123073 File
    123074 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123075 packages/chimerax/geometry/place.py", line 201, in inverse 
    123076 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    123077 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123078 File
    123079 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123080 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    123081 rinv[:, :] = matrix_inverse(r) 
    123082 ^^^^^^^^^^^^^^^^^ 
    123083 File
    123084 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123085 packages/numpy/linalg/linalg.py", line 561, in inv 
    123086 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    123087 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123088 File
    123089 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123090 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    123091 raise LinAlgError("Singular matrix") 
    123092 numpy.linalg.LinAlgError: Singular matrix 
    123093  
    123094 numpy.linalg.LinAlgError: Singular matrix 
    123095  
    123096 File
    123097 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123098 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    123099 raise LinAlgError("Singular matrix") 
    123100  
    123101 See log for complete Python traceback. 
    123102  
    123103 Traceback (most recent call last): 
    123104 File
    123105 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123106 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    123107 self.session.ui.mouse_modes.mouse_pause_tracking() 
    123108 File
    123109 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123110 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    123111 mouse_pause_tracking 
    123112 self._mouse_pause() 
    123113 File
    123114 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123115 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    123116 m.pause(self._mouse_pause_position) 
    123117 File
    123118 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123119 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    123120 p = self.view.picked_object(x, y) 
    123121 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123122 File
    123123 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123124 packages/chimerax/graphics/view.py", line 838, in picked_object 
    123125 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    123126 beyond, 
    123127 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123128 File
    123129 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123130 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    123131 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    123132 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123133 File
    123134 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123135 packages/chimerax/core/models.py", line 143, in first_intercept 
    123136 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    123137 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123138 File
    123139 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123140 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    123141 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    123142 exclude=exclude) 
    123143 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123144 File
    123145 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123146 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    123147 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    123148 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123149 File
    123150 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123151 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    123152 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    123153 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123154 File
    123155 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123156 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    123157 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    123158 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123159 File
    123160 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123161 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    123162 p = super().first_intercept(mxyz1, mxyz2) 
    123163 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123164 File
    123165 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123166 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    123167 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    123168 exclude=exclude) 
    123169 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123170 File
    123171 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123172 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    123173 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    123174 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123175 File
    123176 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123177 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    123178 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    123179 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123180 File
    123181 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123182 packages/chimerax/graphics/drawing.py", line 1108, in
    123183 _first_intercept_excluding_children 
    123184 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    123185 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123186 File
    123187 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123188 packages/chimerax/geometry/place.py", line 201, in inverse 
    123189 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    123190 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123191 File
    123192 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123193 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    123194 rinv[:, :] = matrix_inverse(r) 
    123195 ^^^^^^^^^^^^^^^^^ 
    123196 File
    123197 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123198 packages/numpy/linalg/linalg.py", line 561, in inv 
    123199 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    123200 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123201 File
    123202 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123203 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    123204 raise LinAlgError("Singular matrix") 
    123205 numpy.linalg.LinAlgError: Singular matrix 
    123206  
    123207 numpy.linalg.LinAlgError: Singular matrix 
    123208  
    123209 File
    123210 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123211 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    123212 raise LinAlgError("Singular matrix") 
    123213  
    123214 See log for complete Python traceback. 
    123215  
    123216 Traceback (most recent call last): 
    123217 File
    123218 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123219 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    123220 self.session.ui.mouse_modes.mouse_pause_tracking() 
    123221 File
    123222 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123223 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    123224 mouse_pause_tracking 
    123225 self._mouse_pause() 
    123226 File
    123227 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123228 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    123229 m.pause(self._mouse_pause_position) 
    123230 File
    123231 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123232 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    123233 p = self.view.picked_object(x, y) 
    123234 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123235 File
    123236 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123237 packages/chimerax/graphics/view.py", line 838, in picked_object 
    123238 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    123239 beyond, 
    123240 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123241 File
    123242 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123243 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    123244 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    123245 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123246 File
    123247 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123248 packages/chimerax/core/models.py", line 143, in first_intercept 
    123249 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    123250 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123251 File
    123252 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123253 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    123254 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    123255 exclude=exclude) 
    123256 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123257 File
    123258 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123259 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    123260 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    123261 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123262 File
    123263 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123264 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    123265 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    123266 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123267 File
    123268 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123269 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    123270 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    123271 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123272 File
    123273 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123274 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    123275 p = super().first_intercept(mxyz1, mxyz2) 
    123276 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123277 File
    123278 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123279 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    123280 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    123281 exclude=exclude) 
    123282 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123283 File
    123284 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123285 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    123286 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    123287 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123288 File
    123289 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123290 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    123291 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    123292 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123293 File
    123294 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123295 packages/chimerax/graphics/drawing.py", line 1108, in
    123296 _first_intercept_excluding_children 
    123297 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    123298 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123299 File
    123300 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123301 packages/chimerax/geometry/place.py", line 201, in inverse 
    123302 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    123303 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123304 File
    123305 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123306 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    123307 rinv[:, :] = matrix_inverse(r) 
    123308 ^^^^^^^^^^^^^^^^^ 
    123309 File
    123310 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123311 packages/numpy/linalg/linalg.py", line 561, in inv 
    123312 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    123313 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123314 File
    123315 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123316 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    123317 raise LinAlgError("Singular matrix") 
    123318 numpy.linalg.LinAlgError: Singular matrix 
    123319  
    123320 numpy.linalg.LinAlgError: Singular matrix 
    123321  
    123322 File
    123323 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123324 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    123325 raise LinAlgError("Singular matrix") 
    123326  
    123327 See log for complete Python traceback. 
    123328  
    123329 Traceback (most recent call last): 
    123330 File
    123331 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123332 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    123333 self.session.ui.mouse_modes.mouse_pause_tracking() 
    123334 File
    123335 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123336 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    123337 mouse_pause_tracking 
    123338 self._mouse_pause() 
    123339 File
    123340 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123341 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    123342 m.pause(self._mouse_pause_position) 
    123343 File
    123344 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123345 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    123346 p = self.view.picked_object(x, y) 
    123347 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123348 File
    123349 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123350 packages/chimerax/graphics/view.py", line 838, in picked_object 
    123351 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    123352 beyond, 
    123353 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123354 File
    123355 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123356 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    123357 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    123358 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123359 File
    123360 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123361 packages/chimerax/core/models.py", line 143, in first_intercept 
    123362 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    123363 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123364 File
    123365 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123366 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    123367 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    123368 exclude=exclude) 
    123369 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123370 File
    123371 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123372 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    123373 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    123374 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123375 File
    123376 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123377 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    123378 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    123379 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123380 File
    123381 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123382 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    123383 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    123384 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123385 File
    123386 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123387 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    123388 p = super().first_intercept(mxyz1, mxyz2) 
    123389 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123390 File
    123391 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123392 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    123393 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    123394 exclude=exclude) 
    123395 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123396 File
    123397 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123398 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    123399 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    123400 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123401 File
    123402 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123403 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    123404 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    123405 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123406 File
    123407 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123408 packages/chimerax/graphics/drawing.py", line 1108, in
    123409 _first_intercept_excluding_children 
    123410 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    123411 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123412 File
    123413 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123414 packages/chimerax/geometry/place.py", line 201, in inverse 
    123415 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    123416 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123417 File
    123418 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123419 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    123420 rinv[:, :] = matrix_inverse(r) 
    123421 ^^^^^^^^^^^^^^^^^ 
    123422 File
    123423 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123424 packages/numpy/linalg/linalg.py", line 561, in inv 
    123425 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    123426 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123427 File
    123428 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123429 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    123430 raise LinAlgError("Singular matrix") 
    123431 numpy.linalg.LinAlgError: Singular matrix 
    123432  
    123433 numpy.linalg.LinAlgError: Singular matrix 
    123434  
    123435 File
    123436 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123437 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    123438 raise LinAlgError("Singular matrix") 
    123439  
    123440 See log for complete Python traceback. 
    123441  
    123442 Traceback (most recent call last): 
    123443 File
    123444 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123445 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    123446 self.session.ui.mouse_modes.mouse_pause_tracking() 
    123447 File
    123448 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123449 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    123450 mouse_pause_tracking 
    123451 self._mouse_pause() 
    123452 File
    123453 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123454 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    123455 m.pause(self._mouse_pause_position) 
    123456 File
    123457 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123458 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    123459 p = self.view.picked_object(x, y) 
    123460 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123461 File
    123462 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123463 packages/chimerax/graphics/view.py", line 838, in picked_object 
    123464 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    123465 beyond, 
    123466 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123467 File
    123468 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123469 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    123470 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    123471 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123472 File
    123473 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123474 packages/chimerax/core/models.py", line 143, in first_intercept 
    123475 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    123476 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123477 File
    123478 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123479 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    123480 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    123481 exclude=exclude) 
    123482 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123483 File
    123484 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123485 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    123486 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    123487 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123488 File
    123489 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123490 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    123491 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    123492 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123493 File
    123494 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123495 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    123496 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    123497 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123498 File
    123499 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123500 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    123501 p = super().first_intercept(mxyz1, mxyz2) 
    123502 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123503 File
    123504 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123505 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    123506 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    123507 exclude=exclude) 
    123508 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123509 File
    123510 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123511 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    123512 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    123513 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123514 File
    123515 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123516 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    123517 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    123518 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123519 File
    123520 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123521 packages/chimerax/graphics/drawing.py", line 1108, in
    123522 _first_intercept_excluding_children 
    123523 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    123524 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123525 File
    123526 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123527 packages/chimerax/geometry/place.py", line 201, in inverse 
    123528 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    123529 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123530 File
    123531 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123532 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    123533 rinv[:, :] = matrix_inverse(r) 
    123534 ^^^^^^^^^^^^^^^^^ 
    123535 File
    123536 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123537 packages/numpy/linalg/linalg.py", line 561, in inv 
    123538 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    123539 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123540 File
    123541 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123542 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    123543 raise LinAlgError("Singular matrix") 
    123544 numpy.linalg.LinAlgError: Singular matrix 
    123545  
    123546 numpy.linalg.LinAlgError: Singular matrix 
    123547  
    123548 File
    123549 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123550 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    123551 raise LinAlgError("Singular matrix") 
    123552  
    123553 See log for complete Python traceback. 
    123554  
    123555 Traceback (most recent call last): 
    123556 File
    123557 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123558 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    123559 self.session.ui.mouse_modes.mouse_pause_tracking() 
    123560 File
    123561 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123562 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    123563 mouse_pause_tracking 
    123564 self._mouse_pause() 
    123565 File
    123566 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123567 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    123568 m.pause(self._mouse_pause_position) 
    123569 File
    123570 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123571 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    123572 p = self.view.picked_object(x, y) 
    123573 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123574 File
    123575 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123576 packages/chimerax/graphics/view.py", line 838, in picked_object 
    123577 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    123578 beyond, 
    123579 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123580 File
    123581 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123582 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    123583 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    123584 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123585 File
    123586 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123587 packages/chimerax/core/models.py", line 143, in first_intercept 
    123588 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    123589 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123590 File
    123591 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123592 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    123593 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    123594 exclude=exclude) 
    123595 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123596 File
    123597 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123598 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    123599 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    123600 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123601 File
    123602 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123603 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    123604 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    123605 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123606 File
    123607 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123608 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    123609 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    123610 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123611 File
    123612 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123613 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    123614 p = super().first_intercept(mxyz1, mxyz2) 
    123615 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123616 File
    123617 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123618 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    123619 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    123620 exclude=exclude) 
    123621 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123622 File
    123623 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123624 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    123625 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    123626 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123627 File
    123628 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123629 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    123630 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    123631 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123632 File
    123633 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123634 packages/chimerax/graphics/drawing.py", line 1108, in
    123635 _first_intercept_excluding_children 
    123636 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    123637 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123638 File
    123639 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123640 packages/chimerax/geometry/place.py", line 201, in inverse 
    123641 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    123642 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123643 File
    123644 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123645 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    123646 rinv[:, :] = matrix_inverse(r) 
    123647 ^^^^^^^^^^^^^^^^^ 
    123648 File
    123649 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123650 packages/numpy/linalg/linalg.py", line 561, in inv 
    123651 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    123652 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123653 File
    123654 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123655 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    123656 raise LinAlgError("Singular matrix") 
    123657 numpy.linalg.LinAlgError: Singular matrix 
    123658  
    123659 numpy.linalg.LinAlgError: Singular matrix 
    123660  
    123661 File
    123662 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123663 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    123664 raise LinAlgError("Singular matrix") 
    123665  
    123666 See log for complete Python traceback. 
    123667  
    123668 Traceback (most recent call last): 
    123669 File
    123670 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123671 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    123672 self.session.ui.mouse_modes.mouse_pause_tracking() 
    123673 File
    123674 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123675 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    123676 mouse_pause_tracking 
    123677 self._mouse_pause() 
    123678 File
    123679 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123680 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    123681 m.pause(self._mouse_pause_position) 
    123682 File
    123683 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123684 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    123685 p = self.view.picked_object(x, y) 
    123686 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123687 File
    123688 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123689 packages/chimerax/graphics/view.py", line 838, in picked_object 
    123690 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    123691 beyond, 
    123692 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123693 File
    123694 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123695 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    123696 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    123697 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123698 File
    123699 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123700 packages/chimerax/core/models.py", line 143, in first_intercept 
    123701 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    123702 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123703 File
    123704 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123705 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    123706 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    123707 exclude=exclude) 
    123708 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123709 File
    123710 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123711 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    123712 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    123713 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123714 File
    123715 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123716 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    123717 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    123718 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123719 File
    123720 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123721 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    123722 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    123723 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123724 File
    123725 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123726 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    123727 p = super().first_intercept(mxyz1, mxyz2) 
    123728 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123729 File
    123730 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123731 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    123732 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    123733 exclude=exclude) 
    123734 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123735 File
    123736 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123737 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    123738 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    123739 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123740 File
    123741 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123742 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    123743 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    123744 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123745 File
    123746 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123747 packages/chimerax/graphics/drawing.py", line 1108, in
    123748 _first_intercept_excluding_children 
    123749 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    123750 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123751 File
    123752 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123753 packages/chimerax/geometry/place.py", line 201, in inverse 
    123754 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    123755 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123756 File
    123757 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123758 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    123759 rinv[:, :] = matrix_inverse(r) 
    123760 ^^^^^^^^^^^^^^^^^ 
    123761 File
    123762 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123763 packages/numpy/linalg/linalg.py", line 561, in inv 
    123764 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    123765 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123766 File
    123767 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123768 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    123769 raise LinAlgError("Singular matrix") 
    123770 numpy.linalg.LinAlgError: Singular matrix 
    123771  
    123772 numpy.linalg.LinAlgError: Singular matrix 
    123773  
    123774 File
    123775 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123776 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    123777 raise LinAlgError("Singular matrix") 
    123778  
    123779 See log for complete Python traceback. 
    123780  
    123781 Traceback (most recent call last): 
    123782 File
    123783 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123784 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    123785 self.session.ui.mouse_modes.mouse_pause_tracking() 
    123786 File
    123787 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123788 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    123789 mouse_pause_tracking 
    123790 self._mouse_pause() 
    123791 File
    123792 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123793 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    123794 m.pause(self._mouse_pause_position) 
    123795 File
    123796 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123797 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    123798 p = self.view.picked_object(x, y) 
    123799 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123800 File
    123801 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123802 packages/chimerax/graphics/view.py", line 838, in picked_object 
    123803 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    123804 beyond, 
    123805 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123806 File
    123807 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123808 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    123809 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    123810 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123811 File
    123812 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123813 packages/chimerax/core/models.py", line 143, in first_intercept 
    123814 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    123815 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123816 File
    123817 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123818 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    123819 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    123820 exclude=exclude) 
    123821 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123822 File
    123823 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123824 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    123825 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    123826 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123827 File
    123828 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123829 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    123830 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    123831 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123832 File
    123833 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123834 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    123835 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    123836 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123837 File
    123838 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123839 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    123840 p = super().first_intercept(mxyz1, mxyz2) 
    123841 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123842 File
    123843 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123844 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    123845 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    123846 exclude=exclude) 
    123847 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123848 File
    123849 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123850 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    123851 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    123852 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123853 File
    123854 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123855 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    123856 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    123857 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123858 File
    123859 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123860 packages/chimerax/graphics/drawing.py", line 1108, in
    123861 _first_intercept_excluding_children 
    123862 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    123863 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123864 File
    123865 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123866 packages/chimerax/geometry/place.py", line 201, in inverse 
    123867 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    123868 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123869 File
    123870 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123871 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    123872 rinv[:, :] = matrix_inverse(r) 
    123873 ^^^^^^^^^^^^^^^^^ 
    123874 File
    123875 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123876 packages/numpy/linalg/linalg.py", line 561, in inv 
    123877 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    123878 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123879 File
    123880 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123881 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    123882 raise LinAlgError("Singular matrix") 
    123883 numpy.linalg.LinAlgError: Singular matrix 
    123884  
    123885 numpy.linalg.LinAlgError: Singular matrix 
    123886  
    123887 File
    123888 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123889 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    123890 raise LinAlgError("Singular matrix") 
    123891  
    123892 See log for complete Python traceback. 
    123893  
    123894 Traceback (most recent call last): 
    123895 File
    123896 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123897 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    123898 self.session.ui.mouse_modes.mouse_pause_tracking() 
    123899 File
    123900 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123901 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    123902 mouse_pause_tracking 
    123903 self._mouse_pause() 
    123904 File
    123905 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123906 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    123907 m.pause(self._mouse_pause_position) 
    123908 File
    123909 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123910 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    123911 p = self.view.picked_object(x, y) 
    123912 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123913 File
    123914 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123915 packages/chimerax/graphics/view.py", line 838, in picked_object 
    123916 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    123917 beyond, 
    123918 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123919 File
    123920 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123921 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    123922 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    123923 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123924 File
    123925 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123926 packages/chimerax/core/models.py", line 143, in first_intercept 
    123927 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    123928 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123929 File
    123930 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123931 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    123932 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    123933 exclude=exclude) 
    123934 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123935 File
    123936 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123937 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    123938 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    123939 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123940 File
    123941 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123942 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    123943 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    123944 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123945 File
    123946 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123947 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    123948 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    123949 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123950 File
    123951 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123952 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    123953 p = super().first_intercept(mxyz1, mxyz2) 
    123954 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123955 File
    123956 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123957 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    123958 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    123959 exclude=exclude) 
    123960 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123961 File
    123962 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123963 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    123964 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    123965 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123966 File
    123967 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123968 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    123969 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    123970 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123971 File
    123972 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123973 packages/chimerax/graphics/drawing.py", line 1108, in
    123974 _first_intercept_excluding_children 
    123975 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    123976 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123977 File
    123978 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123979 packages/chimerax/geometry/place.py", line 201, in inverse 
    123980 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    123981 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123982 File
    123983 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123984 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    123985 rinv[:, :] = matrix_inverse(r) 
    123986 ^^^^^^^^^^^^^^^^^ 
    123987 File
    123988 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123989 packages/numpy/linalg/linalg.py", line 561, in inv 
    123990 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    123991 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    123992 File
    123993 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    123994 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    123995 raise LinAlgError("Singular matrix") 
    123996 numpy.linalg.LinAlgError: Singular matrix 
    123997  
    123998 numpy.linalg.LinAlgError: Singular matrix 
    123999  
    124000 File
    124001 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124002 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    124003 raise LinAlgError("Singular matrix") 
    124004  
    124005 See log for complete Python traceback. 
    124006  
    124007 Traceback (most recent call last): 
    124008 File
    124009 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124010 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    124011 self.session.ui.mouse_modes.mouse_pause_tracking() 
    124012 File
    124013 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124014 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    124015 mouse_pause_tracking 
    124016 self._mouse_pause() 
    124017 File
    124018 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124019 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    124020 m.pause(self._mouse_pause_position) 
    124021 File
    124022 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124023 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    124024 p = self.view.picked_object(x, y) 
    124025 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124026 File
    124027 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124028 packages/chimerax/graphics/view.py", line 838, in picked_object 
    124029 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    124030 beyond, 
    124031 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124032 File
    124033 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124034 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    124035 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    124036 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124037 File
    124038 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124039 packages/chimerax/core/models.py", line 143, in first_intercept 
    124040 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    124041 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124042 File
    124043 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124044 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    124045 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    124046 exclude=exclude) 
    124047 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124048 File
    124049 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124050 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    124051 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    124052 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124053 File
    124054 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124055 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    124056 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    124057 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124058 File
    124059 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124060 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    124061 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    124062 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124063 File
    124064 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124065 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    124066 p = super().first_intercept(mxyz1, mxyz2) 
    124067 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124068 File
    124069 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124070 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    124071 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    124072 exclude=exclude) 
    124073 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124074 File
    124075 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124076 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    124077 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    124078 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124079 File
    124080 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124081 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    124082 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    124083 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124084 File
    124085 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124086 packages/chimerax/graphics/drawing.py", line 1108, in
    124087 _first_intercept_excluding_children 
    124088 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    124089 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124090 File
    124091 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124092 packages/chimerax/geometry/place.py", line 201, in inverse 
    124093 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    124094 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124095 File
    124096 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124097 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    124098 rinv[:, :] = matrix_inverse(r) 
    124099 ^^^^^^^^^^^^^^^^^ 
    124100 File
    124101 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124102 packages/numpy/linalg/linalg.py", line 561, in inv 
    124103 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    124104 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124105 File
    124106 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124107 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    124108 raise LinAlgError("Singular matrix") 
    124109 numpy.linalg.LinAlgError: Singular matrix 
    124110  
    124111 numpy.linalg.LinAlgError: Singular matrix 
    124112  
    124113 File
    124114 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124115 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    124116 raise LinAlgError("Singular matrix") 
    124117  
    124118 See log for complete Python traceback. 
    124119  
    124120 Traceback (most recent call last): 
    124121 File
    124122 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124123 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    124124 self.session.ui.mouse_modes.mouse_pause_tracking() 
    124125 File
    124126 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124127 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    124128 mouse_pause_tracking 
    124129 self._mouse_pause() 
    124130 File
    124131 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124132 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    124133 m.pause(self._mouse_pause_position) 
    124134 File
    124135 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124136 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    124137 p = self.view.picked_object(x, y) 
    124138 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124139 File
    124140 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124141 packages/chimerax/graphics/view.py", line 838, in picked_object 
    124142 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    124143 beyond, 
    124144 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124145 File
    124146 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124147 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    124148 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    124149 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124150 File
    124151 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124152 packages/chimerax/core/models.py", line 143, in first_intercept 
    124153 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    124154 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124155 File
    124156 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124157 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    124158 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    124159 exclude=exclude) 
    124160 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124161 File
    124162 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124163 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    124164 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    124165 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124166 File
    124167 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124168 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    124169 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    124170 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124171 File
    124172 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124173 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    124174 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    124175 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124176 File
    124177 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124178 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    124179 p = super().first_intercept(mxyz1, mxyz2) 
    124180 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124181 File
    124182 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124183 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    124184 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    124185 exclude=exclude) 
    124186 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124187 File
    124188 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124189 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    124190 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    124191 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124192 File
    124193 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124194 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    124195 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    124196 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124197 File
    124198 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124199 packages/chimerax/graphics/drawing.py", line 1108, in
    124200 _first_intercept_excluding_children 
    124201 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    124202 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124203 File
    124204 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124205 packages/chimerax/geometry/place.py", line 201, in inverse 
    124206 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    124207 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124208 File
    124209 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124210 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    124211 rinv[:, :] = matrix_inverse(r) 
    124212 ^^^^^^^^^^^^^^^^^ 
    124213 File
    124214 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124215 packages/numpy/linalg/linalg.py", line 561, in inv 
    124216 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    124217 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124218 File
    124219 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124220 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    124221 raise LinAlgError("Singular matrix") 
    124222 numpy.linalg.LinAlgError: Singular matrix 
    124223  
    124224 numpy.linalg.LinAlgError: Singular matrix 
    124225  
    124226 File
    124227 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124228 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    124229 raise LinAlgError("Singular matrix") 
    124230  
    124231 See log for complete Python traceback. 
    124232  
    124233 Traceback (most recent call last): 
    124234 File
    124235 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124236 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    124237 self.session.ui.mouse_modes.mouse_pause_tracking() 
    124238 File
    124239 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124240 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    124241 mouse_pause_tracking 
    124242 self._mouse_pause() 
    124243 File
    124244 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124245 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    124246 m.pause(self._mouse_pause_position) 
    124247 File
    124248 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124249 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    124250 p = self.view.picked_object(x, y) 
    124251 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124252 File
    124253 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124254 packages/chimerax/graphics/view.py", line 838, in picked_object 
    124255 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    124256 beyond, 
    124257 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124258 File
    124259 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124260 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    124261 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    124262 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124263 File
    124264 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124265 packages/chimerax/core/models.py", line 143, in first_intercept 
    124266 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    124267 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124268 File
    124269 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124270 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    124271 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    124272 exclude=exclude) 
    124273 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124274 File
    124275 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124276 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    124277 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    124278 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124279 File
    124280 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124281 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    124282 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    124283 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124284 File
    124285 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124286 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    124287 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    124288 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124289 File
    124290 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124291 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    124292 p = super().first_intercept(mxyz1, mxyz2) 
    124293 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124294 File
    124295 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124296 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    124297 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    124298 exclude=exclude) 
    124299 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124300 File
    124301 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124302 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    124303 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    124304 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124305 File
    124306 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124307 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    124308 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    124309 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124310 File
    124311 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124312 packages/chimerax/graphics/drawing.py", line 1108, in
    124313 _first_intercept_excluding_children 
    124314 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    124315 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124316 File
    124317 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124318 packages/chimerax/geometry/place.py", line 201, in inverse 
    124319 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    124320 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124321 File
    124322 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124323 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    124324 rinv[:, :] = matrix_inverse(r) 
    124325 ^^^^^^^^^^^^^^^^^ 
    124326 File
    124327 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124328 packages/numpy/linalg/linalg.py", line 561, in inv 
    124329 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    124330 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124331 File
    124332 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124333 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    124334 raise LinAlgError("Singular matrix") 
    124335 numpy.linalg.LinAlgError: Singular matrix 
    124336  
    124337 numpy.linalg.LinAlgError: Singular matrix 
    124338  
    124339 File
    124340 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124341 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    124342 raise LinAlgError("Singular matrix") 
    124343  
    124344 See log for complete Python traceback. 
    124345  
    124346 Traceback (most recent call last): 
    124347 File
    124348 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124349 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    124350 self.session.ui.mouse_modes.mouse_pause_tracking() 
    124351 File
    124352 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124353 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    124354 mouse_pause_tracking 
    124355 self._mouse_pause() 
    124356 File
    124357 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124358 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    124359 m.pause(self._mouse_pause_position) 
    124360 File
    124361 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124362 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    124363 p = self.view.picked_object(x, y) 
    124364 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124365 File
    124366 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124367 packages/chimerax/graphics/view.py", line 838, in picked_object 
    124368 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    124369 beyond, 
    124370 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124371 File
    124372 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124373 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    124374 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    124375 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124376 File
    124377 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124378 packages/chimerax/core/models.py", line 143, in first_intercept 
    124379 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    124380 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124381 File
    124382 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124383 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    124384 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    124385 exclude=exclude) 
    124386 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124387 File
    124388 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124389 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    124390 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    124391 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124392 File
    124393 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124394 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    124395 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    124396 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124397 File
    124398 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124399 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    124400 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    124401 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124402 File
    124403 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124404 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    124405 p = super().first_intercept(mxyz1, mxyz2) 
    124406 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124407 File
    124408 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124409 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    124410 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    124411 exclude=exclude) 
    124412 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124413 File
    124414 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124415 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    124416 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    124417 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124418 File
    124419 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124420 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    124421 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    124422 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124423 File
    124424 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124425 packages/chimerax/graphics/drawing.py", line 1108, in
    124426 _first_intercept_excluding_children 
    124427 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    124428 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124429 File
    124430 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124431 packages/chimerax/geometry/place.py", line 201, in inverse 
    124432 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    124433 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124434 File
    124435 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124436 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    124437 rinv[:, :] = matrix_inverse(r) 
    124438 ^^^^^^^^^^^^^^^^^ 
    124439 File
    124440 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124441 packages/numpy/linalg/linalg.py", line 561, in inv 
    124442 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    124443 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124444 File
    124445 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124446 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    124447 raise LinAlgError("Singular matrix") 
    124448 numpy.linalg.LinAlgError: Singular matrix 
    124449  
    124450 numpy.linalg.LinAlgError: Singular matrix 
    124451  
    124452 File
    124453 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124454 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    124455 raise LinAlgError("Singular matrix") 
    124456  
    124457 See log for complete Python traceback. 
    124458  
    124459 Traceback (most recent call last): 
    124460 File
    124461 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124462 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    124463 self.session.ui.mouse_modes.mouse_pause_tracking() 
    124464 File
    124465 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124466 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    124467 mouse_pause_tracking 
    124468 self._mouse_pause() 
    124469 File
    124470 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124471 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    124472 m.pause(self._mouse_pause_position) 
    124473 File
    124474 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124475 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    124476 p = self.view.picked_object(x, y) 
    124477 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124478 File
    124479 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124480 packages/chimerax/graphics/view.py", line 838, in picked_object 
    124481 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    124482 beyond, 
    124483 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124484 File
    124485 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124486 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    124487 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    124488 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124489 File
    124490 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124491 packages/chimerax/core/models.py", line 143, in first_intercept 
    124492 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    124493 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124494 File
    124495 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124496 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    124497 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    124498 exclude=exclude) 
    124499 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124500 File
    124501 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124502 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    124503 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    124504 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124505 File
    124506 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124507 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    124508 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    124509 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124510 File
    124511 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124512 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    124513 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    124514 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124515 File
    124516 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124517 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    124518 p = super().first_intercept(mxyz1, mxyz2) 
    124519 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124520 File
    124521 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124522 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    124523 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    124524 exclude=exclude) 
    124525 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124526 File
    124527 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124528 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    124529 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    124530 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124531 File
    124532 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124533 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    124534 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    124535 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124536 File
    124537 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124538 packages/chimerax/graphics/drawing.py", line 1108, in
    124539 _first_intercept_excluding_children 
    124540 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    124541 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124542 File
    124543 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124544 packages/chimerax/geometry/place.py", line 201, in inverse 
    124545 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    124546 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124547 File
    124548 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124549 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    124550 rinv[:, :] = matrix_inverse(r) 
    124551 ^^^^^^^^^^^^^^^^^ 
    124552 File
    124553 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124554 packages/numpy/linalg/linalg.py", line 561, in inv 
    124555 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    124556 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124557 File
    124558 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124559 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    124560 raise LinAlgError("Singular matrix") 
    124561 numpy.linalg.LinAlgError: Singular matrix 
    124562  
    124563 numpy.linalg.LinAlgError: Singular matrix 
    124564  
    124565 File
    124566 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124567 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    124568 raise LinAlgError("Singular matrix") 
    124569  
    124570 See log for complete Python traceback. 
    124571  
    124572 Traceback (most recent call last): 
    124573 File
    124574 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124575 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    124576 self.session.ui.mouse_modes.mouse_pause_tracking() 
    124577 File
    124578 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124579 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    124580 mouse_pause_tracking 
    124581 self._mouse_pause() 
    124582 File
    124583 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124584 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    124585 m.pause(self._mouse_pause_position) 
    124586 File
    124587 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124588 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    124589 p = self.view.picked_object(x, y) 
    124590 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124591 File
    124592 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124593 packages/chimerax/graphics/view.py", line 838, in picked_object 
    124594 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    124595 beyond, 
    124596 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124597 File
    124598 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124599 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    124600 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    124601 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124602 File
    124603 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124604 packages/chimerax/core/models.py", line 143, in first_intercept 
    124605 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    124606 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124607 File
    124608 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124609 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    124610 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    124611 exclude=exclude) 
    124612 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124613 File
    124614 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124615 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    124616 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    124617 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124618 File
    124619 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124620 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    124621 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    124622 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124623 File
    124624 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124625 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    124626 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    124627 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124628 File
    124629 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124630 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    124631 p = super().first_intercept(mxyz1, mxyz2) 
    124632 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124633 File
    124634 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124635 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    124636 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    124637 exclude=exclude) 
    124638 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124639 File
    124640 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124641 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    124642 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    124643 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124644 File
    124645 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124646 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    124647 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    124648 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124649 File
    124650 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124651 packages/chimerax/graphics/drawing.py", line 1108, in
    124652 _first_intercept_excluding_children 
    124653 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    124654 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124655 File
    124656 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124657 packages/chimerax/geometry/place.py", line 201, in inverse 
    124658 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    124659 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124660 File
    124661 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124662 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    124663 rinv[:, :] = matrix_inverse(r) 
    124664 ^^^^^^^^^^^^^^^^^ 
    124665 File
    124666 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124667 packages/numpy/linalg/linalg.py", line 561, in inv 
    124668 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    124669 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124670 File
    124671 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124672 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    124673 raise LinAlgError("Singular matrix") 
    124674 numpy.linalg.LinAlgError: Singular matrix 
    124675  
    124676 numpy.linalg.LinAlgError: Singular matrix 
    124677  
    124678 File
    124679 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124680 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    124681 raise LinAlgError("Singular matrix") 
    124682  
    124683 See log for complete Python traceback. 
    124684  
    124685 Traceback (most recent call last): 
    124686 File
    124687 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124688 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    124689 self.session.ui.mouse_modes.mouse_pause_tracking() 
    124690 File
    124691 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124692 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    124693 mouse_pause_tracking 
    124694 self._mouse_pause() 
    124695 File
    124696 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124697 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    124698 m.pause(self._mouse_pause_position) 
    124699 File
    124700 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124701 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    124702 p = self.view.picked_object(x, y) 
    124703 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124704 File
    124705 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124706 packages/chimerax/graphics/view.py", line 838, in picked_object 
    124707 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    124708 beyond, 
    124709 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124710 File
    124711 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124712 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    124713 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    124714 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124715 File
    124716 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124717 packages/chimerax/core/models.py", line 143, in first_intercept 
    124718 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    124719 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124720 File
    124721 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124722 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    124723 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    124724 exclude=exclude) 
    124725 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124726 File
    124727 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124728 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    124729 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    124730 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124731 File
    124732 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124733 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    124734 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    124735 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124736 File
    124737 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124738 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    124739 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    124740 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124741 File
    124742 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124743 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    124744 p = super().first_intercept(mxyz1, mxyz2) 
    124745 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124746 File
    124747 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124748 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    124749 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    124750 exclude=exclude) 
    124751 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124752 File
    124753 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124754 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    124755 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    124756 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124757 File
    124758 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124759 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    124760 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    124761 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124762 File
    124763 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124764 packages/chimerax/graphics/drawing.py", line 1108, in
    124765 _first_intercept_excluding_children 
    124766 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    124767 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124768 File
    124769 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124770 packages/chimerax/geometry/place.py", line 201, in inverse 
    124771 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    124772 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124773 File
    124774 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124775 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    124776 rinv[:, :] = matrix_inverse(r) 
    124777 ^^^^^^^^^^^^^^^^^ 
    124778 File
    124779 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124780 packages/numpy/linalg/linalg.py", line 561, in inv 
    124781 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    124782 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124783 File
    124784 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124785 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    124786 raise LinAlgError("Singular matrix") 
    124787 numpy.linalg.LinAlgError: Singular matrix 
    124788  
    124789 numpy.linalg.LinAlgError: Singular matrix 
    124790  
    124791 File
    124792 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124793 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    124794 raise LinAlgError("Singular matrix") 
    124795  
    124796 See log for complete Python traceback. 
    124797  
    124798 Traceback (most recent call last): 
    124799 File
    124800 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124801 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    124802 self.session.ui.mouse_modes.mouse_pause_tracking() 
    124803 File
    124804 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124805 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    124806 mouse_pause_tracking 
    124807 self._mouse_pause() 
    124808 File
    124809 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124810 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    124811 m.pause(self._mouse_pause_position) 
    124812 File
    124813 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124814 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    124815 p = self.view.picked_object(x, y) 
    124816 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124817 File
    124818 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124819 packages/chimerax/graphics/view.py", line 838, in picked_object 
    124820 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    124821 beyond, 
    124822 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124823 File
    124824 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124825 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    124826 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    124827 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124828 File
    124829 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124830 packages/chimerax/core/models.py", line 143, in first_intercept 
    124831 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    124832 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124833 File
    124834 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124835 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    124836 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    124837 exclude=exclude) 
    124838 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124839 File
    124840 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124841 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    124842 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    124843 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124844 File
    124845 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124846 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    124847 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    124848 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124849 File
    124850 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124851 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    124852 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    124853 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124854 File
    124855 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124856 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    124857 p = super().first_intercept(mxyz1, mxyz2) 
    124858 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124859 File
    124860 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124861 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    124862 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    124863 exclude=exclude) 
    124864 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124865 File
    124866 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124867 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    124868 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    124869 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124870 File
    124871 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124872 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    124873 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    124874 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124875 File
    124876 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124877 packages/chimerax/graphics/drawing.py", line 1108, in
    124878 _first_intercept_excluding_children 
    124879 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    124880 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124881 File
    124882 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124883 packages/chimerax/geometry/place.py", line 201, in inverse 
    124884 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    124885 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124886 File
    124887 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124888 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    124889 rinv[:, :] = matrix_inverse(r) 
    124890 ^^^^^^^^^^^^^^^^^ 
    124891 File
    124892 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124893 packages/numpy/linalg/linalg.py", line 561, in inv 
    124894 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    124895 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124896 File
    124897 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124898 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    124899 raise LinAlgError("Singular matrix") 
    124900 numpy.linalg.LinAlgError: Singular matrix 
    124901  
    124902 numpy.linalg.LinAlgError: Singular matrix 
    124903  
    124904 File
    124905 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124906 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    124907 raise LinAlgError("Singular matrix") 
    124908  
    124909 See log for complete Python traceback. 
    124910  
    124911 Traceback (most recent call last): 
    124912 File
    124913 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124914 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    124915 self.session.ui.mouse_modes.mouse_pause_tracking() 
    124916 File
    124917 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124918 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    124919 mouse_pause_tracking 
    124920 self._mouse_pause() 
    124921 File
    124922 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124923 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    124924 m.pause(self._mouse_pause_position) 
    124925 File
    124926 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124927 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    124928 p = self.view.picked_object(x, y) 
    124929 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124930 File
    124931 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124932 packages/chimerax/graphics/view.py", line 838, in picked_object 
    124933 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    124934 beyond, 
    124935 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124936 File
    124937 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124938 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    124939 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    124940 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124941 File
    124942 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124943 packages/chimerax/core/models.py", line 143, in first_intercept 
    124944 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    124945 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124946 File
    124947 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124948 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    124949 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    124950 exclude=exclude) 
    124951 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124952 File
    124953 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124954 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    124955 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    124956 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124957 File
    124958 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124959 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    124960 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    124961 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124962 File
    124963 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124964 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    124965 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    124966 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124967 File
    124968 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124969 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    124970 p = super().first_intercept(mxyz1, mxyz2) 
    124971 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124972 File
    124973 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124974 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    124975 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    124976 exclude=exclude) 
    124977 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124978 File
    124979 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124980 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    124981 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    124982 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124983 File
    124984 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124985 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    124986 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    124987 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124988 File
    124989 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124990 packages/chimerax/graphics/drawing.py", line 1108, in
    124991 _first_intercept_excluding_children 
    124992 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    124993 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124994 File
    124995 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    124996 packages/chimerax/geometry/place.py", line 201, in inverse 
    124997 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    124998 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    124999 File
    125000 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125001 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    125002 rinv[:, :] = matrix_inverse(r) 
    125003 ^^^^^^^^^^^^^^^^^ 
    125004 File
    125005 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125006 packages/numpy/linalg/linalg.py", line 561, in inv 
    125007 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    125008 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125009 File
    125010 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125011 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    125012 raise LinAlgError("Singular matrix") 
    125013 numpy.linalg.LinAlgError: Singular matrix 
    125014  
    125015 numpy.linalg.LinAlgError: Singular matrix 
    125016  
    125017 File
    125018 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125019 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    125020 raise LinAlgError("Singular matrix") 
    125021  
    125022 See log for complete Python traceback. 
    125023  
    125024 Traceback (most recent call last): 
    125025 File
    125026 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125027 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    125028 self.session.ui.mouse_modes.mouse_pause_tracking() 
    125029 File
    125030 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125031 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    125032 mouse_pause_tracking 
    125033 self._mouse_pause() 
    125034 File
    125035 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125036 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    125037 m.pause(self._mouse_pause_position) 
    125038 File
    125039 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125040 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    125041 p = self.view.picked_object(x, y) 
    125042 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125043 File
    125044 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125045 packages/chimerax/graphics/view.py", line 838, in picked_object 
    125046 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    125047 beyond, 
    125048 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125049 File
    125050 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125051 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    125052 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    125053 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125054 File
    125055 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125056 packages/chimerax/core/models.py", line 143, in first_intercept 
    125057 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    125058 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125059 File
    125060 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125061 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    125062 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    125063 exclude=exclude) 
    125064 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125065 File
    125066 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125067 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    125068 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    125069 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125070 File
    125071 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125072 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    125073 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    125074 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125075 File
    125076 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125077 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    125078 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    125079 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125080 File
    125081 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125082 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    125083 p = super().first_intercept(mxyz1, mxyz2) 
    125084 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125085 File
    125086 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125087 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    125088 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    125089 exclude=exclude) 
    125090 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125091 File
    125092 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125093 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    125094 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    125095 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125096 File
    125097 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125098 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    125099 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    125100 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125101 File
    125102 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125103 packages/chimerax/graphics/drawing.py", line 1108, in
    125104 _first_intercept_excluding_children 
    125105 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    125106 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125107 File
    125108 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125109 packages/chimerax/geometry/place.py", line 201, in inverse 
    125110 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    125111 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125112 File
    125113 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125114 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    125115 rinv[:, :] = matrix_inverse(r) 
    125116 ^^^^^^^^^^^^^^^^^ 
    125117 File
    125118 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125119 packages/numpy/linalg/linalg.py", line 561, in inv 
    125120 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    125121 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125122 File
    125123 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125124 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    125125 raise LinAlgError("Singular matrix") 
    125126 numpy.linalg.LinAlgError: Singular matrix 
    125127  
    125128 numpy.linalg.LinAlgError: Singular matrix 
    125129  
    125130 File
    125131 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125132 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    125133 raise LinAlgError("Singular matrix") 
    125134  
    125135 See log for complete Python traceback. 
    125136  
    125137 Traceback (most recent call last): 
    125138 File
    125139 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125140 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    125141 self.session.ui.mouse_modes.mouse_pause_tracking() 
    125142 File
    125143 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125144 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    125145 mouse_pause_tracking 
    125146 self._mouse_pause() 
    125147 File
    125148 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125149 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    125150 m.pause(self._mouse_pause_position) 
    125151 File
    125152 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125153 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    125154 p = self.view.picked_object(x, y) 
    125155 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125156 File
    125157 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125158 packages/chimerax/graphics/view.py", line 838, in picked_object 
    125159 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    125160 beyond, 
    125161 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125162 File
    125163 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125164 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    125165 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    125166 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125167 File
    125168 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125169 packages/chimerax/core/models.py", line 143, in first_intercept 
    125170 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    125171 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125172 File
    125173 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125174 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    125175 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    125176 exclude=exclude) 
    125177 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125178 File
    125179 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125180 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    125181 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    125182 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125183 File
    125184 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125185 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    125186 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    125187 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125188 File
    125189 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125190 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    125191 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    125192 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125193 File
    125194 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125195 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    125196 p = super().first_intercept(mxyz1, mxyz2) 
    125197 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125198 File
    125199 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125200 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    125201 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    125202 exclude=exclude) 
    125203 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125204 File
    125205 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125206 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    125207 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    125208 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125209 File
    125210 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125211 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    125212 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    125213 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125214 File
    125215 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125216 packages/chimerax/graphics/drawing.py", line 1108, in
    125217 _first_intercept_excluding_children 
    125218 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    125219 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125220 File
    125221 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125222 packages/chimerax/geometry/place.py", line 201, in inverse 
    125223 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    125224 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125225 File
    125226 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125227 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    125228 rinv[:, :] = matrix_inverse(r) 
    125229 ^^^^^^^^^^^^^^^^^ 
    125230 File
    125231 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125232 packages/numpy/linalg/linalg.py", line 561, in inv 
    125233 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    125234 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125235 File
    125236 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125237 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    125238 raise LinAlgError("Singular matrix") 
    125239 numpy.linalg.LinAlgError: Singular matrix 
    125240  
    125241 numpy.linalg.LinAlgError: Singular matrix 
    125242  
    125243 File
    125244 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125245 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    125246 raise LinAlgError("Singular matrix") 
    125247  
    125248 See log for complete Python traceback. 
    125249  
    125250 Traceback (most recent call last): 
    125251 File
    125252 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125253 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    125254 self.session.ui.mouse_modes.mouse_pause_tracking() 
    125255 File
    125256 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125257 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    125258 mouse_pause_tracking 
    125259 self._mouse_pause() 
    125260 File
    125261 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125262 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    125263 m.pause(self._mouse_pause_position) 
    125264 File
    125265 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125266 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    125267 p = self.view.picked_object(x, y) 
    125268 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125269 File
    125270 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125271 packages/chimerax/graphics/view.py", line 838, in picked_object 
    125272 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    125273 beyond, 
    125274 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125275 File
    125276 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125277 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    125278 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    125279 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125280 File
    125281 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125282 packages/chimerax/core/models.py", line 143, in first_intercept 
    125283 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    125284 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125285 File
    125286 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125287 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    125288 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    125289 exclude=exclude) 
    125290 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125291 File
    125292 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125293 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    125294 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    125295 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125296 File
    125297 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125298 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    125299 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    125300 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125301 File
    125302 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125303 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    125304 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    125305 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125306 File
    125307 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125308 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    125309 p = super().first_intercept(mxyz1, mxyz2) 
    125310 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125311 File
    125312 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125313 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    125314 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    125315 exclude=exclude) 
    125316 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125317 File
    125318 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125319 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    125320 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    125321 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125322 File
    125323 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125324 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    125325 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    125326 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125327 File
    125328 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125329 packages/chimerax/graphics/drawing.py", line 1108, in
    125330 _first_intercept_excluding_children 
    125331 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    125332 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125333 File
    125334 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125335 packages/chimerax/geometry/place.py", line 201, in inverse 
    125336 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    125337 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125338 File
    125339 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125340 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    125341 rinv[:, :] = matrix_inverse(r) 
    125342 ^^^^^^^^^^^^^^^^^ 
    125343 File
    125344 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125345 packages/numpy/linalg/linalg.py", line 561, in inv 
    125346 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    125347 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125348 File
    125349 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125350 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    125351 raise LinAlgError("Singular matrix") 
    125352 numpy.linalg.LinAlgError: Singular matrix 
    125353  
    125354 numpy.linalg.LinAlgError: Singular matrix 
    125355  
    125356 File
    125357 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125358 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    125359 raise LinAlgError("Singular matrix") 
    125360  
    125361 See log for complete Python traceback. 
    125362  
    125363 Traceback (most recent call last): 
    125364 File
    125365 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125366 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    125367 self.session.ui.mouse_modes.mouse_pause_tracking() 
    125368 File
    125369 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125370 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    125371 mouse_pause_tracking 
    125372 self._mouse_pause() 
    125373 File
    125374 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125375 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    125376 m.pause(self._mouse_pause_position) 
    125377 File
    125378 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125379 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    125380 p = self.view.picked_object(x, y) 
    125381 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125382 File
    125383 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125384 packages/chimerax/graphics/view.py", line 838, in picked_object 
    125385 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    125386 beyond, 
    125387 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125388 File
    125389 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125390 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    125391 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    125392 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125393 File
    125394 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125395 packages/chimerax/core/models.py", line 143, in first_intercept 
    125396 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    125397 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125398 File
    125399 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125400 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    125401 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    125402 exclude=exclude) 
    125403 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125404 File
    125405 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125406 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    125407 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    125408 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125409 File
    125410 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125411 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    125412 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    125413 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125414 File
    125415 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125416 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    125417 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    125418 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125419 File
    125420 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125421 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    125422 p = super().first_intercept(mxyz1, mxyz2) 
    125423 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125424 File
    125425 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125426 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    125427 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    125428 exclude=exclude) 
    125429 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125430 File
    125431 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125432 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    125433 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    125434 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125435 File
    125436 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125437 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    125438 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    125439 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125440 File
    125441 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125442 packages/chimerax/graphics/drawing.py", line 1108, in
    125443 _first_intercept_excluding_children 
    125444 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    125445 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125446 File
    125447 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125448 packages/chimerax/geometry/place.py", line 201, in inverse 
    125449 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    125450 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125451 File
    125452 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125453 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    125454 rinv[:, :] = matrix_inverse(r) 
    125455 ^^^^^^^^^^^^^^^^^ 
    125456 File
    125457 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125458 packages/numpy/linalg/linalg.py", line 561, in inv 
    125459 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    125460 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125461 File
    125462 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125463 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    125464 raise LinAlgError("Singular matrix") 
    125465 numpy.linalg.LinAlgError: Singular matrix 
    125466  
    125467 numpy.linalg.LinAlgError: Singular matrix 
    125468  
    125469 File
    125470 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125471 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    125472 raise LinAlgError("Singular matrix") 
    125473  
    125474 See log for complete Python traceback. 
    125475  
    125476 Traceback (most recent call last): 
    125477 File
    125478 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125479 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    125480 self.session.ui.mouse_modes.mouse_pause_tracking() 
    125481 File
    125482 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125483 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    125484 mouse_pause_tracking 
    125485 self._mouse_pause() 
    125486 File
    125487 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125488 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    125489 m.pause(self._mouse_pause_position) 
    125490 File
    125491 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125492 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    125493 p = self.view.picked_object(x, y) 
    125494 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125495 File
    125496 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125497 packages/chimerax/graphics/view.py", line 838, in picked_object 
    125498 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    125499 beyond, 
    125500 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125501 File
    125502 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125503 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    125504 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    125505 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125506 File
    125507 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125508 packages/chimerax/core/models.py", line 143, in first_intercept 
    125509 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    125510 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125511 File
    125512 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125513 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    125514 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    125515 exclude=exclude) 
    125516 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125517 File
    125518 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125519 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    125520 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    125521 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125522 File
    125523 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125524 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    125525 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    125526 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125527 File
    125528 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125529 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    125530 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    125531 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125532 File
    125533 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125534 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    125535 p = super().first_intercept(mxyz1, mxyz2) 
    125536 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125537 File
    125538 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125539 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    125540 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    125541 exclude=exclude) 
    125542 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125543 File
    125544 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125545 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    125546 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    125547 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125548 File
    125549 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125550 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    125551 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    125552 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125553 File
    125554 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125555 packages/chimerax/graphics/drawing.py", line 1108, in
    125556 _first_intercept_excluding_children 
    125557 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    125558 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125559 File
    125560 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125561 packages/chimerax/geometry/place.py", line 201, in inverse 
    125562 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    125563 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125564 File
    125565 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125566 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    125567 rinv[:, :] = matrix_inverse(r) 
    125568 ^^^^^^^^^^^^^^^^^ 
    125569 File
    125570 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125571 packages/numpy/linalg/linalg.py", line 561, in inv 
    125572 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    125573 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125574 File
    125575 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125576 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    125577 raise LinAlgError("Singular matrix") 
    125578 numpy.linalg.LinAlgError: Singular matrix 
    125579  
    125580 numpy.linalg.LinAlgError: Singular matrix 
    125581  
    125582 File
    125583 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125584 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    125585 raise LinAlgError("Singular matrix") 
    125586  
    125587 See log for complete Python traceback. 
    125588  
    125589 Traceback (most recent call last): 
    125590 File
    125591 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125592 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    125593 self.session.ui.mouse_modes.mouse_pause_tracking() 
    125594 File
    125595 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125596 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    125597 mouse_pause_tracking 
    125598 self._mouse_pause() 
    125599 File
    125600 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125601 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    125602 m.pause(self._mouse_pause_position) 
    125603 File
    125604 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125605 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    125606 p = self.view.picked_object(x, y) 
    125607 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125608 File
    125609 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125610 packages/chimerax/graphics/view.py", line 838, in picked_object 
    125611 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    125612 beyond, 
    125613 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125614 File
    125615 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125616 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    125617 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    125618 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125619 File
    125620 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125621 packages/chimerax/core/models.py", line 143, in first_intercept 
    125622 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    125623 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125624 File
    125625 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125626 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    125627 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    125628 exclude=exclude) 
    125629 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125630 File
    125631 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125632 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    125633 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    125634 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125635 File
    125636 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125637 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    125638 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    125639 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125640 File
    125641 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125642 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    125643 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    125644 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125645 File
    125646 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125647 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    125648 p = super().first_intercept(mxyz1, mxyz2) 
    125649 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125650 File
    125651 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125652 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    125653 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    125654 exclude=exclude) 
    125655 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125656 File
    125657 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125658 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    125659 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    125660 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125661 File
    125662 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125663 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    125664 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    125665 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125666 File
    125667 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125668 packages/chimerax/graphics/drawing.py", line 1108, in
    125669 _first_intercept_excluding_children 
    125670 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    125671 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125672 File
    125673 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125674 packages/chimerax/geometry/place.py", line 201, in inverse 
    125675 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    125676 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125677 File
    125678 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125679 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    125680 rinv[:, :] = matrix_inverse(r) 
    125681 ^^^^^^^^^^^^^^^^^ 
    125682 File
    125683 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125684 packages/numpy/linalg/linalg.py", line 561, in inv 
    125685 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    125686 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125687 File
    125688 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125689 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    125690 raise LinAlgError("Singular matrix") 
    125691 numpy.linalg.LinAlgError: Singular matrix 
    125692  
    125693 numpy.linalg.LinAlgError: Singular matrix 
    125694  
    125695 File
    125696 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125697 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    125698 raise LinAlgError("Singular matrix") 
    125699  
    125700 See log for complete Python traceback. 
    125701  
    125702 Traceback (most recent call last): 
    125703 File
    125704 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125705 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    125706 self.session.ui.mouse_modes.mouse_pause_tracking() 
    125707 File
    125708 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125709 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    125710 mouse_pause_tracking 
    125711 self._mouse_pause() 
    125712 File
    125713 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125714 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    125715 m.pause(self._mouse_pause_position) 
    125716 File
    125717 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125718 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    125719 p = self.view.picked_object(x, y) 
    125720 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125721 File
    125722 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125723 packages/chimerax/graphics/view.py", line 838, in picked_object 
    125724 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    125725 beyond, 
    125726 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125727 File
    125728 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125729 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    125730 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    125731 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125732 File
    125733 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125734 packages/chimerax/core/models.py", line 143, in first_intercept 
    125735 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    125736 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125737 File
    125738 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125739 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    125740 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    125741 exclude=exclude) 
    125742 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125743 File
    125744 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125745 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    125746 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    125747 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125748 File
    125749 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125750 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    125751 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    125752 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125753 File
    125754 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125755 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    125756 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    125757 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125758 File
    125759 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125760 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    125761 p = super().first_intercept(mxyz1, mxyz2) 
    125762 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125763 File
    125764 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125765 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    125766 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    125767 exclude=exclude) 
    125768 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125769 File
    125770 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125771 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    125772 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    125773 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125774 File
    125775 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125776 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    125777 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    125778 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125779 File
    125780 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125781 packages/chimerax/graphics/drawing.py", line 1108, in
    125782 _first_intercept_excluding_children 
    125783 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    125784 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125785 File
    125786 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125787 packages/chimerax/geometry/place.py", line 201, in inverse 
    125788 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    125789 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125790 File
    125791 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125792 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    125793 rinv[:, :] = matrix_inverse(r) 
    125794 ^^^^^^^^^^^^^^^^^ 
    125795 File
    125796 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125797 packages/numpy/linalg/linalg.py", line 561, in inv 
    125798 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    125799 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125800 File
    125801 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125802 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    125803 raise LinAlgError("Singular matrix") 
    125804 numpy.linalg.LinAlgError: Singular matrix 
    125805  
    125806 numpy.linalg.LinAlgError: Singular matrix 
    125807  
    125808 File
    125809 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125810 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    125811 raise LinAlgError("Singular matrix") 
    125812  
    125813 See log for complete Python traceback. 
    125814  
    125815 Traceback (most recent call last): 
    125816 File
    125817 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125818 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    125819 self.session.ui.mouse_modes.mouse_pause_tracking() 
    125820 File
    125821 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125822 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    125823 mouse_pause_tracking 
    125824 self._mouse_pause() 
    125825 File
    125826 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125827 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    125828 m.pause(self._mouse_pause_position) 
    125829 File
    125830 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125831 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    125832 p = self.view.picked_object(x, y) 
    125833 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125834 File
    125835 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125836 packages/chimerax/graphics/view.py", line 838, in picked_object 
    125837 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    125838 beyond, 
    125839 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125840 File
    125841 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125842 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    125843 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    125844 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125845 File
    125846 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125847 packages/chimerax/core/models.py", line 143, in first_intercept 
    125848 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    125849 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125850 File
    125851 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125852 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    125853 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    125854 exclude=exclude) 
    125855 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125856 File
    125857 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125858 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    125859 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    125860 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125861 File
    125862 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125863 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    125864 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    125865 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125866 File
    125867 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125868 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    125869 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    125870 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125871 File
    125872 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125873 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    125874 p = super().first_intercept(mxyz1, mxyz2) 
    125875 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125876 File
    125877 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125878 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    125879 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    125880 exclude=exclude) 
    125881 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125882 File
    125883 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125884 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    125885 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    125886 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125887 File
    125888 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125889 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    125890 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    125891 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125892 File
    125893 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125894 packages/chimerax/graphics/drawing.py", line 1108, in
    125895 _first_intercept_excluding_children 
    125896 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    125897 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125898 File
    125899 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125900 packages/chimerax/geometry/place.py", line 201, in inverse 
    125901 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    125902 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125903 File
    125904 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125905 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    125906 rinv[:, :] = matrix_inverse(r) 
    125907 ^^^^^^^^^^^^^^^^^ 
    125908 File
    125909 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125910 packages/numpy/linalg/linalg.py", line 561, in inv 
    125911 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    125912 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125913 File
    125914 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125915 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    125916 raise LinAlgError("Singular matrix") 
    125917 numpy.linalg.LinAlgError: Singular matrix 
    125918  
    125919 numpy.linalg.LinAlgError: Singular matrix 
    125920  
    125921 File
    125922 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125923 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    125924 raise LinAlgError("Singular matrix") 
    125925  
    125926 See log for complete Python traceback. 
    125927  
    125928 Traceback (most recent call last): 
    125929 File
    125930 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125931 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    125932 self.session.ui.mouse_modes.mouse_pause_tracking() 
    125933 File
    125934 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125935 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    125936 mouse_pause_tracking 
    125937 self._mouse_pause() 
    125938 File
    125939 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125940 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    125941 m.pause(self._mouse_pause_position) 
    125942 File
    125943 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125944 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    125945 p = self.view.picked_object(x, y) 
    125946 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125947 File
    125948 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125949 packages/chimerax/graphics/view.py", line 838, in picked_object 
    125950 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    125951 beyond, 
    125952 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125953 File
    125954 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125955 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    125956 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    125957 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125958 File
    125959 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125960 packages/chimerax/core/models.py", line 143, in first_intercept 
    125961 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    125962 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125963 File
    125964 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125965 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    125966 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    125967 exclude=exclude) 
    125968 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125969 File
    125970 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125971 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    125972 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    125973 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125974 File
    125975 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125976 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    125977 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    125978 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125979 File
    125980 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125981 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    125982 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    125983 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125984 File
    125985 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125986 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    125987 p = super().first_intercept(mxyz1, mxyz2) 
    125988 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125989 File
    125990 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125991 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    125992 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    125993 exclude=exclude) 
    125994 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    125995 File
    125996 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    125997 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    125998 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    125999 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126000 File
    126001 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126002 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    126003 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    126004 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126005 File
    126006 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126007 packages/chimerax/graphics/drawing.py", line 1108, in
    126008 _first_intercept_excluding_children 
    126009 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    126010 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126011 File
    126012 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126013 packages/chimerax/geometry/place.py", line 201, in inverse 
    126014 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    126015 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126016 File
    126017 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126018 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    126019 rinv[:, :] = matrix_inverse(r) 
    126020 ^^^^^^^^^^^^^^^^^ 
    126021 File
    126022 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126023 packages/numpy/linalg/linalg.py", line 561, in inv 
    126024 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    126025 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126026 File
    126027 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126028 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    126029 raise LinAlgError("Singular matrix") 
    126030 numpy.linalg.LinAlgError: Singular matrix 
    126031  
    126032 numpy.linalg.LinAlgError: Singular matrix 
    126033  
    126034 File
    126035 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126036 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    126037 raise LinAlgError("Singular matrix") 
    126038  
    126039 See log for complete Python traceback. 
    126040  
    126041 Traceback (most recent call last): 
    126042 File
    126043 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126044 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    126045 self.session.ui.mouse_modes.mouse_pause_tracking() 
    126046 File
    126047 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126048 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    126049 mouse_pause_tracking 
    126050 self._mouse_pause() 
    126051 File
    126052 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126053 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    126054 m.pause(self._mouse_pause_position) 
    126055 File
    126056 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126057 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    126058 p = self.view.picked_object(x, y) 
    126059 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126060 File
    126061 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126062 packages/chimerax/graphics/view.py", line 838, in picked_object 
    126063 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    126064 beyond, 
    126065 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126066 File
    126067 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126068 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    126069 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    126070 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126071 File
    126072 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126073 packages/chimerax/core/models.py", line 143, in first_intercept 
    126074 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    126075 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126076 File
    126077 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126078 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    126079 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    126080 exclude=exclude) 
    126081 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126082 File
    126083 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126084 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    126085 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    126086 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126087 File
    126088 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126089 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    126090 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    126091 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126092 File
    126093 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126094 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    126095 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    126096 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126097 File
    126098 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126099 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    126100 p = super().first_intercept(mxyz1, mxyz2) 
    126101 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126102 File
    126103 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126104 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    126105 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    126106 exclude=exclude) 
    126107 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126108 File
    126109 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126110 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    126111 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    126112 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126113 File
    126114 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126115 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    126116 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    126117 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126118 File
    126119 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126120 packages/chimerax/graphics/drawing.py", line 1108, in
    126121 _first_intercept_excluding_children 
    126122 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    126123 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126124 File
    126125 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126126 packages/chimerax/geometry/place.py", line 201, in inverse 
    126127 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    126128 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126129 File
    126130 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126131 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    126132 rinv[:, :] = matrix_inverse(r) 
    126133 ^^^^^^^^^^^^^^^^^ 
    126134 File
    126135 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126136 packages/numpy/linalg/linalg.py", line 561, in inv 
    126137 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    126138 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126139 File
    126140 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126141 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    126142 raise LinAlgError("Singular matrix") 
    126143 numpy.linalg.LinAlgError: Singular matrix 
    126144  
    126145 numpy.linalg.LinAlgError: Singular matrix 
    126146  
    126147 File
    126148 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126149 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    126150 raise LinAlgError("Singular matrix") 
    126151  
    126152 See log for complete Python traceback. 
    126153  
    126154 Traceback (most recent call last): 
    126155 File
    126156 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126157 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    126158 self.session.ui.mouse_modes.mouse_pause_tracking() 
    126159 File
    126160 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126161 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    126162 mouse_pause_tracking 
    126163 self._mouse_pause() 
    126164 File
    126165 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126166 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    126167 m.pause(self._mouse_pause_position) 
    126168 File
    126169 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126170 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    126171 p = self.view.picked_object(x, y) 
    126172 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126173 File
    126174 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126175 packages/chimerax/graphics/view.py", line 838, in picked_object 
    126176 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    126177 beyond, 
    126178 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126179 File
    126180 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126181 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    126182 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    126183 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126184 File
    126185 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126186 packages/chimerax/core/models.py", line 143, in first_intercept 
    126187 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    126188 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126189 File
    126190 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126191 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    126192 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    126193 exclude=exclude) 
    126194 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126195 File
    126196 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126197 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    126198 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    126199 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126200 File
    126201 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126202 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    126203 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    126204 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126205 File
    126206 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126207 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    126208 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    126209 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126210 File
    126211 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126212 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    126213 p = super().first_intercept(mxyz1, mxyz2) 
    126214 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126215 File
    126216 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126217 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    126218 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    126219 exclude=exclude) 
    126220 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126221 File
    126222 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126223 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    126224 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    126225 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126226 File
    126227 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126228 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    126229 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    126230 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126231 File
    126232 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126233 packages/chimerax/graphics/drawing.py", line 1108, in
    126234 _first_intercept_excluding_children 
    126235 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    126236 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126237 File
    126238 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126239 packages/chimerax/geometry/place.py", line 201, in inverse 
    126240 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    126241 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126242 File
    126243 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126244 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    126245 rinv[:, :] = matrix_inverse(r) 
    126246 ^^^^^^^^^^^^^^^^^ 
    126247 File
    126248 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126249 packages/numpy/linalg/linalg.py", line 561, in inv 
    126250 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    126251 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126252 File
    126253 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126254 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    126255 raise LinAlgError("Singular matrix") 
    126256 numpy.linalg.LinAlgError: Singular matrix 
    126257  
    126258 numpy.linalg.LinAlgError: Singular matrix 
    126259  
    126260 File
    126261 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126262 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    126263 raise LinAlgError("Singular matrix") 
    126264  
    126265 See log for complete Python traceback. 
    126266  
    126267 Traceback (most recent call last): 
    126268 File
    126269 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126270 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    126271 self.session.ui.mouse_modes.mouse_pause_tracking() 
    126272 File
    126273 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126274 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    126275 mouse_pause_tracking 
    126276 self._mouse_pause() 
    126277 File
    126278 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126279 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    126280 m.pause(self._mouse_pause_position) 
    126281 File
    126282 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126283 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    126284 p = self.view.picked_object(x, y) 
    126285 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126286 File
    126287 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126288 packages/chimerax/graphics/view.py", line 838, in picked_object 
    126289 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    126290 beyond, 
    126291 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126292 File
    126293 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126294 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    126295 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    126296 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126297 File
    126298 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126299 packages/chimerax/core/models.py", line 143, in first_intercept 
    126300 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    126301 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126302 File
    126303 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126304 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    126305 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    126306 exclude=exclude) 
    126307 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126308 File
    126309 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126310 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    126311 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    126312 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126313 File
    126314 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126315 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    126316 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    126317 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126318 File
    126319 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126320 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    126321 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    126322 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126323 File
    126324 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126325 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    126326 p = super().first_intercept(mxyz1, mxyz2) 
    126327 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126328 File
    126329 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126330 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    126331 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    126332 exclude=exclude) 
    126333 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126334 File
    126335 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126336 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    126337 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    126338 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126339 File
    126340 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126341 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    126342 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    126343 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126344 File
    126345 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126346 packages/chimerax/graphics/drawing.py", line 1108, in
    126347 _first_intercept_excluding_children 
    126348 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    126349 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126350 File
    126351 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126352 packages/chimerax/geometry/place.py", line 201, in inverse 
    126353 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    126354 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126355 File
    126356 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126357 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    126358 rinv[:, :] = matrix_inverse(r) 
    126359 ^^^^^^^^^^^^^^^^^ 
    126360 File
    126361 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126362 packages/numpy/linalg/linalg.py", line 561, in inv 
    126363 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    126364 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126365 File
    126366 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126367 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    126368 raise LinAlgError("Singular matrix") 
    126369 numpy.linalg.LinAlgError: Singular matrix 
    126370  
    126371 numpy.linalg.LinAlgError: Singular matrix 
    126372  
    126373 File
    126374 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126375 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    126376 raise LinAlgError("Singular matrix") 
    126377  
    126378 See log for complete Python traceback. 
    126379  
    126380 Traceback (most recent call last): 
    126381 File
    126382 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126383 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    126384 self.session.ui.mouse_modes.mouse_pause_tracking() 
    126385 File
    126386 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126387 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    126388 mouse_pause_tracking 
    126389 self._mouse_pause() 
    126390 File
    126391 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126392 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    126393 m.pause(self._mouse_pause_position) 
    126394 File
    126395 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126396 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    126397 p = self.view.picked_object(x, y) 
    126398 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126399 File
    126400 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126401 packages/chimerax/graphics/view.py", line 838, in picked_object 
    126402 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    126403 beyond, 
    126404 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126405 File
    126406 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126407 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    126408 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    126409 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126410 File
    126411 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126412 packages/chimerax/core/models.py", line 143, in first_intercept 
    126413 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    126414 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126415 File
    126416 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126417 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    126418 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    126419 exclude=exclude) 
    126420 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126421 File
    126422 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126423 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    126424 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    126425 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126426 File
    126427 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126428 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    126429 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    126430 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126431 File
    126432 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126433 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    126434 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    126435 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126436 File
    126437 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126438 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    126439 p = super().first_intercept(mxyz1, mxyz2) 
    126440 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126441 File
    126442 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126443 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    126444 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    126445 exclude=exclude) 
    126446 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126447 File
    126448 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126449 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    126450 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    126451 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126452 File
    126453 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126454 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    126455 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    126456 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126457 File
    126458 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126459 packages/chimerax/graphics/drawing.py", line 1108, in
    126460 _first_intercept_excluding_children 
    126461 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    126462 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126463 File
    126464 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126465 packages/chimerax/geometry/place.py", line 201, in inverse 
    126466 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    126467 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126468 File
    126469 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126470 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    126471 rinv[:, :] = matrix_inverse(r) 
    126472 ^^^^^^^^^^^^^^^^^ 
    126473 File
    126474 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126475 packages/numpy/linalg/linalg.py", line 561, in inv 
    126476 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    126477 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126478 File
    126479 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126480 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    126481 raise LinAlgError("Singular matrix") 
    126482 numpy.linalg.LinAlgError: Singular matrix 
    126483  
    126484 numpy.linalg.LinAlgError: Singular matrix 
    126485  
    126486 File
    126487 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126488 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    126489 raise LinAlgError("Singular matrix") 
    126490  
    126491 See log for complete Python traceback. 
    126492  
    126493 Traceback (most recent call last): 
    126494 File
    126495 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126496 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    126497 self.session.ui.mouse_modes.mouse_pause_tracking() 
    126498 File
    126499 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126500 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    126501 mouse_pause_tracking 
    126502 self._mouse_pause() 
    126503 File
    126504 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126505 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    126506 m.pause(self._mouse_pause_position) 
    126507 File
    126508 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126509 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    126510 p = self.view.picked_object(x, y) 
    126511 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126512 File
    126513 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126514 packages/chimerax/graphics/view.py", line 838, in picked_object 
    126515 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    126516 beyond, 
    126517 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126518 File
    126519 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126520 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    126521 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    126522 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126523 File
    126524 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126525 packages/chimerax/core/models.py", line 143, in first_intercept 
    126526 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    126527 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126528 File
    126529 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126530 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    126531 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    126532 exclude=exclude) 
    126533 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126534 File
    126535 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126536 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    126537 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    126538 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126539 File
    126540 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126541 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    126542 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    126543 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126544 File
    126545 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126546 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    126547 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    126548 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126549 File
    126550 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126551 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    126552 p = super().first_intercept(mxyz1, mxyz2) 
    126553 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126554 File
    126555 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126556 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    126557 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    126558 exclude=exclude) 
    126559 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126560 File
    126561 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126562 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    126563 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    126564 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126565 File
    126566 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126567 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    126568 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    126569 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126570 File
    126571 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126572 packages/chimerax/graphics/drawing.py", line 1108, in
    126573 _first_intercept_excluding_children 
    126574 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    126575 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126576 File
    126577 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126578 packages/chimerax/geometry/place.py", line 201, in inverse 
    126579 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    126580 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126581 File
    126582 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126583 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    126584 rinv[:, :] = matrix_inverse(r) 
    126585 ^^^^^^^^^^^^^^^^^ 
    126586 File
    126587 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126588 packages/numpy/linalg/linalg.py", line 561, in inv 
    126589 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    126590 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126591 File
    126592 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126593 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    126594 raise LinAlgError("Singular matrix") 
    126595 numpy.linalg.LinAlgError: Singular matrix 
    126596  
    126597 numpy.linalg.LinAlgError: Singular matrix 
    126598  
    126599 File
    126600 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126601 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    126602 raise LinAlgError("Singular matrix") 
    126603  
    126604 See log for complete Python traceback. 
    126605  
    126606 Traceback (most recent call last): 
    126607 File
    126608 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126609 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    126610 self.session.ui.mouse_modes.mouse_pause_tracking() 
    126611 File
    126612 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126613 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    126614 mouse_pause_tracking 
    126615 self._mouse_pause() 
    126616 File
    126617 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126618 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    126619 m.pause(self._mouse_pause_position) 
    126620 File
    126621 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126622 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    126623 p = self.view.picked_object(x, y) 
    126624 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126625 File
    126626 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126627 packages/chimerax/graphics/view.py", line 838, in picked_object 
    126628 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    126629 beyond, 
    126630 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126631 File
    126632 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126633 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    126634 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    126635 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126636 File
    126637 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126638 packages/chimerax/core/models.py", line 143, in first_intercept 
    126639 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    126640 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126641 File
    126642 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126643 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    126644 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    126645 exclude=exclude) 
    126646 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126647 File
    126648 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126649 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    126650 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    126651 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126652 File
    126653 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126654 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    126655 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    126656 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126657 File
    126658 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126659 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    126660 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    126661 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126662 File
    126663 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126664 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    126665 p = super().first_intercept(mxyz1, mxyz2) 
    126666 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126667 File
    126668 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126669 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    126670 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    126671 exclude=exclude) 
    126672 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126673 File
    126674 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126675 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    126676 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    126677 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126678 File
    126679 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126680 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    126681 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    126682 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126683 File
    126684 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126685 packages/chimerax/graphics/drawing.py", line 1108, in
    126686 _first_intercept_excluding_children 
    126687 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    126688 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126689 File
    126690 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126691 packages/chimerax/geometry/place.py", line 201, in inverse 
    126692 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    126693 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126694 File
    126695 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126696 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    126697 rinv[:, :] = matrix_inverse(r) 
    126698 ^^^^^^^^^^^^^^^^^ 
    126699 File
    126700 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126701 packages/numpy/linalg/linalg.py", line 561, in inv 
    126702 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    126703 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126704 File
    126705 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126706 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    126707 raise LinAlgError("Singular matrix") 
    126708 numpy.linalg.LinAlgError: Singular matrix 
    126709  
    126710 numpy.linalg.LinAlgError: Singular matrix 
    126711  
    126712 File
    126713 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126714 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    126715 raise LinAlgError("Singular matrix") 
    126716  
    126717 See log for complete Python traceback. 
    126718  
    126719 Traceback (most recent call last): 
    126720 File
    126721 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126722 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    126723 self.session.ui.mouse_modes.mouse_pause_tracking() 
    126724 File
    126725 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126726 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    126727 mouse_pause_tracking 
    126728 self._mouse_pause() 
    126729 File
    126730 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126731 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    126732 m.pause(self._mouse_pause_position) 
    126733 File
    126734 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126735 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    126736 p = self.view.picked_object(x, y) 
    126737 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126738 File
    126739 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126740 packages/chimerax/graphics/view.py", line 838, in picked_object 
    126741 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    126742 beyond, 
    126743 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126744 File
    126745 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126746 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    126747 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    126748 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126749 File
    126750 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126751 packages/chimerax/core/models.py", line 143, in first_intercept 
    126752 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    126753 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126754 File
    126755 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126756 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    126757 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    126758 exclude=exclude) 
    126759 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126760 File
    126761 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126762 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    126763 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    126764 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126765 File
    126766 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126767 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    126768 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    126769 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126770 File
    126771 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126772 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    126773 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    126774 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126775 File
    126776 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126777 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    126778 p = super().first_intercept(mxyz1, mxyz2) 
    126779 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126780 File
    126781 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126782 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    126783 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    126784 exclude=exclude) 
    126785 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126786 File
    126787 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126788 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    126789 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    126790 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126791 File
    126792 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126793 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    126794 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    126795 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126796 File
    126797 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126798 packages/chimerax/graphics/drawing.py", line 1108, in
    126799 _first_intercept_excluding_children 
    126800 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    126801 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126802 File
    126803 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126804 packages/chimerax/geometry/place.py", line 201, in inverse 
    126805 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    126806 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126807 File
    126808 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126809 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    126810 rinv[:, :] = matrix_inverse(r) 
    126811 ^^^^^^^^^^^^^^^^^ 
    126812 File
    126813 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126814 packages/numpy/linalg/linalg.py", line 561, in inv 
    126815 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    126816 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126817 File
    126818 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126819 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    126820 raise LinAlgError("Singular matrix") 
    126821 numpy.linalg.LinAlgError: Singular matrix 
    126822  
    126823 numpy.linalg.LinAlgError: Singular matrix 
    126824  
    126825 File
    126826 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126827 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    126828 raise LinAlgError("Singular matrix") 
    126829  
    126830 See log for complete Python traceback. 
    126831  
    126832 Traceback (most recent call last): 
    126833 File
    126834 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126835 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    126836 self.session.ui.mouse_modes.mouse_pause_tracking() 
    126837 File
    126838 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126839 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    126840 mouse_pause_tracking 
    126841 self._mouse_pause() 
    126842 File
    126843 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126844 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    126845 m.pause(self._mouse_pause_position) 
    126846 File
    126847 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126848 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    126849 p = self.view.picked_object(x, y) 
    126850 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126851 File
    126852 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126853 packages/chimerax/graphics/view.py", line 838, in picked_object 
    126854 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    126855 beyond, 
    126856 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126857 File
    126858 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126859 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    126860 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    126861 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126862 File
    126863 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126864 packages/chimerax/core/models.py", line 143, in first_intercept 
    126865 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    126866 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126867 File
    126868 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126869 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    126870 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    126871 exclude=exclude) 
    126872 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126873 File
    126874 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126875 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    126876 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    126877 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126878 File
    126879 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126880 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    126881 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    126882 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126883 File
    126884 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126885 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    126886 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    126887 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126888 File
    126889 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126890 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    126891 p = super().first_intercept(mxyz1, mxyz2) 
    126892 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126893 File
    126894 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126895 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    126896 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    126897 exclude=exclude) 
    126898 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126899 File
    126900 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126901 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    126902 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    126903 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126904 File
    126905 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126906 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    126907 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    126908 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126909 File
    126910 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126911 packages/chimerax/graphics/drawing.py", line 1108, in
    126912 _first_intercept_excluding_children 
    126913 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    126914 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126915 File
    126916 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126917 packages/chimerax/geometry/place.py", line 201, in inverse 
    126918 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    126919 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126920 File
    126921 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126922 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    126923 rinv[:, :] = matrix_inverse(r) 
    126924 ^^^^^^^^^^^^^^^^^ 
    126925 File
    126926 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126927 packages/numpy/linalg/linalg.py", line 561, in inv 
    126928 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    126929 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126930 File
    126931 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126932 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    126933 raise LinAlgError("Singular matrix") 
    126934 numpy.linalg.LinAlgError: Singular matrix 
    126935  
    126936 numpy.linalg.LinAlgError: Singular matrix 
    126937  
    126938 File
    126939 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126940 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    126941 raise LinAlgError("Singular matrix") 
    126942  
    126943 See log for complete Python traceback. 
    126944  
    126945 Traceback (most recent call last): 
    126946 File
    126947 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126948 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    126949 self.session.ui.mouse_modes.mouse_pause_tracking() 
    126950 File
    126951 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126952 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    126953 mouse_pause_tracking 
    126954 self._mouse_pause() 
    126955 File
    126956 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126957 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    126958 m.pause(self._mouse_pause_position) 
    126959 File
    126960 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126961 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    126962 p = self.view.picked_object(x, y) 
    126963 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126964 File
    126965 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126966 packages/chimerax/graphics/view.py", line 838, in picked_object 
    126967 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    126968 beyond, 
    126969 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126970 File
    126971 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126972 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    126973 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    126974 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126975 File
    126976 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126977 packages/chimerax/core/models.py", line 143, in first_intercept 
    126978 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    126979 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126980 File
    126981 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126982 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    126983 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    126984 exclude=exclude) 
    126985 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126986 File
    126987 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126988 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    126989 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    126990 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126991 File
    126992 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126993 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    126994 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    126995 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    126996 File
    126997 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    126998 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    126999 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    127000 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127001 File
    127002 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127003 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    127004 p = super().first_intercept(mxyz1, mxyz2) 
    127005 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127006 File
    127007 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127008 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    127009 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    127010 exclude=exclude) 
    127011 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127012 File
    127013 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127014 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    127015 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    127016 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127017 File
    127018 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127019 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    127020 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    127021 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127022 File
    127023 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127024 packages/chimerax/graphics/drawing.py", line 1108, in
    127025 _first_intercept_excluding_children 
    127026 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    127027 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127028 File
    127029 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127030 packages/chimerax/geometry/place.py", line 201, in inverse 
    127031 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    127032 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127033 File
    127034 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127035 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    127036 rinv[:, :] = matrix_inverse(r) 
    127037 ^^^^^^^^^^^^^^^^^ 
    127038 File
    127039 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127040 packages/numpy/linalg/linalg.py", line 561, in inv 
    127041 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    127042 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127043 File
    127044 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127045 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    127046 raise LinAlgError("Singular matrix") 
    127047 numpy.linalg.LinAlgError: Singular matrix 
    127048  
    127049 numpy.linalg.LinAlgError: Singular matrix 
    127050  
    127051 File
    127052 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127053 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    127054 raise LinAlgError("Singular matrix") 
    127055  
    127056 See log for complete Python traceback. 
    127057  
    127058 Traceback (most recent call last): 
    127059 File
    127060 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127061 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    127062 self.session.ui.mouse_modes.mouse_pause_tracking() 
    127063 File
    127064 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127065 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    127066 mouse_pause_tracking 
    127067 self._mouse_pause() 
    127068 File
    127069 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127070 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    127071 m.pause(self._mouse_pause_position) 
    127072 File
    127073 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127074 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    127075 p = self.view.picked_object(x, y) 
    127076 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127077 File
    127078 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127079 packages/chimerax/graphics/view.py", line 838, in picked_object 
    127080 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    127081 beyond, 
    127082 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127083 File
    127084 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127085 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    127086 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    127087 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127088 File
    127089 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127090 packages/chimerax/core/models.py", line 143, in first_intercept 
    127091 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    127092 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127093 File
    127094 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127095 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    127096 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    127097 exclude=exclude) 
    127098 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127099 File
    127100 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127101 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    127102 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    127103 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127104 File
    127105 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127106 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    127107 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    127108 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127109 File
    127110 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127111 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    127112 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    127113 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127114 File
    127115 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127116 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    127117 p = super().first_intercept(mxyz1, mxyz2) 
    127118 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127119 File
    127120 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127121 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    127122 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    127123 exclude=exclude) 
    127124 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127125 File
    127126 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127127 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    127128 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    127129 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127130 File
    127131 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127132 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    127133 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    127134 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127135 File
    127136 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127137 packages/chimerax/graphics/drawing.py", line 1108, in
    127138 _first_intercept_excluding_children 
    127139 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    127140 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127141 File
    127142 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127143 packages/chimerax/geometry/place.py", line 201, in inverse 
    127144 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    127145 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127146 File
    127147 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127148 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    127149 rinv[:, :] = matrix_inverse(r) 
    127150 ^^^^^^^^^^^^^^^^^ 
    127151 File
    127152 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127153 packages/numpy/linalg/linalg.py", line 561, in inv 
    127154 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    127155 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127156 File
    127157 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127158 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    127159 raise LinAlgError("Singular matrix") 
    127160 numpy.linalg.LinAlgError: Singular matrix 
    127161  
    127162 numpy.linalg.LinAlgError: Singular matrix 
    127163  
    127164 File
    127165 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127166 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    127167 raise LinAlgError("Singular matrix") 
    127168  
    127169 See log for complete Python traceback. 
    127170  
    127171 Traceback (most recent call last): 
    127172 File
    127173 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127174 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    127175 self.session.ui.mouse_modes.mouse_pause_tracking() 
    127176 File
    127177 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127178 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    127179 mouse_pause_tracking 
    127180 self._mouse_pause() 
    127181 File
    127182 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127183 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    127184 m.pause(self._mouse_pause_position) 
    127185 File
    127186 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127187 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    127188 p = self.view.picked_object(x, y) 
    127189 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127190 File
    127191 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127192 packages/chimerax/graphics/view.py", line 838, in picked_object 
    127193 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    127194 beyond, 
    127195 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127196 File
    127197 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127198 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    127199 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    127200 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127201 File
    127202 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127203 packages/chimerax/core/models.py", line 143, in first_intercept 
    127204 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    127205 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127206 File
    127207 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127208 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    127209 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    127210 exclude=exclude) 
    127211 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127212 File
    127213 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127214 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    127215 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    127216 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127217 File
    127218 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127219 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    127220 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    127221 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127222 File
    127223 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127224 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    127225 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    127226 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127227 File
    127228 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127229 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    127230 p = super().first_intercept(mxyz1, mxyz2) 
    127231 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127232 File
    127233 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127234 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    127235 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    127236 exclude=exclude) 
    127237 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127238 File
    127239 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127240 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    127241 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    127242 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127243 File
    127244 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127245 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    127246 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    127247 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127248 File
    127249 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127250 packages/chimerax/graphics/drawing.py", line 1108, in
    127251 _first_intercept_excluding_children 
    127252 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    127253 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127254 File
    127255 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127256 packages/chimerax/geometry/place.py", line 201, in inverse 
    127257 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    127258 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127259 File
    127260 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127261 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    127262 rinv[:, :] = matrix_inverse(r) 
    127263 ^^^^^^^^^^^^^^^^^ 
    127264 File
    127265 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127266 packages/numpy/linalg/linalg.py", line 561, in inv 
    127267 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    127268 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127269 File
    127270 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127271 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    127272 raise LinAlgError("Singular matrix") 
    127273 numpy.linalg.LinAlgError: Singular matrix 
    127274  
    127275 numpy.linalg.LinAlgError: Singular matrix 
    127276  
    127277 File
    127278 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127279 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    127280 raise LinAlgError("Singular matrix") 
    127281  
    127282 See log for complete Python traceback. 
    127283  
    127284 Traceback (most recent call last): 
    127285 File
    127286 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127287 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    127288 self.session.ui.mouse_modes.mouse_pause_tracking() 
    127289 File
    127290 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127291 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    127292 mouse_pause_tracking 
    127293 self._mouse_pause() 
    127294 File
    127295 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127296 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    127297 m.pause(self._mouse_pause_position) 
    127298 File
    127299 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127300 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    127301 p = self.view.picked_object(x, y) 
    127302 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127303 File
    127304 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127305 packages/chimerax/graphics/view.py", line 838, in picked_object 
    127306 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    127307 beyond, 
    127308 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127309 File
    127310 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127311 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    127312 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    127313 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127314 File
    127315 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127316 packages/chimerax/core/models.py", line 143, in first_intercept 
    127317 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    127318 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127319 File
    127320 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127321 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    127322 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    127323 exclude=exclude) 
    127324 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127325 File
    127326 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127327 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    127328 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    127329 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127330 File
    127331 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127332 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    127333 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    127334 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127335 File
    127336 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127337 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    127338 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    127339 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127340 File
    127341 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127342 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    127343 p = super().first_intercept(mxyz1, mxyz2) 
    127344 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127345 File
    127346 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127347 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    127348 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    127349 exclude=exclude) 
    127350 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127351 File
    127352 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127353 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    127354 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    127355 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127356 File
    127357 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127358 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    127359 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    127360 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127361 File
    127362 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127363 packages/chimerax/graphics/drawing.py", line 1108, in
    127364 _first_intercept_excluding_children 
    127365 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    127366 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127367 File
    127368 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127369 packages/chimerax/geometry/place.py", line 201, in inverse 
    127370 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    127371 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127372 File
    127373 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127374 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    127375 rinv[:, :] = matrix_inverse(r) 
    127376 ^^^^^^^^^^^^^^^^^ 
    127377 File
    127378 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127379 packages/numpy/linalg/linalg.py", line 561, in inv 
    127380 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    127381 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127382 File
    127383 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127384 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    127385 raise LinAlgError("Singular matrix") 
    127386 numpy.linalg.LinAlgError: Singular matrix 
    127387  
    127388 numpy.linalg.LinAlgError: Singular matrix 
    127389  
    127390 File
    127391 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127392 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    127393 raise LinAlgError("Singular matrix") 
    127394  
    127395 See log for complete Python traceback. 
    127396  
    127397 Traceback (most recent call last): 
    127398 File
    127399 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127400 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    127401 self.session.ui.mouse_modes.mouse_pause_tracking() 
    127402 File
    127403 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127404 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    127405 mouse_pause_tracking 
    127406 self._mouse_pause() 
    127407 File
    127408 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127409 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    127410 m.pause(self._mouse_pause_position) 
    127411 File
    127412 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127413 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    127414 p = self.view.picked_object(x, y) 
    127415 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127416 File
    127417 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127418 packages/chimerax/graphics/view.py", line 838, in picked_object 
    127419 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    127420 beyond, 
    127421 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127422 File
    127423 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127424 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    127425 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    127426 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127427 File
    127428 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127429 packages/chimerax/core/models.py", line 143, in first_intercept 
    127430 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    127431 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127432 File
    127433 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127434 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    127435 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    127436 exclude=exclude) 
    127437 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127438 File
    127439 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127440 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    127441 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    127442 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127443 File
    127444 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127445 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    127446 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    127447 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127448 File
    127449 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127450 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    127451 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    127452 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127453 File
    127454 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127455 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    127456 p = super().first_intercept(mxyz1, mxyz2) 
    127457 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127458 File
    127459 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127460 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    127461 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    127462 exclude=exclude) 
    127463 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127464 File
    127465 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127466 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    127467 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    127468 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127469 File
    127470 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127471 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    127472 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    127473 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127474 File
    127475 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127476 packages/chimerax/graphics/drawing.py", line 1108, in
    127477 _first_intercept_excluding_children 
    127478 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    127479 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127480 File
    127481 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127482 packages/chimerax/geometry/place.py", line 201, in inverse 
    127483 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    127484 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127485 File
    127486 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127487 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    127488 rinv[:, :] = matrix_inverse(r) 
    127489 ^^^^^^^^^^^^^^^^^ 
    127490 File
    127491 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127492 packages/numpy/linalg/linalg.py", line 561, in inv 
    127493 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    127494 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127495 File
    127496 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127497 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    127498 raise LinAlgError("Singular matrix") 
    127499 numpy.linalg.LinAlgError: Singular matrix 
    127500  
    127501 numpy.linalg.LinAlgError: Singular matrix 
    127502  
    127503 File
    127504 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127505 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    127506 raise LinAlgError("Singular matrix") 
    127507  
    127508 See log for complete Python traceback. 
    127509  
    127510 Traceback (most recent call last): 
    127511 File
    127512 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127513 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    127514 self.session.ui.mouse_modes.mouse_pause_tracking() 
    127515 File
    127516 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127517 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    127518 mouse_pause_tracking 
    127519 self._mouse_pause() 
    127520 File
    127521 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127522 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    127523 m.pause(self._mouse_pause_position) 
    127524 File
    127525 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127526 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    127527 p = self.view.picked_object(x, y) 
    127528 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127529 File
    127530 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127531 packages/chimerax/graphics/view.py", line 838, in picked_object 
    127532 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    127533 beyond, 
    127534 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127535 File
    127536 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127537 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    127538 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    127539 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127540 File
    127541 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127542 packages/chimerax/core/models.py", line 143, in first_intercept 
    127543 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    127544 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127545 File
    127546 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127547 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    127548 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    127549 exclude=exclude) 
    127550 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127551 File
    127552 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127553 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    127554 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    127555 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127556 File
    127557 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127558 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    127559 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    127560 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127561 File
    127562 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127563 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    127564 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    127565 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127566 File
    127567 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127568 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    127569 p = super().first_intercept(mxyz1, mxyz2) 
    127570 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127571 File
    127572 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127573 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    127574 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    127575 exclude=exclude) 
    127576 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127577 File
    127578 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127579 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    127580 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    127581 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127582 File
    127583 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127584 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    127585 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    127586 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127587 File
    127588 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127589 packages/chimerax/graphics/drawing.py", line 1108, in
    127590 _first_intercept_excluding_children 
    127591 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    127592 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127593 File
    127594 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127595 packages/chimerax/geometry/place.py", line 201, in inverse 
    127596 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    127597 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127598 File
    127599 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127600 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    127601 rinv[:, :] = matrix_inverse(r) 
    127602 ^^^^^^^^^^^^^^^^^ 
    127603 File
    127604 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127605 packages/numpy/linalg/linalg.py", line 561, in inv 
    127606 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    127607 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127608 File
    127609 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127610 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    127611 raise LinAlgError("Singular matrix") 
    127612 numpy.linalg.LinAlgError: Singular matrix 
    127613  
    127614 numpy.linalg.LinAlgError: Singular matrix 
    127615  
    127616 File
    127617 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127618 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    127619 raise LinAlgError("Singular matrix") 
    127620  
    127621 See log for complete Python traceback. 
    127622  
    127623 Traceback (most recent call last): 
    127624 File
    127625 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127626 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    127627 self.session.ui.mouse_modes.mouse_pause_tracking() 
    127628 File
    127629 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127630 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    127631 mouse_pause_tracking 
    127632 self._mouse_pause() 
    127633 File
    127634 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127635 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    127636 m.pause(self._mouse_pause_position) 
    127637 File
    127638 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127639 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    127640 p = self.view.picked_object(x, y) 
    127641 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127642 File
    127643 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127644 packages/chimerax/graphics/view.py", line 838, in picked_object 
    127645 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    127646 beyond, 
    127647 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127648 File
    127649 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127650 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    127651 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    127652 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127653 File
    127654 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127655 packages/chimerax/core/models.py", line 143, in first_intercept 
    127656 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    127657 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127658 File
    127659 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127660 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    127661 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    127662 exclude=exclude) 
    127663 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127664 File
    127665 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127666 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    127667 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    127668 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127669 File
    127670 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127671 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    127672 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    127673 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127674 File
    127675 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127676 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    127677 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    127678 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127679 File
    127680 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127681 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    127682 p = super().first_intercept(mxyz1, mxyz2) 
    127683 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127684 File
    127685 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127686 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    127687 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    127688 exclude=exclude) 
    127689 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127690 File
    127691 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127692 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    127693 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    127694 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127695 File
    127696 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127697 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    127698 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    127699 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127700 File
    127701 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127702 packages/chimerax/graphics/drawing.py", line 1108, in
    127703 _first_intercept_excluding_children 
    127704 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    127705 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127706 File
    127707 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127708 packages/chimerax/geometry/place.py", line 201, in inverse 
    127709 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    127710 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127711 File
    127712 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127713 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    127714 rinv[:, :] = matrix_inverse(r) 
    127715 ^^^^^^^^^^^^^^^^^ 
    127716 File
    127717 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127718 packages/numpy/linalg/linalg.py", line 561, in inv 
    127719 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    127720 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127721 File
    127722 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127723 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    127724 raise LinAlgError("Singular matrix") 
    127725 numpy.linalg.LinAlgError: Singular matrix 
    127726  
    127727 numpy.linalg.LinAlgError: Singular matrix 
    127728  
    127729 File
    127730 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127731 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    127732 raise LinAlgError("Singular matrix") 
    127733  
    127734 See log for complete Python traceback. 
    127735  
    127736 Traceback (most recent call last): 
    127737 File
    127738 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127739 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    127740 self.session.ui.mouse_modes.mouse_pause_tracking() 
    127741 File
    127742 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127743 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    127744 mouse_pause_tracking 
    127745 self._mouse_pause() 
    127746 File
    127747 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127748 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    127749 m.pause(self._mouse_pause_position) 
    127750 File
    127751 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127752 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    127753 p = self.view.picked_object(x, y) 
    127754 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127755 File
    127756 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127757 packages/chimerax/graphics/view.py", line 838, in picked_object 
    127758 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    127759 beyond, 
    127760 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127761 File
    127762 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127763 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    127764 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    127765 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127766 File
    127767 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127768 packages/chimerax/core/models.py", line 143, in first_intercept 
    127769 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    127770 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127771 File
    127772 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127773 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    127774 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    127775 exclude=exclude) 
    127776 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127777 File
    127778 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127779 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    127780 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    127781 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127782 File
    127783 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127784 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    127785 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    127786 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127787 File
    127788 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127789 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    127790 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    127791 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127792 File
    127793 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127794 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    127795 p = super().first_intercept(mxyz1, mxyz2) 
    127796 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127797 File
    127798 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127799 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    127800 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    127801 exclude=exclude) 
    127802 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127803 File
    127804 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127805 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    127806 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    127807 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127808 File
    127809 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127810 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    127811 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    127812 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127813 File
    127814 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127815 packages/chimerax/graphics/drawing.py", line 1108, in
    127816 _first_intercept_excluding_children 
    127817 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    127818 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127819 File
    127820 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127821 packages/chimerax/geometry/place.py", line 201, in inverse 
    127822 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    127823 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127824 File
    127825 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127826 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    127827 rinv[:, :] = matrix_inverse(r) 
    127828 ^^^^^^^^^^^^^^^^^ 
    127829 File
    127830 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127831 packages/numpy/linalg/linalg.py", line 561, in inv 
    127832 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    127833 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127834 File
    127835 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127836 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    127837 raise LinAlgError("Singular matrix") 
    127838 numpy.linalg.LinAlgError: Singular matrix 
    127839  
    127840 numpy.linalg.LinAlgError: Singular matrix 
    127841  
    127842 File
    127843 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127844 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    127845 raise LinAlgError("Singular matrix") 
    127846  
    127847 See log for complete Python traceback. 
    127848  
    127849 Traceback (most recent call last): 
    127850 File
    127851 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127852 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    127853 self.session.ui.mouse_modes.mouse_pause_tracking() 
    127854 File
    127855 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127856 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    127857 mouse_pause_tracking 
    127858 self._mouse_pause() 
    127859 File
    127860 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127861 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    127862 m.pause(self._mouse_pause_position) 
    127863 File
    127864 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127865 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    127866 p = self.view.picked_object(x, y) 
    127867 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127868 File
    127869 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127870 packages/chimerax/graphics/view.py", line 838, in picked_object 
    127871 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    127872 beyond, 
    127873 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127874 File
    127875 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127876 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    127877 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    127878 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127879 File
    127880 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127881 packages/chimerax/core/models.py", line 143, in first_intercept 
    127882 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    127883 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127884 File
    127885 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127886 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    127887 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    127888 exclude=exclude) 
    127889 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127890 File
    127891 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127892 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    127893 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    127894 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127895 File
    127896 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127897 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    127898 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    127899 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127900 File
    127901 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127902 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    127903 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    127904 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127905 File
    127906 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127907 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    127908 p = super().first_intercept(mxyz1, mxyz2) 
    127909 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127910 File
    127911 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127912 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    127913 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    127914 exclude=exclude) 
    127915 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127916 File
    127917 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127918 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    127919 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    127920 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127921 File
    127922 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127923 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    127924 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    127925 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127926 File
    127927 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127928 packages/chimerax/graphics/drawing.py", line 1108, in
    127929 _first_intercept_excluding_children 
    127930 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    127931 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127932 File
    127933 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127934 packages/chimerax/geometry/place.py", line 201, in inverse 
    127935 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    127936 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127937 File
    127938 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127939 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    127940 rinv[:, :] = matrix_inverse(r) 
    127941 ^^^^^^^^^^^^^^^^^ 
    127942 File
    127943 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127944 packages/numpy/linalg/linalg.py", line 561, in inv 
    127945 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    127946 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127947 File
    127948 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127949 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    127950 raise LinAlgError("Singular matrix") 
    127951 numpy.linalg.LinAlgError: Singular matrix 
    127952  
    127953 numpy.linalg.LinAlgError: Singular matrix 
    127954  
    127955 File
    127956 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127957 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    127958 raise LinAlgError("Singular matrix") 
    127959  
    127960 See log for complete Python traceback. 
    127961  
    127962 Traceback (most recent call last): 
    127963 File
    127964 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127965 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    127966 self.session.ui.mouse_modes.mouse_pause_tracking() 
    127967 File
    127968 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127969 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    127970 mouse_pause_tracking 
    127971 self._mouse_pause() 
    127972 File
    127973 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127974 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    127975 m.pause(self._mouse_pause_position) 
    127976 File
    127977 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127978 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    127979 p = self.view.picked_object(x, y) 
    127980 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127981 File
    127982 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127983 packages/chimerax/graphics/view.py", line 838, in picked_object 
    127984 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    127985 beyond, 
    127986 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127987 File
    127988 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127989 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    127990 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    127991 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127992 File
    127993 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127994 packages/chimerax/core/models.py", line 143, in first_intercept 
    127995 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    127996 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    127997 File
    127998 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    127999 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    128000 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    128001 exclude=exclude) 
    128002 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128003 File
    128004 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128005 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    128006 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    128007 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128008 File
    128009 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128010 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    128011 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    128012 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128013 File
    128014 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128015 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    128016 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    128017 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128018 File
    128019 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128020 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    128021 p = super().first_intercept(mxyz1, mxyz2) 
    128022 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128023 File
    128024 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128025 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    128026 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    128027 exclude=exclude) 
    128028 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128029 File
    128030 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128031 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    128032 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    128033 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128034 File
    128035 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128036 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    128037 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    128038 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128039 File
    128040 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128041 packages/chimerax/graphics/drawing.py", line 1108, in
    128042 _first_intercept_excluding_children 
    128043 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    128044 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128045 File
    128046 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128047 packages/chimerax/geometry/place.py", line 201, in inverse 
    128048 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    128049 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128050 File
    128051 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128052 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    128053 rinv[:, :] = matrix_inverse(r) 
    128054 ^^^^^^^^^^^^^^^^^ 
    128055 File
    128056 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128057 packages/numpy/linalg/linalg.py", line 561, in inv 
    128058 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    128059 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128060 File
    128061 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128062 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    128063 raise LinAlgError("Singular matrix") 
    128064 numpy.linalg.LinAlgError: Singular matrix 
    128065  
    128066 numpy.linalg.LinAlgError: Singular matrix 
    128067  
    128068 File
    128069 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128070 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    128071 raise LinAlgError("Singular matrix") 
    128072  
    128073 See log for complete Python traceback. 
    128074  
    128075 Traceback (most recent call last): 
    128076 File
    128077 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128078 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    128079 self.session.ui.mouse_modes.mouse_pause_tracking() 
    128080 File
    128081 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128082 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    128083 mouse_pause_tracking 
    128084 self._mouse_pause() 
    128085 File
    128086 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128087 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    128088 m.pause(self._mouse_pause_position) 
    128089 File
    128090 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128091 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    128092 p = self.view.picked_object(x, y) 
    128093 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128094 File
    128095 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128096 packages/chimerax/graphics/view.py", line 838, in picked_object 
    128097 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    128098 beyond, 
    128099 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128100 File
    128101 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128102 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    128103 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    128104 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128105 File
    128106 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128107 packages/chimerax/core/models.py", line 143, in first_intercept 
    128108 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    128109 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128110 File
    128111 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128112 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    128113 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    128114 exclude=exclude) 
    128115 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128116 File
    128117 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128118 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    128119 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    128120 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128121 File
    128122 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128123 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    128124 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    128125 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128126 File
    128127 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128128 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    128129 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    128130 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128131 File
    128132 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128133 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    128134 p = super().first_intercept(mxyz1, mxyz2) 
    128135 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128136 File
    128137 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128138 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    128139 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    128140 exclude=exclude) 
    128141 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128142 File
    128143 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128144 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    128145 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    128146 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128147 File
    128148 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128149 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    128150 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    128151 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128152 File
    128153 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128154 packages/chimerax/graphics/drawing.py", line 1108, in
    128155 _first_intercept_excluding_children 
    128156 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    128157 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128158 File
    128159 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128160 packages/chimerax/geometry/place.py", line 201, in inverse 
    128161 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    128162 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128163 File
    128164 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128165 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    128166 rinv[:, :] = matrix_inverse(r) 
    128167 ^^^^^^^^^^^^^^^^^ 
    128168 File
    128169 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128170 packages/numpy/linalg/linalg.py", line 561, in inv 
    128171 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    128172 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128173 File
    128174 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128175 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    128176 raise LinAlgError("Singular matrix") 
    128177 numpy.linalg.LinAlgError: Singular matrix 
    128178  
    128179 numpy.linalg.LinAlgError: Singular matrix 
    128180  
    128181 File
    128182 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128183 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    128184 raise LinAlgError("Singular matrix") 
    128185  
    128186 See log for complete Python traceback. 
    128187  
    128188 Traceback (most recent call last): 
    128189 File
    128190 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128191 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    128192 self.session.ui.mouse_modes.mouse_pause_tracking() 
    128193 File
    128194 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128195 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    128196 mouse_pause_tracking 
    128197 self._mouse_pause() 
    128198 File
    128199 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128200 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    128201 m.pause(self._mouse_pause_position) 
    128202 File
    128203 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128204 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    128205 p = self.view.picked_object(x, y) 
    128206 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128207 File
    128208 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128209 packages/chimerax/graphics/view.py", line 838, in picked_object 
    128210 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    128211 beyond, 
    128212 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128213 File
    128214 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128215 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    128216 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    128217 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128218 File
    128219 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128220 packages/chimerax/core/models.py", line 143, in first_intercept 
    128221 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    128222 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128223 File
    128224 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128225 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    128226 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    128227 exclude=exclude) 
    128228 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128229 File
    128230 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128231 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    128232 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    128233 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128234 File
    128235 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128236 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    128237 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    128238 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128239 File
    128240 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128241 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    128242 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    128243 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128244 File
    128245 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128246 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    128247 p = super().first_intercept(mxyz1, mxyz2) 
    128248 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128249 File
    128250 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128251 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    128252 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    128253 exclude=exclude) 
    128254 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128255 File
    128256 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128257 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    128258 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    128259 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128260 File
    128261 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128262 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    128263 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    128264 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128265 File
    128266 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128267 packages/chimerax/graphics/drawing.py", line 1108, in
    128268 _first_intercept_excluding_children 
    128269 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    128270 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128271 File
    128272 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128273 packages/chimerax/geometry/place.py", line 201, in inverse 
    128274 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    128275 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128276 File
    128277 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128278 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    128279 rinv[:, :] = matrix_inverse(r) 
    128280 ^^^^^^^^^^^^^^^^^ 
    128281 File
    128282 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128283 packages/numpy/linalg/linalg.py", line 561, in inv 
    128284 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    128285 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128286 File
    128287 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128288 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    128289 raise LinAlgError("Singular matrix") 
    128290 numpy.linalg.LinAlgError: Singular matrix 
    128291  
    128292 numpy.linalg.LinAlgError: Singular matrix 
    128293  
    128294 File
    128295 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128296 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    128297 raise LinAlgError("Singular matrix") 
    128298  
    128299 See log for complete Python traceback. 
    128300  
    128301 Traceback (most recent call last): 
    128302 File
    128303 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128304 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    128305 self.session.ui.mouse_modes.mouse_pause_tracking() 
    128306 File
    128307 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128308 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    128309 mouse_pause_tracking 
    128310 self._mouse_pause() 
    128311 File
    128312 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128313 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    128314 m.pause(self._mouse_pause_position) 
    128315 File
    128316 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128317 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    128318 p = self.view.picked_object(x, y) 
    128319 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128320 File
    128321 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128322 packages/chimerax/graphics/view.py", line 838, in picked_object 
    128323 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    128324 beyond, 
    128325 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128326 File
    128327 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128328 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    128329 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    128330 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128331 File
    128332 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128333 packages/chimerax/core/models.py", line 143, in first_intercept 
    128334 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    128335 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128336 File
    128337 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128338 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    128339 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    128340 exclude=exclude) 
    128341 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128342 File
    128343 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128344 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    128345 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    128346 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128347 File
    128348 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128349 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    128350 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    128351 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128352 File
    128353 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128354 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    128355 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    128356 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128357 File
    128358 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128359 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    128360 p = super().first_intercept(mxyz1, mxyz2) 
    128361 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128362 File
    128363 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128364 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    128365 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    128366 exclude=exclude) 
    128367 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128368 File
    128369 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128370 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    128371 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    128372 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128373 File
    128374 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128375 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    128376 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    128377 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128378 File
    128379 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128380 packages/chimerax/graphics/drawing.py", line 1108, in
    128381 _first_intercept_excluding_children 
    128382 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    128383 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128384 File
    128385 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128386 packages/chimerax/geometry/place.py", line 201, in inverse 
    128387 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    128388 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128389 File
    128390 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128391 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    128392 rinv[:, :] = matrix_inverse(r) 
    128393 ^^^^^^^^^^^^^^^^^ 
    128394 File
    128395 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128396 packages/numpy/linalg/linalg.py", line 561, in inv 
    128397 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    128398 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128399 File
    128400 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128401 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    128402 raise LinAlgError("Singular matrix") 
    128403 numpy.linalg.LinAlgError: Singular matrix 
    128404  
    128405 numpy.linalg.LinAlgError: Singular matrix 
    128406  
    128407 File
    128408 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128409 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    128410 raise LinAlgError("Singular matrix") 
    128411  
    128412 See log for complete Python traceback. 
    128413  
    128414 Traceback (most recent call last): 
    128415 File
    128416 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128417 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    128418 self.session.ui.mouse_modes.mouse_pause_tracking() 
    128419 File
    128420 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128421 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    128422 mouse_pause_tracking 
    128423 self._mouse_pause() 
    128424 File
    128425 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128426 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    128427 m.pause(self._mouse_pause_position) 
    128428 File
    128429 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128430 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    128431 p = self.view.picked_object(x, y) 
    128432 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128433 File
    128434 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128435 packages/chimerax/graphics/view.py", line 838, in picked_object 
    128436 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    128437 beyond, 
    128438 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128439 File
    128440 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128441 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    128442 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    128443 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128444 File
    128445 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128446 packages/chimerax/core/models.py", line 143, in first_intercept 
    128447 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    128448 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128449 File
    128450 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128451 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    128452 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    128453 exclude=exclude) 
    128454 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128455 File
    128456 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128457 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    128458 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    128459 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128460 File
    128461 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128462 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    128463 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    128464 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128465 File
    128466 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128467 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    128468 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    128469 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128470 File
    128471 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128472 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    128473 p = super().first_intercept(mxyz1, mxyz2) 
    128474 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128475 File
    128476 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128477 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    128478 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    128479 exclude=exclude) 
    128480 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128481 File
    128482 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128483 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    128484 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    128485 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128486 File
    128487 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128488 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    128489 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    128490 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128491 File
    128492 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128493 packages/chimerax/graphics/drawing.py", line 1108, in
    128494 _first_intercept_excluding_children 
    128495 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    128496 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128497 File
    128498 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128499 packages/chimerax/geometry/place.py", line 201, in inverse 
    128500 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    128501 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128502 File
    128503 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128504 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    128505 rinv[:, :] = matrix_inverse(r) 
    128506 ^^^^^^^^^^^^^^^^^ 
    128507 File
    128508 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128509 packages/numpy/linalg/linalg.py", line 561, in inv 
    128510 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    128511 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128512 File
    128513 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128514 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    128515 raise LinAlgError("Singular matrix") 
    128516 numpy.linalg.LinAlgError: Singular matrix 
    128517  
    128518 numpy.linalg.LinAlgError: Singular matrix 
    128519  
    128520 File
    128521 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128522 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    128523 raise LinAlgError("Singular matrix") 
    128524  
    128525 See log for complete Python traceback. 
    128526  
    128527 Traceback (most recent call last): 
    128528 File
    128529 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128530 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    128531 self.session.ui.mouse_modes.mouse_pause_tracking() 
    128532 File
    128533 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128534 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    128535 mouse_pause_tracking 
    128536 self._mouse_pause() 
    128537 File
    128538 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128539 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    128540 m.pause(self._mouse_pause_position) 
    128541 File
    128542 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128543 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    128544 p = self.view.picked_object(x, y) 
    128545 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128546 File
    128547 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128548 packages/chimerax/graphics/view.py", line 838, in picked_object 
    128549 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    128550 beyond, 
    128551 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128552 File
    128553 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128554 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    128555 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    128556 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128557 File
    128558 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128559 packages/chimerax/core/models.py", line 143, in first_intercept 
    128560 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    128561 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128562 File
    128563 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128564 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    128565 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    128566 exclude=exclude) 
    128567 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128568 File
    128569 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128570 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    128571 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    128572 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128573 File
    128574 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128575 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    128576 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    128577 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128578 File
    128579 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128580 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    128581 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    128582 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128583 File
    128584 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128585 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    128586 p = super().first_intercept(mxyz1, mxyz2) 
    128587 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128588 File
    128589 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128590 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    128591 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    128592 exclude=exclude) 
    128593 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128594 File
    128595 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128596 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    128597 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    128598 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128599 File
    128600 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128601 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    128602 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    128603 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128604 File
    128605 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128606 packages/chimerax/graphics/drawing.py", line 1108, in
    128607 _first_intercept_excluding_children 
    128608 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    128609 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128610 File
    128611 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128612 packages/chimerax/geometry/place.py", line 201, in inverse 
    128613 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    128614 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128615 File
    128616 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128617 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    128618 rinv[:, :] = matrix_inverse(r) 
    128619 ^^^^^^^^^^^^^^^^^ 
    128620 File
    128621 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128622 packages/numpy/linalg/linalg.py", line 561, in inv 
    128623 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    128624 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128625 File
    128626 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128627 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    128628 raise LinAlgError("Singular matrix") 
    128629 numpy.linalg.LinAlgError: Singular matrix 
    128630  
    128631 numpy.linalg.LinAlgError: Singular matrix 
    128632  
    128633 File
    128634 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128635 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    128636 raise LinAlgError("Singular matrix") 
    128637  
    128638 See log for complete Python traceback. 
    128639  
    128640 Traceback (most recent call last): 
    128641 File
    128642 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128643 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    128644 self.session.ui.mouse_modes.mouse_pause_tracking() 
    128645 File
    128646 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128647 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    128648 mouse_pause_tracking 
    128649 self._mouse_pause() 
    128650 File
    128651 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128652 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    128653 m.pause(self._mouse_pause_position) 
    128654 File
    128655 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128656 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    128657 p = self.view.picked_object(x, y) 
    128658 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128659 File
    128660 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128661 packages/chimerax/graphics/view.py", line 838, in picked_object 
    128662 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    128663 beyond, 
    128664 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128665 File
    128666 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128667 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    128668 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    128669 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128670 File
    128671 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128672 packages/chimerax/core/models.py", line 143, in first_intercept 
    128673 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    128674 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128675 File
    128676 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128677 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    128678 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    128679 exclude=exclude) 
    128680 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128681 File
    128682 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128683 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    128684 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    128685 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128686 File
    128687 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128688 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    128689 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    128690 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128691 File
    128692 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128693 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    128694 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    128695 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128696 File
    128697 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128698 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    128699 p = super().first_intercept(mxyz1, mxyz2) 
    128700 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128701 File
    128702 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128703 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    128704 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    128705 exclude=exclude) 
    128706 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128707 File
    128708 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128709 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    128710 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    128711 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128712 File
    128713 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128714 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    128715 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    128716 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128717 File
    128718 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128719 packages/chimerax/graphics/drawing.py", line 1108, in
    128720 _first_intercept_excluding_children 
    128721 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    128722 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128723 File
    128724 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128725 packages/chimerax/geometry/place.py", line 201, in inverse 
    128726 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    128727 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128728 File
    128729 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128730 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    128731 rinv[:, :] = matrix_inverse(r) 
    128732 ^^^^^^^^^^^^^^^^^ 
    128733 File
    128734 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128735 packages/numpy/linalg/linalg.py", line 561, in inv 
    128736 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    128737 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128738 File
    128739 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128740 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    128741 raise LinAlgError("Singular matrix") 
    128742 numpy.linalg.LinAlgError: Singular matrix 
    128743  
    128744 numpy.linalg.LinAlgError: Singular matrix 
    128745  
    128746 File
    128747 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128748 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    128749 raise LinAlgError("Singular matrix") 
    128750  
    128751 See log for complete Python traceback. 
    128752  
    128753 Traceback (most recent call last): 
    128754 File
    128755 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128756 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    128757 self.session.ui.mouse_modes.mouse_pause_tracking() 
    128758 File
    128759 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128760 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    128761 mouse_pause_tracking 
    128762 self._mouse_pause() 
    128763 File
    128764 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128765 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    128766 m.pause(self._mouse_pause_position) 
    128767 File
    128768 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128769 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    128770 p = self.view.picked_object(x, y) 
    128771 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128772 File
    128773 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128774 packages/chimerax/graphics/view.py", line 838, in picked_object 
    128775 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    128776 beyond, 
    128777 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128778 File
    128779 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128780 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    128781 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    128782 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128783 File
    128784 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128785 packages/chimerax/core/models.py", line 143, in first_intercept 
    128786 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    128787 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128788 File
    128789 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128790 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    128791 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    128792 exclude=exclude) 
    128793 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128794 File
    128795 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128796 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    128797 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    128798 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128799 File
    128800 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128801 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    128802 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    128803 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128804 File
    128805 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128806 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    128807 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    128808 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128809 File
    128810 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128811 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    128812 p = super().first_intercept(mxyz1, mxyz2) 
    128813 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128814 File
    128815 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128816 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    128817 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    128818 exclude=exclude) 
    128819 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128820 File
    128821 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128822 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    128823 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    128824 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128825 File
    128826 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128827 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    128828 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    128829 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128830 File
    128831 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128832 packages/chimerax/graphics/drawing.py", line 1108, in
    128833 _first_intercept_excluding_children 
    128834 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    128835 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128836 File
    128837 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128838 packages/chimerax/geometry/place.py", line 201, in inverse 
    128839 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    128840 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128841 File
    128842 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128843 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    128844 rinv[:, :] = matrix_inverse(r) 
    128845 ^^^^^^^^^^^^^^^^^ 
    128846 File
    128847 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128848 packages/numpy/linalg/linalg.py", line 561, in inv 
    128849 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    128850 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128851 File
    128852 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128853 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    128854 raise LinAlgError("Singular matrix") 
    128855 numpy.linalg.LinAlgError: Singular matrix 
    128856  
    128857 numpy.linalg.LinAlgError: Singular matrix 
    128858  
    128859 File
    128860 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128861 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    128862 raise LinAlgError("Singular matrix") 
    128863  
    128864 See log for complete Python traceback. 
    128865  
    128866 Traceback (most recent call last): 
    128867 File
    128868 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128869 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    128870 self.session.ui.mouse_modes.mouse_pause_tracking() 
    128871 File
    128872 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128873 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    128874 mouse_pause_tracking 
    128875 self._mouse_pause() 
    128876 File
    128877 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128878 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    128879 m.pause(self._mouse_pause_position) 
    128880 File
    128881 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128882 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    128883 p = self.view.picked_object(x, y) 
    128884 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128885 File
    128886 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128887 packages/chimerax/graphics/view.py", line 838, in picked_object 
    128888 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    128889 beyond, 
    128890 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128891 File
    128892 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128893 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    128894 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    128895 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128896 File
    128897 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128898 packages/chimerax/core/models.py", line 143, in first_intercept 
    128899 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    128900 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128901 File
    128902 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128903 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    128904 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    128905 exclude=exclude) 
    128906 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128907 File
    128908 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128909 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    128910 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    128911 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128912 File
    128913 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128914 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    128915 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    128916 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128917 File
    128918 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128919 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    128920 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    128921 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128922 File
    128923 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128924 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    128925 p = super().first_intercept(mxyz1, mxyz2) 
    128926 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128927 File
    128928 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128929 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    128930 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    128931 exclude=exclude) 
    128932 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128933 File
    128934 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128935 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    128936 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    128937 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128938 File
    128939 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128940 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    128941 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    128942 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128943 File
    128944 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128945 packages/chimerax/graphics/drawing.py", line 1108, in
    128946 _first_intercept_excluding_children 
    128947 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    128948 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128949 File
    128950 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128951 packages/chimerax/geometry/place.py", line 201, in inverse 
    128952 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    128953 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128954 File
    128955 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128956 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    128957 rinv[:, :] = matrix_inverse(r) 
    128958 ^^^^^^^^^^^^^^^^^ 
    128959 File
    128960 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128961 packages/numpy/linalg/linalg.py", line 561, in inv 
    128962 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    128963 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128964 File
    128965 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128966 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    128967 raise LinAlgError("Singular matrix") 
    128968 numpy.linalg.LinAlgError: Singular matrix 
    128969  
    128970 numpy.linalg.LinAlgError: Singular matrix 
    128971  
    128972 File
    128973 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128974 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    128975 raise LinAlgError("Singular matrix") 
    128976  
    128977 See log for complete Python traceback. 
    128978  
    128979 Traceback (most recent call last): 
    128980 File
    128981 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128982 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    128983 self.session.ui.mouse_modes.mouse_pause_tracking() 
    128984 File
    128985 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128986 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    128987 mouse_pause_tracking 
    128988 self._mouse_pause() 
    128989 File
    128990 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128991 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    128992 m.pause(self._mouse_pause_position) 
    128993 File
    128994 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    128995 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    128996 p = self.view.picked_object(x, y) 
    128997 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    128998 File
    128999 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129000 packages/chimerax/graphics/view.py", line 838, in picked_object 
    129001 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    129002 beyond, 
    129003 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129004 File
    129005 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129006 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    129007 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    129008 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129009 File
    129010 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129011 packages/chimerax/core/models.py", line 143, in first_intercept 
    129012 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    129013 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129014 File
    129015 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129016 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    129017 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    129018 exclude=exclude) 
    129019 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129020 File
    129021 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129022 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    129023 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    129024 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129025 File
    129026 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129027 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    129028 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    129029 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129030 File
    129031 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129032 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    129033 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    129034 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129035 File
    129036 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129037 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    129038 p = super().first_intercept(mxyz1, mxyz2) 
    129039 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129040 File
    129041 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129042 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    129043 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    129044 exclude=exclude) 
    129045 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129046 File
    129047 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129048 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    129049 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    129050 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129051 File
    129052 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129053 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    129054 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    129055 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129056 File
    129057 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129058 packages/chimerax/graphics/drawing.py", line 1108, in
    129059 _first_intercept_excluding_children 
    129060 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    129061 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129062 File
    129063 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129064 packages/chimerax/geometry/place.py", line 201, in inverse 
    129065 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    129066 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129067 File
    129068 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129069 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    129070 rinv[:, :] = matrix_inverse(r) 
    129071 ^^^^^^^^^^^^^^^^^ 
    129072 File
    129073 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129074 packages/numpy/linalg/linalg.py", line 561, in inv 
    129075 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    129076 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129077 File
    129078 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129079 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    129080 raise LinAlgError("Singular matrix") 
    129081 numpy.linalg.LinAlgError: Singular matrix 
    129082  
    129083 numpy.linalg.LinAlgError: Singular matrix 
    129084  
    129085 File
    129086 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129087 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    129088 raise LinAlgError("Singular matrix") 
    129089  
    129090 See log for complete Python traceback. 
    129091  
    129092 Traceback (most recent call last): 
    129093 File
    129094 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129095 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    129096 self.session.ui.mouse_modes.mouse_pause_tracking() 
    129097 File
    129098 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129099 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    129100 mouse_pause_tracking 
    129101 self._mouse_pause() 
    129102 File
    129103 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129104 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    129105 m.pause(self._mouse_pause_position) 
    129106 File
    129107 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129108 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    129109 p = self.view.picked_object(x, y) 
    129110 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129111 File
    129112 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129113 packages/chimerax/graphics/view.py", line 838, in picked_object 
    129114 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    129115 beyond, 
    129116 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129117 File
    129118 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129119 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    129120 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    129121 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129122 File
    129123 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129124 packages/chimerax/core/models.py", line 143, in first_intercept 
    129125 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    129126 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129127 File
    129128 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129129 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    129130 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    129131 exclude=exclude) 
    129132 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129133 File
    129134 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129135 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    129136 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    129137 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129138 File
    129139 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129140 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    129141 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    129142 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129143 File
    129144 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129145 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    129146 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    129147 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129148 File
    129149 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129150 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    129151 p = super().first_intercept(mxyz1, mxyz2) 
    129152 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129153 File
    129154 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129155 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    129156 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    129157 exclude=exclude) 
    129158 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129159 File
    129160 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129161 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    129162 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    129163 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129164 File
    129165 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129166 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    129167 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    129168 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129169 File
    129170 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129171 packages/chimerax/graphics/drawing.py", line 1108, in
    129172 _first_intercept_excluding_children 
    129173 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    129174 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129175 File
    129176 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129177 packages/chimerax/geometry/place.py", line 201, in inverse 
    129178 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    129179 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129180 File
    129181 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129182 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    129183 rinv[:, :] = matrix_inverse(r) 
    129184 ^^^^^^^^^^^^^^^^^ 
    129185 File
    129186 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129187 packages/numpy/linalg/linalg.py", line 561, in inv 
    129188 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    129189 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129190 File
    129191 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129192 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    129193 raise LinAlgError("Singular matrix") 
    129194 numpy.linalg.LinAlgError: Singular matrix 
    129195  
    129196 numpy.linalg.LinAlgError: Singular matrix 
    129197  
    129198 File
    129199 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129200 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    129201 raise LinAlgError("Singular matrix") 
    129202  
    129203 See log for complete Python traceback. 
    129204  
    129205 Traceback (most recent call last): 
    129206 File
    129207 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129208 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    129209 self.session.ui.mouse_modes.mouse_pause_tracking() 
    129210 File
    129211 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129212 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    129213 mouse_pause_tracking 
    129214 self._mouse_pause() 
    129215 File
    129216 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129217 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    129218 m.pause(self._mouse_pause_position) 
    129219 File
    129220 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129221 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    129222 p = self.view.picked_object(x, y) 
    129223 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129224 File
    129225 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129226 packages/chimerax/graphics/view.py", line 838, in picked_object 
    129227 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    129228 beyond, 
    129229 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129230 File
    129231 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129232 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    129233 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    129234 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129235 File
    129236 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129237 packages/chimerax/core/models.py", line 143, in first_intercept 
    129238 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    129239 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129240 File
    129241 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129242 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    129243 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    129244 exclude=exclude) 
    129245 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129246 File
    129247 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129248 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    129249 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    129250 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129251 File
    129252 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129253 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    129254 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    129255 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129256 File
    129257 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129258 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    129259 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    129260 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129261 File
    129262 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129263 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    129264 p = super().first_intercept(mxyz1, mxyz2) 
    129265 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129266 File
    129267 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129268 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    129269 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    129270 exclude=exclude) 
    129271 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129272 File
    129273 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129274 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    129275 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    129276 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129277 File
    129278 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129279 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    129280 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    129281 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129282 File
    129283 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129284 packages/chimerax/graphics/drawing.py", line 1108, in
    129285 _first_intercept_excluding_children 
    129286 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    129287 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129288 File
    129289 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129290 packages/chimerax/geometry/place.py", line 201, in inverse 
    129291 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    129292 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129293 File
    129294 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129295 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    129296 rinv[:, :] = matrix_inverse(r) 
    129297 ^^^^^^^^^^^^^^^^^ 
    129298 File
    129299 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129300 packages/numpy/linalg/linalg.py", line 561, in inv 
    129301 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    129302 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129303 File
    129304 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129305 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    129306 raise LinAlgError("Singular matrix") 
    129307 numpy.linalg.LinAlgError: Singular matrix 
    129308  
    129309 numpy.linalg.LinAlgError: Singular matrix 
    129310  
    129311 File
    129312 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129313 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    129314 raise LinAlgError("Singular matrix") 
    129315  
    129316 See log for complete Python traceback. 
    129317  
    129318 Traceback (most recent call last): 
    129319 File
    129320 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129321 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    129322 self.session.ui.mouse_modes.mouse_pause_tracking() 
    129323 File
    129324 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129325 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    129326 mouse_pause_tracking 
    129327 self._mouse_pause() 
    129328 File
    129329 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129330 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    129331 m.pause(self._mouse_pause_position) 
    129332 File
    129333 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129334 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    129335 p = self.view.picked_object(x, y) 
    129336 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129337 File
    129338 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129339 packages/chimerax/graphics/view.py", line 838, in picked_object 
    129340 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    129341 beyond, 
    129342 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129343 File
    129344 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129345 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    129346 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    129347 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129348 File
    129349 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129350 packages/chimerax/core/models.py", line 143, in first_intercept 
    129351 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    129352 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129353 File
    129354 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129355 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    129356 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    129357 exclude=exclude) 
    129358 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129359 File
    129360 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129361 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    129362 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    129363 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129364 File
    129365 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129366 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    129367 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    129368 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129369 File
    129370 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129371 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    129372 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    129373 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129374 File
    129375 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129376 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    129377 p = super().first_intercept(mxyz1, mxyz2) 
    129378 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129379 File
    129380 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129381 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    129382 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    129383 exclude=exclude) 
    129384 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129385 File
    129386 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129387 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    129388 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    129389 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129390 File
    129391 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129392 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    129393 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    129394 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129395 File
    129396 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129397 packages/chimerax/graphics/drawing.py", line 1108, in
    129398 _first_intercept_excluding_children 
    129399 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    129400 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129401 File
    129402 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129403 packages/chimerax/geometry/place.py", line 201, in inverse 
    129404 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    129405 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129406 File
    129407 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129408 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    129409 rinv[:, :] = matrix_inverse(r) 
    129410 ^^^^^^^^^^^^^^^^^ 
    129411 File
    129412 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129413 packages/numpy/linalg/linalg.py", line 561, in inv 
    129414 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    129415 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129416 File
    129417 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129418 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    129419 raise LinAlgError("Singular matrix") 
    129420 numpy.linalg.LinAlgError: Singular matrix 
    129421  
    129422 numpy.linalg.LinAlgError: Singular matrix 
    129423  
    129424 File
    129425 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129426 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    129427 raise LinAlgError("Singular matrix") 
    129428  
    129429 See log for complete Python traceback. 
    129430  
    129431 Traceback (most recent call last): 
    129432 File
    129433 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129434 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    129435 self.session.ui.mouse_modes.mouse_pause_tracking() 
    129436 File
    129437 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129438 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    129439 mouse_pause_tracking 
    129440 self._mouse_pause() 
    129441 File
    129442 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129443 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    129444 m.pause(self._mouse_pause_position) 
    129445 File
    129446 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129447 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    129448 p = self.view.picked_object(x, y) 
    129449 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129450 File
    129451 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129452 packages/chimerax/graphics/view.py", line 838, in picked_object 
    129453 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    129454 beyond, 
    129455 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129456 File
    129457 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129458 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    129459 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    129460 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129461 File
    129462 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129463 packages/chimerax/core/models.py", line 143, in first_intercept 
    129464 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    129465 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129466 File
    129467 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129468 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    129469 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    129470 exclude=exclude) 
    129471 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129472 File
    129473 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129474 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    129475 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    129476 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129477 File
    129478 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129479 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    129480 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    129481 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129482 File
    129483 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129484 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    129485 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    129486 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129487 File
    129488 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129489 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    129490 p = super().first_intercept(mxyz1, mxyz2) 
    129491 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129492 File
    129493 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129494 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    129495 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    129496 exclude=exclude) 
    129497 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129498 File
    129499 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129500 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    129501 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    129502 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129503 File
    129504 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129505 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    129506 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    129507 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129508 File
    129509 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129510 packages/chimerax/graphics/drawing.py", line 1108, in
    129511 _first_intercept_excluding_children 
    129512 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    129513 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129514 File
    129515 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129516 packages/chimerax/geometry/place.py", line 201, in inverse 
    129517 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    129518 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129519 File
    129520 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129521 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    129522 rinv[:, :] = matrix_inverse(r) 
    129523 ^^^^^^^^^^^^^^^^^ 
    129524 File
    129525 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129526 packages/numpy/linalg/linalg.py", line 561, in inv 
    129527 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    129528 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129529 File
    129530 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129531 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    129532 raise LinAlgError("Singular matrix") 
    129533 numpy.linalg.LinAlgError: Singular matrix 
    129534  
    129535 numpy.linalg.LinAlgError: Singular matrix 
    129536  
    129537 File
    129538 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129539 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    129540 raise LinAlgError("Singular matrix") 
    129541  
    129542 See log for complete Python traceback. 
    129543  
    129544 Traceback (most recent call last): 
    129545 File
    129546 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129547 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    129548 self.session.ui.mouse_modes.mouse_pause_tracking() 
    129549 File
    129550 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129551 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    129552 mouse_pause_tracking 
    129553 self._mouse_pause() 
    129554 File
    129555 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129556 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    129557 m.pause(self._mouse_pause_position) 
    129558 File
    129559 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129560 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    129561 p = self.view.picked_object(x, y) 
    129562 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129563 File
    129564 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129565 packages/chimerax/graphics/view.py", line 838, in picked_object 
    129566 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    129567 beyond, 
    129568 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129569 File
    129570 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129571 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    129572 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    129573 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129574 File
    129575 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129576 packages/chimerax/core/models.py", line 143, in first_intercept 
    129577 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    129578 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129579 File
    129580 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129581 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    129582 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    129583 exclude=exclude) 
    129584 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129585 File
    129586 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129587 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    129588 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    129589 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129590 File
    129591 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129592 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    129593 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    129594 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129595 File
    129596 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129597 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    129598 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    129599 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129600 File
    129601 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129602 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    129603 p = super().first_intercept(mxyz1, mxyz2) 
    129604 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129605 File
    129606 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129607 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    129608 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    129609 exclude=exclude) 
    129610 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129611 File
    129612 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129613 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    129614 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    129615 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129616 File
    129617 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129618 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    129619 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    129620 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129621 File
    129622 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129623 packages/chimerax/graphics/drawing.py", line 1108, in
    129624 _first_intercept_excluding_children 
    129625 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    129626 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129627 File
    129628 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129629 packages/chimerax/geometry/place.py", line 201, in inverse 
    129630 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    129631 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129632 File
    129633 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129634 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    129635 rinv[:, :] = matrix_inverse(r) 
    129636 ^^^^^^^^^^^^^^^^^ 
    129637 File
    129638 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129639 packages/numpy/linalg/linalg.py", line 561, in inv 
    129640 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    129641 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129642 File
    129643 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129644 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    129645 raise LinAlgError("Singular matrix") 
    129646 numpy.linalg.LinAlgError: Singular matrix 
    129647  
    129648 numpy.linalg.LinAlgError: Singular matrix 
    129649  
    129650 File
    129651 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129652 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    129653 raise LinAlgError("Singular matrix") 
    129654  
    129655 See log for complete Python traceback. 
    129656  
    129657 Traceback (most recent call last): 
    129658 File
    129659 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129660 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    129661 self.session.ui.mouse_modes.mouse_pause_tracking() 
    129662 File
    129663 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129664 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    129665 mouse_pause_tracking 
    129666 self._mouse_pause() 
    129667 File
    129668 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129669 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    129670 m.pause(self._mouse_pause_position) 
    129671 File
    129672 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129673 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    129674 p = self.view.picked_object(x, y) 
    129675 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129676 File
    129677 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129678 packages/chimerax/graphics/view.py", line 838, in picked_object 
    129679 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    129680 beyond, 
    129681 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129682 File
    129683 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129684 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    129685 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    129686 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129687 File
    129688 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129689 packages/chimerax/core/models.py", line 143, in first_intercept 
    129690 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    129691 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129692 File
    129693 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129694 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    129695 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    129696 exclude=exclude) 
    129697 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129698 File
    129699 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129700 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    129701 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    129702 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129703 File
    129704 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129705 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    129706 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    129707 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129708 File
    129709 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129710 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    129711 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    129712 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129713 File
    129714 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129715 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    129716 p = super().first_intercept(mxyz1, mxyz2) 
    129717 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129718 File
    129719 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129720 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    129721 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    129722 exclude=exclude) 
    129723 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129724 File
    129725 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129726 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    129727 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    129728 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129729 File
    129730 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129731 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    129732 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    129733 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129734 File
    129735 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129736 packages/chimerax/graphics/drawing.py", line 1108, in
    129737 _first_intercept_excluding_children 
    129738 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    129739 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129740 File
    129741 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129742 packages/chimerax/geometry/place.py", line 201, in inverse 
    129743 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    129744 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129745 File
    129746 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129747 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    129748 rinv[:, :] = matrix_inverse(r) 
    129749 ^^^^^^^^^^^^^^^^^ 
    129750 File
    129751 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129752 packages/numpy/linalg/linalg.py", line 561, in inv 
    129753 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    129754 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129755 File
    129756 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129757 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    129758 raise LinAlgError("Singular matrix") 
    129759 numpy.linalg.LinAlgError: Singular matrix 
    129760  
    129761 numpy.linalg.LinAlgError: Singular matrix 
    129762  
    129763 File
    129764 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129765 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    129766 raise LinAlgError("Singular matrix") 
    129767  
    129768 See log for complete Python traceback. 
    129769  
    129770 Traceback (most recent call last): 
    129771 File
    129772 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129773 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    129774 self.session.ui.mouse_modes.mouse_pause_tracking() 
    129775 File
    129776 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129777 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    129778 mouse_pause_tracking 
    129779 self._mouse_pause() 
    129780 File
    129781 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129782 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    129783 m.pause(self._mouse_pause_position) 
    129784 File
    129785 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129786 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    129787 p = self.view.picked_object(x, y) 
    129788 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129789 File
    129790 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129791 packages/chimerax/graphics/view.py", line 838, in picked_object 
    129792 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    129793 beyond, 
    129794 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129795 File
    129796 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129797 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    129798 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    129799 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129800 File
    129801 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129802 packages/chimerax/core/models.py", line 143, in first_intercept 
    129803 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    129804 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129805 File
    129806 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129807 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    129808 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    129809 exclude=exclude) 
    129810 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129811 File
    129812 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129813 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    129814 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    129815 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129816 File
    129817 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129818 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    129819 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    129820 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129821 File
    129822 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129823 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    129824 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    129825 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129826 File
    129827 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129828 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    129829 p = super().first_intercept(mxyz1, mxyz2) 
    129830 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129831 File
    129832 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129833 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    129834 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    129835 exclude=exclude) 
    129836 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129837 File
    129838 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129839 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    129840 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    129841 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129842 File
    129843 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129844 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    129845 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    129846 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129847 File
    129848 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129849 packages/chimerax/graphics/drawing.py", line 1108, in
    129850 _first_intercept_excluding_children 
    129851 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    129852 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129853 File
    129854 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129855 packages/chimerax/geometry/place.py", line 201, in inverse 
    129856 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    129857 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129858 File
    129859 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129860 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    129861 rinv[:, :] = matrix_inverse(r) 
    129862 ^^^^^^^^^^^^^^^^^ 
    129863 File
    129864 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129865 packages/numpy/linalg/linalg.py", line 561, in inv 
    129866 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    129867 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129868 File
    129869 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129870 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    129871 raise LinAlgError("Singular matrix") 
    129872 numpy.linalg.LinAlgError: Singular matrix 
    129873  
    129874 numpy.linalg.LinAlgError: Singular matrix 
    129875  
    129876 File
    129877 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129878 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    129879 raise LinAlgError("Singular matrix") 
    129880  
    129881 See log for complete Python traceback. 
    129882  
    129883 Traceback (most recent call last): 
    129884 File
    129885 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129886 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    129887 self.session.ui.mouse_modes.mouse_pause_tracking() 
    129888 File
    129889 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129890 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    129891 mouse_pause_tracking 
    129892 self._mouse_pause() 
    129893 File
    129894 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129895 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    129896 m.pause(self._mouse_pause_position) 
    129897 File
    129898 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129899 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    129900 p = self.view.picked_object(x, y) 
    129901 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129902 File
    129903 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129904 packages/chimerax/graphics/view.py", line 838, in picked_object 
    129905 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    129906 beyond, 
    129907 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129908 File
    129909 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129910 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    129911 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    129912 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129913 File
    129914 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129915 packages/chimerax/core/models.py", line 143, in first_intercept 
    129916 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    129917 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129918 File
    129919 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129920 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    129921 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    129922 exclude=exclude) 
    129923 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129924 File
    129925 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129926 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    129927 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    129928 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129929 File
    129930 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129931 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    129932 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    129933 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129934 File
    129935 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129936 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    129937 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    129938 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129939 File
    129940 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129941 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    129942 p = super().first_intercept(mxyz1, mxyz2) 
    129943 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129944 File
    129945 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129946 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    129947 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    129948 exclude=exclude) 
    129949 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129950 File
    129951 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129952 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    129953 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    129954 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129955 File
    129956 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129957 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    129958 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    129959 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129960 File
    129961 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129962 packages/chimerax/graphics/drawing.py", line 1108, in
    129963 _first_intercept_excluding_children 
    129964 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    129965 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129966 File
    129967 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129968 packages/chimerax/geometry/place.py", line 201, in inverse 
    129969 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    129970 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129971 File
    129972 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129973 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    129974 rinv[:, :] = matrix_inverse(r) 
    129975 ^^^^^^^^^^^^^^^^^ 
    129976 File
    129977 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129978 packages/numpy/linalg/linalg.py", line 561, in inv 
    129979 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    129980 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    129981 File
    129982 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129983 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    129984 raise LinAlgError("Singular matrix") 
    129985 numpy.linalg.LinAlgError: Singular matrix 
    129986  
    129987 numpy.linalg.LinAlgError: Singular matrix 
    129988  
    129989 File
    129990 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129991 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    129992 raise LinAlgError("Singular matrix") 
    129993  
    129994 See log for complete Python traceback. 
    129995  
    129996 Traceback (most recent call last): 
    129997 File
    129998 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    129999 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    130000 self.session.ui.mouse_modes.mouse_pause_tracking() 
    130001 File
    130002 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130003 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    130004 mouse_pause_tracking 
    130005 self._mouse_pause() 
    130006 File
    130007 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130008 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    130009 m.pause(self._mouse_pause_position) 
    130010 File
    130011 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130012 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    130013 p = self.view.picked_object(x, y) 
    130014 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130015 File
    130016 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130017 packages/chimerax/graphics/view.py", line 838, in picked_object 
    130018 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    130019 beyond, 
    130020 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130021 File
    130022 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130023 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    130024 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    130025 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130026 File
    130027 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130028 packages/chimerax/core/models.py", line 143, in first_intercept 
    130029 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    130030 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130031 File
    130032 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130033 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    130034 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    130035 exclude=exclude) 
    130036 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130037 File
    130038 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130039 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    130040 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    130041 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130042 File
    130043 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130044 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    130045 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    130046 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130047 File
    130048 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130049 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    130050 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    130051 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130052 File
    130053 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130054 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    130055 p = super().first_intercept(mxyz1, mxyz2) 
    130056 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130057 File
    130058 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130059 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    130060 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    130061 exclude=exclude) 
    130062 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130063 File
    130064 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130065 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    130066 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    130067 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130068 File
    130069 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130070 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    130071 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    130072 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130073 File
    130074 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130075 packages/chimerax/graphics/drawing.py", line 1108, in
    130076 _first_intercept_excluding_children 
    130077 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    130078 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130079 File
    130080 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130081 packages/chimerax/geometry/place.py", line 201, in inverse 
    130082 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    130083 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130084 File
    130085 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130086 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    130087 rinv[:, :] = matrix_inverse(r) 
    130088 ^^^^^^^^^^^^^^^^^ 
    130089 File
    130090 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130091 packages/numpy/linalg/linalg.py", line 561, in inv 
    130092 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    130093 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130094 File
    130095 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130096 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    130097 raise LinAlgError("Singular matrix") 
    130098 numpy.linalg.LinAlgError: Singular matrix 
    130099  
    130100 numpy.linalg.LinAlgError: Singular matrix 
    130101  
    130102 File
    130103 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130104 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    130105 raise LinAlgError("Singular matrix") 
    130106  
    130107 See log for complete Python traceback. 
    130108  
    130109 Traceback (most recent call last): 
    130110 File
    130111 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130112 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    130113 self.session.ui.mouse_modes.mouse_pause_tracking() 
    130114 File
    130115 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130116 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    130117 mouse_pause_tracking 
    130118 self._mouse_pause() 
    130119 File
    130120 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130121 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    130122 m.pause(self._mouse_pause_position) 
    130123 File
    130124 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130125 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    130126 p = self.view.picked_object(x, y) 
    130127 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130128 File
    130129 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130130 packages/chimerax/graphics/view.py", line 838, in picked_object 
    130131 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    130132 beyond, 
    130133 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130134 File
    130135 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130136 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    130137 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    130138 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130139 File
    130140 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130141 packages/chimerax/core/models.py", line 143, in first_intercept 
    130142 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    130143 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130144 File
    130145 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130146 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    130147 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    130148 exclude=exclude) 
    130149 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130150 File
    130151 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130152 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    130153 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    130154 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130155 File
    130156 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130157 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    130158 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    130159 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130160 File
    130161 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130162 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    130163 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    130164 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130165 File
    130166 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130167 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    130168 p = super().first_intercept(mxyz1, mxyz2) 
    130169 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130170 File
    130171 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130172 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    130173 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    130174 exclude=exclude) 
    130175 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130176 File
    130177 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130178 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    130179 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    130180 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130181 File
    130182 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130183 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    130184 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    130185 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130186 File
    130187 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130188 packages/chimerax/graphics/drawing.py", line 1108, in
    130189 _first_intercept_excluding_children 
    130190 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    130191 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130192 File
    130193 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130194 packages/chimerax/geometry/place.py", line 201, in inverse 
    130195 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    130196 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130197 File
    130198 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130199 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    130200 rinv[:, :] = matrix_inverse(r) 
    130201 ^^^^^^^^^^^^^^^^^ 
    130202 File
    130203 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130204 packages/numpy/linalg/linalg.py", line 561, in inv 
    130205 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    130206 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130207 File
    130208 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130209 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    130210 raise LinAlgError("Singular matrix") 
    130211 numpy.linalg.LinAlgError: Singular matrix 
    130212  
    130213 numpy.linalg.LinAlgError: Singular matrix 
    130214  
    130215 File
    130216 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130217 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    130218 raise LinAlgError("Singular matrix") 
    130219  
    130220 See log for complete Python traceback. 
    130221  
    130222 Traceback (most recent call last): 
    130223 File
    130224 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130225 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    130226 self.session.ui.mouse_modes.mouse_pause_tracking() 
    130227 File
    130228 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130229 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    130230 mouse_pause_tracking 
    130231 self._mouse_pause() 
    130232 File
    130233 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130234 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    130235 m.pause(self._mouse_pause_position) 
    130236 File
    130237 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130238 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    130239 p = self.view.picked_object(x, y) 
    130240 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130241 File
    130242 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130243 packages/chimerax/graphics/view.py", line 838, in picked_object 
    130244 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    130245 beyond, 
    130246 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130247 File
    130248 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130249 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    130250 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    130251 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130252 File
    130253 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130254 packages/chimerax/core/models.py", line 143, in first_intercept 
    130255 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    130256 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130257 File
    130258 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130259 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    130260 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    130261 exclude=exclude) 
    130262 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130263 File
    130264 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130265 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    130266 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    130267 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130268 File
    130269 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130270 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    130271 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    130272 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130273 File
    130274 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130275 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    130276 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    130277 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130278 File
    130279 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130280 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    130281 p = super().first_intercept(mxyz1, mxyz2) 
    130282 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130283 File
    130284 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130285 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    130286 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    130287 exclude=exclude) 
    130288 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130289 File
    130290 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130291 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    130292 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    130293 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130294 File
    130295 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130296 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    130297 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    130298 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130299 File
    130300 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130301 packages/chimerax/graphics/drawing.py", line 1108, in
    130302 _first_intercept_excluding_children 
    130303 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    130304 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130305 File
    130306 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130307 packages/chimerax/geometry/place.py", line 201, in inverse 
    130308 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    130309 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130310 File
    130311 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130312 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    130313 rinv[:, :] = matrix_inverse(r) 
    130314 ^^^^^^^^^^^^^^^^^ 
    130315 File
    130316 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130317 packages/numpy/linalg/linalg.py", line 561, in inv 
    130318 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    130319 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130320 File
    130321 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130322 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    130323 raise LinAlgError("Singular matrix") 
    130324 numpy.linalg.LinAlgError: Singular matrix 
    130325  
    130326 numpy.linalg.LinAlgError: Singular matrix 
    130327  
    130328 File
    130329 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130330 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    130331 raise LinAlgError("Singular matrix") 
    130332  
    130333 See log for complete Python traceback. 
    130334  
    130335 Traceback (most recent call last): 
    130336 File
    130337 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130338 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    130339 self.session.ui.mouse_modes.mouse_pause_tracking() 
    130340 File
    130341 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130342 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    130343 mouse_pause_tracking 
    130344 self._mouse_pause() 
    130345 File
    130346 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130347 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    130348 m.pause(self._mouse_pause_position) 
    130349 File
    130350 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130351 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    130352 p = self.view.picked_object(x, y) 
    130353 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130354 File
    130355 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130356 packages/chimerax/graphics/view.py", line 838, in picked_object 
    130357 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    130358 beyond, 
    130359 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130360 File
    130361 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130362 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    130363 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    130364 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130365 File
    130366 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130367 packages/chimerax/core/models.py", line 143, in first_intercept 
    130368 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    130369 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130370 File
    130371 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130372 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    130373 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    130374 exclude=exclude) 
    130375 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130376 File
    130377 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130378 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    130379 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    130380 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130381 File
    130382 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130383 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    130384 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    130385 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130386 File
    130387 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130388 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    130389 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    130390 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130391 File
    130392 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130393 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    130394 p = super().first_intercept(mxyz1, mxyz2) 
    130395 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130396 File
    130397 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130398 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    130399 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    130400 exclude=exclude) 
    130401 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130402 File
    130403 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130404 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    130405 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    130406 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130407 File
    130408 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130409 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    130410 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    130411 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130412 File
    130413 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130414 packages/chimerax/graphics/drawing.py", line 1108, in
    130415 _first_intercept_excluding_children 
    130416 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    130417 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130418 File
    130419 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130420 packages/chimerax/geometry/place.py", line 201, in inverse 
    130421 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    130422 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130423 File
    130424 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130425 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    130426 rinv[:, :] = matrix_inverse(r) 
    130427 ^^^^^^^^^^^^^^^^^ 
    130428 File
    130429 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130430 packages/numpy/linalg/linalg.py", line 561, in inv 
    130431 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    130432 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130433 File
    130434 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130435 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    130436 raise LinAlgError("Singular matrix") 
    130437 numpy.linalg.LinAlgError: Singular matrix 
    130438  
    130439 numpy.linalg.LinAlgError: Singular matrix 
    130440  
    130441 File
    130442 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130443 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    130444 raise LinAlgError("Singular matrix") 
    130445  
    130446 See log for complete Python traceback. 
    130447  
    130448 Traceback (most recent call last): 
    130449 File
    130450 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130451 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    130452 self.session.ui.mouse_modes.mouse_pause_tracking() 
    130453 File
    130454 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130455 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    130456 mouse_pause_tracking 
    130457 self._mouse_pause() 
    130458 File
    130459 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130460 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    130461 m.pause(self._mouse_pause_position) 
    130462 File
    130463 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130464 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    130465 p = self.view.picked_object(x, y) 
    130466 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130467 File
    130468 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130469 packages/chimerax/graphics/view.py", line 838, in picked_object 
    130470 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    130471 beyond, 
    130472 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130473 File
    130474 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130475 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    130476 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    130477 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130478 File
    130479 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130480 packages/chimerax/core/models.py", line 143, in first_intercept 
    130481 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    130482 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130483 File
    130484 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130485 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    130486 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    130487 exclude=exclude) 
    130488 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130489 File
    130490 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130491 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    130492 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    130493 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130494 File
    130495 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130496 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    130497 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    130498 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130499 File
    130500 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130501 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    130502 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    130503 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130504 File
    130505 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130506 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    130507 p = super().first_intercept(mxyz1, mxyz2) 
    130508 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130509 File
    130510 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130511 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    130512 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    130513 exclude=exclude) 
    130514 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130515 File
    130516 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130517 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    130518 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    130519 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130520 File
    130521 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130522 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    130523 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    130524 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130525 File
    130526 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130527 packages/chimerax/graphics/drawing.py", line 1108, in
    130528 _first_intercept_excluding_children 
    130529 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    130530 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130531 File
    130532 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130533 packages/chimerax/geometry/place.py", line 201, in inverse 
    130534 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    130535 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130536 File
    130537 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130538 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    130539 rinv[:, :] = matrix_inverse(r) 
    130540 ^^^^^^^^^^^^^^^^^ 
    130541 File
    130542 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130543 packages/numpy/linalg/linalg.py", line 561, in inv 
    130544 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    130545 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130546 File
    130547 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130548 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    130549 raise LinAlgError("Singular matrix") 
    130550 numpy.linalg.LinAlgError: Singular matrix 
    130551  
    130552 numpy.linalg.LinAlgError: Singular matrix 
    130553  
    130554 File
    130555 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130556 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    130557 raise LinAlgError("Singular matrix") 
    130558  
    130559 See log for complete Python traceback. 
    130560  
    130561 Traceback (most recent call last): 
    130562 File
    130563 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130564 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    130565 self.session.ui.mouse_modes.mouse_pause_tracking() 
    130566 File
    130567 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130568 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    130569 mouse_pause_tracking 
    130570 self._mouse_pause() 
    130571 File
    130572 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130573 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    130574 m.pause(self._mouse_pause_position) 
    130575 File
    130576 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130577 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    130578 p = self.view.picked_object(x, y) 
    130579 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130580 File
    130581 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130582 packages/chimerax/graphics/view.py", line 838, in picked_object 
    130583 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    130584 beyond, 
    130585 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130586 File
    130587 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130588 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    130589 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    130590 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130591 File
    130592 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130593 packages/chimerax/core/models.py", line 143, in first_intercept 
    130594 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    130595 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130596 File
    130597 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130598 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    130599 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    130600 exclude=exclude) 
    130601 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130602 File
    130603 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130604 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    130605 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    130606 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130607 File
    130608 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130609 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    130610 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    130611 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130612 File
    130613 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130614 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    130615 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    130616 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130617 File
    130618 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130619 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    130620 p = super().first_intercept(mxyz1, mxyz2) 
    130621 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130622 File
    130623 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130624 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    130625 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    130626 exclude=exclude) 
    130627 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130628 File
    130629 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130630 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    130631 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    130632 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130633 File
    130634 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130635 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    130636 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    130637 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130638 File
    130639 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130640 packages/chimerax/graphics/drawing.py", line 1108, in
    130641 _first_intercept_excluding_children 
    130642 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    130643 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130644 File
    130645 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130646 packages/chimerax/geometry/place.py", line 201, in inverse 
    130647 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    130648 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130649 File
    130650 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130651 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    130652 rinv[:, :] = matrix_inverse(r) 
    130653 ^^^^^^^^^^^^^^^^^ 
    130654 File
    130655 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130656 packages/numpy/linalg/linalg.py", line 561, in inv 
    130657 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    130658 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130659 File
    130660 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130661 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    130662 raise LinAlgError("Singular matrix") 
    130663 numpy.linalg.LinAlgError: Singular matrix 
    130664  
    130665 numpy.linalg.LinAlgError: Singular matrix 
    130666  
    130667 File
    130668 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130669 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    130670 raise LinAlgError("Singular matrix") 
    130671  
    130672 See log for complete Python traceback. 
    130673  
    130674 Traceback (most recent call last): 
    130675 File
    130676 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130677 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    130678 self.session.ui.mouse_modes.mouse_pause_tracking() 
    130679 File
    130680 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130681 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    130682 mouse_pause_tracking 
    130683 self._mouse_pause() 
    130684 File
    130685 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130686 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    130687 m.pause(self._mouse_pause_position) 
    130688 File
    130689 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130690 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    130691 p = self.view.picked_object(x, y) 
    130692 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130693 File
    130694 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130695 packages/chimerax/graphics/view.py", line 838, in picked_object 
    130696 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    130697 beyond, 
    130698 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130699 File
    130700 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130701 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    130702 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    130703 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130704 File
    130705 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130706 packages/chimerax/core/models.py", line 143, in first_intercept 
    130707 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    130708 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130709 File
    130710 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130711 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    130712 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    130713 exclude=exclude) 
    130714 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130715 File
    130716 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130717 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    130718 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    130719 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130720 File
    130721 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130722 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    130723 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    130724 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130725 File
    130726 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130727 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    130728 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    130729 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130730 File
    130731 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130732 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    130733 p = super().first_intercept(mxyz1, mxyz2) 
    130734 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130735 File
    130736 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130737 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    130738 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    130739 exclude=exclude) 
    130740 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130741 File
    130742 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130743 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    130744 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    130745 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130746 File
    130747 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130748 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    130749 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    130750 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130751 File
    130752 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130753 packages/chimerax/graphics/drawing.py", line 1108, in
    130754 _first_intercept_excluding_children 
    130755 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    130756 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130757 File
    130758 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130759 packages/chimerax/geometry/place.py", line 201, in inverse 
    130760 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    130761 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130762 File
    130763 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130764 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    130765 rinv[:, :] = matrix_inverse(r) 
    130766 ^^^^^^^^^^^^^^^^^ 
    130767 File
    130768 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130769 packages/numpy/linalg/linalg.py", line 561, in inv 
    130770 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    130771 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130772 File
    130773 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130774 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    130775 raise LinAlgError("Singular matrix") 
    130776 numpy.linalg.LinAlgError: Singular matrix 
    130777  
    130778 numpy.linalg.LinAlgError: Singular matrix 
    130779  
    130780 File
    130781 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130782 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    130783 raise LinAlgError("Singular matrix") 
    130784  
    130785 See log for complete Python traceback. 
    130786  
    130787 Traceback (most recent call last): 
    130788 File
    130789 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130790 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    130791 self.session.ui.mouse_modes.mouse_pause_tracking() 
    130792 File
    130793 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130794 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    130795 mouse_pause_tracking 
    130796 self._mouse_pause() 
    130797 File
    130798 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130799 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    130800 m.pause(self._mouse_pause_position) 
    130801 File
    130802 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130803 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    130804 p = self.view.picked_object(x, y) 
    130805 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130806 File
    130807 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130808 packages/chimerax/graphics/view.py", line 838, in picked_object 
    130809 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    130810 beyond, 
    130811 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130812 File
    130813 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130814 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    130815 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    130816 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130817 File
    130818 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130819 packages/chimerax/core/models.py", line 143, in first_intercept 
    130820 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    130821 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130822 File
    130823 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130824 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    130825 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    130826 exclude=exclude) 
    130827 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130828 File
    130829 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130830 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    130831 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    130832 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130833 File
    130834 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130835 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    130836 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    130837 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130838 File
    130839 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130840 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    130841 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    130842 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130843 File
    130844 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130845 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    130846 p = super().first_intercept(mxyz1, mxyz2) 
    130847 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130848 File
    130849 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130850 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    130851 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    130852 exclude=exclude) 
    130853 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130854 File
    130855 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130856 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    130857 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    130858 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130859 File
    130860 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130861 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    130862 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    130863 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130864 File
    130865 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130866 packages/chimerax/graphics/drawing.py", line 1108, in
    130867 _first_intercept_excluding_children 
    130868 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    130869 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130870 File
    130871 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130872 packages/chimerax/geometry/place.py", line 201, in inverse 
    130873 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    130874 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130875 File
    130876 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130877 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    130878 rinv[:, :] = matrix_inverse(r) 
    130879 ^^^^^^^^^^^^^^^^^ 
    130880 File
    130881 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130882 packages/numpy/linalg/linalg.py", line 561, in inv 
    130883 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    130884 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130885 File
    130886 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130887 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    130888 raise LinAlgError("Singular matrix") 
    130889 numpy.linalg.LinAlgError: Singular matrix 
    130890  
    130891 numpy.linalg.LinAlgError: Singular matrix 
    130892  
    130893 File
    130894 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130895 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    130896 raise LinAlgError("Singular matrix") 
    130897  
    130898 See log for complete Python traceback. 
    130899  
    130900 Traceback (most recent call last): 
    130901 File
    130902 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130903 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    130904 self.session.ui.mouse_modes.mouse_pause_tracking() 
    130905 File
    130906 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130907 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    130908 mouse_pause_tracking 
    130909 self._mouse_pause() 
    130910 File
    130911 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130912 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    130913 m.pause(self._mouse_pause_position) 
    130914 File
    130915 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130916 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    130917 p = self.view.picked_object(x, y) 
    130918 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130919 File
    130920 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130921 packages/chimerax/graphics/view.py", line 838, in picked_object 
    130922 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    130923 beyond, 
    130924 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130925 File
    130926 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130927 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    130928 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    130929 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130930 File
    130931 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130932 packages/chimerax/core/models.py", line 143, in first_intercept 
    130933 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    130934 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130935 File
    130936 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130937 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    130938 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    130939 exclude=exclude) 
    130940 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130941 File
    130942 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130943 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    130944 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    130945 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130946 File
    130947 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130948 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    130949 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    130950 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130951 File
    130952 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130953 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    130954 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    130955 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130956 File
    130957 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130958 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    130959 p = super().first_intercept(mxyz1, mxyz2) 
    130960 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130961 File
    130962 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130963 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    130964 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    130965 exclude=exclude) 
    130966 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130967 File
    130968 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130969 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    130970 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    130971 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130972 File
    130973 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130974 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    130975 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    130976 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130977 File
    130978 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130979 packages/chimerax/graphics/drawing.py", line 1108, in
    130980 _first_intercept_excluding_children 
    130981 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    130982 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130983 File
    130984 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130985 packages/chimerax/geometry/place.py", line 201, in inverse 
    130986 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    130987 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130988 File
    130989 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130990 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    130991 rinv[:, :] = matrix_inverse(r) 
    130992 ^^^^^^^^^^^^^^^^^ 
    130993 File
    130994 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    130995 packages/numpy/linalg/linalg.py", line 561, in inv 
    130996 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    130997 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    130998 File
    130999 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131000 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    131001 raise LinAlgError("Singular matrix") 
    131002 numpy.linalg.LinAlgError: Singular matrix 
    131003  
    131004 numpy.linalg.LinAlgError: Singular matrix 
    131005  
    131006 File
    131007 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131008 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    131009 raise LinAlgError("Singular matrix") 
    131010  
    131011 See log for complete Python traceback. 
    131012  
    131013 Traceback (most recent call last): 
    131014 File
    131015 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131016 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    131017 self.session.ui.mouse_modes.mouse_pause_tracking() 
    131018 File
    131019 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131020 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    131021 mouse_pause_tracking 
    131022 self._mouse_pause() 
    131023 File
    131024 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131025 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    131026 m.pause(self._mouse_pause_position) 
    131027 File
    131028 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131029 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    131030 p = self.view.picked_object(x, y) 
    131031 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131032 File
    131033 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131034 packages/chimerax/graphics/view.py", line 838, in picked_object 
    131035 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    131036 beyond, 
    131037 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131038 File
    131039 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131040 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    131041 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    131042 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131043 File
    131044 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131045 packages/chimerax/core/models.py", line 143, in first_intercept 
    131046 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    131047 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131048 File
    131049 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131050 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    131051 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    131052 exclude=exclude) 
    131053 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131054 File
    131055 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131056 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    131057 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    131058 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131059 File
    131060 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131061 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    131062 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    131063 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131064 File
    131065 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131066 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    131067 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    131068 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131069 File
    131070 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131071 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    131072 p = super().first_intercept(mxyz1, mxyz2) 
    131073 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131074 File
    131075 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131076 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    131077 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    131078 exclude=exclude) 
    131079 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131080 File
    131081 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131082 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    131083 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    131084 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131085 File
    131086 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131087 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    131088 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    131089 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131090 File
    131091 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131092 packages/chimerax/graphics/drawing.py", line 1108, in
    131093 _first_intercept_excluding_children 
    131094 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    131095 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131096 File
    131097 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131098 packages/chimerax/geometry/place.py", line 201, in inverse 
    131099 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    131100 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131101 File
    131102 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131103 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    131104 rinv[:, :] = matrix_inverse(r) 
    131105 ^^^^^^^^^^^^^^^^^ 
    131106 File
    131107 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131108 packages/numpy/linalg/linalg.py", line 561, in inv 
    131109 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    131110 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131111 File
    131112 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131113 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    131114 raise LinAlgError("Singular matrix") 
    131115 numpy.linalg.LinAlgError: Singular matrix 
    131116  
    131117 numpy.linalg.LinAlgError: Singular matrix 
    131118  
    131119 File
    131120 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131121 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    131122 raise LinAlgError("Singular matrix") 
    131123  
    131124 See log for complete Python traceback. 
    131125  
    131126 Traceback (most recent call last): 
    131127 File
    131128 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131129 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    131130 self.session.ui.mouse_modes.mouse_pause_tracking() 
    131131 File
    131132 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131133 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    131134 mouse_pause_tracking 
    131135 self._mouse_pause() 
    131136 File
    131137 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131138 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    131139 m.pause(self._mouse_pause_position) 
    131140 File
    131141 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131142 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    131143 p = self.view.picked_object(x, y) 
    131144 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131145 File
    131146 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131147 packages/chimerax/graphics/view.py", line 838, in picked_object 
    131148 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    131149 beyond, 
    131150 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131151 File
    131152 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131153 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    131154 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    131155 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131156 File
    131157 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131158 packages/chimerax/core/models.py", line 143, in first_intercept 
    131159 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    131160 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131161 File
    131162 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131163 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    131164 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    131165 exclude=exclude) 
    131166 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131167 File
    131168 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131169 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    131170 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    131171 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131172 File
    131173 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131174 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    131175 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    131176 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131177 File
    131178 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131179 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    131180 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    131181 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131182 File
    131183 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131184 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    131185 p = super().first_intercept(mxyz1, mxyz2) 
    131186 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131187 File
    131188 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131189 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    131190 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    131191 exclude=exclude) 
    131192 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131193 File
    131194 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131195 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    131196 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    131197 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131198 File
    131199 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131200 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    131201 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    131202 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131203 File
    131204 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131205 packages/chimerax/graphics/drawing.py", line 1108, in
    131206 _first_intercept_excluding_children 
    131207 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    131208 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131209 File
    131210 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131211 packages/chimerax/geometry/place.py", line 201, in inverse 
    131212 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    131213 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131214 File
    131215 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131216 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    131217 rinv[:, :] = matrix_inverse(r) 
    131218 ^^^^^^^^^^^^^^^^^ 
    131219 File
    131220 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131221 packages/numpy/linalg/linalg.py", line 561, in inv 
    131222 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    131223 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131224 File
    131225 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131226 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    131227 raise LinAlgError("Singular matrix") 
    131228 numpy.linalg.LinAlgError: Singular matrix 
    131229  
    131230 numpy.linalg.LinAlgError: Singular matrix 
    131231  
    131232 File
    131233 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131234 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    131235 raise LinAlgError("Singular matrix") 
    131236  
    131237 See log for complete Python traceback. 
    131238  
    131239 Traceback (most recent call last): 
    131240 File
    131241 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131242 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    131243 self.session.ui.mouse_modes.mouse_pause_tracking() 
    131244 File
    131245 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131246 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    131247 mouse_pause_tracking 
    131248 self._mouse_pause() 
    131249 File
    131250 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131251 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    131252 m.pause(self._mouse_pause_position) 
    131253 File
    131254 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131255 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    131256 p = self.view.picked_object(x, y) 
    131257 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131258 File
    131259 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131260 packages/chimerax/graphics/view.py", line 838, in picked_object 
    131261 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    131262 beyond, 
    131263 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131264 File
    131265 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131266 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    131267 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    131268 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131269 File
    131270 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131271 packages/chimerax/core/models.py", line 143, in first_intercept 
    131272 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    131273 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131274 File
    131275 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131276 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    131277 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    131278 exclude=exclude) 
    131279 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131280 File
    131281 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131282 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    131283 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    131284 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131285 File
    131286 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131287 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    131288 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    131289 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131290 File
    131291 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131292 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    131293 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    131294 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131295 File
    131296 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131297 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    131298 p = super().first_intercept(mxyz1, mxyz2) 
    131299 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131300 File
    131301 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131302 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    131303 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    131304 exclude=exclude) 
    131305 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131306 File
    131307 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131308 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    131309 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    131310 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131311 File
    131312 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131313 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    131314 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    131315 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131316 File
    131317 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131318 packages/chimerax/graphics/drawing.py", line 1108, in
    131319 _first_intercept_excluding_children 
    131320 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    131321 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131322 File
    131323 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131324 packages/chimerax/geometry/place.py", line 201, in inverse 
    131325 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    131326 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131327 File
    131328 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131329 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    131330 rinv[:, :] = matrix_inverse(r) 
    131331 ^^^^^^^^^^^^^^^^^ 
    131332 File
    131333 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131334 packages/numpy/linalg/linalg.py", line 561, in inv 
    131335 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    131336 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131337 File
    131338 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131339 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    131340 raise LinAlgError("Singular matrix") 
    131341 numpy.linalg.LinAlgError: Singular matrix 
    131342  
    131343 numpy.linalg.LinAlgError: Singular matrix 
    131344  
    131345 File
    131346 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131347 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    131348 raise LinAlgError("Singular matrix") 
    131349  
    131350 See log for complete Python traceback. 
    131351  
    131352 Traceback (most recent call last): 
    131353 File
    131354 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131355 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    131356 self.session.ui.mouse_modes.mouse_pause_tracking() 
    131357 File
    131358 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131359 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    131360 mouse_pause_tracking 
    131361 self._mouse_pause() 
    131362 File
    131363 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131364 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    131365 m.pause(self._mouse_pause_position) 
    131366 File
    131367 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131368 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    131369 p = self.view.picked_object(x, y) 
    131370 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131371 File
    131372 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131373 packages/chimerax/graphics/view.py", line 838, in picked_object 
    131374 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    131375 beyond, 
    131376 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131377 File
    131378 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131379 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    131380 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    131381 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131382 File
    131383 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131384 packages/chimerax/core/models.py", line 143, in first_intercept 
    131385 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    131386 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131387 File
    131388 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131389 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    131390 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    131391 exclude=exclude) 
    131392 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131393 File
    131394 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131395 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    131396 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    131397 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131398 File
    131399 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131400 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    131401 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    131402 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131403 File
    131404 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131405 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    131406 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    131407 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131408 File
    131409 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131410 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    131411 p = super().first_intercept(mxyz1, mxyz2) 
    131412 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131413 File
    131414 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131415 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    131416 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    131417 exclude=exclude) 
    131418 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131419 File
    131420 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131421 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    131422 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    131423 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131424 File
    131425 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131426 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    131427 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    131428 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131429 File
    131430 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131431 packages/chimerax/graphics/drawing.py", line 1108, in
    131432 _first_intercept_excluding_children 
    131433 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    131434 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131435 File
    131436 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131437 packages/chimerax/geometry/place.py", line 201, in inverse 
    131438 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    131439 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131440 File
    131441 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131442 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    131443 rinv[:, :] = matrix_inverse(r) 
    131444 ^^^^^^^^^^^^^^^^^ 
    131445 File
    131446 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131447 packages/numpy/linalg/linalg.py", line 561, in inv 
    131448 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    131449 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131450 File
    131451 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131452 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    131453 raise LinAlgError("Singular matrix") 
    131454 numpy.linalg.LinAlgError: Singular matrix 
    131455  
    131456 numpy.linalg.LinAlgError: Singular matrix 
    131457  
    131458 File
    131459 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131460 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    131461 raise LinAlgError("Singular matrix") 
    131462  
    131463 See log for complete Python traceback. 
    131464  
    131465 Traceback (most recent call last): 
    131466 File
    131467 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131468 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    131469 self.session.ui.mouse_modes.mouse_pause_tracking() 
    131470 File
    131471 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131472 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    131473 mouse_pause_tracking 
    131474 self._mouse_pause() 
    131475 File
    131476 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131477 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    131478 m.pause(self._mouse_pause_position) 
    131479 File
    131480 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131481 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    131482 p = self.view.picked_object(x, y) 
    131483 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131484 File
    131485 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131486 packages/chimerax/graphics/view.py", line 838, in picked_object 
    131487 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    131488 beyond, 
    131489 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131490 File
    131491 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131492 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    131493 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    131494 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131495 File
    131496 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131497 packages/chimerax/core/models.py", line 143, in first_intercept 
    131498 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    131499 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131500 File
    131501 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131502 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    131503 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    131504 exclude=exclude) 
    131505 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131506 File
    131507 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131508 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    131509 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    131510 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131511 File
    131512 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131513 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    131514 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    131515 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131516 File
    131517 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131518 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    131519 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    131520 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131521 File
    131522 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131523 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    131524 p = super().first_intercept(mxyz1, mxyz2) 
    131525 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131526 File
    131527 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131528 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    131529 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    131530 exclude=exclude) 
    131531 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131532 File
    131533 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131534 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    131535 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    131536 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131537 File
    131538 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131539 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    131540 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    131541 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131542 File
    131543 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131544 packages/chimerax/graphics/drawing.py", line 1108, in
    131545 _first_intercept_excluding_children 
    131546 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    131547 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131548 File
    131549 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131550 packages/chimerax/geometry/place.py", line 201, in inverse 
    131551 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    131552 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131553 File
    131554 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131555 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    131556 rinv[:, :] = matrix_inverse(r) 
    131557 ^^^^^^^^^^^^^^^^^ 
    131558 File
    131559 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131560 packages/numpy/linalg/linalg.py", line 561, in inv 
    131561 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    131562 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131563 File
    131564 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131565 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    131566 raise LinAlgError("Singular matrix") 
    131567 numpy.linalg.LinAlgError: Singular matrix 
    131568  
    131569 numpy.linalg.LinAlgError: Singular matrix 
    131570  
    131571 File
    131572 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131573 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    131574 raise LinAlgError("Singular matrix") 
    131575  
    131576 See log for complete Python traceback. 
    131577  
    131578 Traceback (most recent call last): 
    131579 File
    131580 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131581 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    131582 self.session.ui.mouse_modes.mouse_pause_tracking() 
    131583 File
    131584 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131585 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    131586 mouse_pause_tracking 
    131587 self._mouse_pause() 
    131588 File
    131589 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131590 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    131591 m.pause(self._mouse_pause_position) 
    131592 File
    131593 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131594 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    131595 p = self.view.picked_object(x, y) 
    131596 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131597 File
    131598 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131599 packages/chimerax/graphics/view.py", line 838, in picked_object 
    131600 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    131601 beyond, 
    131602 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131603 File
    131604 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131605 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    131606 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    131607 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131608 File
    131609 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131610 packages/chimerax/core/models.py", line 143, in first_intercept 
    131611 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    131612 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131613 File
    131614 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131615 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    131616 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    131617 exclude=exclude) 
    131618 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131619 File
    131620 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131621 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    131622 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    131623 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131624 File
    131625 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131626 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    131627 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    131628 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131629 File
    131630 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131631 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    131632 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    131633 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131634 File
    131635 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131636 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    131637 p = super().first_intercept(mxyz1, mxyz2) 
    131638 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131639 File
    131640 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131641 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    131642 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    131643 exclude=exclude) 
    131644 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131645 File
    131646 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131647 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    131648 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    131649 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131650 File
    131651 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131652 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    131653 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    131654 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131655 File
    131656 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131657 packages/chimerax/graphics/drawing.py", line 1108, in
    131658 _first_intercept_excluding_children 
    131659 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    131660 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131661 File
    131662 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131663 packages/chimerax/geometry/place.py", line 201, in inverse 
    131664 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    131665 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131666 File
    131667 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131668 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    131669 rinv[:, :] = matrix_inverse(r) 
    131670 ^^^^^^^^^^^^^^^^^ 
    131671 File
    131672 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131673 packages/numpy/linalg/linalg.py", line 561, in inv 
    131674 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    131675 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131676 File
    131677 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131678 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    131679 raise LinAlgError("Singular matrix") 
    131680 numpy.linalg.LinAlgError: Singular matrix 
    131681  
    131682 numpy.linalg.LinAlgError: Singular matrix 
    131683  
    131684 File
    131685 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131686 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    131687 raise LinAlgError("Singular matrix") 
    131688  
    131689 See log for complete Python traceback. 
    131690  
    131691 Traceback (most recent call last): 
    131692 File
    131693 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131694 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    131695 self.session.ui.mouse_modes.mouse_pause_tracking() 
    131696 File
    131697 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131698 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    131699 mouse_pause_tracking 
    131700 self._mouse_pause() 
    131701 File
    131702 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131703 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    131704 m.pause(self._mouse_pause_position) 
    131705 File
    131706 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131707 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    131708 p = self.view.picked_object(x, y) 
    131709 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131710 File
    131711 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131712 packages/chimerax/graphics/view.py", line 838, in picked_object 
    131713 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    131714 beyond, 
    131715 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131716 File
    131717 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131718 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    131719 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    131720 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131721 File
    131722 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131723 packages/chimerax/core/models.py", line 143, in first_intercept 
    131724 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    131725 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131726 File
    131727 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131728 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    131729 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    131730 exclude=exclude) 
    131731 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131732 File
    131733 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131734 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    131735 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    131736 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131737 File
    131738 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131739 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    131740 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    131741 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131742 File
    131743 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131744 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    131745 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    131746 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131747 File
    131748 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131749 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    131750 p = super().first_intercept(mxyz1, mxyz2) 
    131751 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131752 File
    131753 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131754 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    131755 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    131756 exclude=exclude) 
    131757 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131758 File
    131759 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131760 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    131761 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    131762 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131763 File
    131764 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131765 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    131766 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    131767 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131768 File
    131769 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131770 packages/chimerax/graphics/drawing.py", line 1108, in
    131771 _first_intercept_excluding_children 
    131772 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    131773 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131774 File
    131775 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131776 packages/chimerax/geometry/place.py", line 201, in inverse 
    131777 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    131778 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131779 File
    131780 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131781 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    131782 rinv[:, :] = matrix_inverse(r) 
    131783 ^^^^^^^^^^^^^^^^^ 
    131784 File
    131785 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131786 packages/numpy/linalg/linalg.py", line 561, in inv 
    131787 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    131788 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131789 File
    131790 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131791 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    131792 raise LinAlgError("Singular matrix") 
    131793 numpy.linalg.LinAlgError: Singular matrix 
    131794  
    131795 numpy.linalg.LinAlgError: Singular matrix 
    131796  
    131797 File
    131798 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131799 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    131800 raise LinAlgError("Singular matrix") 
    131801  
    131802 See log for complete Python traceback. 
    131803  
    131804 Traceback (most recent call last): 
    131805 File
    131806 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131807 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    131808 self.session.ui.mouse_modes.mouse_pause_tracking() 
    131809 File
    131810 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131811 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    131812 mouse_pause_tracking 
    131813 self._mouse_pause() 
    131814 File
    131815 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131816 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    131817 m.pause(self._mouse_pause_position) 
    131818 File
    131819 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131820 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    131821 p = self.view.picked_object(x, y) 
    131822 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131823 File
    131824 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131825 packages/chimerax/graphics/view.py", line 838, in picked_object 
    131826 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    131827 beyond, 
    131828 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131829 File
    131830 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131831 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    131832 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    131833 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131834 File
    131835 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131836 packages/chimerax/core/models.py", line 143, in first_intercept 
    131837 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    131838 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131839 File
    131840 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131841 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    131842 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    131843 exclude=exclude) 
    131844 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131845 File
    131846 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131847 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    131848 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    131849 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131850 File
    131851 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131852 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    131853 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    131854 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131855 File
    131856 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131857 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    131858 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    131859 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131860 File
    131861 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131862 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    131863 p = super().first_intercept(mxyz1, mxyz2) 
    131864 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131865 File
    131866 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131867 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    131868 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    131869 exclude=exclude) 
    131870 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131871 File
    131872 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131873 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    131874 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    131875 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131876 File
    131877 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131878 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    131879 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    131880 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131881 File
    131882 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131883 packages/chimerax/graphics/drawing.py", line 1108, in
    131884 _first_intercept_excluding_children 
    131885 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    131886 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131887 File
    131888 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131889 packages/chimerax/geometry/place.py", line 201, in inverse 
    131890 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    131891 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131892 File
    131893 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131894 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    131895 rinv[:, :] = matrix_inverse(r) 
    131896 ^^^^^^^^^^^^^^^^^ 
    131897 File
    131898 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131899 packages/numpy/linalg/linalg.py", line 561, in inv 
    131900 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    131901 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131902 File
    131903 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131904 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    131905 raise LinAlgError("Singular matrix") 
    131906 numpy.linalg.LinAlgError: Singular matrix 
    131907  
    131908 numpy.linalg.LinAlgError: Singular matrix 
    131909  
    131910 File
    131911 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131912 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    131913 raise LinAlgError("Singular matrix") 
    131914  
    131915 See log for complete Python traceback. 
    131916  
    131917 Traceback (most recent call last): 
    131918 File
    131919 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131920 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    131921 self.session.ui.mouse_modes.mouse_pause_tracking() 
    131922 File
    131923 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131924 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    131925 mouse_pause_tracking 
    131926 self._mouse_pause() 
    131927 File
    131928 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131929 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    131930 m.pause(self._mouse_pause_position) 
    131931 File
    131932 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131933 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    131934 p = self.view.picked_object(x, y) 
    131935 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131936 File
    131937 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131938 packages/chimerax/graphics/view.py", line 838, in picked_object 
    131939 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    131940 beyond, 
    131941 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131942 File
    131943 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131944 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    131945 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    131946 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131947 File
    131948 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131949 packages/chimerax/core/models.py", line 143, in first_intercept 
    131950 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    131951 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131952 File
    131953 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131954 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    131955 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    131956 exclude=exclude) 
    131957 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131958 File
    131959 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131960 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    131961 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    131962 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131963 File
    131964 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131965 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    131966 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    131967 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131968 File
    131969 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131970 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    131971 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    131972 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131973 File
    131974 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131975 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    131976 p = super().first_intercept(mxyz1, mxyz2) 
    131977 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131978 File
    131979 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131980 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    131981 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    131982 exclude=exclude) 
    131983 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131984 File
    131985 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131986 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    131987 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    131988 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131989 File
    131990 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131991 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    131992 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    131993 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    131994 File
    131995 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    131996 packages/chimerax/graphics/drawing.py", line 1108, in
    131997 _first_intercept_excluding_children 
    131998 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    131999 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132000 File
    132001 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132002 packages/chimerax/geometry/place.py", line 201, in inverse 
    132003 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    132004 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132005 File
    132006 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132007 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    132008 rinv[:, :] = matrix_inverse(r) 
    132009 ^^^^^^^^^^^^^^^^^ 
    132010 File
    132011 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132012 packages/numpy/linalg/linalg.py", line 561, in inv 
    132013 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    132014 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132015 File
    132016 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132017 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    132018 raise LinAlgError("Singular matrix") 
    132019 numpy.linalg.LinAlgError: Singular matrix 
    132020  
    132021 numpy.linalg.LinAlgError: Singular matrix 
    132022  
    132023 File
    132024 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132025 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    132026 raise LinAlgError("Singular matrix") 
    132027  
    132028 See log for complete Python traceback. 
    132029  
    132030 Traceback (most recent call last): 
    132031 File
    132032 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132033 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    132034 self.session.ui.mouse_modes.mouse_pause_tracking() 
    132035 File
    132036 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132037 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    132038 mouse_pause_tracking 
    132039 self._mouse_pause() 
    132040 File
    132041 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132042 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    132043 m.pause(self._mouse_pause_position) 
    132044 File
    132045 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132046 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    132047 p = self.view.picked_object(x, y) 
    132048 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132049 File
    132050 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132051 packages/chimerax/graphics/view.py", line 838, in picked_object 
    132052 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    132053 beyond, 
    132054 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132055 File
    132056 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132057 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    132058 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    132059 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132060 File
    132061 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132062 packages/chimerax/core/models.py", line 143, in first_intercept 
    132063 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    132064 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132065 File
    132066 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132067 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    132068 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    132069 exclude=exclude) 
    132070 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132071 File
    132072 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132073 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    132074 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    132075 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132076 File
    132077 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132078 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    132079 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    132080 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132081 File
    132082 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132083 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    132084 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    132085 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132086 File
    132087 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132088 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    132089 p = super().first_intercept(mxyz1, mxyz2) 
    132090 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132091 File
    132092 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132093 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    132094 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    132095 exclude=exclude) 
    132096 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132097 File
    132098 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132099 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    132100 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    132101 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132102 File
    132103 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132104 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    132105 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    132106 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132107 File
    132108 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132109 packages/chimerax/graphics/drawing.py", line 1108, in
    132110 _first_intercept_excluding_children 
    132111 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    132112 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132113 File
    132114 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132115 packages/chimerax/geometry/place.py", line 201, in inverse 
    132116 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    132117 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132118 File
    132119 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132120 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    132121 rinv[:, :] = matrix_inverse(r) 
    132122 ^^^^^^^^^^^^^^^^^ 
    132123 File
    132124 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132125 packages/numpy/linalg/linalg.py", line 561, in inv 
    132126 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    132127 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132128 File
    132129 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132130 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    132131 raise LinAlgError("Singular matrix") 
    132132 numpy.linalg.LinAlgError: Singular matrix 
    132133  
    132134 numpy.linalg.LinAlgError: Singular matrix 
    132135  
    132136 File
    132137 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132138 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    132139 raise LinAlgError("Singular matrix") 
    132140  
    132141 See log for complete Python traceback. 
    132142  
    132143 Traceback (most recent call last): 
    132144 File
    132145 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132146 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    132147 self.session.ui.mouse_modes.mouse_pause_tracking() 
    132148 File
    132149 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132150 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    132151 mouse_pause_tracking 
    132152 self._mouse_pause() 
    132153 File
    132154 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132155 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    132156 m.pause(self._mouse_pause_position) 
    132157 File
    132158 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132159 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    132160 p = self.view.picked_object(x, y) 
    132161 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132162 File
    132163 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132164 packages/chimerax/graphics/view.py", line 838, in picked_object 
    132165 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    132166 beyond, 
    132167 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132168 File
    132169 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132170 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    132171 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    132172 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132173 File
    132174 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132175 packages/chimerax/core/models.py", line 143, in first_intercept 
    132176 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    132177 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132178 File
    132179 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132180 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    132181 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    132182 exclude=exclude) 
    132183 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132184 File
    132185 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132186 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    132187 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    132188 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132189 File
    132190 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132191 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    132192 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    132193 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132194 File
    132195 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132196 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    132197 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    132198 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132199 File
    132200 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132201 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    132202 p = super().first_intercept(mxyz1, mxyz2) 
    132203 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132204 File
    132205 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132206 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    132207 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    132208 exclude=exclude) 
    132209 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132210 File
    132211 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132212 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    132213 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    132214 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132215 File
    132216 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132217 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    132218 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    132219 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132220 File
    132221 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132222 packages/chimerax/graphics/drawing.py", line 1108, in
    132223 _first_intercept_excluding_children 
    132224 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    132225 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132226 File
    132227 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132228 packages/chimerax/geometry/place.py", line 201, in inverse 
    132229 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    132230 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132231 File
    132232 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132233 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    132234 rinv[:, :] = matrix_inverse(r) 
    132235 ^^^^^^^^^^^^^^^^^ 
    132236 File
    132237 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132238 packages/numpy/linalg/linalg.py", line 561, in inv 
    132239 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    132240 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132241 File
    132242 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132243 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    132244 raise LinAlgError("Singular matrix") 
    132245 numpy.linalg.LinAlgError: Singular matrix 
    132246  
    132247 numpy.linalg.LinAlgError: Singular matrix 
    132248  
    132249 File
    132250 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132251 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    132252 raise LinAlgError("Singular matrix") 
    132253  
    132254 See log for complete Python traceback. 
    132255  
    132256 Traceback (most recent call last): 
    132257 File
    132258 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132259 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    132260 self.session.ui.mouse_modes.mouse_pause_tracking() 
    132261 File
    132262 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132263 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    132264 mouse_pause_tracking 
    132265 self._mouse_pause() 
    132266 File
    132267 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132268 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    132269 m.pause(self._mouse_pause_position) 
    132270 File
    132271 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132272 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    132273 p = self.view.picked_object(x, y) 
    132274 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132275 File
    132276 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132277 packages/chimerax/graphics/view.py", line 838, in picked_object 
    132278 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    132279 beyond, 
    132280 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132281 File
    132282 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132283 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    132284 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    132285 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132286 File
    132287 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132288 packages/chimerax/core/models.py", line 143, in first_intercept 
    132289 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    132290 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132291 File
    132292 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132293 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    132294 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    132295 exclude=exclude) 
    132296 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132297 File
    132298 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132299 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    132300 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    132301 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132302 File
    132303 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132304 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    132305 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    132306 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132307 File
    132308 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132309 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    132310 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    132311 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132312 File
    132313 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132314 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    132315 p = super().first_intercept(mxyz1, mxyz2) 
    132316 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132317 File
    132318 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132319 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    132320 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    132321 exclude=exclude) 
    132322 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132323 File
    132324 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132325 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    132326 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    132327 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132328 File
    132329 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132330 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    132331 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    132332 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132333 File
    132334 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132335 packages/chimerax/graphics/drawing.py", line 1108, in
    132336 _first_intercept_excluding_children 
    132337 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    132338 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132339 File
    132340 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132341 packages/chimerax/geometry/place.py", line 201, in inverse 
    132342 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    132343 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132344 File
    132345 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132346 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    132347 rinv[:, :] = matrix_inverse(r) 
    132348 ^^^^^^^^^^^^^^^^^ 
    132349 File
    132350 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132351 packages/numpy/linalg/linalg.py", line 561, in inv 
    132352 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    132353 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132354 File
    132355 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132356 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    132357 raise LinAlgError("Singular matrix") 
    132358 numpy.linalg.LinAlgError: Singular matrix 
    132359  
    132360 numpy.linalg.LinAlgError: Singular matrix 
    132361  
    132362 File
    132363 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132364 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    132365 raise LinAlgError("Singular matrix") 
    132366  
    132367 See log for complete Python traceback. 
    132368  
    132369 Traceback (most recent call last): 
    132370 File
    132371 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132372 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    132373 self.session.ui.mouse_modes.mouse_pause_tracking() 
    132374 File
    132375 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132376 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    132377 mouse_pause_tracking 
    132378 self._mouse_pause() 
    132379 File
    132380 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132381 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    132382 m.pause(self._mouse_pause_position) 
    132383 File
    132384 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132385 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    132386 p = self.view.picked_object(x, y) 
    132387 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132388 File
    132389 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132390 packages/chimerax/graphics/view.py", line 838, in picked_object 
    132391 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    132392 beyond, 
    132393 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132394 File
    132395 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132396 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    132397 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    132398 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132399 File
    132400 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132401 packages/chimerax/core/models.py", line 143, in first_intercept 
    132402 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    132403 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132404 File
    132405 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132406 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    132407 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    132408 exclude=exclude) 
    132409 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132410 File
    132411 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132412 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    132413 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    132414 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132415 File
    132416 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132417 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    132418 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    132419 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132420 File
    132421 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132422 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    132423 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    132424 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132425 File
    132426 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132427 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    132428 p = super().first_intercept(mxyz1, mxyz2) 
    132429 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132430 File
    132431 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132432 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    132433 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    132434 exclude=exclude) 
    132435 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132436 File
    132437 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132438 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    132439 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    132440 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132441 File
    132442 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132443 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    132444 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    132445 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132446 File
    132447 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132448 packages/chimerax/graphics/drawing.py", line 1108, in
    132449 _first_intercept_excluding_children 
    132450 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    132451 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132452 File
    132453 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132454 packages/chimerax/geometry/place.py", line 201, in inverse 
    132455 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    132456 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132457 File
    132458 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132459 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    132460 rinv[:, :] = matrix_inverse(r) 
    132461 ^^^^^^^^^^^^^^^^^ 
    132462 File
    132463 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132464 packages/numpy/linalg/linalg.py", line 561, in inv 
    132465 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    132466 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132467 File
    132468 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132469 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    132470 raise LinAlgError("Singular matrix") 
    132471 numpy.linalg.LinAlgError: Singular matrix 
    132472  
    132473 numpy.linalg.LinAlgError: Singular matrix 
    132474  
    132475 File
    132476 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132477 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    132478 raise LinAlgError("Singular matrix") 
    132479  
    132480 See log for complete Python traceback. 
    132481  
    132482 Traceback (most recent call last): 
    132483 File
    132484 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132485 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    132486 self.session.ui.mouse_modes.mouse_pause_tracking() 
    132487 File
    132488 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132489 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    132490 mouse_pause_tracking 
    132491 self._mouse_pause() 
    132492 File
    132493 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132494 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    132495 m.pause(self._mouse_pause_position) 
    132496 File
    132497 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132498 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    132499 p = self.view.picked_object(x, y) 
    132500 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132501 File
    132502 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132503 packages/chimerax/graphics/view.py", line 838, in picked_object 
    132504 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    132505 beyond, 
    132506 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132507 File
    132508 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132509 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    132510 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    132511 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132512 File
    132513 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132514 packages/chimerax/core/models.py", line 143, in first_intercept 
    132515 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    132516 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132517 File
    132518 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132519 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    132520 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    132521 exclude=exclude) 
    132522 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132523 File
    132524 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132525 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    132526 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    132527 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132528 File
    132529 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132530 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    132531 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    132532 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132533 File
    132534 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132535 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    132536 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    132537 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132538 File
    132539 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132540 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    132541 p = super().first_intercept(mxyz1, mxyz2) 
    132542 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132543 File
    132544 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132545 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    132546 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    132547 exclude=exclude) 
    132548 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132549 File
    132550 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132551 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    132552 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    132553 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132554 File
    132555 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132556 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    132557 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    132558 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132559 File
    132560 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132561 packages/chimerax/graphics/drawing.py", line 1108, in
    132562 _first_intercept_excluding_children 
    132563 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    132564 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132565 File
    132566 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132567 packages/chimerax/geometry/place.py", line 201, in inverse 
    132568 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    132569 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132570 File
    132571 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132572 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    132573 rinv[:, :] = matrix_inverse(r) 
    132574 ^^^^^^^^^^^^^^^^^ 
    132575 File
    132576 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132577 packages/numpy/linalg/linalg.py", line 561, in inv 
    132578 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    132579 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132580 File
    132581 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132582 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    132583 raise LinAlgError("Singular matrix") 
    132584 numpy.linalg.LinAlgError: Singular matrix 
    132585  
    132586 numpy.linalg.LinAlgError: Singular matrix 
    132587  
    132588 File
    132589 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132590 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    132591 raise LinAlgError("Singular matrix") 
    132592  
    132593 See log for complete Python traceback. 
    132594  
    132595 Traceback (most recent call last): 
    132596 File
    132597 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132598 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    132599 self.session.ui.mouse_modes.mouse_pause_tracking() 
    132600 File
    132601 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132602 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    132603 mouse_pause_tracking 
    132604 self._mouse_pause() 
    132605 File
    132606 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132607 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    132608 m.pause(self._mouse_pause_position) 
    132609 File
    132610 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132611 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    132612 p = self.view.picked_object(x, y) 
    132613 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132614 File
    132615 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132616 packages/chimerax/graphics/view.py", line 838, in picked_object 
    132617 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    132618 beyond, 
    132619 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132620 File
    132621 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132622 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    132623 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    132624 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132625 File
    132626 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132627 packages/chimerax/core/models.py", line 143, in first_intercept 
    132628 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    132629 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132630 File
    132631 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132632 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    132633 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    132634 exclude=exclude) 
    132635 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132636 File
    132637 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132638 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    132639 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    132640 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132641 File
    132642 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132643 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    132644 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    132645 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132646 File
    132647 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132648 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    132649 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    132650 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132651 File
    132652 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132653 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    132654 p = super().first_intercept(mxyz1, mxyz2) 
    132655 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132656 File
    132657 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132658 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    132659 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    132660 exclude=exclude) 
    132661 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132662 File
    132663 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132664 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    132665 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    132666 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132667 File
    132668 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132669 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    132670 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    132671 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132672 File
    132673 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132674 packages/chimerax/graphics/drawing.py", line 1108, in
    132675 _first_intercept_excluding_children 
    132676 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    132677 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132678 File
    132679 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132680 packages/chimerax/geometry/place.py", line 201, in inverse 
    132681 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    132682 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132683 File
    132684 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132685 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    132686 rinv[:, :] = matrix_inverse(r) 
    132687 ^^^^^^^^^^^^^^^^^ 
    132688 File
    132689 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132690 packages/numpy/linalg/linalg.py", line 561, in inv 
    132691 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    132692 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132693 File
    132694 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132695 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    132696 raise LinAlgError("Singular matrix") 
    132697 numpy.linalg.LinAlgError: Singular matrix 
    132698  
    132699 numpy.linalg.LinAlgError: Singular matrix 
    132700  
    132701 File
    132702 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132703 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    132704 raise LinAlgError("Singular matrix") 
    132705  
    132706 See log for complete Python traceback. 
    132707  
    132708 Traceback (most recent call last): 
    132709 File
    132710 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132711 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    132712 self.session.ui.mouse_modes.mouse_pause_tracking() 
    132713 File
    132714 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132715 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    132716 mouse_pause_tracking 
    132717 self._mouse_pause() 
    132718 File
    132719 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132720 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    132721 m.pause(self._mouse_pause_position) 
    132722 File
    132723 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132724 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    132725 p = self.view.picked_object(x, y) 
    132726 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132727 File
    132728 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132729 packages/chimerax/graphics/view.py", line 838, in picked_object 
    132730 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    132731 beyond, 
    132732 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132733 File
    132734 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132735 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    132736 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    132737 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132738 File
    132739 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132740 packages/chimerax/core/models.py", line 143, in first_intercept 
    132741 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    132742 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132743 File
    132744 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132745 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    132746 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    132747 exclude=exclude) 
    132748 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132749 File
    132750 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132751 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    132752 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    132753 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132754 File
    132755 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132756 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    132757 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    132758 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132759 File
    132760 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132761 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    132762 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    132763 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132764 File
    132765 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132766 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    132767 p = super().first_intercept(mxyz1, mxyz2) 
    132768 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132769 File
    132770 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132771 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    132772 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    132773 exclude=exclude) 
    132774 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132775 File
    132776 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132777 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    132778 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    132779 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132780 File
    132781 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132782 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    132783 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    132784 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132785 File
    132786 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132787 packages/chimerax/graphics/drawing.py", line 1108, in
    132788 _first_intercept_excluding_children 
    132789 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    132790 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132791 File
    132792 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132793 packages/chimerax/geometry/place.py", line 201, in inverse 
    132794 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    132795 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132796 File
    132797 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132798 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    132799 rinv[:, :] = matrix_inverse(r) 
    132800 ^^^^^^^^^^^^^^^^^ 
    132801 File
    132802 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132803 packages/numpy/linalg/linalg.py", line 561, in inv 
    132804 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    132805 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132806 File
    132807 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132808 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    132809 raise LinAlgError("Singular matrix") 
    132810 numpy.linalg.LinAlgError: Singular matrix 
    132811  
    132812 numpy.linalg.LinAlgError: Singular matrix 
    132813  
    132814 File
    132815 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132816 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    132817 raise LinAlgError("Singular matrix") 
    132818  
    132819 See log for complete Python traceback. 
    132820  
    132821 Traceback (most recent call last): 
    132822 File
    132823 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132824 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    132825 self.session.ui.mouse_modes.mouse_pause_tracking() 
    132826 File
    132827 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132828 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    132829 mouse_pause_tracking 
    132830 self._mouse_pause() 
    132831 File
    132832 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132833 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    132834 m.pause(self._mouse_pause_position) 
    132835 File
    132836 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132837 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    132838 p = self.view.picked_object(x, y) 
    132839 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132840 File
    132841 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132842 packages/chimerax/graphics/view.py", line 838, in picked_object 
    132843 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    132844 beyond, 
    132845 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132846 File
    132847 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132848 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    132849 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    132850 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132851 File
    132852 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132853 packages/chimerax/core/models.py", line 143, in first_intercept 
    132854 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    132855 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132856 File
    132857 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132858 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    132859 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    132860 exclude=exclude) 
    132861 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132862 File
    132863 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132864 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    132865 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    132866 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132867 File
    132868 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132869 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    132870 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    132871 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132872 File
    132873 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132874 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    132875 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    132876 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132877 File
    132878 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132879 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    132880 p = super().first_intercept(mxyz1, mxyz2) 
    132881 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132882 File
    132883 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132884 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    132885 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    132886 exclude=exclude) 
    132887 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132888 File
    132889 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132890 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    132891 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    132892 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132893 File
    132894 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132895 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    132896 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    132897 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132898 File
    132899 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132900 packages/chimerax/graphics/drawing.py", line 1108, in
    132901 _first_intercept_excluding_children 
    132902 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    132903 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132904 File
    132905 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132906 packages/chimerax/geometry/place.py", line 201, in inverse 
    132907 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    132908 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132909 File
    132910 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132911 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    132912 rinv[:, :] = matrix_inverse(r) 
    132913 ^^^^^^^^^^^^^^^^^ 
    132914 File
    132915 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132916 packages/numpy/linalg/linalg.py", line 561, in inv 
    132917 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    132918 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132919 File
    132920 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132921 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    132922 raise LinAlgError("Singular matrix") 
    132923 numpy.linalg.LinAlgError: Singular matrix 
    132924  
    132925 numpy.linalg.LinAlgError: Singular matrix 
    132926  
    132927 File
    132928 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132929 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    132930 raise LinAlgError("Singular matrix") 
    132931  
    132932 See log for complete Python traceback. 
    132933  
    132934 Traceback (most recent call last): 
    132935 File
    132936 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132937 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    132938 self.session.ui.mouse_modes.mouse_pause_tracking() 
    132939 File
    132940 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132941 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    132942 mouse_pause_tracking 
    132943 self._mouse_pause() 
    132944 File
    132945 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132946 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    132947 m.pause(self._mouse_pause_position) 
    132948 File
    132949 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132950 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    132951 p = self.view.picked_object(x, y) 
    132952 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132953 File
    132954 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132955 packages/chimerax/graphics/view.py", line 838, in picked_object 
    132956 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    132957 beyond, 
    132958 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132959 File
    132960 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132961 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    132962 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    132963 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132964 File
    132965 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132966 packages/chimerax/core/models.py", line 143, in first_intercept 
    132967 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    132968 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132969 File
    132970 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132971 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    132972 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    132973 exclude=exclude) 
    132974 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132975 File
    132976 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132977 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    132978 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    132979 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132980 File
    132981 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132982 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    132983 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    132984 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132985 File
    132986 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132987 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    132988 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    132989 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132990 File
    132991 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132992 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    132993 p = super().first_intercept(mxyz1, mxyz2) 
    132994 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    132995 File
    132996 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    132997 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    132998 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    132999 exclude=exclude) 
    133000 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133001 File
    133002 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133003 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    133004 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    133005 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133006 File
    133007 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133008 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    133009 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    133010 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133011 File
    133012 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133013 packages/chimerax/graphics/drawing.py", line 1108, in
    133014 _first_intercept_excluding_children 
    133015 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    133016 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133017 File
    133018 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133019 packages/chimerax/geometry/place.py", line 201, in inverse 
    133020 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    133021 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133022 File
    133023 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133024 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    133025 rinv[:, :] = matrix_inverse(r) 
    133026 ^^^^^^^^^^^^^^^^^ 
    133027 File
    133028 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133029 packages/numpy/linalg/linalg.py", line 561, in inv 
    133030 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    133031 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133032 File
    133033 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133034 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    133035 raise LinAlgError("Singular matrix") 
    133036 numpy.linalg.LinAlgError: Singular matrix 
    133037  
    133038 numpy.linalg.LinAlgError: Singular matrix 
    133039  
    133040 File
    133041 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133042 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    133043 raise LinAlgError("Singular matrix") 
    133044  
    133045 See log for complete Python traceback. 
    133046  
    133047 Traceback (most recent call last): 
    133048 File
    133049 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133050 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    133051 self.session.ui.mouse_modes.mouse_pause_tracking() 
    133052 File
    133053 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133054 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    133055 mouse_pause_tracking 
    133056 self._mouse_pause() 
    133057 File
    133058 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133059 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    133060 m.pause(self._mouse_pause_position) 
    133061 File
    133062 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133063 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    133064 p = self.view.picked_object(x, y) 
    133065 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133066 File
    133067 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133068 packages/chimerax/graphics/view.py", line 838, in picked_object 
    133069 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    133070 beyond, 
    133071 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133072 File
    133073 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133074 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    133075 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    133076 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133077 File
    133078 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133079 packages/chimerax/core/models.py", line 143, in first_intercept 
    133080 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    133081 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133082 File
    133083 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133084 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    133085 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    133086 exclude=exclude) 
    133087 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133088 File
    133089 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133090 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    133091 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    133092 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133093 File
    133094 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133095 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    133096 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    133097 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133098 File
    133099 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133100 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    133101 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    133102 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133103 File
    133104 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133105 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    133106 p = super().first_intercept(mxyz1, mxyz2) 
    133107 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133108 File
    133109 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133110 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    133111 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    133112 exclude=exclude) 
    133113 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133114 File
    133115 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133116 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    133117 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    133118 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133119 File
    133120 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133121 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    133122 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    133123 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133124 File
    133125 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133126 packages/chimerax/graphics/drawing.py", line 1108, in
    133127 _first_intercept_excluding_children 
    133128 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    133129 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133130 File
    133131 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133132 packages/chimerax/geometry/place.py", line 201, in inverse 
    133133 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    133134 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133135 File
    133136 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133137 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    133138 rinv[:, :] = matrix_inverse(r) 
    133139 ^^^^^^^^^^^^^^^^^ 
    133140 File
    133141 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133142 packages/numpy/linalg/linalg.py", line 561, in inv 
    133143 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    133144 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133145 File
    133146 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133147 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    133148 raise LinAlgError("Singular matrix") 
    133149 numpy.linalg.LinAlgError: Singular matrix 
    133150  
    133151 numpy.linalg.LinAlgError: Singular matrix 
    133152  
    133153 File
    133154 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133155 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    133156 raise LinAlgError("Singular matrix") 
    133157  
    133158 See log for complete Python traceback. 
    133159  
    133160 Traceback (most recent call last): 
    133161 File
    133162 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133163 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    133164 self.session.ui.mouse_modes.mouse_pause_tracking() 
    133165 File
    133166 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133167 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    133168 mouse_pause_tracking 
    133169 self._mouse_pause() 
    133170 File
    133171 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133172 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    133173 m.pause(self._mouse_pause_position) 
    133174 File
    133175 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133176 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    133177 p = self.view.picked_object(x, y) 
    133178 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133179 File
    133180 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133181 packages/chimerax/graphics/view.py", line 838, in picked_object 
    133182 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    133183 beyond, 
    133184 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133185 File
    133186 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133187 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    133188 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    133189 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133190 File
    133191 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133192 packages/chimerax/core/models.py", line 143, in first_intercept 
    133193 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    133194 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133195 File
    133196 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133197 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    133198 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    133199 exclude=exclude) 
    133200 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133201 File
    133202 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133203 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    133204 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    133205 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133206 File
    133207 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133208 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    133209 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    133210 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133211 File
    133212 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133213 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    133214 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    133215 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133216 File
    133217 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133218 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    133219 p = super().first_intercept(mxyz1, mxyz2) 
    133220 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133221 File
    133222 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133223 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    133224 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    133225 exclude=exclude) 
    133226 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133227 File
    133228 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133229 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    133230 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    133231 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133232 File
    133233 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133234 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    133235 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    133236 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133237 File
    133238 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133239 packages/chimerax/graphics/drawing.py", line 1108, in
    133240 _first_intercept_excluding_children 
    133241 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    133242 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133243 File
    133244 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133245 packages/chimerax/geometry/place.py", line 201, in inverse 
    133246 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    133247 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133248 File
    133249 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133250 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    133251 rinv[:, :] = matrix_inverse(r) 
    133252 ^^^^^^^^^^^^^^^^^ 
    133253 File
    133254 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133255 packages/numpy/linalg/linalg.py", line 561, in inv 
    133256 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    133257 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133258 File
    133259 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133260 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    133261 raise LinAlgError("Singular matrix") 
    133262 numpy.linalg.LinAlgError: Singular matrix 
    133263  
    133264 numpy.linalg.LinAlgError: Singular matrix 
    133265  
    133266 File
    133267 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133268 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    133269 raise LinAlgError("Singular matrix") 
    133270  
    133271 See log for complete Python traceback. 
    133272  
    133273 Traceback (most recent call last): 
    133274 File
    133275 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133276 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    133277 self.session.ui.mouse_modes.mouse_pause_tracking() 
    133278 File
    133279 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133280 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    133281 mouse_pause_tracking 
    133282 self._mouse_pause() 
    133283 File
    133284 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133285 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    133286 m.pause(self._mouse_pause_position) 
    133287 File
    133288 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133289 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    133290 p = self.view.picked_object(x, y) 
    133291 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133292 File
    133293 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133294 packages/chimerax/graphics/view.py", line 838, in picked_object 
    133295 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    133296 beyond, 
    133297 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133298 File
    133299 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133300 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    133301 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    133302 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133303 File
    133304 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133305 packages/chimerax/core/models.py", line 143, in first_intercept 
    133306 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    133307 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133308 File
    133309 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133310 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    133311 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    133312 exclude=exclude) 
    133313 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133314 File
    133315 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133316 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    133317 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    133318 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133319 File
    133320 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133321 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    133322 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    133323 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133324 File
    133325 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133326 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    133327 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    133328 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133329 File
    133330 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133331 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    133332 p = super().first_intercept(mxyz1, mxyz2) 
    133333 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133334 File
    133335 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133336 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    133337 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    133338 exclude=exclude) 
    133339 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133340 File
    133341 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133342 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    133343 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    133344 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133345 File
    133346 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133347 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    133348 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    133349 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133350 File
    133351 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133352 packages/chimerax/graphics/drawing.py", line 1108, in
    133353 _first_intercept_excluding_children 
    133354 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    133355 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133356 File
    133357 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133358 packages/chimerax/geometry/place.py", line 201, in inverse 
    133359 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    133360 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133361 File
    133362 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133363 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    133364 rinv[:, :] = matrix_inverse(r) 
    133365 ^^^^^^^^^^^^^^^^^ 
    133366 File
    133367 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133368 packages/numpy/linalg/linalg.py", line 561, in inv 
    133369 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    133370 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133371 File
    133372 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133373 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    133374 raise LinAlgError("Singular matrix") 
    133375 numpy.linalg.LinAlgError: Singular matrix 
    133376  
    133377 numpy.linalg.LinAlgError: Singular matrix 
    133378  
    133379 File
    133380 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133381 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    133382 raise LinAlgError("Singular matrix") 
    133383  
    133384 See log for complete Python traceback. 
    133385  
    133386 Traceback (most recent call last): 
    133387 File
    133388 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133389 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    133390 self.session.ui.mouse_modes.mouse_pause_tracking() 
    133391 File
    133392 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133393 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    133394 mouse_pause_tracking 
    133395 self._mouse_pause() 
    133396 File
    133397 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133398 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    133399 m.pause(self._mouse_pause_position) 
    133400 File
    133401 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133402 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    133403 p = self.view.picked_object(x, y) 
    133404 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133405 File
    133406 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133407 packages/chimerax/graphics/view.py", line 838, in picked_object 
    133408 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    133409 beyond, 
    133410 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133411 File
    133412 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133413 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    133414 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    133415 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133416 File
    133417 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133418 packages/chimerax/core/models.py", line 143, in first_intercept 
    133419 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    133420 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133421 File
    133422 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133423 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    133424 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    133425 exclude=exclude) 
    133426 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133427 File
    133428 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133429 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    133430 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    133431 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133432 File
    133433 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133434 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    133435 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    133436 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133437 File
    133438 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133439 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    133440 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    133441 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133442 File
    133443 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133444 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    133445 p = super().first_intercept(mxyz1, mxyz2) 
    133446 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133447 File
    133448 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133449 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    133450 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    133451 exclude=exclude) 
    133452 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133453 File
    133454 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133455 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    133456 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    133457 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133458 File
    133459 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133460 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    133461 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    133462 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133463 File
    133464 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133465 packages/chimerax/graphics/drawing.py", line 1108, in
    133466 _first_intercept_excluding_children 
    133467 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    133468 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133469 File
    133470 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133471 packages/chimerax/geometry/place.py", line 201, in inverse 
    133472 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    133473 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133474 File
    133475 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133476 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    133477 rinv[:, :] = matrix_inverse(r) 
    133478 ^^^^^^^^^^^^^^^^^ 
    133479 File
    133480 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133481 packages/numpy/linalg/linalg.py", line 561, in inv 
    133482 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    133483 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133484 File
    133485 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133486 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    133487 raise LinAlgError("Singular matrix") 
    133488 numpy.linalg.LinAlgError: Singular matrix 
    133489  
    133490 numpy.linalg.LinAlgError: Singular matrix 
    133491  
    133492 File
    133493 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133494 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    133495 raise LinAlgError("Singular matrix") 
    133496  
    133497 See log for complete Python traceback. 
    133498  
    133499 Traceback (most recent call last): 
    133500 File
    133501 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133502 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    133503 self.session.ui.mouse_modes.mouse_pause_tracking() 
    133504 File
    133505 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133506 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    133507 mouse_pause_tracking 
    133508 self._mouse_pause() 
    133509 File
    133510 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133511 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    133512 m.pause(self._mouse_pause_position) 
    133513 File
    133514 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133515 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    133516 p = self.view.picked_object(x, y) 
    133517 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133518 File
    133519 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133520 packages/chimerax/graphics/view.py", line 838, in picked_object 
    133521 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    133522 beyond, 
    133523 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133524 File
    133525 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133526 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    133527 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    133528 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133529 File
    133530 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133531 packages/chimerax/core/models.py", line 143, in first_intercept 
    133532 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    133533 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133534 File
    133535 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133536 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    133537 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    133538 exclude=exclude) 
    133539 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133540 File
    133541 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133542 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    133543 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    133544 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133545 File
    133546 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133547 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    133548 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    133549 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133550 File
    133551 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133552 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    133553 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    133554 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133555 File
    133556 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133557 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    133558 p = super().first_intercept(mxyz1, mxyz2) 
    133559 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133560 File
    133561 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133562 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    133563 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    133564 exclude=exclude) 
    133565 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133566 File
    133567 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133568 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    133569 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    133570 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133571 File
    133572 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133573 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    133574 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    133575 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133576 File
    133577 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133578 packages/chimerax/graphics/drawing.py", line 1108, in
    133579 _first_intercept_excluding_children 
    133580 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    133581 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133582 File
    133583 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133584 packages/chimerax/geometry/place.py", line 201, in inverse 
    133585 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    133586 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133587 File
    133588 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133589 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    133590 rinv[:, :] = matrix_inverse(r) 
    133591 ^^^^^^^^^^^^^^^^^ 
    133592 File
    133593 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133594 packages/numpy/linalg/linalg.py", line 561, in inv 
    133595 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    133596 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133597 File
    133598 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133599 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    133600 raise LinAlgError("Singular matrix") 
    133601 numpy.linalg.LinAlgError: Singular matrix 
    133602  
    133603 numpy.linalg.LinAlgError: Singular matrix 
    133604  
    133605 File
    133606 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133607 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    133608 raise LinAlgError("Singular matrix") 
    133609  
    133610 See log for complete Python traceback. 
    133611  
    133612 Traceback (most recent call last): 
    133613 File
    133614 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133615 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    133616 self.session.ui.mouse_modes.mouse_pause_tracking() 
    133617 File
    133618 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133619 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    133620 mouse_pause_tracking 
    133621 self._mouse_pause() 
    133622 File
    133623 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133624 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    133625 m.pause(self._mouse_pause_position) 
    133626 File
    133627 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133628 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    133629 p = self.view.picked_object(x, y) 
    133630 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133631 File
    133632 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133633 packages/chimerax/graphics/view.py", line 838, in picked_object 
    133634 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    133635 beyond, 
    133636 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133637 File
    133638 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133639 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    133640 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    133641 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133642 File
    133643 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133644 packages/chimerax/core/models.py", line 143, in first_intercept 
    133645 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    133646 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133647 File
    133648 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133649 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    133650 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    133651 exclude=exclude) 
    133652 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133653 File
    133654 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133655 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    133656 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    133657 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133658 File
    133659 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133660 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    133661 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    133662 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133663 File
    133664 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133665 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    133666 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    133667 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133668 File
    133669 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133670 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    133671 p = super().first_intercept(mxyz1, mxyz2) 
    133672 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133673 File
    133674 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133675 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    133676 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    133677 exclude=exclude) 
    133678 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133679 File
    133680 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133681 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    133682 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    133683 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133684 File
    133685 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133686 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    133687 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    133688 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133689 File
    133690 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133691 packages/chimerax/graphics/drawing.py", line 1108, in
    133692 _first_intercept_excluding_children 
    133693 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    133694 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133695 File
    133696 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133697 packages/chimerax/geometry/place.py", line 201, in inverse 
    133698 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    133699 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133700 File
    133701 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133702 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    133703 rinv[:, :] = matrix_inverse(r) 
    133704 ^^^^^^^^^^^^^^^^^ 
    133705 File
    133706 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133707 packages/numpy/linalg/linalg.py", line 561, in inv 
    133708 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    133709 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133710 File
    133711 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133712 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    133713 raise LinAlgError("Singular matrix") 
    133714 numpy.linalg.LinAlgError: Singular matrix 
    133715  
    133716 numpy.linalg.LinAlgError: Singular matrix 
    133717  
    133718 File
    133719 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133720 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    133721 raise LinAlgError("Singular matrix") 
    133722  
    133723 See log for complete Python traceback. 
    133724  
    133725 Traceback (most recent call last): 
    133726 File
    133727 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133728 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    133729 self.session.ui.mouse_modes.mouse_pause_tracking() 
    133730 File
    133731 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133732 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    133733 mouse_pause_tracking 
    133734 self._mouse_pause() 
    133735 File
    133736 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133737 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    133738 m.pause(self._mouse_pause_position) 
    133739 File
    133740 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133741 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    133742 p = self.view.picked_object(x, y) 
    133743 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133744 File
    133745 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133746 packages/chimerax/graphics/view.py", line 838, in picked_object 
    133747 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    133748 beyond, 
    133749 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133750 File
    133751 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133752 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    133753 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    133754 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133755 File
    133756 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133757 packages/chimerax/core/models.py", line 143, in first_intercept 
    133758 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    133759 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133760 File
    133761 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133762 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    133763 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    133764 exclude=exclude) 
    133765 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133766 File
    133767 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133768 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    133769 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    133770 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133771 File
    133772 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133773 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    133774 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    133775 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133776 File
    133777 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133778 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    133779 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    133780 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133781 File
    133782 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133783 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    133784 p = super().first_intercept(mxyz1, mxyz2) 
    133785 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133786 File
    133787 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133788 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    133789 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    133790 exclude=exclude) 
    133791 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133792 File
    133793 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133794 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    133795 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    133796 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133797 File
    133798 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133799 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    133800 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    133801 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133802 File
    133803 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133804 packages/chimerax/graphics/drawing.py", line 1108, in
    133805 _first_intercept_excluding_children 
    133806 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    133807 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133808 File
    133809 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133810 packages/chimerax/geometry/place.py", line 201, in inverse 
    133811 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    133812 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133813 File
    133814 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133815 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    133816 rinv[:, :] = matrix_inverse(r) 
    133817 ^^^^^^^^^^^^^^^^^ 
    133818 File
    133819 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133820 packages/numpy/linalg/linalg.py", line 561, in inv 
    133821 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    133822 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133823 File
    133824 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133825 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    133826 raise LinAlgError("Singular matrix") 
    133827 numpy.linalg.LinAlgError: Singular matrix 
    133828  
    133829 numpy.linalg.LinAlgError: Singular matrix 
    133830  
    133831 File
    133832 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133833 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    133834 raise LinAlgError("Singular matrix") 
    133835  
    133836 See log for complete Python traceback. 
    133837  
    133838 Traceback (most recent call last): 
    133839 File
    133840 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133841 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    133842 self.session.ui.mouse_modes.mouse_pause_tracking() 
    133843 File
    133844 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133845 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    133846 mouse_pause_tracking 
    133847 self._mouse_pause() 
    133848 File
    133849 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133850 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    133851 m.pause(self._mouse_pause_position) 
    133852 File
    133853 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133854 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    133855 p = self.view.picked_object(x, y) 
    133856 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133857 File
    133858 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133859 packages/chimerax/graphics/view.py", line 838, in picked_object 
    133860 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    133861 beyond, 
    133862 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133863 File
    133864 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133865 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    133866 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    133867 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133868 File
    133869 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133870 packages/chimerax/core/models.py", line 143, in first_intercept 
    133871 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    133872 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133873 File
    133874 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133875 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    133876 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    133877 exclude=exclude) 
    133878 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133879 File
    133880 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133881 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    133882 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    133883 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133884 File
    133885 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133886 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    133887 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    133888 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133889 File
    133890 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133891 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    133892 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    133893 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133894 File
    133895 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133896 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    133897 p = super().first_intercept(mxyz1, mxyz2) 
    133898 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133899 File
    133900 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133901 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    133902 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    133903 exclude=exclude) 
    133904 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133905 File
    133906 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133907 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    133908 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    133909 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133910 File
    133911 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133912 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    133913 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    133914 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133915 File
    133916 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133917 packages/chimerax/graphics/drawing.py", line 1108, in
    133918 _first_intercept_excluding_children 
    133919 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    133920 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133921 File
    133922 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133923 packages/chimerax/geometry/place.py", line 201, in inverse 
    133924 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    133925 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133926 File
    133927 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133928 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    133929 rinv[:, :] = matrix_inverse(r) 
    133930 ^^^^^^^^^^^^^^^^^ 
    133931 File
    133932 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133933 packages/numpy/linalg/linalg.py", line 561, in inv 
    133934 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    133935 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133936 File
    133937 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133938 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    133939 raise LinAlgError("Singular matrix") 
    133940 numpy.linalg.LinAlgError: Singular matrix 
    133941  
    133942 numpy.linalg.LinAlgError: Singular matrix 
    133943  
    133944 File
    133945 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133946 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    133947 raise LinAlgError("Singular matrix") 
    133948  
    133949 See log for complete Python traceback. 
    133950  
    133951 Traceback (most recent call last): 
    133952 File
    133953 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133954 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    133955 self.session.ui.mouse_modes.mouse_pause_tracking() 
    133956 File
    133957 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133958 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    133959 mouse_pause_tracking 
    133960 self._mouse_pause() 
    133961 File
    133962 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133963 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    133964 m.pause(self._mouse_pause_position) 
    133965 File
    133966 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133967 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    133968 p = self.view.picked_object(x, y) 
    133969 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133970 File
    133971 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133972 packages/chimerax/graphics/view.py", line 838, in picked_object 
    133973 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    133974 beyond, 
    133975 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133976 File
    133977 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133978 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    133979 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    133980 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133981 File
    133982 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133983 packages/chimerax/core/models.py", line 143, in first_intercept 
    133984 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    133985 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133986 File
    133987 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133988 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    133989 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    133990 exclude=exclude) 
    133991 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133992 File
    133993 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133994 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    133995 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    133996 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    133997 File
    133998 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    133999 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    134000 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    134001 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134002 File
    134003 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134004 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    134005 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    134006 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134007 File
    134008 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134009 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    134010 p = super().first_intercept(mxyz1, mxyz2) 
    134011 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134012 File
    134013 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134014 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    134015 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    134016 exclude=exclude) 
    134017 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134018 File
    134019 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134020 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    134021 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    134022 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134023 File
    134024 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134025 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    134026 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    134027 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134028 File
    134029 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134030 packages/chimerax/graphics/drawing.py", line 1108, in
    134031 _first_intercept_excluding_children 
    134032 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    134033 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134034 File
    134035 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134036 packages/chimerax/geometry/place.py", line 201, in inverse 
    134037 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    134038 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134039 File
    134040 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134041 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    134042 rinv[:, :] = matrix_inverse(r) 
    134043 ^^^^^^^^^^^^^^^^^ 
    134044 File
    134045 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134046 packages/numpy/linalg/linalg.py", line 561, in inv 
    134047 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    134048 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134049 File
    134050 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134051 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    134052 raise LinAlgError("Singular matrix") 
    134053 numpy.linalg.LinAlgError: Singular matrix 
    134054  
    134055 numpy.linalg.LinAlgError: Singular matrix 
    134056  
    134057 File
    134058 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134059 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    134060 raise LinAlgError("Singular matrix") 
    134061  
    134062 See log for complete Python traceback. 
    134063  
    134064 Traceback (most recent call last): 
    134065 File
    134066 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134067 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    134068 self.session.ui.mouse_modes.mouse_pause_tracking() 
    134069 File
    134070 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134071 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    134072 mouse_pause_tracking 
    134073 self._mouse_pause() 
    134074 File
    134075 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134076 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    134077 m.pause(self._mouse_pause_position) 
    134078 File
    134079 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134080 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    134081 p = self.view.picked_object(x, y) 
    134082 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134083 File
    134084 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134085 packages/chimerax/graphics/view.py", line 838, in picked_object 
    134086 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    134087 beyond, 
    134088 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134089 File
    134090 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134091 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    134092 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    134093 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134094 File
    134095 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134096 packages/chimerax/core/models.py", line 143, in first_intercept 
    134097 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    134098 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134099 File
    134100 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134101 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    134102 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    134103 exclude=exclude) 
    134104 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134105 File
    134106 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134107 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    134108 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    134109 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134110 File
    134111 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134112 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    134113 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    134114 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134115 File
    134116 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134117 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    134118 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    134119 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134120 File
    134121 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134122 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    134123 p = super().first_intercept(mxyz1, mxyz2) 
    134124 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134125 File
    134126 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134127 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    134128 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    134129 exclude=exclude) 
    134130 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134131 File
    134132 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134133 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    134134 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    134135 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134136 File
    134137 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134138 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    134139 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    134140 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134141 File
    134142 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134143 packages/chimerax/graphics/drawing.py", line 1108, in
    134144 _first_intercept_excluding_children 
    134145 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    134146 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134147 File
    134148 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134149 packages/chimerax/geometry/place.py", line 201, in inverse 
    134150 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    134151 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134152 File
    134153 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134154 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    134155 rinv[:, :] = matrix_inverse(r) 
    134156 ^^^^^^^^^^^^^^^^^ 
    134157 File
    134158 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134159 packages/numpy/linalg/linalg.py", line 561, in inv 
    134160 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    134161 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134162 File
    134163 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134164 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    134165 raise LinAlgError("Singular matrix") 
    134166 numpy.linalg.LinAlgError: Singular matrix 
    134167  
    134168 numpy.linalg.LinAlgError: Singular matrix 
    134169  
    134170 File
    134171 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134172 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    134173 raise LinAlgError("Singular matrix") 
    134174  
    134175 See log for complete Python traceback. 
    134176  
    134177 Traceback (most recent call last): 
    134178 File
    134179 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134180 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    134181 self.session.ui.mouse_modes.mouse_pause_tracking() 
    134182 File
    134183 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134184 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    134185 mouse_pause_tracking 
    134186 self._mouse_pause() 
    134187 File
    134188 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134189 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    134190 m.pause(self._mouse_pause_position) 
    134191 File
    134192 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134193 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    134194 p = self.view.picked_object(x, y) 
    134195 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134196 File
    134197 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134198 packages/chimerax/graphics/view.py", line 838, in picked_object 
    134199 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    134200 beyond, 
    134201 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134202 File
    134203 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134204 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    134205 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    134206 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134207 File
    134208 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134209 packages/chimerax/core/models.py", line 143, in first_intercept 
    134210 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    134211 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134212 File
    134213 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134214 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    134215 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    134216 exclude=exclude) 
    134217 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134218 File
    134219 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134220 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    134221 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    134222 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134223 File
    134224 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134225 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    134226 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    134227 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134228 File
    134229 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134230 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    134231 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    134232 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134233 File
    134234 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134235 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    134236 p = super().first_intercept(mxyz1, mxyz2) 
    134237 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134238 File
    134239 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134240 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    134241 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    134242 exclude=exclude) 
    134243 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134244 File
    134245 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134246 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    134247 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    134248 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134249 File
    134250 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134251 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    134252 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    134253 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134254 File
    134255 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134256 packages/chimerax/graphics/drawing.py", line 1108, in
    134257 _first_intercept_excluding_children 
    134258 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    134259 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134260 File
    134261 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134262 packages/chimerax/geometry/place.py", line 201, in inverse 
    134263 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    134264 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134265 File
    134266 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134267 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    134268 rinv[:, :] = matrix_inverse(r) 
    134269 ^^^^^^^^^^^^^^^^^ 
    134270 File
    134271 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134272 packages/numpy/linalg/linalg.py", line 561, in inv 
    134273 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    134274 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134275 File
    134276 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134277 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    134278 raise LinAlgError("Singular matrix") 
    134279 numpy.linalg.LinAlgError: Singular matrix 
    134280  
    134281 numpy.linalg.LinAlgError: Singular matrix 
    134282  
    134283 File
    134284 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134285 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    134286 raise LinAlgError("Singular matrix") 
    134287  
    134288 See log for complete Python traceback. 
    134289  
    134290 Traceback (most recent call last): 
    134291 File
    134292 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134293 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    134294 self.session.ui.mouse_modes.mouse_pause_tracking() 
    134295 File
    134296 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134297 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    134298 mouse_pause_tracking 
    134299 self._mouse_pause() 
    134300 File
    134301 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134302 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    134303 m.pause(self._mouse_pause_position) 
    134304 File
    134305 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134306 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    134307 p = self.view.picked_object(x, y) 
    134308 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134309 File
    134310 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134311 packages/chimerax/graphics/view.py", line 838, in picked_object 
    134312 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    134313 beyond, 
    134314 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134315 File
    134316 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134317 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    134318 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    134319 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134320 File
    134321 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134322 packages/chimerax/core/models.py", line 143, in first_intercept 
    134323 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    134324 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134325 File
    134326 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134327 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    134328 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    134329 exclude=exclude) 
    134330 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134331 File
    134332 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134333 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    134334 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    134335 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134336 File
    134337 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134338 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    134339 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    134340 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134341 File
    134342 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134343 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    134344 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    134345 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134346 File
    134347 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134348 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    134349 p = super().first_intercept(mxyz1, mxyz2) 
    134350 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134351 File
    134352 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134353 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    134354 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    134355 exclude=exclude) 
    134356 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134357 File
    134358 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134359 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    134360 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    134361 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134362 File
    134363 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134364 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    134365 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    134366 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134367 File
    134368 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134369 packages/chimerax/graphics/drawing.py", line 1108, in
    134370 _first_intercept_excluding_children 
    134371 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    134372 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134373 File
    134374 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134375 packages/chimerax/geometry/place.py", line 201, in inverse 
    134376 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    134377 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134378 File
    134379 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134380 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    134381 rinv[:, :] = matrix_inverse(r) 
    134382 ^^^^^^^^^^^^^^^^^ 
    134383 File
    134384 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134385 packages/numpy/linalg/linalg.py", line 561, in inv 
    134386 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    134387 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134388 File
    134389 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134390 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    134391 raise LinAlgError("Singular matrix") 
    134392 numpy.linalg.LinAlgError: Singular matrix 
    134393  
    134394 numpy.linalg.LinAlgError: Singular matrix 
    134395  
    134396 File
    134397 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134398 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    134399 raise LinAlgError("Singular matrix") 
    134400  
    134401 See log for complete Python traceback. 
    134402  
    134403 Traceback (most recent call last): 
    134404 File
    134405 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134406 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    134407 self.session.ui.mouse_modes.mouse_pause_tracking() 
    134408 File
    134409 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134410 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    134411 mouse_pause_tracking 
    134412 self._mouse_pause() 
    134413 File
    134414 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134415 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    134416 m.pause(self._mouse_pause_position) 
    134417 File
    134418 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134419 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    134420 p = self.view.picked_object(x, y) 
    134421 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134422 File
    134423 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134424 packages/chimerax/graphics/view.py", line 838, in picked_object 
    134425 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    134426 beyond, 
    134427 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134428 File
    134429 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134430 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    134431 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    134432 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134433 File
    134434 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134435 packages/chimerax/core/models.py", line 143, in first_intercept 
    134436 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    134437 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134438 File
    134439 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134440 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    134441 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    134442 exclude=exclude) 
    134443 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134444 File
    134445 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134446 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    134447 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    134448 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134449 File
    134450 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134451 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    134452 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    134453 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134454 File
    134455 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134456 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    134457 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    134458 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134459 File
    134460 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134461 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    134462 p = super().first_intercept(mxyz1, mxyz2) 
    134463 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134464 File
    134465 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134466 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    134467 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    134468 exclude=exclude) 
    134469 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134470 File
    134471 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134472 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    134473 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    134474 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134475 File
    134476 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134477 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    134478 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    134479 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134480 File
    134481 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134482 packages/chimerax/graphics/drawing.py", line 1108, in
    134483 _first_intercept_excluding_children 
    134484 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    134485 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134486 File
    134487 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134488 packages/chimerax/geometry/place.py", line 201, in inverse 
    134489 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    134490 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134491 File
    134492 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134493 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    134494 rinv[:, :] = matrix_inverse(r) 
    134495 ^^^^^^^^^^^^^^^^^ 
    134496 File
    134497 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134498 packages/numpy/linalg/linalg.py", line 561, in inv 
    134499 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    134500 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134501 File
    134502 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134503 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    134504 raise LinAlgError("Singular matrix") 
    134505 numpy.linalg.LinAlgError: Singular matrix 
    134506  
    134507 numpy.linalg.LinAlgError: Singular matrix 
    134508  
    134509 File
    134510 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134511 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    134512 raise LinAlgError("Singular matrix") 
    134513  
    134514 See log for complete Python traceback. 
    134515  
    134516 Traceback (most recent call last): 
    134517 File
    134518 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134519 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    134520 self.session.ui.mouse_modes.mouse_pause_tracking() 
    134521 File
    134522 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134523 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    134524 mouse_pause_tracking 
    134525 self._mouse_pause() 
    134526 File
    134527 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134528 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    134529 m.pause(self._mouse_pause_position) 
    134530 File
    134531 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134532 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    134533 p = self.view.picked_object(x, y) 
    134534 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134535 File
    134536 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134537 packages/chimerax/graphics/view.py", line 838, in picked_object 
    134538 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    134539 beyond, 
    134540 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134541 File
    134542 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134543 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    134544 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    134545 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134546 File
    134547 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134548 packages/chimerax/core/models.py", line 143, in first_intercept 
    134549 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    134550 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134551 File
    134552 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134553 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    134554 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    134555 exclude=exclude) 
    134556 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134557 File
    134558 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134559 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    134560 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    134561 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134562 File
    134563 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134564 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    134565 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    134566 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134567 File
    134568 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134569 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    134570 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    134571 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134572 File
    134573 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134574 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    134575 p = super().first_intercept(mxyz1, mxyz2) 
    134576 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134577 File
    134578 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134579 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    134580 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    134581 exclude=exclude) 
    134582 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134583 File
    134584 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134585 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    134586 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    134587 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134588 File
    134589 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134590 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    134591 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    134592 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134593 File
    134594 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134595 packages/chimerax/graphics/drawing.py", line 1108, in
    134596 _first_intercept_excluding_children 
    134597 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    134598 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134599 File
    134600 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134601 packages/chimerax/geometry/place.py", line 201, in inverse 
    134602 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    134603 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134604 File
    134605 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134606 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    134607 rinv[:, :] = matrix_inverse(r) 
    134608 ^^^^^^^^^^^^^^^^^ 
    134609 File
    134610 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134611 packages/numpy/linalg/linalg.py", line 561, in inv 
    134612 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    134613 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134614 File
    134615 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134616 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    134617 raise LinAlgError("Singular matrix") 
    134618 numpy.linalg.LinAlgError: Singular matrix 
    134619  
    134620 numpy.linalg.LinAlgError: Singular matrix 
    134621  
    134622 File
    134623 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134624 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    134625 raise LinAlgError("Singular matrix") 
    134626  
    134627 See log for complete Python traceback. 
    134628  
    134629 Traceback (most recent call last): 
    134630 File
    134631 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134632 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    134633 self.session.ui.mouse_modes.mouse_pause_tracking() 
    134634 File
    134635 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134636 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    134637 mouse_pause_tracking 
    134638 self._mouse_pause() 
    134639 File
    134640 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134641 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    134642 m.pause(self._mouse_pause_position) 
    134643 File
    134644 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134645 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    134646 p = self.view.picked_object(x, y) 
    134647 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134648 File
    134649 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134650 packages/chimerax/graphics/view.py", line 838, in picked_object 
    134651 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    134652 beyond, 
    134653 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134654 File
    134655 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134656 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    134657 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    134658 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134659 File
    134660 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134661 packages/chimerax/core/models.py", line 143, in first_intercept 
    134662 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    134663 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134664 File
    134665 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134666 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    134667 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    134668 exclude=exclude) 
    134669 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134670 File
    134671 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134672 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    134673 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    134674 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134675 File
    134676 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134677 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    134678 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    134679 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134680 File
    134681 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134682 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    134683 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    134684 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134685 File
    134686 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134687 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    134688 p = super().first_intercept(mxyz1, mxyz2) 
    134689 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134690 File
    134691 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134692 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    134693 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    134694 exclude=exclude) 
    134695 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134696 File
    134697 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134698 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    134699 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    134700 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134701 File
    134702 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134703 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    134704 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    134705 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134706 File
    134707 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134708 packages/chimerax/graphics/drawing.py", line 1108, in
    134709 _first_intercept_excluding_children 
    134710 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    134711 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134712 File
    134713 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134714 packages/chimerax/geometry/place.py", line 201, in inverse 
    134715 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    134716 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134717 File
    134718 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134719 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    134720 rinv[:, :] = matrix_inverse(r) 
    134721 ^^^^^^^^^^^^^^^^^ 
    134722 File
    134723 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134724 packages/numpy/linalg/linalg.py", line 561, in inv 
    134725 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    134726 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134727 File
    134728 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134729 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    134730 raise LinAlgError("Singular matrix") 
    134731 numpy.linalg.LinAlgError: Singular matrix 
    134732  
    134733 numpy.linalg.LinAlgError: Singular matrix 
    134734  
    134735 File
    134736 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134737 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    134738 raise LinAlgError("Singular matrix") 
    134739  
    134740 See log for complete Python traceback. 
    134741  
    134742 Traceback (most recent call last): 
    134743 File
    134744 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134745 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    134746 self.session.ui.mouse_modes.mouse_pause_tracking() 
    134747 File
    134748 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134749 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    134750 mouse_pause_tracking 
    134751 self._mouse_pause() 
    134752 File
    134753 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134754 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    134755 m.pause(self._mouse_pause_position) 
    134756 File
    134757 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134758 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    134759 p = self.view.picked_object(x, y) 
    134760 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134761 File
    134762 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134763 packages/chimerax/graphics/view.py", line 838, in picked_object 
    134764 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    134765 beyond, 
    134766 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134767 File
    134768 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134769 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    134770 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    134771 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134772 File
    134773 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134774 packages/chimerax/core/models.py", line 143, in first_intercept 
    134775 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    134776 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134777 File
    134778 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134779 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    134780 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    134781 exclude=exclude) 
    134782 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134783 File
    134784 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134785 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    134786 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    134787 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134788 File
    134789 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134790 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    134791 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    134792 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134793 File
    134794 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134795 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    134796 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    134797 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134798 File
    134799 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134800 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    134801 p = super().first_intercept(mxyz1, mxyz2) 
    134802 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134803 File
    134804 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134805 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    134806 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    134807 exclude=exclude) 
    134808 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134809 File
    134810 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134811 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    134812 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    134813 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134814 File
    134815 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134816 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    134817 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    134818 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134819 File
    134820 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134821 packages/chimerax/graphics/drawing.py", line 1108, in
    134822 _first_intercept_excluding_children 
    134823 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    134824 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134825 File
    134826 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134827 packages/chimerax/geometry/place.py", line 201, in inverse 
    134828 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    134829 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134830 File
    134831 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134832 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    134833 rinv[:, :] = matrix_inverse(r) 
    134834 ^^^^^^^^^^^^^^^^^ 
    134835 File
    134836 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134837 packages/numpy/linalg/linalg.py", line 561, in inv 
    134838 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    134839 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134840 File
    134841 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134842 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    134843 raise LinAlgError("Singular matrix") 
    134844 numpy.linalg.LinAlgError: Singular matrix 
    134845  
    134846 numpy.linalg.LinAlgError: Singular matrix 
    134847  
    134848 File
    134849 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134850 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    134851 raise LinAlgError("Singular matrix") 
    134852  
    134853 See log for complete Python traceback. 
    134854  
    134855 Traceback (most recent call last): 
    134856 File
    134857 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134858 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    134859 self.session.ui.mouse_modes.mouse_pause_tracking() 
    134860 File
    134861 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134862 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    134863 mouse_pause_tracking 
    134864 self._mouse_pause() 
    134865 File
    134866 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134867 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    134868 m.pause(self._mouse_pause_position) 
    134869 File
    134870 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134871 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    134872 p = self.view.picked_object(x, y) 
    134873 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134874 File
    134875 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134876 packages/chimerax/graphics/view.py", line 838, in picked_object 
    134877 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    134878 beyond, 
    134879 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134880 File
    134881 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134882 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    134883 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    134884 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134885 File
    134886 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134887 packages/chimerax/core/models.py", line 143, in first_intercept 
    134888 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    134889 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134890 File
    134891 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134892 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    134893 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    134894 exclude=exclude) 
    134895 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134896 File
    134897 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134898 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    134899 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    134900 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134901 File
    134902 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134903 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    134904 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    134905 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134906 File
    134907 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134908 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    134909 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    134910 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134911 File
    134912 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134913 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    134914 p = super().first_intercept(mxyz1, mxyz2) 
    134915 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134916 File
    134917 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134918 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    134919 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    134920 exclude=exclude) 
    134921 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134922 File
    134923 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134924 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    134925 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    134926 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134927 File
    134928 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134929 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    134930 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    134931 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134932 File
    134933 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134934 packages/chimerax/graphics/drawing.py", line 1108, in
    134935 _first_intercept_excluding_children 
    134936 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    134937 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134938 File
    134939 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134940 packages/chimerax/geometry/place.py", line 201, in inverse 
    134941 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    134942 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134943 File
    134944 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134945 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    134946 rinv[:, :] = matrix_inverse(r) 
    134947 ^^^^^^^^^^^^^^^^^ 
    134948 File
    134949 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134950 packages/numpy/linalg/linalg.py", line 561, in inv 
    134951 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    134952 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134953 File
    134954 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134955 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    134956 raise LinAlgError("Singular matrix") 
    134957 numpy.linalg.LinAlgError: Singular matrix 
    134958  
    134959 numpy.linalg.LinAlgError: Singular matrix 
    134960  
    134961 File
    134962 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134963 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    134964 raise LinAlgError("Singular matrix") 
    134965  
    134966 See log for complete Python traceback. 
    134967  
    134968 Traceback (most recent call last): 
    134969 File
    134970 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134971 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    134972 self.session.ui.mouse_modes.mouse_pause_tracking() 
    134973 File
    134974 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134975 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    134976 mouse_pause_tracking 
    134977 self._mouse_pause() 
    134978 File
    134979 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134980 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    134981 m.pause(self._mouse_pause_position) 
    134982 File
    134983 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134984 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    134985 p = self.view.picked_object(x, y) 
    134986 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134987 File
    134988 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134989 packages/chimerax/graphics/view.py", line 838, in picked_object 
    134990 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    134991 beyond, 
    134992 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134993 File
    134994 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    134995 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    134996 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    134997 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    134998 File
    134999 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135000 packages/chimerax/core/models.py", line 143, in first_intercept 
    135001 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    135002 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135003 File
    135004 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135005 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    135006 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    135007 exclude=exclude) 
    135008 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135009 File
    135010 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135011 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    135012 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    135013 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135014 File
    135015 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135016 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    135017 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    135018 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135019 File
    135020 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135021 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    135022 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    135023 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135024 File
    135025 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135026 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    135027 p = super().first_intercept(mxyz1, mxyz2) 
    135028 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135029 File
    135030 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135031 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    135032 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    135033 exclude=exclude) 
    135034 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135035 File
    135036 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135037 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    135038 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    135039 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135040 File
    135041 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135042 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    135043 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    135044 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135045 File
    135046 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135047 packages/chimerax/graphics/drawing.py", line 1108, in
    135048 _first_intercept_excluding_children 
    135049 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    135050 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135051 File
    135052 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135053 packages/chimerax/geometry/place.py", line 201, in inverse 
    135054 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    135055 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135056 File
    135057 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135058 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    135059 rinv[:, :] = matrix_inverse(r) 
    135060 ^^^^^^^^^^^^^^^^^ 
    135061 File
    135062 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135063 packages/numpy/linalg/linalg.py", line 561, in inv 
    135064 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    135065 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135066 File
    135067 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135068 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    135069 raise LinAlgError("Singular matrix") 
    135070 numpy.linalg.LinAlgError: Singular matrix 
    135071  
    135072 numpy.linalg.LinAlgError: Singular matrix 
    135073  
    135074 File
    135075 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135076 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    135077 raise LinAlgError("Singular matrix") 
    135078  
    135079 See log for complete Python traceback. 
    135080  
    135081 Traceback (most recent call last): 
    135082 File
    135083 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135084 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    135085 self.session.ui.mouse_modes.mouse_pause_tracking() 
    135086 File
    135087 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135088 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    135089 mouse_pause_tracking 
    135090 self._mouse_pause() 
    135091 File
    135092 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135093 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    135094 m.pause(self._mouse_pause_position) 
    135095 File
    135096 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135097 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    135098 p = self.view.picked_object(x, y) 
    135099 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135100 File
    135101 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135102 packages/chimerax/graphics/view.py", line 838, in picked_object 
    135103 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    135104 beyond, 
    135105 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135106 File
    135107 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135108 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    135109 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    135110 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135111 File
    135112 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135113 packages/chimerax/core/models.py", line 143, in first_intercept 
    135114 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    135115 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135116 File
    135117 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135118 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    135119 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    135120 exclude=exclude) 
    135121 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135122 File
    135123 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135124 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    135125 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    135126 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135127 File
    135128 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135129 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    135130 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    135131 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135132 File
    135133 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135134 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    135135 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    135136 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135137 File
    135138 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135139 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    135140 p = super().first_intercept(mxyz1, mxyz2) 
    135141 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135142 File
    135143 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135144 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    135145 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    135146 exclude=exclude) 
    135147 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135148 File
    135149 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135150 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    135151 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    135152 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135153 File
    135154 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135155 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    135156 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    135157 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135158 File
    135159 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135160 packages/chimerax/graphics/drawing.py", line 1108, in
    135161 _first_intercept_excluding_children 
    135162 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    135163 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135164 File
    135165 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135166 packages/chimerax/geometry/place.py", line 201, in inverse 
    135167 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    135168 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135169 File
    135170 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135171 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    135172 rinv[:, :] = matrix_inverse(r) 
    135173 ^^^^^^^^^^^^^^^^^ 
    135174 File
    135175 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135176 packages/numpy/linalg/linalg.py", line 561, in inv 
    135177 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    135178 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135179 File
    135180 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135181 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    135182 raise LinAlgError("Singular matrix") 
    135183 numpy.linalg.LinAlgError: Singular matrix 
    135184  
    135185 numpy.linalg.LinAlgError: Singular matrix 
    135186  
    135187 File
    135188 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135189 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    135190 raise LinAlgError("Singular matrix") 
    135191  
    135192 See log for complete Python traceback. 
    135193  
    135194 Traceback (most recent call last): 
    135195 File
    135196 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135197 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    135198 self.session.ui.mouse_modes.mouse_pause_tracking() 
    135199 File
    135200 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135201 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    135202 mouse_pause_tracking 
    135203 self._mouse_pause() 
    135204 File
    135205 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135206 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    135207 m.pause(self._mouse_pause_position) 
    135208 File
    135209 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135210 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    135211 p = self.view.picked_object(x, y) 
    135212 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135213 File
    135214 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135215 packages/chimerax/graphics/view.py", line 838, in picked_object 
    135216 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    135217 beyond, 
    135218 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135219 File
    135220 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135221 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    135222 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    135223 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135224 File
    135225 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135226 packages/chimerax/core/models.py", line 143, in first_intercept 
    135227 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    135228 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135229 File
    135230 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135231 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    135232 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    135233 exclude=exclude) 
    135234 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135235 File
    135236 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135237 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    135238 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    135239 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135240 File
    135241 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135242 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    135243 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    135244 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135245 File
    135246 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135247 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    135248 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    135249 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135250 File
    135251 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135252 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    135253 p = super().first_intercept(mxyz1, mxyz2) 
    135254 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135255 File
    135256 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135257 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    135258 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    135259 exclude=exclude) 
    135260 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135261 File
    135262 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135263 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    135264 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    135265 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135266 File
    135267 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135268 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    135269 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    135270 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135271 File
    135272 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135273 packages/chimerax/graphics/drawing.py", line 1108, in
    135274 _first_intercept_excluding_children 
    135275 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    135276 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135277 File
    135278 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135279 packages/chimerax/geometry/place.py", line 201, in inverse 
    135280 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    135281 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135282 File
    135283 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135284 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    135285 rinv[:, :] = matrix_inverse(r) 
    135286 ^^^^^^^^^^^^^^^^^ 
    135287 File
    135288 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135289 packages/numpy/linalg/linalg.py", line 561, in inv 
    135290 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    135291 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135292 File
    135293 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135294 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    135295 raise LinAlgError("Singular matrix") 
    135296 numpy.linalg.LinAlgError: Singular matrix 
    135297  
    135298 numpy.linalg.LinAlgError: Singular matrix 
    135299  
    135300 File
    135301 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135302 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    135303 raise LinAlgError("Singular matrix") 
    135304  
    135305 See log for complete Python traceback. 
    135306  
    135307 Traceback (most recent call last): 
    135308 File
    135309 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135310 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    135311 self.session.ui.mouse_modes.mouse_pause_tracking() 
    135312 File
    135313 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135314 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    135315 mouse_pause_tracking 
    135316 self._mouse_pause() 
    135317 File
    135318 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135319 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    135320 m.pause(self._mouse_pause_position) 
    135321 File
    135322 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135323 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    135324 p = self.view.picked_object(x, y) 
    135325 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135326 File
    135327 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135328 packages/chimerax/graphics/view.py", line 838, in picked_object 
    135329 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    135330 beyond, 
    135331 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135332 File
    135333 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135334 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    135335 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    135336 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135337 File
    135338 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135339 packages/chimerax/core/models.py", line 143, in first_intercept 
    135340 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    135341 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135342 File
    135343 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135344 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    135345 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    135346 exclude=exclude) 
    135347 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135348 File
    135349 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135350 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    135351 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    135352 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135353 File
    135354 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135355 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    135356 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    135357 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135358 File
    135359 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135360 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    135361 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    135362 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135363 File
    135364 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135365 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    135366 p = super().first_intercept(mxyz1, mxyz2) 
    135367 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135368 File
    135369 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135370 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    135371 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    135372 exclude=exclude) 
    135373 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135374 File
    135375 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135376 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    135377 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    135378 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135379 File
    135380 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135381 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    135382 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    135383 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135384 File
    135385 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135386 packages/chimerax/graphics/drawing.py", line 1108, in
    135387 _first_intercept_excluding_children 
    135388 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    135389 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135390 File
    135391 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135392 packages/chimerax/geometry/place.py", line 201, in inverse 
    135393 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    135394 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135395 File
    135396 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135397 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    135398 rinv[:, :] = matrix_inverse(r) 
    135399 ^^^^^^^^^^^^^^^^^ 
    135400 File
    135401 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135402 packages/numpy/linalg/linalg.py", line 561, in inv 
    135403 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    135404 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135405 File
    135406 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135407 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    135408 raise LinAlgError("Singular matrix") 
    135409 numpy.linalg.LinAlgError: Singular matrix 
    135410  
    135411 numpy.linalg.LinAlgError: Singular matrix 
    135412  
    135413 File
    135414 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135415 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    135416 raise LinAlgError("Singular matrix") 
    135417  
    135418 See log for complete Python traceback. 
    135419  
    135420 Traceback (most recent call last): 
    135421 File
    135422 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135423 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    135424 self.session.ui.mouse_modes.mouse_pause_tracking() 
    135425 File
    135426 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135427 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    135428 mouse_pause_tracking 
    135429 self._mouse_pause() 
    135430 File
    135431 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135432 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    135433 m.pause(self._mouse_pause_position) 
    135434 File
    135435 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135436 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    135437 p = self.view.picked_object(x, y) 
    135438 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135439 File
    135440 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135441 packages/chimerax/graphics/view.py", line 838, in picked_object 
    135442 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    135443 beyond, 
    135444 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135445 File
    135446 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135447 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    135448 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    135449 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135450 File
    135451 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135452 packages/chimerax/core/models.py", line 143, in first_intercept 
    135453 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    135454 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135455 File
    135456 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135457 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    135458 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    135459 exclude=exclude) 
    135460 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135461 File
    135462 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135463 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    135464 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    135465 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135466 File
    135467 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135468 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    135469 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    135470 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135471 File
    135472 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135473 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    135474 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    135475 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135476 File
    135477 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135478 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    135479 p = super().first_intercept(mxyz1, mxyz2) 
    135480 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135481 File
    135482 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135483 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    135484 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    135485 exclude=exclude) 
    135486 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135487 File
    135488 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135489 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    135490 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    135491 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135492 File
    135493 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135494 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    135495 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    135496 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135497 File
    135498 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135499 packages/chimerax/graphics/drawing.py", line 1108, in
    135500 _first_intercept_excluding_children 
    135501 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    135502 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135503 File
    135504 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135505 packages/chimerax/geometry/place.py", line 201, in inverse 
    135506 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    135507 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135508 File
    135509 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135510 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    135511 rinv[:, :] = matrix_inverse(r) 
    135512 ^^^^^^^^^^^^^^^^^ 
    135513 File
    135514 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135515 packages/numpy/linalg/linalg.py", line 561, in inv 
    135516 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    135517 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135518 File
    135519 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135520 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    135521 raise LinAlgError("Singular matrix") 
    135522 numpy.linalg.LinAlgError: Singular matrix 
    135523  
    135524 numpy.linalg.LinAlgError: Singular matrix 
    135525  
    135526 File
    135527 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135528 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    135529 raise LinAlgError("Singular matrix") 
    135530  
    135531 See log for complete Python traceback. 
    135532  
    135533 Traceback (most recent call last): 
    135534 File
    135535 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135536 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    135537 self.session.ui.mouse_modes.mouse_pause_tracking() 
    135538 File
    135539 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135540 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    135541 mouse_pause_tracking 
    135542 self._mouse_pause() 
    135543 File
    135544 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135545 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    135546 m.pause(self._mouse_pause_position) 
    135547 File
    135548 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135549 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    135550 p = self.view.picked_object(x, y) 
    135551 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135552 File
    135553 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135554 packages/chimerax/graphics/view.py", line 838, in picked_object 
    135555 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    135556 beyond, 
    135557 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135558 File
    135559 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135560 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    135561 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    135562 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135563 File
    135564 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135565 packages/chimerax/core/models.py", line 143, in first_intercept 
    135566 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    135567 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135568 File
    135569 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135570 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    135571 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    135572 exclude=exclude) 
    135573 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135574 File
    135575 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135576 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    135577 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    135578 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135579 File
    135580 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135581 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    135582 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    135583 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135584 File
    135585 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135586 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    135587 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    135588 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135589 File
    135590 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135591 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    135592 p = super().first_intercept(mxyz1, mxyz2) 
    135593 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135594 File
    135595 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135596 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    135597 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    135598 exclude=exclude) 
    135599 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135600 File
    135601 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135602 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    135603 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    135604 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135605 File
    135606 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135607 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    135608 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    135609 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135610 File
    135611 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135612 packages/chimerax/graphics/drawing.py", line 1108, in
    135613 _first_intercept_excluding_children 
    135614 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    135615 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135616 File
    135617 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135618 packages/chimerax/geometry/place.py", line 201, in inverse 
    135619 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    135620 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135621 File
    135622 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135623 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    135624 rinv[:, :] = matrix_inverse(r) 
    135625 ^^^^^^^^^^^^^^^^^ 
    135626 File
    135627 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135628 packages/numpy/linalg/linalg.py", line 561, in inv 
    135629 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    135630 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135631 File
    135632 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135633 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    135634 raise LinAlgError("Singular matrix") 
    135635 numpy.linalg.LinAlgError: Singular matrix 
    135636  
    135637 numpy.linalg.LinAlgError: Singular matrix 
    135638  
    135639 File
    135640 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135641 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    135642 raise LinAlgError("Singular matrix") 
    135643  
    135644 See log for complete Python traceback. 
    135645  
    135646 Traceback (most recent call last): 
    135647 File
    135648 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135649 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    135650 self.session.ui.mouse_modes.mouse_pause_tracking() 
    135651 File
    135652 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135653 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    135654 mouse_pause_tracking 
    135655 self._mouse_pause() 
    135656 File
    135657 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135658 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    135659 m.pause(self._mouse_pause_position) 
    135660 File
    135661 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135662 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    135663 p = self.view.picked_object(x, y) 
    135664 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135665 File
    135666 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135667 packages/chimerax/graphics/view.py", line 838, in picked_object 
    135668 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    135669 beyond, 
    135670 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135671 File
    135672 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135673 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    135674 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    135675 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135676 File
    135677 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135678 packages/chimerax/core/models.py", line 143, in first_intercept 
    135679 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    135680 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135681 File
    135682 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135683 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    135684 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    135685 exclude=exclude) 
    135686 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135687 File
    135688 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135689 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    135690 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    135691 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135692 File
    135693 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135694 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    135695 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    135696 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135697 File
    135698 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135699 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    135700 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    135701 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135702 File
    135703 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135704 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    135705 p = super().first_intercept(mxyz1, mxyz2) 
    135706 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135707 File
    135708 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135709 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    135710 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    135711 exclude=exclude) 
    135712 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135713 File
    135714 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135715 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    135716 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    135717 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135718 File
    135719 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135720 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    135721 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    135722 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135723 File
    135724 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135725 packages/chimerax/graphics/drawing.py", line 1108, in
    135726 _first_intercept_excluding_children 
    135727 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    135728 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135729 File
    135730 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135731 packages/chimerax/geometry/place.py", line 201, in inverse 
    135732 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    135733 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135734 File
    135735 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135736 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    135737 rinv[:, :] = matrix_inverse(r) 
    135738 ^^^^^^^^^^^^^^^^^ 
    135739 File
    135740 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135741 packages/numpy/linalg/linalg.py", line 561, in inv 
    135742 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    135743 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135744 File
    135745 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135746 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    135747 raise LinAlgError("Singular matrix") 
    135748 numpy.linalg.LinAlgError: Singular matrix 
    135749  
    135750 numpy.linalg.LinAlgError: Singular matrix 
    135751  
    135752 File
    135753 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135754 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    135755 raise LinAlgError("Singular matrix") 
    135756  
    135757 See log for complete Python traceback. 
    135758  
    135759 Traceback (most recent call last): 
    135760 File
    135761 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135762 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    135763 self.session.ui.mouse_modes.mouse_pause_tracking() 
    135764 File
    135765 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135766 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    135767 mouse_pause_tracking 
    135768 self._mouse_pause() 
    135769 File
    135770 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135771 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    135772 m.pause(self._mouse_pause_position) 
    135773 File
    135774 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135775 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    135776 p = self.view.picked_object(x, y) 
    135777 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135778 File
    135779 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135780 packages/chimerax/graphics/view.py", line 838, in picked_object 
    135781 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    135782 beyond, 
    135783 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135784 File
    135785 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135786 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    135787 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    135788 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135789 File
    135790 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135791 packages/chimerax/core/models.py", line 143, in first_intercept 
    135792 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    135793 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135794 File
    135795 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135796 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    135797 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    135798 exclude=exclude) 
    135799 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135800 File
    135801 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135802 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    135803 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    135804 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135805 File
    135806 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135807 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    135808 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    135809 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135810 File
    135811 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135812 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    135813 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    135814 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135815 File
    135816 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135817 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    135818 p = super().first_intercept(mxyz1, mxyz2) 
    135819 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135820 File
    135821 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135822 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    135823 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    135824 exclude=exclude) 
    135825 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135826 File
    135827 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135828 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    135829 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    135830 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135831 File
    135832 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135833 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    135834 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    135835 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135836 File
    135837 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135838 packages/chimerax/graphics/drawing.py", line 1108, in
    135839 _first_intercept_excluding_children 
    135840 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    135841 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135842 File
    135843 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135844 packages/chimerax/geometry/place.py", line 201, in inverse 
    135845 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    135846 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135847 File
    135848 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135849 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    135850 rinv[:, :] = matrix_inverse(r) 
    135851 ^^^^^^^^^^^^^^^^^ 
    135852 File
    135853 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135854 packages/numpy/linalg/linalg.py", line 561, in inv 
    135855 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    135856 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135857 File
    135858 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135859 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    135860 raise LinAlgError("Singular matrix") 
    135861 numpy.linalg.LinAlgError: Singular matrix 
    135862  
    135863 numpy.linalg.LinAlgError: Singular matrix 
    135864  
    135865 File
    135866 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135867 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    135868 raise LinAlgError("Singular matrix") 
    135869  
    135870 See log for complete Python traceback. 
    135871  
    135872 Traceback (most recent call last): 
    135873 File
    135874 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135875 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    135876 self.session.ui.mouse_modes.mouse_pause_tracking() 
    135877 File
    135878 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135879 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    135880 mouse_pause_tracking 
    135881 self._mouse_pause() 
    135882 File
    135883 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135884 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    135885 m.pause(self._mouse_pause_position) 
    135886 File
    135887 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135888 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    135889 p = self.view.picked_object(x, y) 
    135890 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135891 File
    135892 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135893 packages/chimerax/graphics/view.py", line 838, in picked_object 
    135894 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    135895 beyond, 
    135896 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135897 File
    135898 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135899 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    135900 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    135901 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135902 File
    135903 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135904 packages/chimerax/core/models.py", line 143, in first_intercept 
    135905 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    135906 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135907 File
    135908 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135909 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    135910 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    135911 exclude=exclude) 
    135912 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135913 File
    135914 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135915 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    135916 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    135917 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135918 File
    135919 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135920 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    135921 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    135922 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135923 File
    135924 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135925 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    135926 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    135927 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135928 File
    135929 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135930 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    135931 p = super().first_intercept(mxyz1, mxyz2) 
    135932 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135933 File
    135934 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135935 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    135936 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    135937 exclude=exclude) 
    135938 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135939 File
    135940 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135941 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    135942 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    135943 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135944 File
    135945 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135946 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    135947 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    135948 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135949 File
    135950 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135951 packages/chimerax/graphics/drawing.py", line 1108, in
    135952 _first_intercept_excluding_children 
    135953 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    135954 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135955 File
    135956 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135957 packages/chimerax/geometry/place.py", line 201, in inverse 
    135958 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    135959 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135960 File
    135961 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135962 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    135963 rinv[:, :] = matrix_inverse(r) 
    135964 ^^^^^^^^^^^^^^^^^ 
    135965 File
    135966 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135967 packages/numpy/linalg/linalg.py", line 561, in inv 
    135968 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    135969 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    135970 File
    135971 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135972 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    135973 raise LinAlgError("Singular matrix") 
    135974 numpy.linalg.LinAlgError: Singular matrix 
    135975  
    135976 numpy.linalg.LinAlgError: Singular matrix 
    135977  
    135978 File
    135979 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135980 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    135981 raise LinAlgError("Singular matrix") 
    135982  
    135983 See log for complete Python traceback. 
    135984  
    135985 Traceback (most recent call last): 
    135986 File
    135987 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135988 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    135989 self.session.ui.mouse_modes.mouse_pause_tracking() 
    135990 File
    135991 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135992 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    135993 mouse_pause_tracking 
    135994 self._mouse_pause() 
    135995 File
    135996 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    135997 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    135998 m.pause(self._mouse_pause_position) 
    135999 File
    136000 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136001 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    136002 p = self.view.picked_object(x, y) 
    136003 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136004 File
    136005 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136006 packages/chimerax/graphics/view.py", line 838, in picked_object 
    136007 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    136008 beyond, 
    136009 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136010 File
    136011 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136012 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    136013 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    136014 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136015 File
    136016 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136017 packages/chimerax/core/models.py", line 143, in first_intercept 
    136018 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    136019 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136020 File
    136021 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136022 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    136023 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    136024 exclude=exclude) 
    136025 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136026 File
    136027 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136028 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    136029 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    136030 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136031 File
    136032 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136033 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    136034 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    136035 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136036 File
    136037 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136038 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    136039 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    136040 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136041 File
    136042 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136043 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    136044 p = super().first_intercept(mxyz1, mxyz2) 
    136045 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136046 File
    136047 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136048 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    136049 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    136050 exclude=exclude) 
    136051 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136052 File
    136053 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136054 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    136055 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    136056 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136057 File
    136058 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136059 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    136060 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    136061 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136062 File
    136063 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136064 packages/chimerax/graphics/drawing.py", line 1108, in
    136065 _first_intercept_excluding_children 
    136066 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    136067 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136068 File
    136069 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136070 packages/chimerax/geometry/place.py", line 201, in inverse 
    136071 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    136072 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136073 File
    136074 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136075 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    136076 rinv[:, :] = matrix_inverse(r) 
    136077 ^^^^^^^^^^^^^^^^^ 
    136078 File
    136079 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136080 packages/numpy/linalg/linalg.py", line 561, in inv 
    136081 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    136082 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136083 File
    136084 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136085 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    136086 raise LinAlgError("Singular matrix") 
    136087 numpy.linalg.LinAlgError: Singular matrix 
    136088  
    136089 numpy.linalg.LinAlgError: Singular matrix 
    136090  
    136091 File
    136092 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136093 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    136094 raise LinAlgError("Singular matrix") 
    136095  
    136096 See log for complete Python traceback. 
    136097  
    136098 Traceback (most recent call last): 
    136099 File
    136100 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136101 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    136102 self.session.ui.mouse_modes.mouse_pause_tracking() 
    136103 File
    136104 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136105 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    136106 mouse_pause_tracking 
    136107 self._mouse_pause() 
    136108 File
    136109 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136110 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    136111 m.pause(self._mouse_pause_position) 
    136112 File
    136113 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136114 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    136115 p = self.view.picked_object(x, y) 
    136116 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136117 File
    136118 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136119 packages/chimerax/graphics/view.py", line 838, in picked_object 
    136120 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    136121 beyond, 
    136122 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136123 File
    136124 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136125 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    136126 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    136127 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136128 File
    136129 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136130 packages/chimerax/core/models.py", line 143, in first_intercept 
    136131 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    136132 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136133 File
    136134 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136135 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    136136 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    136137 exclude=exclude) 
    136138 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136139 File
    136140 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136141 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    136142 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    136143 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136144 File
    136145 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136146 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    136147 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    136148 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136149 File
    136150 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136151 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    136152 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    136153 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136154 File
    136155 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136156 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    136157 p = super().first_intercept(mxyz1, mxyz2) 
    136158 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136159 File
    136160 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136161 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    136162 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    136163 exclude=exclude) 
    136164 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136165 File
    136166 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136167 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    136168 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    136169 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136170 File
    136171 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136172 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    136173 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    136174 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136175 File
    136176 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136177 packages/chimerax/graphics/drawing.py", line 1108, in
    136178 _first_intercept_excluding_children 
    136179 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    136180 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136181 File
    136182 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136183 packages/chimerax/geometry/place.py", line 201, in inverse 
    136184 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    136185 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136186 File
    136187 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136188 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    136189 rinv[:, :] = matrix_inverse(r) 
    136190 ^^^^^^^^^^^^^^^^^ 
    136191 File
    136192 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136193 packages/numpy/linalg/linalg.py", line 561, in inv 
    136194 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    136195 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136196 File
    136197 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136198 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    136199 raise LinAlgError("Singular matrix") 
    136200 numpy.linalg.LinAlgError: Singular matrix 
    136201  
    136202 numpy.linalg.LinAlgError: Singular matrix 
    136203  
    136204 File
    136205 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136206 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    136207 raise LinAlgError("Singular matrix") 
    136208  
    136209 See log for complete Python traceback. 
    136210  
    136211 Traceback (most recent call last): 
    136212 File
    136213 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136214 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    136215 self.session.ui.mouse_modes.mouse_pause_tracking() 
    136216 File
    136217 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136218 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    136219 mouse_pause_tracking 
    136220 self._mouse_pause() 
    136221 File
    136222 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136223 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    136224 m.pause(self._mouse_pause_position) 
    136225 File
    136226 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136227 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    136228 p = self.view.picked_object(x, y) 
    136229 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136230 File
    136231 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136232 packages/chimerax/graphics/view.py", line 838, in picked_object 
    136233 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    136234 beyond, 
    136235 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136236 File
    136237 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136238 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    136239 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    136240 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136241 File
    136242 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136243 packages/chimerax/core/models.py", line 143, in first_intercept 
    136244 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    136245 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136246 File
    136247 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136248 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    136249 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    136250 exclude=exclude) 
    136251 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136252 File
    136253 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136254 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    136255 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    136256 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136257 File
    136258 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136259 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    136260 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    136261 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136262 File
    136263 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136264 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    136265 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    136266 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136267 File
    136268 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136269 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    136270 p = super().first_intercept(mxyz1, mxyz2) 
    136271 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136272 File
    136273 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136274 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    136275 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    136276 exclude=exclude) 
    136277 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136278 File
    136279 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136280 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    136281 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    136282 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136283 File
    136284 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136285 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    136286 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    136287 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136288 File
    136289 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136290 packages/chimerax/graphics/drawing.py", line 1108, in
    136291 _first_intercept_excluding_children 
    136292 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    136293 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136294 File
    136295 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136296 packages/chimerax/geometry/place.py", line 201, in inverse 
    136297 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    136298 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136299 File
    136300 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136301 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    136302 rinv[:, :] = matrix_inverse(r) 
    136303 ^^^^^^^^^^^^^^^^^ 
    136304 File
    136305 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136306 packages/numpy/linalg/linalg.py", line 561, in inv 
    136307 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    136308 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136309 File
    136310 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136311 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    136312 raise LinAlgError("Singular matrix") 
    136313 numpy.linalg.LinAlgError: Singular matrix 
    136314  
    136315 numpy.linalg.LinAlgError: Singular matrix 
    136316  
    136317 File
    136318 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136319 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    136320 raise LinAlgError("Singular matrix") 
    136321  
    136322 See log for complete Python traceback. 
    136323  
    136324 Traceback (most recent call last): 
    136325 File
    136326 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136327 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    136328 self.session.ui.mouse_modes.mouse_pause_tracking() 
    136329 File
    136330 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136331 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    136332 mouse_pause_tracking 
    136333 self._mouse_pause() 
    136334 File
    136335 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136336 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    136337 m.pause(self._mouse_pause_position) 
    136338 File
    136339 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136340 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    136341 p = self.view.picked_object(x, y) 
    136342 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136343 File
    136344 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136345 packages/chimerax/graphics/view.py", line 838, in picked_object 
    136346 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    136347 beyond, 
    136348 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136349 File
    136350 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136351 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    136352 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    136353 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136354 File
    136355 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136356 packages/chimerax/core/models.py", line 143, in first_intercept 
    136357 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    136358 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136359 File
    136360 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136361 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    136362 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    136363 exclude=exclude) 
    136364 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136365 File
    136366 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136367 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    136368 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    136369 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136370 File
    136371 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136372 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    136373 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    136374 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136375 File
    136376 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136377 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    136378 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    136379 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136380 File
    136381 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136382 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    136383 p = super().first_intercept(mxyz1, mxyz2) 
    136384 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136385 File
    136386 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136387 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    136388 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    136389 exclude=exclude) 
    136390 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136391 File
    136392 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136393 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    136394 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    136395 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136396 File
    136397 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136398 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    136399 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    136400 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136401 File
    136402 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136403 packages/chimerax/graphics/drawing.py", line 1108, in
    136404 _first_intercept_excluding_children 
    136405 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    136406 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136407 File
    136408 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136409 packages/chimerax/geometry/place.py", line 201, in inverse 
    136410 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    136411 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136412 File
    136413 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136414 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    136415 rinv[:, :] = matrix_inverse(r) 
    136416 ^^^^^^^^^^^^^^^^^ 
    136417 File
    136418 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136419 packages/numpy/linalg/linalg.py", line 561, in inv 
    136420 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    136421 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136422 File
    136423 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136424 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    136425 raise LinAlgError("Singular matrix") 
    136426 numpy.linalg.LinAlgError: Singular matrix 
    136427  
    136428 numpy.linalg.LinAlgError: Singular matrix 
    136429  
    136430 File
    136431 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136432 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    136433 raise LinAlgError("Singular matrix") 
    136434  
    136435 See log for complete Python traceback. 
    136436  
    136437 Traceback (most recent call last): 
    136438 File
    136439 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136440 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    136441 self.session.ui.mouse_modes.mouse_pause_tracking() 
    136442 File
    136443 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136444 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    136445 mouse_pause_tracking 
    136446 self._mouse_pause() 
    136447 File
    136448 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136449 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    136450 m.pause(self._mouse_pause_position) 
    136451 File
    136452 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136453 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    136454 p = self.view.picked_object(x, y) 
    136455 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136456 File
    136457 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136458 packages/chimerax/graphics/view.py", line 838, in picked_object 
    136459 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    136460 beyond, 
    136461 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136462 File
    136463 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136464 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    136465 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    136466 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136467 File
    136468 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136469 packages/chimerax/core/models.py", line 143, in first_intercept 
    136470 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    136471 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136472 File
    136473 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136474 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    136475 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    136476 exclude=exclude) 
    136477 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136478 File
    136479 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136480 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    136481 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    136482 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136483 File
    136484 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136485 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    136486 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    136487 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136488 File
    136489 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136490 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    136491 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    136492 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136493 File
    136494 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136495 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    136496 p = super().first_intercept(mxyz1, mxyz2) 
    136497 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136498 File
    136499 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136500 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    136501 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    136502 exclude=exclude) 
    136503 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136504 File
    136505 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136506 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    136507 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    136508 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136509 File
    136510 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136511 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    136512 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    136513 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136514 File
    136515 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136516 packages/chimerax/graphics/drawing.py", line 1108, in
    136517 _first_intercept_excluding_children 
    136518 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    136519 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136520 File
    136521 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136522 packages/chimerax/geometry/place.py", line 201, in inverse 
    136523 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    136524 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136525 File
    136526 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136527 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    136528 rinv[:, :] = matrix_inverse(r) 
    136529 ^^^^^^^^^^^^^^^^^ 
    136530 File
    136531 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136532 packages/numpy/linalg/linalg.py", line 561, in inv 
    136533 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    136534 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136535 File
    136536 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136537 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    136538 raise LinAlgError("Singular matrix") 
    136539 numpy.linalg.LinAlgError: Singular matrix 
    136540  
    136541 numpy.linalg.LinAlgError: Singular matrix 
    136542  
    136543 File
    136544 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136545 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    136546 raise LinAlgError("Singular matrix") 
    136547  
    136548 See log for complete Python traceback. 
    136549  
    136550 Traceback (most recent call last): 
    136551 File
    136552 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136553 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    136554 self.session.ui.mouse_modes.mouse_pause_tracking() 
    136555 File
    136556 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136557 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    136558 mouse_pause_tracking 
    136559 self._mouse_pause() 
    136560 File
    136561 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136562 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    136563 m.pause(self._mouse_pause_position) 
    136564 File
    136565 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136566 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    136567 p = self.view.picked_object(x, y) 
    136568 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136569 File
    136570 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136571 packages/chimerax/graphics/view.py", line 838, in picked_object 
    136572 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    136573 beyond, 
    136574 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136575 File
    136576 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136577 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    136578 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    136579 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136580 File
    136581 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136582 packages/chimerax/core/models.py", line 143, in first_intercept 
    136583 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    136584 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136585 File
    136586 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136587 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    136588 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    136589 exclude=exclude) 
    136590 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136591 File
    136592 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136593 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    136594 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    136595 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136596 File
    136597 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136598 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    136599 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    136600 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136601 File
    136602 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136603 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    136604 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    136605 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136606 File
    136607 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136608 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    136609 p = super().first_intercept(mxyz1, mxyz2) 
    136610 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136611 File
    136612 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136613 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    136614 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    136615 exclude=exclude) 
    136616 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136617 File
    136618 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136619 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    136620 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    136621 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136622 File
    136623 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136624 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    136625 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    136626 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136627 File
    136628 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136629 packages/chimerax/graphics/drawing.py", line 1108, in
    136630 _first_intercept_excluding_children 
    136631 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    136632 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136633 File
    136634 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136635 packages/chimerax/geometry/place.py", line 201, in inverse 
    136636 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    136637 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136638 File
    136639 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136640 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    136641 rinv[:, :] = matrix_inverse(r) 
    136642 ^^^^^^^^^^^^^^^^^ 
    136643 File
    136644 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136645 packages/numpy/linalg/linalg.py", line 561, in inv 
    136646 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    136647 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136648 File
    136649 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136650 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    136651 raise LinAlgError("Singular matrix") 
    136652 numpy.linalg.LinAlgError: Singular matrix 
    136653  
    136654 numpy.linalg.LinAlgError: Singular matrix 
    136655  
    136656 File
    136657 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136658 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    136659 raise LinAlgError("Singular matrix") 
    136660  
    136661 See log for complete Python traceback. 
    136662  
    136663 Traceback (most recent call last): 
    136664 File
    136665 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136666 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    136667 self.session.ui.mouse_modes.mouse_pause_tracking() 
    136668 File
    136669 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136670 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    136671 mouse_pause_tracking 
    136672 self._mouse_pause() 
    136673 File
    136674 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136675 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    136676 m.pause(self._mouse_pause_position) 
    136677 File
    136678 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136679 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    136680 p = self.view.picked_object(x, y) 
    136681 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136682 File
    136683 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136684 packages/chimerax/graphics/view.py", line 838, in picked_object 
    136685 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    136686 beyond, 
    136687 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136688 File
    136689 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136690 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    136691 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    136692 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136693 File
    136694 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136695 packages/chimerax/core/models.py", line 143, in first_intercept 
    136696 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    136697 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136698 File
    136699 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136700 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    136701 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    136702 exclude=exclude) 
    136703 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136704 File
    136705 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136706 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    136707 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    136708 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136709 File
    136710 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136711 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    136712 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    136713 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136714 File
    136715 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136716 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    136717 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    136718 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136719 File
    136720 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136721 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    136722 p = super().first_intercept(mxyz1, mxyz2) 
    136723 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136724 File
    136725 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136726 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    136727 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    136728 exclude=exclude) 
    136729 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136730 File
    136731 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136732 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    136733 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    136734 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136735 File
    136736 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136737 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    136738 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    136739 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136740 File
    136741 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136742 packages/chimerax/graphics/drawing.py", line 1108, in
    136743 _first_intercept_excluding_children 
    136744 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    136745 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136746 File
    136747 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136748 packages/chimerax/geometry/place.py", line 201, in inverse 
    136749 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    136750 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136751 File
    136752 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136753 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    136754 rinv[:, :] = matrix_inverse(r) 
    136755 ^^^^^^^^^^^^^^^^^ 
    136756 File
    136757 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136758 packages/numpy/linalg/linalg.py", line 561, in inv 
    136759 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    136760 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136761 File
    136762 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136763 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    136764 raise LinAlgError("Singular matrix") 
    136765 numpy.linalg.LinAlgError: Singular matrix 
    136766  
    136767 numpy.linalg.LinAlgError: Singular matrix 
    136768  
    136769 File
    136770 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136771 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    136772 raise LinAlgError("Singular matrix") 
    136773  
    136774 See log for complete Python traceback. 
    136775  
    136776 Traceback (most recent call last): 
    136777 File
    136778 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136779 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    136780 self.session.ui.mouse_modes.mouse_pause_tracking() 
    136781 File
    136782 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136783 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    136784 mouse_pause_tracking 
    136785 self._mouse_pause() 
    136786 File
    136787 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136788 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    136789 m.pause(self._mouse_pause_position) 
    136790 File
    136791 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136792 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    136793 p = self.view.picked_object(x, y) 
    136794 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136795 File
    136796 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136797 packages/chimerax/graphics/view.py", line 838, in picked_object 
    136798 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    136799 beyond, 
    136800 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136801 File
    136802 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136803 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    136804 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    136805 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136806 File
    136807 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136808 packages/chimerax/core/models.py", line 143, in first_intercept 
    136809 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    136810 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136811 File
    136812 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136813 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    136814 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    136815 exclude=exclude) 
    136816 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136817 File
    136818 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136819 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    136820 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    136821 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136822 File
    136823 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136824 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    136825 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    136826 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136827 File
    136828 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136829 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    136830 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    136831 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136832 File
    136833 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136834 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    136835 p = super().first_intercept(mxyz1, mxyz2) 
    136836 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136837 File
    136838 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136839 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    136840 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    136841 exclude=exclude) 
    136842 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136843 File
    136844 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136845 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    136846 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    136847 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136848 File
    136849 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136850 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    136851 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    136852 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136853 File
    136854 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136855 packages/chimerax/graphics/drawing.py", line 1108, in
    136856 _first_intercept_excluding_children 
    136857 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    136858 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136859 File
    136860 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136861 packages/chimerax/geometry/place.py", line 201, in inverse 
    136862 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    136863 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136864 File
    136865 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136866 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    136867 rinv[:, :] = matrix_inverse(r) 
    136868 ^^^^^^^^^^^^^^^^^ 
    136869 File
    136870 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136871 packages/numpy/linalg/linalg.py", line 561, in inv 
    136872 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    136873 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136874 File
    136875 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136876 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    136877 raise LinAlgError("Singular matrix") 
    136878 numpy.linalg.LinAlgError: Singular matrix 
    136879  
    136880 numpy.linalg.LinAlgError: Singular matrix 
    136881  
    136882 File
    136883 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136884 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    136885 raise LinAlgError("Singular matrix") 
    136886  
    136887 See log for complete Python traceback. 
    136888  
    136889 Traceback (most recent call last): 
    136890 File
    136891 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136892 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    136893 self.session.ui.mouse_modes.mouse_pause_tracking() 
    136894 File
    136895 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136896 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    136897 mouse_pause_tracking 
    136898 self._mouse_pause() 
    136899 File
    136900 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136901 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    136902 m.pause(self._mouse_pause_position) 
    136903 File
    136904 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136905 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    136906 p = self.view.picked_object(x, y) 
    136907 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136908 File
    136909 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136910 packages/chimerax/graphics/view.py", line 838, in picked_object 
    136911 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    136912 beyond, 
    136913 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136914 File
    136915 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136916 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    136917 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    136918 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136919 File
    136920 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136921 packages/chimerax/core/models.py", line 143, in first_intercept 
    136922 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    136923 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136924 File
    136925 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136926 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    136927 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    136928 exclude=exclude) 
    136929 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136930 File
    136931 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136932 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    136933 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    136934 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136935 File
    136936 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136937 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    136938 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    136939 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136940 File
    136941 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136942 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    136943 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    136944 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136945 File
    136946 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136947 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    136948 p = super().first_intercept(mxyz1, mxyz2) 
    136949 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136950 File
    136951 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136952 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    136953 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    136954 exclude=exclude) 
    136955 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136956 File
    136957 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136958 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    136959 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    136960 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136961 File
    136962 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136963 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    136964 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    136965 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136966 File
    136967 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136968 packages/chimerax/graphics/drawing.py", line 1108, in
    136969 _first_intercept_excluding_children 
    136970 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    136971 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136972 File
    136973 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136974 packages/chimerax/geometry/place.py", line 201, in inverse 
    136975 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    136976 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136977 File
    136978 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136979 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    136980 rinv[:, :] = matrix_inverse(r) 
    136981 ^^^^^^^^^^^^^^^^^ 
    136982 File
    136983 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136984 packages/numpy/linalg/linalg.py", line 561, in inv 
    136985 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    136986 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    136987 File
    136988 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136989 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    136990 raise LinAlgError("Singular matrix") 
    136991 numpy.linalg.LinAlgError: Singular matrix 
    136992  
    136993 numpy.linalg.LinAlgError: Singular matrix 
    136994  
    136995 File
    136996 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    136997 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    136998 raise LinAlgError("Singular matrix") 
    136999  
    137000 See log for complete Python traceback. 
    137001  
    137002 Traceback (most recent call last): 
    137003 File
    137004 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137005 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    137006 self.session.ui.mouse_modes.mouse_pause_tracking() 
    137007 File
    137008 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137009 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    137010 mouse_pause_tracking 
    137011 self._mouse_pause() 
    137012 File
    137013 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137014 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    137015 m.pause(self._mouse_pause_position) 
    137016 File
    137017 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137018 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    137019 p = self.view.picked_object(x, y) 
    137020 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137021 File
    137022 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137023 packages/chimerax/graphics/view.py", line 838, in picked_object 
    137024 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    137025 beyond, 
    137026 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137027 File
    137028 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137029 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    137030 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    137031 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137032 File
    137033 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137034 packages/chimerax/core/models.py", line 143, in first_intercept 
    137035 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    137036 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137037 File
    137038 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137039 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    137040 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    137041 exclude=exclude) 
    137042 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137043 File
    137044 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137045 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    137046 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    137047 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137048 File
    137049 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137050 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    137051 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    137052 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137053 File
    137054 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137055 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    137056 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    137057 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137058 File
    137059 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137060 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    137061 p = super().first_intercept(mxyz1, mxyz2) 
    137062 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137063 File
    137064 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137065 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    137066 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    137067 exclude=exclude) 
    137068 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137069 File
    137070 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137071 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    137072 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    137073 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137074 File
    137075 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137076 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    137077 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    137078 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137079 File
    137080 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137081 packages/chimerax/graphics/drawing.py", line 1108, in
    137082 _first_intercept_excluding_children 
    137083 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    137084 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137085 File
    137086 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137087 packages/chimerax/geometry/place.py", line 201, in inverse 
    137088 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    137089 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137090 File
    137091 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137092 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    137093 rinv[:, :] = matrix_inverse(r) 
    137094 ^^^^^^^^^^^^^^^^^ 
    137095 File
    137096 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137097 packages/numpy/linalg/linalg.py", line 561, in inv 
    137098 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    137099 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137100 File
    137101 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137102 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    137103 raise LinAlgError("Singular matrix") 
    137104 numpy.linalg.LinAlgError: Singular matrix 
    137105  
    137106 numpy.linalg.LinAlgError: Singular matrix 
    137107  
    137108 File
    137109 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137110 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    137111 raise LinAlgError("Singular matrix") 
    137112  
    137113 See log for complete Python traceback. 
    137114  
    137115 Traceback (most recent call last): 
    137116 File
    137117 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137118 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    137119 self.session.ui.mouse_modes.mouse_pause_tracking() 
    137120 File
    137121 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137122 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    137123 mouse_pause_tracking 
    137124 self._mouse_pause() 
    137125 File
    137126 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137127 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    137128 m.pause(self._mouse_pause_position) 
    137129 File
    137130 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137131 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    137132 p = self.view.picked_object(x, y) 
    137133 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137134 File
    137135 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137136 packages/chimerax/graphics/view.py", line 838, in picked_object 
    137137 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    137138 beyond, 
    137139 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137140 File
    137141 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137142 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    137143 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    137144 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137145 File
    137146 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137147 packages/chimerax/core/models.py", line 143, in first_intercept 
    137148 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    137149 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137150 File
    137151 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137152 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    137153 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    137154 exclude=exclude) 
    137155 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137156 File
    137157 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137158 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    137159 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    137160 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137161 File
    137162 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137163 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    137164 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    137165 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137166 File
    137167 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137168 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    137169 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    137170 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137171 File
    137172 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137173 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    137174 p = super().first_intercept(mxyz1, mxyz2) 
    137175 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137176 File
    137177 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137178 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    137179 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    137180 exclude=exclude) 
    137181 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137182 File
    137183 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137184 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    137185 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    137186 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137187 File
    137188 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137189 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    137190 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    137191 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137192 File
    137193 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137194 packages/chimerax/graphics/drawing.py", line 1108, in
    137195 _first_intercept_excluding_children 
    137196 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    137197 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137198 File
    137199 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137200 packages/chimerax/geometry/place.py", line 201, in inverse 
    137201 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    137202 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137203 File
    137204 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137205 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    137206 rinv[:, :] = matrix_inverse(r) 
    137207 ^^^^^^^^^^^^^^^^^ 
    137208 File
    137209 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137210 packages/numpy/linalg/linalg.py", line 561, in inv 
    137211 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    137212 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137213 File
    137214 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137215 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    137216 raise LinAlgError("Singular matrix") 
    137217 numpy.linalg.LinAlgError: Singular matrix 
    137218  
    137219 numpy.linalg.LinAlgError: Singular matrix 
    137220  
    137221 File
    137222 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137223 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    137224 raise LinAlgError("Singular matrix") 
    137225  
    137226 See log for complete Python traceback. 
    137227  
    137228 Traceback (most recent call last): 
    137229 File
    137230 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137231 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    137232 self.session.ui.mouse_modes.mouse_pause_tracking() 
    137233 File
    137234 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137235 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    137236 mouse_pause_tracking 
    137237 self._mouse_pause() 
    137238 File
    137239 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137240 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    137241 m.pause(self._mouse_pause_position) 
    137242 File
    137243 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137244 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    137245 p = self.view.picked_object(x, y) 
    137246 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137247 File
    137248 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137249 packages/chimerax/graphics/view.py", line 838, in picked_object 
    137250 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    137251 beyond, 
    137252 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137253 File
    137254 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137255 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    137256 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    137257 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137258 File
    137259 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137260 packages/chimerax/core/models.py", line 143, in first_intercept 
    137261 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    137262 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137263 File
    137264 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137265 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    137266 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    137267 exclude=exclude) 
    137268 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137269 File
    137270 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137271 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    137272 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    137273 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137274 File
    137275 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137276 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    137277 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    137278 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137279 File
    137280 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137281 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    137282 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    137283 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137284 File
    137285 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137286 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    137287 p = super().first_intercept(mxyz1, mxyz2) 
    137288 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137289 File
    137290 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137291 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    137292 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    137293 exclude=exclude) 
    137294 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137295 File
    137296 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137297 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    137298 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    137299 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137300 File
    137301 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137302 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    137303 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    137304 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137305 File
    137306 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137307 packages/chimerax/graphics/drawing.py", line 1108, in
    137308 _first_intercept_excluding_children 
    137309 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    137310 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137311 File
    137312 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137313 packages/chimerax/geometry/place.py", line 201, in inverse 
    137314 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    137315 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137316 File
    137317 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137318 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    137319 rinv[:, :] = matrix_inverse(r) 
    137320 ^^^^^^^^^^^^^^^^^ 
    137321 File
    137322 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137323 packages/numpy/linalg/linalg.py", line 561, in inv 
    137324 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    137325 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137326 File
    137327 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137328 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    137329 raise LinAlgError("Singular matrix") 
    137330 numpy.linalg.LinAlgError: Singular matrix 
    137331  
    137332 numpy.linalg.LinAlgError: Singular matrix 
    137333  
    137334 File
    137335 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137336 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    137337 raise LinAlgError("Singular matrix") 
    137338  
    137339 See log for complete Python traceback. 
    137340  
    137341 
    137342 > save /Users/angela/Desktop/Structure/Ab_Asps.cxs
    137343 
    137344 > show #!2 models
    137345 
    137346 Traceback (most recent call last): 
    137347 File
    137348 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137349 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    137350 self.session.ui.mouse_modes.mouse_pause_tracking() 
    137351 File
    137352 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137353 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    137354 mouse_pause_tracking 
    137355 self._mouse_pause() 
    137356 File
    137357 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137358 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    137359 m.pause(self._mouse_pause_position) 
    137360 File
    137361 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137362 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    137363 p = self.view.picked_object(x, y) 
    137364 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137365 File
    137366 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137367 packages/chimerax/graphics/view.py", line 838, in picked_object 
    137368 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    137369 beyond, 
    137370 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137371 File
    137372 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137373 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    137374 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    137375 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137376 File
    137377 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137378 packages/chimerax/core/models.py", line 143, in first_intercept 
    137379 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    137380 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137381 File
    137382 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137383 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    137384 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    137385 exclude=exclude) 
    137386 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137387 File
    137388 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137389 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    137390 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    137391 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137392 File
    137393 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137394 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    137395 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    137396 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137397 File
    137398 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137399 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    137400 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    137401 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137402 File
    137403 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137404 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    137405 p = super().first_intercept(mxyz1, mxyz2) 
    137406 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137407 File
    137408 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137409 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    137410 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    137411 exclude=exclude) 
    137412 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137413 File
    137414 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137415 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    137416 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    137417 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137418 File
    137419 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137420 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    137421 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    137422 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137423 File
    137424 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137425 packages/chimerax/graphics/drawing.py", line 1108, in
    137426 _first_intercept_excluding_children 
    137427 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    137428 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137429 File
    137430 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137431 packages/chimerax/geometry/place.py", line 201, in inverse 
    137432 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    137433 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137434 File
    137435 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137436 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    137437 rinv[:, :] = matrix_inverse(r) 
    137438 ^^^^^^^^^^^^^^^^^ 
    137439 File
    137440 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137441 packages/numpy/linalg/linalg.py", line 561, in inv 
    137442 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    137443 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137444 File
    137445 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137446 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    137447 raise LinAlgError("Singular matrix") 
    137448 numpy.linalg.LinAlgError: Singular matrix 
    137449  
    137450 numpy.linalg.LinAlgError: Singular matrix 
    137451  
    137452 File
    137453 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137454 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    137455 raise LinAlgError("Singular matrix") 
    137456  
    137457 See log for complete Python traceback. 
    137458  
    137459 Traceback (most recent call last): 
    137460 File
    137461 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137462 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    137463 self.session.ui.mouse_modes.mouse_pause_tracking() 
    137464 File
    137465 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137466 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    137467 mouse_pause_tracking 
    137468 self._mouse_pause() 
    137469 File
    137470 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137471 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    137472 m.pause(self._mouse_pause_position) 
    137473 File
    137474 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137475 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    137476 p = self.view.picked_object(x, y) 
    137477 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137478 File
    137479 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137480 packages/chimerax/graphics/view.py", line 838, in picked_object 
    137481 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    137482 beyond, 
    137483 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137484 File
    137485 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137486 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    137487 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    137488 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137489 File
    137490 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137491 packages/chimerax/core/models.py", line 143, in first_intercept 
    137492 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    137493 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137494 File
    137495 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137496 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    137497 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    137498 exclude=exclude) 
    137499 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137500 File
    137501 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137502 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    137503 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    137504 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137505 File
    137506 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137507 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    137508 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    137509 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137510 File
    137511 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137512 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    137513 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    137514 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137515 File
    137516 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137517 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    137518 p = super().first_intercept(mxyz1, mxyz2) 
    137519 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137520 File
    137521 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137522 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    137523 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    137524 exclude=exclude) 
    137525 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137526 File
    137527 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137528 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    137529 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    137530 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137531 File
    137532 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137533 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    137534 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    137535 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137536 File
    137537 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137538 packages/chimerax/graphics/drawing.py", line 1108, in
    137539 _first_intercept_excluding_children 
    137540 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    137541 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137542 File
    137543 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137544 packages/chimerax/geometry/place.py", line 201, in inverse 
    137545 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    137546 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137547 File
    137548 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137549 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    137550 rinv[:, :] = matrix_inverse(r) 
    137551 ^^^^^^^^^^^^^^^^^ 
    137552 File
    137553 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137554 packages/numpy/linalg/linalg.py", line 561, in inv 
    137555 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    137556 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137557 File
    137558 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137559 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    137560 raise LinAlgError("Singular matrix") 
    137561 numpy.linalg.LinAlgError: Singular matrix 
    137562  
    137563 numpy.linalg.LinAlgError: Singular matrix 
    137564  
    137565 File
    137566 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137567 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    137568 raise LinAlgError("Singular matrix") 
    137569  
    137570 See log for complete Python traceback. 
    137571  
    137572 Traceback (most recent call last): 
    137573 File
    137574 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137575 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    137576 self.session.ui.mouse_modes.mouse_pause_tracking() 
    137577 File
    137578 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137579 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    137580 mouse_pause_tracking 
    137581 self._mouse_pause() 
    137582 File
    137583 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137584 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    137585 m.pause(self._mouse_pause_position) 
    137586 File
    137587 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137588 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    137589 p = self.view.picked_object(x, y) 
    137590 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137591 File
    137592 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137593 packages/chimerax/graphics/view.py", line 838, in picked_object 
    137594 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    137595 beyond, 
    137596 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137597 File
    137598 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137599 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    137600 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    137601 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137602 File
    137603 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137604 packages/chimerax/core/models.py", line 143, in first_intercept 
    137605 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    137606 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137607 File
    137608 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137609 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    137610 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    137611 exclude=exclude) 
    137612 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137613 File
    137614 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137615 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    137616 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    137617 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137618 File
    137619 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137620 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    137621 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    137622 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137623 File
    137624 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137625 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    137626 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    137627 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137628 File
    137629 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137630 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    137631 p = super().first_intercept(mxyz1, mxyz2) 
    137632 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137633 File
    137634 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137635 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    137636 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    137637 exclude=exclude) 
    137638 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137639 File
    137640 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137641 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    137642 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    137643 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137644 File
    137645 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137646 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    137647 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    137648 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137649 File
    137650 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137651 packages/chimerax/graphics/drawing.py", line 1108, in
    137652 _first_intercept_excluding_children 
    137653 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    137654 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137655 File
    137656 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137657 packages/chimerax/geometry/place.py", line 201, in inverse 
    137658 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    137659 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137660 File
    137661 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137662 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    137663 rinv[:, :] = matrix_inverse(r) 
    137664 ^^^^^^^^^^^^^^^^^ 
    137665 File
    137666 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137667 packages/numpy/linalg/linalg.py", line 561, in inv 
    137668 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    137669 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137670 File
    137671 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137672 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    137673 raise LinAlgError("Singular matrix") 
    137674 numpy.linalg.LinAlgError: Singular matrix 
    137675  
    137676 numpy.linalg.LinAlgError: Singular matrix 
    137677  
    137678 File
    137679 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137680 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    137681 raise LinAlgError("Singular matrix") 
    137682  
    137683 See log for complete Python traceback. 
    137684  
    137685 Traceback (most recent call last): 
    137686 File
    137687 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137688 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    137689 self.session.ui.mouse_modes.mouse_pause_tracking() 
    137690 File
    137691 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137692 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    137693 mouse_pause_tracking 
    137694 self._mouse_pause() 
    137695 File
    137696 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137697 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    137698 m.pause(self._mouse_pause_position) 
    137699 File
    137700 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137701 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    137702 p = self.view.picked_object(x, y) 
    137703 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137704 File
    137705 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137706 packages/chimerax/graphics/view.py", line 838, in picked_object 
    137707 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    137708 beyond, 
    137709 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137710 File
    137711 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137712 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    137713 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    137714 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137715 File
    137716 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137717 packages/chimerax/core/models.py", line 143, in first_intercept 
    137718 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    137719 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137720 File
    137721 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137722 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    137723 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    137724 exclude=exclude) 
    137725 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137726 File
    137727 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137728 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    137729 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    137730 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137731 File
    137732 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137733 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    137734 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    137735 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137736 File
    137737 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137738 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    137739 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    137740 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137741 File
    137742 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137743 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    137744 p = super().first_intercept(mxyz1, mxyz2) 
    137745 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137746 File
    137747 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137748 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    137749 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    137750 exclude=exclude) 
    137751 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137752 File
    137753 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137754 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    137755 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    137756 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137757 File
    137758 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137759 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    137760 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    137761 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137762 File
    137763 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137764 packages/chimerax/graphics/drawing.py", line 1108, in
    137765 _first_intercept_excluding_children 
    137766 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    137767 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137768 File
    137769 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137770 packages/chimerax/geometry/place.py", line 201, in inverse 
    137771 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    137772 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137773 File
    137774 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137775 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    137776 rinv[:, :] = matrix_inverse(r) 
    137777 ^^^^^^^^^^^^^^^^^ 
    137778 File
    137779 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137780 packages/numpy/linalg/linalg.py", line 561, in inv 
    137781 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    137782 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137783 File
    137784 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137785 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    137786 raise LinAlgError("Singular matrix") 
    137787 numpy.linalg.LinAlgError: Singular matrix 
    137788  
    137789 numpy.linalg.LinAlgError: Singular matrix 
    137790  
    137791 File
    137792 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137793 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    137794 raise LinAlgError("Singular matrix") 
    137795  
    137796 See log for complete Python traceback. 
    137797  
    137798 Traceback (most recent call last): 
    137799 File
    137800 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137801 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    137802 self.session.ui.mouse_modes.mouse_pause_tracking() 
    137803 File
    137804 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137805 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    137806 mouse_pause_tracking 
    137807 self._mouse_pause() 
    137808 File
    137809 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137810 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    137811 m.pause(self._mouse_pause_position) 
    137812 File
    137813 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137814 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    137815 p = self.view.picked_object(x, y) 
    137816 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137817 File
    137818 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137819 packages/chimerax/graphics/view.py", line 838, in picked_object 
    137820 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    137821 beyond, 
    137822 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137823 File
    137824 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137825 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    137826 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    137827 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137828 File
    137829 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137830 packages/chimerax/core/models.py", line 143, in first_intercept 
    137831 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    137832 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137833 File
    137834 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137835 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    137836 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    137837 exclude=exclude) 
    137838 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137839 File
    137840 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137841 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    137842 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    137843 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137844 File
    137845 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137846 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    137847 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    137848 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137849 File
    137850 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137851 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    137852 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    137853 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137854 File
    137855 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137856 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    137857 p = super().first_intercept(mxyz1, mxyz2) 
    137858 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137859 File
    137860 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137861 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    137862 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    137863 exclude=exclude) 
    137864 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137865 File
    137866 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137867 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    137868 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    137869 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137870 File
    137871 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137872 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    137873 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    137874 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137875 File
    137876 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137877 packages/chimerax/graphics/drawing.py", line 1108, in
    137878 _first_intercept_excluding_children 
    137879 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    137880 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137881 File
    137882 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137883 packages/chimerax/geometry/place.py", line 201, in inverse 
    137884 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    137885 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137886 File
    137887 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137888 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    137889 rinv[:, :] = matrix_inverse(r) 
    137890 ^^^^^^^^^^^^^^^^^ 
    137891 File
    137892 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137893 packages/numpy/linalg/linalg.py", line 561, in inv 
    137894 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    137895 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    137896 File
    137897 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137898 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    137899 raise LinAlgError("Singular matrix") 
    137900 numpy.linalg.LinAlgError: Singular matrix 
    137901  
    137902 numpy.linalg.LinAlgError: Singular matrix 
    137903  
    137904 File
    137905 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    137906 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    137907 raise LinAlgError("Singular matrix") 
    137908  
    137909 See log for complete Python traceback. 
    137910  
    137911 
    137912 > hide #5.3 models
    137913 
    137914 > hide #5.2 models
    137915 
    137916 > hide #5.1 models
    137917 
    137918 > hide #!5 models
    137919 
    137920 > show #4.1 models
    137921 
    137922 > show #3 models
    137923 
    137924 > hide #4.1 models
    137925 
    137926 > hide #!4 models
    137927 
    137928 > hide #3 models
    137929 
    137930 > select #2:500
    137931 
    137932 34 atoms, 30 bonds, 4 residues, 1 model selected 
    137933 
    137934 > style sel stick
    137935 
    137936 Changed 34 atom styles 
    137937 
    137938 > select #2:B:HOH
    137939 
    137940 10 atoms, 10 residues, 1 model selected 
    137941 
    137942 > color sel red
    137943 
    137944 > size #2/B:HOH atomRadius -0.2
    137945 
    137946 Changed 4 atom radii 
    137947 
    137948 > size #2/B:HOH atomRadius -0.1
    137949 
    137950 Changed 4 atom radii 
    137951 
    137952 > select add #2/B:731
    137953 
    137954 21 atoms, 10 bonds, 11 residues, 1 model selected 
    137955 
    137956 > select add #2/B:732
    137957 
    137958 32 atoms, 20 bonds, 12 residues, 1 model selected 
    137959 
    137960 > select subtract #2/B:732
    137961 
    137962 21 atoms, 10 bonds, 11 residues, 1 model selected 
    137963 
    137964 > select add #1/D:464
    137965 
    137966 29 atoms, 17 bonds, 12 residues, 2 models selected 
    137967 
    137968 > select add #1/D:463
    137969 
    137970 37 atoms, 24 bonds, 13 residues, 2 models selected 
    137971 
    137972 > select add #2/B:449
    137973 
    137974 46 atoms, 32 bonds, 14 residues, 2 models selected 
    137975 
    137976 > select add #2/B:448
    137977 
    137978 50 atoms, 35 bonds, 15 residues, 2 models selected 
    137979 
    137980 > hide sel cartoons
    137981 
    137982 > select add #2/B:450
    137983 
    137984 58 atoms, 42 bonds, 16 residues, 2 models selected 
    137985 
    137986 > select add #2/B:451
    137987 
    137988 66 atoms, 49 bonds, 17 residues, 2 models selected 
    137989 
    137990 > hide sel cartoons
    137991 
    137992 > select add #2/B:737
    137993 
    137994 75 atoms, 57 bonds, 18 residues, 2 models selected 
    137995 
    137996 > select add #2/B:738
    137997 
    137998 86 atoms, 67 bonds, 19 residues, 2 models selected 
    137999 
    138000 > select add #2/B:735
    138001 
    138002 92 atoms, 72 bonds, 20 residues, 2 models selected 
    138003 
    138004 > select add #2/B:734
    138005 
    138006 100 atoms, 79 bonds, 21 residues, 2 models selected 
    138007 
    138008 > select add #2/B:733
    138009 
    138010 104 atoms, 82 bonds, 22 residues, 2 models selected 
    138011 
    138012 > select add #2/B:732
    138013 
    138014 115 atoms, 92 bonds, 23 residues, 2 models selected 
    138015 
    138016 > hide sel cartoons
    138017 
    138018 > select add #2/B:736
    138019 
    138020 123 atoms, 99 bonds, 24 residues, 2 models selected 
    138021 
    138022 > hide sel cartoons
    138023 
    138024 > select add #2/B:739
    138025 
    138026 135 atoms, 111 bonds, 25 residues, 2 models selected 
    138027 
    138028 > select add #2/B:740
    138029 
    138030 144 atoms, 119 bonds, 26 residues, 2 models selected 
    138031 
    138032 > select add #2/B:741
    138033 
    138034 148 atoms, 122 bonds, 27 residues, 2 models selected 
    138035 
    138036 > hide sel cartoons
    138037 
    138038 > select clear
    138039 
    138040 > color #2.2 #df7e26ff models
    138041 
    138042 > color #2.2 #dd8728ff models
    138043 
    138044 > color #2.2 #dc8a28ff models
    138045 
    138046 > save /Users/angela/Desktop/Structure/Ab_7z9c_Aspb.png width 2000 height 1151
    138047 > supersample 3 transparentBackground true
    138048 
    138049 > color #2.2 #ff9300ff models
    138050 
    138051 The cached device pixel ratio value was stale on window expose. Please file a
    138052 QTBUG which explains how to reproduce. 
    138053 
    138054 > save /Users/angela/Desktop/Structure/Ab_Asps.cxs
    138055 
    138056 ——— End of log from Tue Jul 29 16:24:33 2025 ———
    138057 
    138058 opened ChimeraX session 
    138059 
    138060 > open /Users/angela/Desktop/Structure/2024_Gyrase_last-coot-11.pdb
    138061 
    138062 Chain information for 2024_Gyrase_last-coot-11.pdb #6 
    138063 --- 
    138064 Chain | Description 
    138065 A | No description available 
    138066 B | No description available 
    138067 C D | No description available 
    138068 E | No description available 
    138069 F | No description available 
    138070 G | No description available 
    138071 H | No description available 
    138072  
    138073 
    138074 > hide #!2 models
    138075 
    138076 > hide #!1 models
    138077 
    138078 > hide #!6 atoms
    138079 
    138080 > show #!6 cartoons
    138081 
    138082 > select #6/A/B
    138083 
    138084 16370 atoms, 16501 bonds, 2 pseudobonds, 1038 residues, 2 models selected 
    138085 
    138086 > dssp
    138087 
    138088 > select #6/C/D
    138089 
    138090 5660 atoms, 5702 bonds, 2 pseudobonds, 358 residues, 2 models selected 
    138091 
    138092 > color sel dark slate blue
    138093 
    138094 > select #6/E/F/G/H
    138095 
    138096 1276 atoms, 1372 bonds, 40 residues, 1 model selected 
    138097 
    138098 > nucleotides sel tube/slab shape box
    138099 
    138100 > show sel atoms
    138101 
    138102 > nucleotides sel slab
    138103 
    138104 > style nucleic & sel stick
    138105 
    138106 Changed 1276 atom styles 
    138107 
    138108 > nucleotides sel tube/slab shape ellipsoid
    138109 
    138110 > nucleotides sel tube/slab shape muffler
    138111 
    138112 > nucleotides sel stubs
    138113 
    138114 > color sel godenrod
    138115 
    138116 Expected a color or one of 'byatom', 'bychain', 'byelement', 'byhetero',
    138117 'byidentity', 'bymodel', 'bynucleotide', 'bypolymer', 'fromatoms',
    138118 'fromcartoons', 'fromribbons', or 'random' or a keyword 
    138119 
    138120 > color sel goldenrod
    138121 
    138122 > select #6/A/B
    138123 
    138124 16370 atoms, 16501 bonds, 2 pseudobonds, 1038 residues, 2 models selected 
    138125 
    138126 > color sel bisque
    138127 
    138128 > select #6/A:DK4
    138129 
    138130 58 atoms, 63 bonds, 1 residue, 1 model selected 
    138131 
    138132 > show sel atoms
    138133 
    138134 > style sel ball
    138135 
    138136 Changed 58 atom styles 
    138137 
    138138 > color sel orangered
    138139 
    138140 > color sel byhetero
    138141 
    138142 > show #!2 models
    138143 
    138144 > select ~sel & ##selected
    138145 
    138146 23248 atoms, 23512 bonds, 4 pseudobonds, 1435 residues, 2 models selected 
    138147 
    138148 > select ~sel & ##selected
    138149 
    138150 58 atoms, 63 bonds, 1 residue, 1 model selected 
    138151 
    138152 > mmaker #2 to #6 showAlignment true
    138153 
    138154 Parameters 
    138155 --- 
    138156 Chain pairing | bb 
    138157 Alignment algorithm | Needleman-Wunsch 
    138158 Similarity matrix | BLOSUM-62 
    138159 SS fraction | 0.3 
    138160 Gap open (HH/SS/other) | 18/18/6 
    138161 Gap extend | 1 
    138162 SS matrix |  |  | H | S | O 
    138163 ---|---|---|--- 
    138164 H | 6 | -9 | -6 
    138165 S |  | 6 | -6 
    138166 O |  |  | 4 
    138167 Iteration cutoff | 2 
    138168  
    138169 Matchmaker 2024_Gyrase_last-coot-11.pdb, chain B (#6) with 7z9c, chain A (#2),
    138170 sequence alignment score = 1973.9 
    138171 Alignment identifier is 1 
    138172 Showing conservation header ("seq_conservation" residue attribute) for
    138173 alignment 1 
    138174 Hiding conservation header for alignment 1 
    138175 Chains used in RMSD evaluation for alignment 1: 7z9c #2/A, 2024_Gyrase_last-
    138176 coot-11.pdb #6/B 
    138177 Showing rmsd header ("seq_rmsd" residue attribute) for alignment 1 
    138178 RMSD between 444 pruned atom pairs is 0.958 angstroms; (across all 514 pairs:
    138179 1.590) 
    138180  
    138181 
    138182 > show #!1 models
    138183 
    138184 > hide #!6 models
    138185 
    138186 > hide #!1 models
    138187 
    138188 > show #!1 models
    138189 
    138190 > hide #!1 models
    138191 
    138192 > show #!6 models
    138193 
    138194 > color #2/A/B/C/D pink
    138195 
    138196 > select ::name="BWH"
    138197 
    138198 62 atoms, 66 bonds, 1 residue, 1 model selected 
    138199 
    138200 > color sel gray
    138201 
    138202 > color sel byhetero
    138203 
    138204 > select clear
    138205 
    138206 > select #2/E/F/G/H
    138207 
    138208 1306 atoms, 1460 bonds, 66 residues, 1 model selected 
    138209 
    138210 > nucleotides sel stubs
    138211 
    138212 > select clear
    138213 
    138214 The cached device pixel ratio value was stale on window expose. Please file a
    138215 QTBUG which explains how to reproduce. 
    138216 
    138217 > select #2/D:498,500
    138218 
    138219 16 atoms, 14 bonds, 2 residues, 1 model selected 
    138220 
    138221 > show sel atoms
    138222 
    138223 > style sel stick
    138224 
    138225 Changed 16 atom styles 
    138226 
    138227 > color sel byhetero
    138228 
    138229 > select #6/D:511,513
    138230 
    138231 24 atoms, 22 bonds, 2 residues, 1 model selected 
    138232 
    138233 > show sel atoms
    138234 
    138235 > style sel stick
    138236 
    138237 Changed 24 atom styles 
    138238 
    138239 > color sel byhetero
    138240 
    138241 > ui tool show Matchmaker
    138242 
    138243 > matchmaker #!2 to #6
    138244 
    138245 Parameters 
    138246 --- 
    138247 Chain pairing | bb 
    138248 Alignment algorithm | Needleman-Wunsch 
    138249 Similarity matrix | BLOSUM-62 
    138250 SS fraction | 0.3 
    138251 Gap open (HH/SS/other) | 18/18/6 
    138252 Gap extend | 1 
    138253 SS matrix |  |  | H | S | O 
    138254 ---|---|---|--- 
    138255 H | 6 | -9 | -6 
    138256 S |  | 6 | -6 
    138257 O |  |  | 4 
    138258 Iteration cutoff | 2 
    138259  
    138260 Matchmaker 2024_Gyrase_last-coot-11.pdb, chain B (#6) with 7z9c, chain A (#2),
    138261 sequence alignment score = 1973.9 
    138262 RMSD between 444 pruned atom pairs is 0.958 angstroms; (across all 514 pairs:
    138263 1.590) 
    138264  
    138265 
    138266 > ui tool show Matchmaker
    138267 
    138268 > matchmaker #!2 & sel to #6 & sel alg Smith-Waterman
    138269 
    138270 No molecules/chains to match specified 
    138271 
    138272 > select clear
    138273 
    138274 > ui tool show Matchmaker
    138275 
    138276 > mmaker #6 to #2/a pair bs alg sw matrix PAM-150 ss false cut 5.0
    138277 
    138278 Parameters 
    138279 --- 
    138280 Chain pairing | bs 
    138281 Alignment algorithm | Smith-Waterman 
    138282 Similarity matrix | PAM-150 
    138283 No secondary-structure guidance used 
    138284 Gap open | 12 
    138285 Gap extend | 1 
    138286 Iteration cutoff | 5 
    138287  
    138288 Matchmaker 7z9c (#2) with 2024_Gyrase_last-coot-11.pdb (#6), sequence
    138289 alignment score = 1707 
    138290 RMSD between 506 pruned atom pairs is 1.366 angstroms; (across all 514 pairs:
    138291 1.583) 
    138292  
    138293 
    138294 > mmaker #6/a,C to #2/a,b pair ss
    138295 
    138296 Parameters 
    138297 --- 
    138298 Chain pairing | ss 
    138299 Alignment algorithm | Needleman-Wunsch 
    138300 Similarity matrix | BLOSUM-62 
    138301 SS fraction | 0.3 
    138302 Gap open (HH/SS/other) | 18/18/6 
    138303 Gap extend | 1 
    138304 SS matrix |  |  | H | S | O 
    138305 ---|---|---|--- 
    138306 H | 6 | -9 | -6 
    138307 S |  | 6 | -6 
    138308 O |  |  | 4 
    138309 Iteration cutoff | 2 
    138310  
    138311 Matchmaker 7z9c, chain A (#2) with 2024_Gyrase_last-coot-11.pdb, chain A (#6),
    138312 sequence alignment score = 1959.3 
    138313 Matchmaker 7z9c, chain B (#2) with 2024_Gyrase_last-coot-11.pdb, chain C (#6),
    138314 sequence alignment score = 581.8 
    138315 RMSD between 404 pruned atom pairs is 0.910 angstroms; (across all 682 pairs:
    138316 31.157) 
    138317  
    138318 
    138319 > select #2/D:498,500
    138320 
    138321 16 atoms, 14 bonds, 2 residues, 1 model selected 
    138322 
    138323 > select #2/B:498,500
    138324 
    138325 16 atoms, 14 bonds, 2 residues, 1 model selected 
    138326 
    138327 > color sel byhetero
    138328 
    138329 > show sel atoms
    138330 
    138331 > style sel stick
    138332 
    138333 Changed 16 atom styles 
    138334 
    138335 > select #2/B:MG
    138336 
    138337 1 atom, 1 residue, 1 model selected 
    138338 
    138339 > color sel lime green
    138340 
    138341 > select #2/C:HOH
    138342 
    138343 1 atom, 1 residue, 1 model selected 
    138344 
    138345 > color sel red
    138346 
    138347 > style sel sphere
    138348 
    138349 Changed 1 atom style 
    138350 
    138351 > size sel atomRadius -0.2
    138352 
    138353 Changed 1 atom radii 
    138354 
    138355 > size sel atomRadius -0.4
    138356 
    138357 Changed 1 atom radii 
    138358 
    138359 > size sel atomRadius -0.2
    138360 
    138361 Changed 1 atom radii 
    138362 
    138363 > size sel atomRadius -0.1
    138364 
    138365 Changed 1 atom radii 
    138366 
    138367 > size sel atomRadius -0.1
    138368 
    138369 Changed 1 atom radii 
    138370 
    138371 > size sel atomRadius +0.1
    138372 
    138373 Changed 1 atom radii 
    138374 
    138375 > size sel atomRadius -0.05
    138376 
    138377 Changed 1 atom radii 
    138378 
    138379 > select #2/B:HOH
    138380 
    138381 4 atoms, 4 residues, 1 model selected 
    138382 
    138383 > color sel red
    138384 
    138385 > select #6/D:511,513
    138386 
    138387 24 atoms, 22 bonds, 2 residues, 1 model selected 
    138388 
    138389 > color #2.2 #797979ff models
    138390 
    138391 > color #2.2 #5e5e5eff models
    138392 
    138393 > delete sel hydrogen
    138394 
    138395 Expected a keyword 
    138396 
    138397 > delete sel hydrogens
    138398 
    138399 Expected a keyword 
    138400 
    138401 > delete sel H
    138402 
    138403 Expected a keyword 
    138404 
    138405 > delete sel Hydrogen
    138406 
    138407 Expected a keyword 
    138408 
    138409 > delete sel Hydrogens
    138410 
    138411 Expected a keyword 
    138412 
    138413 > delete Hydrogens
    138414 
    138415 Missing or invalid "atoms" argument: invalid atoms specifier 
    138416 
    138417 > delete Hydrogen
    138418 
    138419 Missing or invalid "atoms" argument: invalid atoms specifier 
    138420 
    138421 > delete H
    138422 
    138423 > select clear
    138424 
    138425 > select add #6/A:72
    138426 
    138427 8 atoms, 7 bonds, 1 residue, 1 model selected 
    138428 
    138429 > select add #2/A:74
    138430 
    138431 16 atoms, 14 bonds, 2 residues, 2 models selected 
    138432 
    138433 > select add #6/A:73
    138434 
    138435 20 atoms, 17 bonds, 3 residues, 2 models selected 
    138436 
    138437 > select add #6/A:74
    138438 
    138439 29 atoms, 25 bonds, 4 residues, 2 models selected 
    138440 
    138441 > select add #2/A:75
    138442 
    138443 33 atoms, 28 bonds, 5 residues, 2 models selected 
    138444 
    138445 > select add #2/A:77
    138446 
    138447 45 atoms, 40 bonds, 6 residues, 2 models selected 
    138448 
    138449 > select add #6/A:76
    138450 
    138451 55 atoms, 50 bonds, 7 residues, 2 models selected 
    138452 
    138453 > select add #6/A:75
    138454 
    138455 67 atoms, 62 bonds, 8 residues, 2 models selected 
    138456 
    138457 > select add #2/A:54
    138458 
    138459 74 atoms, 68 bonds, 9 residues, 2 models selected 
    138460 
    138461 > select add #6/A:77
    138462 
    138463 81 atoms, 75 bonds, 10 residues, 2 models selected 
    138464 
    138465 > select add #6/A:53
    138466 
    138467 89 atoms, 82 bonds, 11 residues, 2 models selected 
    138468 
    138469 > select add #6/A:78
    138470 
    138471 99 atoms, 92 bonds, 12 residues, 2 models selected 
    138472 
    138473 > select add #2/A:55
    138474 
    138475 107 atoms, 99 bonds, 13 residues, 2 models selected 
    138476 
    138477 > hide sel cartoons
    138478 
    138479 > select add #2/A:76
    138480 
    138481 116 atoms, 107 bonds, 14 residues, 2 models selected 
    138482 
    138483 > select add #2/A:78
    138484 
    138485 126 atoms, 117 bonds, 15 residues, 2 models selected 
    138486 
    138487 > select add #2/A:79
    138488 
    138489 133 atoms, 124 bonds, 16 residues, 2 models selected 
    138490 
    138491 > select add #2/A:80
    138492 
    138493 143 atoms, 134 bonds, 17 residues, 2 models selected 
    138494 
    138495 > hide sel cartoons
    138496 
    138497 > select add #6/A:52
    138498 
    138499 152 atoms, 142 bonds, 18 residues, 2 models selected 
    138500 
    138501 > hide sel cartoons
    138502 
    138503 > select add #2/A:73
    138504 
    138505 159 atoms, 148 bonds, 19 residues, 2 models selected 
    138506 
    138507 > select add #6/A:71
    138508 
    138509 166 atoms, 154 bonds, 20 residues, 2 models selected 
    138510 
    138511 > select add #2/A:72
    138512 
    138513 174 atoms, 161 bonds, 21 residues, 2 models selected 
    138514 
    138515 > select add #6/A:70
    138516 
    138517 182 atoms, 168 bonds, 22 residues, 2 models selected 
    138518 
    138519 > hide sel cartoons
    138520 
    138521 > select add #2/A:56
    138522 
    138523 186 atoms, 171 bonds, 23 residues, 2 models selected 
    138524 
    138525 > select add #6/A:54
    138526 
    138527 190 atoms, 174 bonds, 24 residues, 2 models selected 
    138528 
    138529 > hide sel cartoons
    138530 
    138531 > select add #2/B:521
    138532 
    138533 198 atoms, 181 bonds, 25 residues, 2 models selected 
    138534 
    138535 > select add #6/D:534
    138536 
    138537 206 atoms, 188 bonds, 26 residues, 2 models selected 
    138538 
    138539 > select add #2/B:522
    138540 
    138541 213 atoms, 194 bonds, 27 residues, 2 models selected 
    138542 
    138543 > select add #6/D:535
    138544 
    138545 220 atoms, 200 bonds, 28 residues, 2 models selected 
    138546 
    138547 > select add #2/B:520
    138548 
    138549 229 atoms, 208 bonds, 29 residues, 2 models selected 
    138550 
    138551 > hide sel cartoons
    138552 
    138553 > select add #6/D:533
    138554 
    138555 238 atoms, 216 bonds, 30 residues, 2 models selected 
    138556 
    138557 > hide sel cartoons
    138558 
    138559 > select add #2/A:150
    138560 
    138561 246 atoms, 223 bonds, 31 residues, 2 models selected 
    138562 
    138563 > select add #2/A:151
    138564 
    138565 250 atoms, 226 bonds, 32 residues, 2 models selected 
    138566 
    138567 > select add #2/A:149
    138568 
    138569 262 atoms, 238 bonds, 33 residues, 2 models selected 
    138570 
    138571 > select add #6/A:147
    138572 
    138573 274 atoms, 250 bonds, 34 residues, 2 models selected 
    138574 
    138575 > select add #6/A:148
    138576 
    138577 282 atoms, 257 bonds, 35 residues, 2 models selected 
    138578 
    138579 > select add #6/A:146
    138580 
    138581 290 atoms, 264 bonds, 36 residues, 2 models selected 
    138582 
    138583 > select add #2/A:148
    138584 
    138585 298 atoms, 271 bonds, 37 residues, 2 models selected 
    138586 
    138587 > select add #6/A:145
    138588 
    138589 306 atoms, 278 bonds, 38 residues, 2 models selected 
    138590 
    138591 > select add #2/A:147
    138592 
    138593 314 atoms, 285 bonds, 39 residues, 2 models selected 
    138594 
    138595 > select add #6/A:149
    138596 
    138597 318 atoms, 288 bonds, 40 residues, 2 models selected 
    138598 
    138599 > hide sel cartoons
    138600 
    138601 > select add #2/A:152
    138602 
    138603 325 atoms, 294 bonds, 41 residues, 2 models selected 
    138604 
    138605 > select add #6/A:150
    138606 
    138607 331 atoms, 299 bonds, 42 residues, 2 models selected 
    138608 
    138609 > select add #2/A:153
    138610 
    138611 340 atoms, 307 bonds, 43 residues, 2 models selected 
    138612 
    138613 > select add #6/A:152
    138614 
    138615 351 atoms, 317 bonds, 44 residues, 2 models selected 
    138616 
    138617 > select add #6/A:151
    138618 
    138619 360 atoms, 325 bonds, 45 residues, 2 models selected 
    138620 
    138621 > hide sel cartoons
    138622 
    138623 > select add #2/A:154
    138624 
    138625 369 atoms, 333 bonds, 46 residues, 2 models selected 
    138626 
    138627 > hide sel cartoons
    138628 
    138629 > lighting simple
    138630 
    138631 > lighting soft
    138632 
    138633 > lighting full
    138634 
    138635 > lighting soft
    138636 
    138637 > lighting simple
    138638 
    138639 > ui tool show Distances
    138640 
    138641 > select add #6/D:513@OD2
    138642 
    138643 370 atoms, 333 bonds, 47 residues, 2 models selected 
    138644 
    138645 > select add #2/B:901@MG
    138646 
    138647 371 atoms, 333 bonds, 48 residues, 2 models selected 
    138648 Exactly two atoms must be selected! 
    138649 [Repeated 1 time(s)]
    138650 
    138651 > select clear
    138652 
    138653 > select add #2/B:901@MG
    138654 
    138655 1 atom, 1 residue, 1 model selected 
    138656 
    138657 > select add #6/D:513@OD2
    138658 
    138659 2 atoms, 2 residues, 2 models selected 
    138660 
    138661 > distance #2/B:901@MG #6/D:513@OD2
    138662 
    138663 Distance between 7z9c #2/B MG 901 MG and 2024_Gyrase_last-coot-11.pdb #6/D ASP
    138664 513 OD2: 1.968Å 
    138665 
    138666 > select clear
    138667 
    138668 > save "/Users/angela/Desktop/Hannover/Results/Cryo/Paper/Final
    138669 > Images/Ab_Eco_Asp.png" width 2000 height 1315 supersample 3
    138670 > transparentBackground true
    138671 
    138672 > show #!5 models
    138673 
    138674 > hide #2.2 models
    138675 
    138676 > hide #!2 models
    138677 
    138678 > show #!4 models
    138679 
    138680 > hide #!4 models
    138681 
    138682 > show #5.1 models
    138683 
    138684 > show #5.2 models
    138685 
    138686 > show #5.3 models
    138687 
    138688 > hide #5.3 models
    138689 
    138690 > show #5.3 models
    138691 
    138692 > hide #5.3 models
    138693 
    138694 > show #5.3 models
    138695 
    138696 > color #5.2 #5e5e5eff models
    138697 
    138698 Traceback (most recent call last): 
    138699 File
    138700 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138701 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    138702 self.session.ui.mouse_modes.mouse_pause_tracking() 
    138703 File
    138704 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138705 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    138706 mouse_pause_tracking 
    138707 self._mouse_pause() 
    138708 File
    138709 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138710 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    138711 m.pause(self._mouse_pause_position) 
    138712 File
    138713 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138714 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    138715 p = self.view.picked_object(x, y) 
    138716 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138717 File
    138718 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138719 packages/chimerax/graphics/view.py", line 838, in picked_object 
    138720 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    138721 beyond, 
    138722 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138723 File
    138724 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138725 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    138726 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    138727 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138728 File
    138729 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138730 packages/chimerax/core/models.py", line 143, in first_intercept 
    138731 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    138732 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138733 File
    138734 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138735 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    138736 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    138737 exclude=exclude) 
    138738 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138739 File
    138740 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138741 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    138742 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    138743 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138744 File
    138745 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138746 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    138747 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    138748 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138749 File
    138750 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138751 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    138752 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    138753 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138754 File
    138755 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138756 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    138757 p = super().first_intercept(mxyz1, mxyz2) 
    138758 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138759 File
    138760 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138761 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    138762 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    138763 exclude=exclude) 
    138764 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138765 File
    138766 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138767 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    138768 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    138769 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138770 File
    138771 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138772 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    138773 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    138774 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138775 File
    138776 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138777 packages/chimerax/graphics/drawing.py", line 1108, in
    138778 _first_intercept_excluding_children 
    138779 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    138780 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138781 File
    138782 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138783 packages/chimerax/geometry/place.py", line 201, in inverse 
    138784 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    138785 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138786 File
    138787 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138788 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    138789 rinv[:, :] = matrix_inverse(r) 
    138790 ^^^^^^^^^^^^^^^^^ 
    138791 File
    138792 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138793 packages/numpy/linalg/linalg.py", line 561, in inv 
    138794 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    138795 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138796 File
    138797 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138798 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    138799 raise LinAlgError("Singular matrix") 
    138800 numpy.linalg.LinAlgError: Singular matrix 
    138801  
    138802 numpy.linalg.LinAlgError: Singular matrix 
    138803  
    138804 File
    138805 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138806 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    138807 raise LinAlgError("Singular matrix") 
    138808  
    138809 See log for complete Python traceback. 
    138810  
    138811 
    138812 > save /Users/angela/Desktop/Structure/Ab_Asps.cxs
    138813 
    138814 ——— End of log from Wed Aug 13 11:08:38 2025 ———
    138815 
    138816 opened ChimeraX session 
    138817 
    138818 > show #!1 models
    138819 
    138820 > close #1
    138821 
    138822 > color #5 pink
    138823 
    138824 Traceback (most recent call last): 
    138825 File
    138826 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138827 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    138828 self.session.ui.mouse_modes.mouse_pause_tracking() 
    138829 File
    138830 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138831 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    138832 mouse_pause_tracking 
    138833 self._mouse_pause() 
    138834 File
    138835 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138836 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    138837 m.pause(self._mouse_pause_position) 
    138838 File
    138839 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138840 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    138841 p = self.view.picked_object(x, y) 
    138842 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138843 File
    138844 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138845 packages/chimerax/graphics/view.py", line 838, in picked_object 
    138846 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    138847 beyond, 
    138848 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138849 File
    138850 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138851 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    138852 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    138853 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138854 File
    138855 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138856 packages/chimerax/core/models.py", line 143, in first_intercept 
    138857 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    138858 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138859 File
    138860 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138861 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    138862 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    138863 exclude=exclude) 
    138864 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138865 File
    138866 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138867 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    138868 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    138869 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138870 File
    138871 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138872 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    138873 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    138874 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138875 File
    138876 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138877 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    138878 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    138879 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138880 File
    138881 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138882 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    138883 p = super().first_intercept(mxyz1, mxyz2) 
    138884 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138885 File
    138886 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138887 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    138888 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    138889 exclude=exclude) 
    138890 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138891 File
    138892 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138893 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    138894 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    138895 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138896 File
    138897 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138898 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    138899 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    138900 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138901 File
    138902 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138903 packages/chimerax/graphics/drawing.py", line 1108, in
    138904 _first_intercept_excluding_children 
    138905 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    138906 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138907 File
    138908 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138909 packages/chimerax/geometry/place.py", line 201, in inverse 
    138910 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    138911 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138912 File
    138913 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138914 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    138915 rinv[:, :] = matrix_inverse(r) 
    138916 ^^^^^^^^^^^^^^^^^ 
    138917 File
    138918 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138919 packages/numpy/linalg/linalg.py", line 561, in inv 
    138920 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    138921 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138922 File
    138923 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138924 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    138925 raise LinAlgError("Singular matrix") 
    138926 numpy.linalg.LinAlgError: Singular matrix 
    138927  
    138928 numpy.linalg.LinAlgError: Singular matrix 
    138929  
    138930 File
    138931 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138932 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    138933 raise LinAlgError("Singular matrix") 
    138934  
    138935 See log for complete Python traceback. 
    138936  
    138937 Traceback (most recent call last): 
    138938 File
    138939 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138940 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    138941 self.session.ui.mouse_modes.mouse_pause_tracking() 
    138942 File
    138943 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138944 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    138945 mouse_pause_tracking 
    138946 self._mouse_pause() 
    138947 File
    138948 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138949 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    138950 m.pause(self._mouse_pause_position) 
    138951 File
    138952 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138953 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    138954 p = self.view.picked_object(x, y) 
    138955 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138956 File
    138957 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138958 packages/chimerax/graphics/view.py", line 838, in picked_object 
    138959 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    138960 beyond, 
    138961 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138962 File
    138963 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138964 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    138965 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    138966 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138967 File
    138968 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138969 packages/chimerax/core/models.py", line 143, in first_intercept 
    138970 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    138971 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138972 File
    138973 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138974 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    138975 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    138976 exclude=exclude) 
    138977 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138978 File
    138979 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138980 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    138981 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    138982 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138983 File
    138984 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138985 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    138986 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    138987 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138988 File
    138989 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138990 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    138991 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    138992 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138993 File
    138994 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    138995 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    138996 p = super().first_intercept(mxyz1, mxyz2) 
    138997 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    138998 File
    138999 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139000 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    139001 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    139002 exclude=exclude) 
    139003 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139004 File
    139005 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139006 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    139007 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    139008 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139009 File
    139010 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139011 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    139012 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    139013 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139014 File
    139015 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139016 packages/chimerax/graphics/drawing.py", line 1108, in
    139017 _first_intercept_excluding_children 
    139018 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    139019 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139020 File
    139021 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139022 packages/chimerax/geometry/place.py", line 201, in inverse 
    139023 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    139024 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139025 File
    139026 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139027 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    139028 rinv[:, :] = matrix_inverse(r) 
    139029 ^^^^^^^^^^^^^^^^^ 
    139030 File
    139031 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139032 packages/numpy/linalg/linalg.py", line 561, in inv 
    139033 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    139034 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139035 File
    139036 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139037 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    139038 raise LinAlgError("Singular matrix") 
    139039 numpy.linalg.LinAlgError: Singular matrix 
    139040  
    139041 numpy.linalg.LinAlgError: Singular matrix 
    139042  
    139043 File
    139044 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139045 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    139046 raise LinAlgError("Singular matrix") 
    139047  
    139048 See log for complete Python traceback. 
    139049  
    139050 Traceback (most recent call last): 
    139051 File
    139052 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139053 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    139054 self.session.ui.mouse_modes.mouse_pause_tracking() 
    139055 File
    139056 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139057 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    139058 mouse_pause_tracking 
    139059 self._mouse_pause() 
    139060 File
    139061 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139062 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    139063 m.pause(self._mouse_pause_position) 
    139064 File
    139065 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139066 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    139067 p = self.view.picked_object(x, y) 
    139068 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139069 File
    139070 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139071 packages/chimerax/graphics/view.py", line 838, in picked_object 
    139072 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    139073 beyond, 
    139074 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139075 File
    139076 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139077 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    139078 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    139079 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139080 File
    139081 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139082 packages/chimerax/core/models.py", line 143, in first_intercept 
    139083 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    139084 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139085 File
    139086 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139087 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    139088 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    139089 exclude=exclude) 
    139090 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139091 File
    139092 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139093 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    139094 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    139095 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139096 File
    139097 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139098 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    139099 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    139100 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139101 File
    139102 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139103 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    139104 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    139105 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139106 File
    139107 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139108 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    139109 p = super().first_intercept(mxyz1, mxyz2) 
    139110 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139111 File
    139112 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139113 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    139114 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    139115 exclude=exclude) 
    139116 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139117 File
    139118 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139119 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    139120 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    139121 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139122 File
    139123 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139124 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    139125 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    139126 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139127 File
    139128 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139129 packages/chimerax/graphics/drawing.py", line 1108, in
    139130 _first_intercept_excluding_children 
    139131 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    139132 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139133 File
    139134 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139135 packages/chimerax/geometry/place.py", line 201, in inverse 
    139136 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    139137 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139138 File
    139139 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139140 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    139141 rinv[:, :] = matrix_inverse(r) 
    139142 ^^^^^^^^^^^^^^^^^ 
    139143 File
    139144 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139145 packages/numpy/linalg/linalg.py", line 561, in inv 
    139146 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    139147 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139148 File
    139149 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139150 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    139151 raise LinAlgError("Singular matrix") 
    139152 numpy.linalg.LinAlgError: Singular matrix 
    139153  
    139154 numpy.linalg.LinAlgError: Singular matrix 
    139155  
    139156 File
    139157 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139158 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    139159 raise LinAlgError("Singular matrix") 
    139160  
    139161 See log for complete Python traceback. 
    139162  
    139163 Traceback (most recent call last): 
    139164 File
    139165 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139166 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    139167 self.session.ui.mouse_modes.mouse_pause_tracking() 
    139168 File
    139169 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139170 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    139171 mouse_pause_tracking 
    139172 self._mouse_pause() 
    139173 File
    139174 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139175 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    139176 m.pause(self._mouse_pause_position) 
    139177 File
    139178 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139179 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    139180 p = self.view.picked_object(x, y) 
    139181 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139182 File
    139183 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139184 packages/chimerax/graphics/view.py", line 838, in picked_object 
    139185 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    139186 beyond, 
    139187 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139188 File
    139189 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139190 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    139191 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    139192 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139193 File
    139194 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139195 packages/chimerax/core/models.py", line 143, in first_intercept 
    139196 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    139197 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139198 File
    139199 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139200 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    139201 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    139202 exclude=exclude) 
    139203 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139204 File
    139205 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139206 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    139207 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    139208 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139209 File
    139210 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139211 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    139212 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    139213 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139214 File
    139215 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139216 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    139217 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    139218 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139219 File
    139220 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139221 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    139222 p = super().first_intercept(mxyz1, mxyz2) 
    139223 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139224 File
    139225 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139226 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    139227 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    139228 exclude=exclude) 
    139229 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139230 File
    139231 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139232 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    139233 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    139234 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139235 File
    139236 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139237 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    139238 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    139239 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139240 File
    139241 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139242 packages/chimerax/graphics/drawing.py", line 1108, in
    139243 _first_intercept_excluding_children 
    139244 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    139245 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139246 File
    139247 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139248 packages/chimerax/geometry/place.py", line 201, in inverse 
    139249 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    139250 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139251 File
    139252 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139253 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    139254 rinv[:, :] = matrix_inverse(r) 
    139255 ^^^^^^^^^^^^^^^^^ 
    139256 File
    139257 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139258 packages/numpy/linalg/linalg.py", line 561, in inv 
    139259 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    139260 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139261 File
    139262 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139263 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    139264 raise LinAlgError("Singular matrix") 
    139265 numpy.linalg.LinAlgError: Singular matrix 
    139266  
    139267 numpy.linalg.LinAlgError: Singular matrix 
    139268  
    139269 File
    139270 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139271 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    139272 raise LinAlgError("Singular matrix") 
    139273  
    139274 See log for complete Python traceback. 
    139275  
    139276 Traceback (most recent call last): 
    139277 File
    139278 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139279 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    139280 self.session.ui.mouse_modes.mouse_pause_tracking() 
    139281 File
    139282 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139283 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    139284 mouse_pause_tracking 
    139285 self._mouse_pause() 
    139286 File
    139287 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139288 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    139289 m.pause(self._mouse_pause_position) 
    139290 File
    139291 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139292 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    139293 p = self.view.picked_object(x, y) 
    139294 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139295 File
    139296 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139297 packages/chimerax/graphics/view.py", line 838, in picked_object 
    139298 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    139299 beyond, 
    139300 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139301 File
    139302 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139303 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    139304 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    139305 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139306 File
    139307 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139308 packages/chimerax/core/models.py", line 143, in first_intercept 
    139309 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    139310 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139311 File
    139312 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139313 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    139314 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    139315 exclude=exclude) 
    139316 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139317 File
    139318 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139319 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    139320 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    139321 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139322 File
    139323 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139324 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    139325 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    139326 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139327 File
    139328 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139329 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    139330 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    139331 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139332 File
    139333 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139334 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    139335 p = super().first_intercept(mxyz1, mxyz2) 
    139336 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139337 File
    139338 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139339 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    139340 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    139341 exclude=exclude) 
    139342 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139343 File
    139344 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139345 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    139346 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    139347 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139348 File
    139349 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139350 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    139351 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    139352 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139353 File
    139354 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139355 packages/chimerax/graphics/drawing.py", line 1108, in
    139356 _first_intercept_excluding_children 
    139357 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    139358 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139359 File
    139360 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139361 packages/chimerax/geometry/place.py", line 201, in inverse 
    139362 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    139363 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139364 File
    139365 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139366 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    139367 rinv[:, :] = matrix_inverse(r) 
    139368 ^^^^^^^^^^^^^^^^^ 
    139369 File
    139370 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139371 packages/numpy/linalg/linalg.py", line 561, in inv 
    139372 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    139373 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139374 File
    139375 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139376 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    139377 raise LinAlgError("Singular matrix") 
    139378 numpy.linalg.LinAlgError: Singular matrix 
    139379  
    139380 numpy.linalg.LinAlgError: Singular matrix 
    139381  
    139382 File
    139383 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139384 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    139385 raise LinAlgError("Singular matrix") 
    139386  
    139387 See log for complete Python traceback. 
    139388  
    139389 Traceback (most recent call last): 
    139390 File
    139391 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139392 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    139393 self.session.ui.mouse_modes.mouse_pause_tracking() 
    139394 File
    139395 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139396 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    139397 mouse_pause_tracking 
    139398 self._mouse_pause() 
    139399 File
    139400 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139401 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    139402 m.pause(self._mouse_pause_position) 
    139403 File
    139404 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139405 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    139406 p = self.view.picked_object(x, y) 
    139407 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139408 File
    139409 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139410 packages/chimerax/graphics/view.py", line 838, in picked_object 
    139411 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    139412 beyond, 
    139413 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139414 File
    139415 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139416 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    139417 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    139418 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139419 File
    139420 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139421 packages/chimerax/core/models.py", line 143, in first_intercept 
    139422 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    139423 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139424 File
    139425 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139426 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    139427 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    139428 exclude=exclude) 
    139429 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139430 File
    139431 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139432 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    139433 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    139434 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139435 File
    139436 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139437 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    139438 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    139439 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139440 File
    139441 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139442 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    139443 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    139444 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139445 File
    139446 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139447 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    139448 p = super().first_intercept(mxyz1, mxyz2) 
    139449 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139450 File
    139451 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139452 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    139453 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    139454 exclude=exclude) 
    139455 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139456 File
    139457 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139458 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    139459 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    139460 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139461 File
    139462 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139463 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    139464 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    139465 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139466 File
    139467 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139468 packages/chimerax/graphics/drawing.py", line 1108, in
    139469 _first_intercept_excluding_children 
    139470 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    139471 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139472 File
    139473 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139474 packages/chimerax/geometry/place.py", line 201, in inverse 
    139475 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    139476 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139477 File
    139478 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139479 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    139480 rinv[:, :] = matrix_inverse(r) 
    139481 ^^^^^^^^^^^^^^^^^ 
    139482 File
    139483 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139484 packages/numpy/linalg/linalg.py", line 561, in inv 
    139485 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    139486 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139487 File
    139488 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139489 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    139490 raise LinAlgError("Singular matrix") 
    139491 numpy.linalg.LinAlgError: Singular matrix 
    139492  
    139493 numpy.linalg.LinAlgError: Singular matrix 
    139494  
    139495 File
    139496 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139497 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    139498 raise LinAlgError("Singular matrix") 
    139499  
    139500 See log for complete Python traceback. 
    139501  
    139502 Traceback (most recent call last): 
    139503 File
    139504 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139505 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    139506 self.session.ui.mouse_modes.mouse_pause_tracking() 
    139507 File
    139508 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139509 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    139510 mouse_pause_tracking 
    139511 self._mouse_pause() 
    139512 File
    139513 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139514 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    139515 m.pause(self._mouse_pause_position) 
    139516 File
    139517 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139518 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    139519 p = self.view.picked_object(x, y) 
    139520 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139521 File
    139522 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139523 packages/chimerax/graphics/view.py", line 838, in picked_object 
    139524 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    139525 beyond, 
    139526 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139527 File
    139528 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139529 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    139530 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    139531 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139532 File
    139533 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139534 packages/chimerax/core/models.py", line 143, in first_intercept 
    139535 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    139536 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139537 File
    139538 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139539 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    139540 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    139541 exclude=exclude) 
    139542 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139543 File
    139544 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139545 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    139546 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    139547 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139548 File
    139549 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139550 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    139551 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    139552 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139553 File
    139554 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139555 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    139556 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    139557 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139558 File
    139559 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139560 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    139561 p = super().first_intercept(mxyz1, mxyz2) 
    139562 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139563 File
    139564 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139565 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    139566 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    139567 exclude=exclude) 
    139568 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139569 File
    139570 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139571 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    139572 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    139573 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139574 File
    139575 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139576 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    139577 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    139578 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139579 File
    139580 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139581 packages/chimerax/graphics/drawing.py", line 1108, in
    139582 _first_intercept_excluding_children 
    139583 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    139584 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139585 File
    139586 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139587 packages/chimerax/geometry/place.py", line 201, in inverse 
    139588 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    139589 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139590 File
    139591 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139592 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    139593 rinv[:, :] = matrix_inverse(r) 
    139594 ^^^^^^^^^^^^^^^^^ 
    139595 File
    139596 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139597 packages/numpy/linalg/linalg.py", line 561, in inv 
    139598 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    139599 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139600 File
    139601 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139602 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    139603 raise LinAlgError("Singular matrix") 
    139604 numpy.linalg.LinAlgError: Singular matrix 
    139605  
    139606 numpy.linalg.LinAlgError: Singular matrix 
    139607  
    139608 File
    139609 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139610 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    139611 raise LinAlgError("Singular matrix") 
    139612  
    139613 See log for complete Python traceback. 
    139614  
    139615 Traceback (most recent call last): 
    139616 File
    139617 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139618 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    139619 self.session.ui.mouse_modes.mouse_pause_tracking() 
    139620 File
    139621 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139622 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    139623 mouse_pause_tracking 
    139624 self._mouse_pause() 
    139625 File
    139626 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139627 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    139628 m.pause(self._mouse_pause_position) 
    139629 File
    139630 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139631 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    139632 p = self.view.picked_object(x, y) 
    139633 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139634 File
    139635 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139636 packages/chimerax/graphics/view.py", line 838, in picked_object 
    139637 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    139638 beyond, 
    139639 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139640 File
    139641 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139642 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    139643 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    139644 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139645 File
    139646 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139647 packages/chimerax/core/models.py", line 143, in first_intercept 
    139648 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    139649 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139650 File
    139651 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139652 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    139653 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    139654 exclude=exclude) 
    139655 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139656 File
    139657 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139658 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    139659 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    139660 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139661 File
    139662 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139663 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    139664 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    139665 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139666 File
    139667 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139668 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    139669 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    139670 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139671 File
    139672 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139673 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    139674 p = super().first_intercept(mxyz1, mxyz2) 
    139675 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139676 File
    139677 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139678 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    139679 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    139680 exclude=exclude) 
    139681 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139682 File
    139683 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139684 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    139685 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    139686 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139687 File
    139688 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139689 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    139690 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    139691 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139692 File
    139693 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139694 packages/chimerax/graphics/drawing.py", line 1108, in
    139695 _first_intercept_excluding_children 
    139696 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    139697 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139698 File
    139699 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139700 packages/chimerax/geometry/place.py", line 201, in inverse 
    139701 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    139702 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139703 File
    139704 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139705 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    139706 rinv[:, :] = matrix_inverse(r) 
    139707 ^^^^^^^^^^^^^^^^^ 
    139708 File
    139709 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139710 packages/numpy/linalg/linalg.py", line 561, in inv 
    139711 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    139712 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139713 File
    139714 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139715 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    139716 raise LinAlgError("Singular matrix") 
    139717 numpy.linalg.LinAlgError: Singular matrix 
    139718  
    139719 numpy.linalg.LinAlgError: Singular matrix 
    139720  
    139721 File
    139722 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139723 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    139724 raise LinAlgError("Singular matrix") 
    139725  
    139726 See log for complete Python traceback. 
    139727  
    139728 Traceback (most recent call last): 
    139729 File
    139730 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139731 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    139732 self.session.ui.mouse_modes.mouse_pause_tracking() 
    139733 File
    139734 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139735 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    139736 mouse_pause_tracking 
    139737 self._mouse_pause() 
    139738 File
    139739 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139740 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    139741 m.pause(self._mouse_pause_position) 
    139742 File
    139743 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139744 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    139745 p = self.view.picked_object(x, y) 
    139746 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139747 File
    139748 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139749 packages/chimerax/graphics/view.py", line 838, in picked_object 
    139750 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    139751 beyond, 
    139752 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139753 File
    139754 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139755 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    139756 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    139757 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139758 File
    139759 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139760 packages/chimerax/core/models.py", line 143, in first_intercept 
    139761 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    139762 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139763 File
    139764 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139765 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    139766 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    139767 exclude=exclude) 
    139768 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139769 File
    139770 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139771 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    139772 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    139773 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139774 File
    139775 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139776 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    139777 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    139778 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139779 File
    139780 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139781 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    139782 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    139783 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139784 File
    139785 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139786 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    139787 p = super().first_intercept(mxyz1, mxyz2) 
    139788 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139789 File
    139790 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139791 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    139792 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    139793 exclude=exclude) 
    139794 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139795 File
    139796 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139797 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    139798 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    139799 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139800 File
    139801 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139802 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    139803 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    139804 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139805 File
    139806 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139807 packages/chimerax/graphics/drawing.py", line 1108, in
    139808 _first_intercept_excluding_children 
    139809 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    139810 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139811 File
    139812 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139813 packages/chimerax/geometry/place.py", line 201, in inverse 
    139814 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    139815 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139816 File
    139817 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139818 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    139819 rinv[:, :] = matrix_inverse(r) 
    139820 ^^^^^^^^^^^^^^^^^ 
    139821 File
    139822 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139823 packages/numpy/linalg/linalg.py", line 561, in inv 
    139824 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    139825 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139826 File
    139827 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139828 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    139829 raise LinAlgError("Singular matrix") 
    139830 numpy.linalg.LinAlgError: Singular matrix 
    139831  
    139832 numpy.linalg.LinAlgError: Singular matrix 
    139833  
    139834 File
    139835 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139836 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    139837 raise LinAlgError("Singular matrix") 
    139838  
    139839 See log for complete Python traceback. 
    139840  
    139841 Traceback (most recent call last): 
    139842 File
    139843 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139844 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    139845 self.session.ui.mouse_modes.mouse_pause_tracking() 
    139846 File
    139847 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139848 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    139849 mouse_pause_tracking 
    139850 self._mouse_pause() 
    139851 File
    139852 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139853 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    139854 m.pause(self._mouse_pause_position) 
    139855 File
    139856 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139857 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    139858 p = self.view.picked_object(x, y) 
    139859 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139860 File
    139861 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139862 packages/chimerax/graphics/view.py", line 838, in picked_object 
    139863 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    139864 beyond, 
    139865 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139866 File
    139867 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139868 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    139869 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    139870 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139871 File
    139872 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139873 packages/chimerax/core/models.py", line 143, in first_intercept 
    139874 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    139875 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139876 File
    139877 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139878 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    139879 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    139880 exclude=exclude) 
    139881 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139882 File
    139883 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139884 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    139885 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    139886 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139887 File
    139888 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139889 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    139890 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    139891 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139892 File
    139893 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139894 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    139895 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    139896 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139897 File
    139898 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139899 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    139900 p = super().first_intercept(mxyz1, mxyz2) 
    139901 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139902 File
    139903 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139904 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    139905 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    139906 exclude=exclude) 
    139907 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139908 File
    139909 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139910 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    139911 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    139912 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139913 File
    139914 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139915 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    139916 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    139917 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139918 File
    139919 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139920 packages/chimerax/graphics/drawing.py", line 1108, in
    139921 _first_intercept_excluding_children 
    139922 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    139923 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139924 File
    139925 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139926 packages/chimerax/geometry/place.py", line 201, in inverse 
    139927 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    139928 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139929 File
    139930 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139931 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    139932 rinv[:, :] = matrix_inverse(r) 
    139933 ^^^^^^^^^^^^^^^^^ 
    139934 File
    139935 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139936 packages/numpy/linalg/linalg.py", line 561, in inv 
    139937 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    139938 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139939 File
    139940 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139941 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    139942 raise LinAlgError("Singular matrix") 
    139943 numpy.linalg.LinAlgError: Singular matrix 
    139944  
    139945 numpy.linalg.LinAlgError: Singular matrix 
    139946  
    139947 File
    139948 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139949 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    139950 raise LinAlgError("Singular matrix") 
    139951  
    139952 See log for complete Python traceback. 
    139953  
    139954 Traceback (most recent call last): 
    139955 File
    139956 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139957 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    139958 self.session.ui.mouse_modes.mouse_pause_tracking() 
    139959 File
    139960 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139961 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    139962 mouse_pause_tracking 
    139963 self._mouse_pause() 
    139964 File
    139965 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139966 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    139967 m.pause(self._mouse_pause_position) 
    139968 File
    139969 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139970 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    139971 p = self.view.picked_object(x, y) 
    139972 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139973 File
    139974 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139975 packages/chimerax/graphics/view.py", line 838, in picked_object 
    139976 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    139977 beyond, 
    139978 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139979 File
    139980 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139981 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    139982 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    139983 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139984 File
    139985 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139986 packages/chimerax/core/models.py", line 143, in first_intercept 
    139987 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    139988 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139989 File
    139990 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139991 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    139992 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    139993 exclude=exclude) 
    139994 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    139995 File
    139996 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    139997 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    139998 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    139999 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140000 File
    140001 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140002 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    140003 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    140004 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140005 File
    140006 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140007 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    140008 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    140009 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140010 File
    140011 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140012 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    140013 p = super().first_intercept(mxyz1, mxyz2) 
    140014 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140015 File
    140016 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140017 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    140018 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    140019 exclude=exclude) 
    140020 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140021 File
    140022 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140023 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    140024 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    140025 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140026 File
    140027 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140028 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    140029 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    140030 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140031 File
    140032 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140033 packages/chimerax/graphics/drawing.py", line 1108, in
    140034 _first_intercept_excluding_children 
    140035 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    140036 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140037 File
    140038 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140039 packages/chimerax/geometry/place.py", line 201, in inverse 
    140040 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    140041 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140042 File
    140043 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140044 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    140045 rinv[:, :] = matrix_inverse(r) 
    140046 ^^^^^^^^^^^^^^^^^ 
    140047 File
    140048 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140049 packages/numpy/linalg/linalg.py", line 561, in inv 
    140050 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    140051 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140052 File
    140053 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140054 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    140055 raise LinAlgError("Singular matrix") 
    140056 numpy.linalg.LinAlgError: Singular matrix 
    140057  
    140058 numpy.linalg.LinAlgError: Singular matrix 
    140059  
    140060 File
    140061 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140062 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    140063 raise LinAlgError("Singular matrix") 
    140064  
    140065 See log for complete Python traceback. 
    140066  
    140067 Traceback (most recent call last): 
    140068 File
    140069 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140070 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    140071 self.session.ui.mouse_modes.mouse_pause_tracking() 
    140072 File
    140073 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140074 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    140075 mouse_pause_tracking 
    140076 self._mouse_pause() 
    140077 File
    140078 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140079 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    140080 m.pause(self._mouse_pause_position) 
    140081 File
    140082 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140083 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    140084 p = self.view.picked_object(x, y) 
    140085 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140086 File
    140087 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140088 packages/chimerax/graphics/view.py", line 838, in picked_object 
    140089 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    140090 beyond, 
    140091 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140092 File
    140093 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140094 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    140095 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    140096 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140097 File
    140098 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140099 packages/chimerax/core/models.py", line 143, in first_intercept 
    140100 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    140101 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140102 File
    140103 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140104 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    140105 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    140106 exclude=exclude) 
    140107 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140108 File
    140109 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140110 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    140111 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    140112 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140113 File
    140114 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140115 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    140116 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    140117 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140118 File
    140119 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140120 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    140121 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    140122 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140123 File
    140124 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140125 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    140126 p = super().first_intercept(mxyz1, mxyz2) 
    140127 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140128 File
    140129 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140130 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    140131 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    140132 exclude=exclude) 
    140133 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140134 File
    140135 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140136 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    140137 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    140138 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140139 File
    140140 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140141 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    140142 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    140143 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140144 File
    140145 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140146 packages/chimerax/graphics/drawing.py", line 1108, in
    140147 _first_intercept_excluding_children 
    140148 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    140149 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140150 File
    140151 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140152 packages/chimerax/geometry/place.py", line 201, in inverse 
    140153 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    140154 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140155 File
    140156 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140157 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    140158 rinv[:, :] = matrix_inverse(r) 
    140159 ^^^^^^^^^^^^^^^^^ 
    140160 File
    140161 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140162 packages/numpy/linalg/linalg.py", line 561, in inv 
    140163 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    140164 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140165 File
    140166 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140167 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    140168 raise LinAlgError("Singular matrix") 
    140169 numpy.linalg.LinAlgError: Singular matrix 
    140170  
    140171 numpy.linalg.LinAlgError: Singular matrix 
    140172  
    140173 File
    140174 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140175 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    140176 raise LinAlgError("Singular matrix") 
    140177  
    140178 See log for complete Python traceback. 
    140179  
    140180 Traceback (most recent call last): 
    140181 File
    140182 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140183 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    140184 self.session.ui.mouse_modes.mouse_pause_tracking() 
    140185 File
    140186 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140187 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    140188 mouse_pause_tracking 
    140189 self._mouse_pause() 
    140190 File
    140191 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140192 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    140193 m.pause(self._mouse_pause_position) 
    140194 File
    140195 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140196 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    140197 p = self.view.picked_object(x, y) 
    140198 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140199 File
    140200 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140201 packages/chimerax/graphics/view.py", line 838, in picked_object 
    140202 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    140203 beyond, 
    140204 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140205 File
    140206 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140207 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    140208 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    140209 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140210 File
    140211 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140212 packages/chimerax/core/models.py", line 143, in first_intercept 
    140213 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    140214 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140215 File
    140216 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140217 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    140218 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    140219 exclude=exclude) 
    140220 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140221 File
    140222 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140223 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    140224 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    140225 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140226 File
    140227 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140228 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    140229 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    140230 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140231 File
    140232 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140233 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    140234 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    140235 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140236 File
    140237 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140238 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    140239 p = super().first_intercept(mxyz1, mxyz2) 
    140240 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140241 File
    140242 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140243 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    140244 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    140245 exclude=exclude) 
    140246 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140247 File
    140248 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140249 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    140250 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    140251 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140252 File
    140253 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140254 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    140255 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    140256 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140257 File
    140258 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140259 packages/chimerax/graphics/drawing.py", line 1108, in
    140260 _first_intercept_excluding_children 
    140261 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    140262 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140263 File
    140264 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140265 packages/chimerax/geometry/place.py", line 201, in inverse 
    140266 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    140267 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140268 File
    140269 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140270 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    140271 rinv[:, :] = matrix_inverse(r) 
    140272 ^^^^^^^^^^^^^^^^^ 
    140273 File
    140274 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140275 packages/numpy/linalg/linalg.py", line 561, in inv 
    140276 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    140277 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140278 File
    140279 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140280 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    140281 raise LinAlgError("Singular matrix") 
    140282 numpy.linalg.LinAlgError: Singular matrix 
    140283  
    140284 numpy.linalg.LinAlgError: Singular matrix 
    140285  
    140286 File
    140287 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140288 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    140289 raise LinAlgError("Singular matrix") 
    140290  
    140291 See log for complete Python traceback. 
    140292  
    140293 Traceback (most recent call last): 
    140294 File
    140295 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140296 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    140297 self.session.ui.mouse_modes.mouse_pause_tracking() 
    140298 File
    140299 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140300 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    140301 mouse_pause_tracking 
    140302 self._mouse_pause() 
    140303 File
    140304 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140305 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    140306 m.pause(self._mouse_pause_position) 
    140307 File
    140308 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140309 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    140310 p = self.view.picked_object(x, y) 
    140311 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140312 File
    140313 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140314 packages/chimerax/graphics/view.py", line 838, in picked_object 
    140315 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    140316 beyond, 
    140317 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140318 File
    140319 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140320 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    140321 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    140322 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140323 File
    140324 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140325 packages/chimerax/core/models.py", line 143, in first_intercept 
    140326 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    140327 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140328 File
    140329 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140330 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    140331 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    140332 exclude=exclude) 
    140333 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140334 File
    140335 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140336 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    140337 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    140338 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140339 File
    140340 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140341 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    140342 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    140343 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140344 File
    140345 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140346 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    140347 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    140348 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140349 File
    140350 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140351 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    140352 p = super().first_intercept(mxyz1, mxyz2) 
    140353 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140354 File
    140355 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140356 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    140357 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    140358 exclude=exclude) 
    140359 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140360 File
    140361 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140362 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    140363 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    140364 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140365 File
    140366 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140367 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    140368 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    140369 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140370 File
    140371 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140372 packages/chimerax/graphics/drawing.py", line 1108, in
    140373 _first_intercept_excluding_children 
    140374 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    140375 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140376 File
    140377 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140378 packages/chimerax/geometry/place.py", line 201, in inverse 
    140379 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    140380 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140381 File
    140382 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140383 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    140384 rinv[:, :] = matrix_inverse(r) 
    140385 ^^^^^^^^^^^^^^^^^ 
    140386 File
    140387 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140388 packages/numpy/linalg/linalg.py", line 561, in inv 
    140389 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    140390 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140391 File
    140392 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140393 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    140394 raise LinAlgError("Singular matrix") 
    140395 numpy.linalg.LinAlgError: Singular matrix 
    140396  
    140397 numpy.linalg.LinAlgError: Singular matrix 
    140398  
    140399 File
    140400 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140401 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    140402 raise LinAlgError("Singular matrix") 
    140403  
    140404 See log for complete Python traceback. 
    140405  
    140406 Traceback (most recent call last): 
    140407 File
    140408 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140409 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    140410 self.session.ui.mouse_modes.mouse_pause_tracking() 
    140411 File
    140412 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140413 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    140414 mouse_pause_tracking 
    140415 self._mouse_pause() 
    140416 File
    140417 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140418 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    140419 m.pause(self._mouse_pause_position) 
    140420 File
    140421 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140422 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    140423 p = self.view.picked_object(x, y) 
    140424 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140425 File
    140426 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140427 packages/chimerax/graphics/view.py", line 838, in picked_object 
    140428 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    140429 beyond, 
    140430 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140431 File
    140432 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140433 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    140434 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    140435 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140436 File
    140437 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140438 packages/chimerax/core/models.py", line 143, in first_intercept 
    140439 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    140440 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140441 File
    140442 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140443 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    140444 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    140445 exclude=exclude) 
    140446 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140447 File
    140448 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140449 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    140450 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    140451 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140452 File
    140453 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140454 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    140455 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    140456 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140457 File
    140458 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140459 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    140460 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    140461 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140462 File
    140463 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140464 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    140465 p = super().first_intercept(mxyz1, mxyz2) 
    140466 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140467 File
    140468 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140469 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    140470 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    140471 exclude=exclude) 
    140472 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140473 File
    140474 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140475 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    140476 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    140477 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140478 File
    140479 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140480 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    140481 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    140482 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140483 File
    140484 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140485 packages/chimerax/graphics/drawing.py", line 1108, in
    140486 _first_intercept_excluding_children 
    140487 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    140488 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140489 File
    140490 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140491 packages/chimerax/geometry/place.py", line 201, in inverse 
    140492 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    140493 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140494 File
    140495 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140496 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    140497 rinv[:, :] = matrix_inverse(r) 
    140498 ^^^^^^^^^^^^^^^^^ 
    140499 File
    140500 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140501 packages/numpy/linalg/linalg.py", line 561, in inv 
    140502 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    140503 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140504 File
    140505 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140506 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    140507 raise LinAlgError("Singular matrix") 
    140508 numpy.linalg.LinAlgError: Singular matrix 
    140509  
    140510 numpy.linalg.LinAlgError: Singular matrix 
    140511  
    140512 File
    140513 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140514 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    140515 raise LinAlgError("Singular matrix") 
    140516  
    140517 See log for complete Python traceback. 
    140518  
    140519 Traceback (most recent call last): 
    140520 File
    140521 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140522 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    140523 self.session.ui.mouse_modes.mouse_pause_tracking() 
    140524 File
    140525 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140526 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    140527 mouse_pause_tracking 
    140528 self._mouse_pause() 
    140529 File
    140530 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140531 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    140532 m.pause(self._mouse_pause_position) 
    140533 File
    140534 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140535 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    140536 p = self.view.picked_object(x, y) 
    140537 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140538 File
    140539 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140540 packages/chimerax/graphics/view.py", line 838, in picked_object 
    140541 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    140542 beyond, 
    140543 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140544 File
    140545 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140546 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    140547 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    140548 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140549 File
    140550 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140551 packages/chimerax/core/models.py", line 143, in first_intercept 
    140552 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    140553 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140554 File
    140555 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140556 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    140557 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    140558 exclude=exclude) 
    140559 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140560 File
    140561 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140562 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    140563 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    140564 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140565 File
    140566 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140567 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    140568 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    140569 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140570 File
    140571 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140572 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    140573 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    140574 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140575 File
    140576 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140577 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    140578 p = super().first_intercept(mxyz1, mxyz2) 
    140579 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140580 File
    140581 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140582 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    140583 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    140584 exclude=exclude) 
    140585 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140586 File
    140587 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140588 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    140589 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    140590 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140591 File
    140592 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140593 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    140594 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    140595 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140596 File
    140597 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140598 packages/chimerax/graphics/drawing.py", line 1108, in
    140599 _first_intercept_excluding_children 
    140600 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    140601 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140602 File
    140603 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140604 packages/chimerax/geometry/place.py", line 201, in inverse 
    140605 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    140606 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140607 File
    140608 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140609 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    140610 rinv[:, :] = matrix_inverse(r) 
    140611 ^^^^^^^^^^^^^^^^^ 
    140612 File
    140613 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140614 packages/numpy/linalg/linalg.py", line 561, in inv 
    140615 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    140616 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140617 File
    140618 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140619 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    140620 raise LinAlgError("Singular matrix") 
    140621 numpy.linalg.LinAlgError: Singular matrix 
    140622  
    140623 numpy.linalg.LinAlgError: Singular matrix 
    140624  
    140625 File
    140626 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140627 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    140628 raise LinAlgError("Singular matrix") 
    140629  
    140630 See log for complete Python traceback. 
    140631  
    140632 Traceback (most recent call last): 
    140633 File
    140634 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140635 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    140636 self.session.ui.mouse_modes.mouse_pause_tracking() 
    140637 File
    140638 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140639 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    140640 mouse_pause_tracking 
    140641 self._mouse_pause() 
    140642 File
    140643 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140644 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    140645 m.pause(self._mouse_pause_position) 
    140646 File
    140647 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140648 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    140649 p = self.view.picked_object(x, y) 
    140650 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140651 File
    140652 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140653 packages/chimerax/graphics/view.py", line 838, in picked_object 
    140654 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    140655 beyond, 
    140656 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140657 File
    140658 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140659 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    140660 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    140661 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140662 File
    140663 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140664 packages/chimerax/core/models.py", line 143, in first_intercept 
    140665 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    140666 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140667 File
    140668 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140669 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    140670 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    140671 exclude=exclude) 
    140672 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140673 File
    140674 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140675 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    140676 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    140677 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140678 File
    140679 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140680 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    140681 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    140682 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140683 File
    140684 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140685 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    140686 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    140687 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140688 File
    140689 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140690 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    140691 p = super().first_intercept(mxyz1, mxyz2) 
    140692 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140693 File
    140694 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140695 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    140696 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    140697 exclude=exclude) 
    140698 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140699 File
    140700 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140701 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    140702 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    140703 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140704 File
    140705 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140706 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    140707 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    140708 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140709 File
    140710 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140711 packages/chimerax/graphics/drawing.py", line 1108, in
    140712 _first_intercept_excluding_children 
    140713 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    140714 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140715 File
    140716 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140717 packages/chimerax/geometry/place.py", line 201, in inverse 
    140718 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    140719 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140720 File
    140721 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140722 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    140723 rinv[:, :] = matrix_inverse(r) 
    140724 ^^^^^^^^^^^^^^^^^ 
    140725 File
    140726 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140727 packages/numpy/linalg/linalg.py", line 561, in inv 
    140728 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    140729 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140730 File
    140731 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140732 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    140733 raise LinAlgError("Singular matrix") 
    140734 numpy.linalg.LinAlgError: Singular matrix 
    140735  
    140736 numpy.linalg.LinAlgError: Singular matrix 
    140737  
    140738 File
    140739 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140740 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    140741 raise LinAlgError("Singular matrix") 
    140742  
    140743 See log for complete Python traceback. 
    140744  
    140745 Traceback (most recent call last): 
    140746 File
    140747 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140748 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    140749 self.session.ui.mouse_modes.mouse_pause_tracking() 
    140750 File
    140751 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140752 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    140753 mouse_pause_tracking 
    140754 self._mouse_pause() 
    140755 File
    140756 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140757 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    140758 m.pause(self._mouse_pause_position) 
    140759 File
    140760 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140761 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    140762 p = self.view.picked_object(x, y) 
    140763 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140764 File
    140765 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140766 packages/chimerax/graphics/view.py", line 838, in picked_object 
    140767 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    140768 beyond, 
    140769 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140770 File
    140771 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140772 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    140773 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    140774 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140775 File
    140776 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140777 packages/chimerax/core/models.py", line 143, in first_intercept 
    140778 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    140779 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140780 File
    140781 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140782 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    140783 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    140784 exclude=exclude) 
    140785 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140786 File
    140787 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140788 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    140789 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    140790 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140791 File
    140792 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140793 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    140794 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    140795 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140796 File
    140797 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140798 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    140799 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    140800 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140801 File
    140802 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140803 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    140804 p = super().first_intercept(mxyz1, mxyz2) 
    140805 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140806 File
    140807 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140808 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    140809 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    140810 exclude=exclude) 
    140811 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140812 File
    140813 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140814 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    140815 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    140816 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140817 File
    140818 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140819 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    140820 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    140821 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140822 File
    140823 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140824 packages/chimerax/graphics/drawing.py", line 1108, in
    140825 _first_intercept_excluding_children 
    140826 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    140827 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140828 File
    140829 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140830 packages/chimerax/geometry/place.py", line 201, in inverse 
    140831 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    140832 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140833 File
    140834 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140835 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    140836 rinv[:, :] = matrix_inverse(r) 
    140837 ^^^^^^^^^^^^^^^^^ 
    140838 File
    140839 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140840 packages/numpy/linalg/linalg.py", line 561, in inv 
    140841 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    140842 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140843 File
    140844 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140845 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    140846 raise LinAlgError("Singular matrix") 
    140847 numpy.linalg.LinAlgError: Singular matrix 
    140848  
    140849 numpy.linalg.LinAlgError: Singular matrix 
    140850  
    140851 File
    140852 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140853 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    140854 raise LinAlgError("Singular matrix") 
    140855  
    140856 See log for complete Python traceback. 
    140857  
    140858 Traceback (most recent call last): 
    140859 File
    140860 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140861 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    140862 self.session.ui.mouse_modes.mouse_pause_tracking() 
    140863 File
    140864 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140865 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    140866 mouse_pause_tracking 
    140867 self._mouse_pause() 
    140868 File
    140869 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140870 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    140871 m.pause(self._mouse_pause_position) 
    140872 File
    140873 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140874 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    140875 p = self.view.picked_object(x, y) 
    140876 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140877 File
    140878 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140879 packages/chimerax/graphics/view.py", line 838, in picked_object 
    140880 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    140881 beyond, 
    140882 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140883 File
    140884 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140885 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    140886 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    140887 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140888 File
    140889 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140890 packages/chimerax/core/models.py", line 143, in first_intercept 
    140891 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    140892 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140893 File
    140894 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140895 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    140896 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    140897 exclude=exclude) 
    140898 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140899 File
    140900 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140901 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    140902 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    140903 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140904 File
    140905 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140906 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    140907 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    140908 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140909 File
    140910 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140911 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    140912 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    140913 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140914 File
    140915 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140916 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    140917 p = super().first_intercept(mxyz1, mxyz2) 
    140918 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140919 File
    140920 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140921 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    140922 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    140923 exclude=exclude) 
    140924 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140925 File
    140926 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140927 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    140928 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    140929 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140930 File
    140931 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140932 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    140933 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    140934 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140935 File
    140936 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140937 packages/chimerax/graphics/drawing.py", line 1108, in
    140938 _first_intercept_excluding_children 
    140939 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    140940 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140941 File
    140942 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140943 packages/chimerax/geometry/place.py", line 201, in inverse 
    140944 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    140945 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140946 File
    140947 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140948 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    140949 rinv[:, :] = matrix_inverse(r) 
    140950 ^^^^^^^^^^^^^^^^^ 
    140951 File
    140952 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140953 packages/numpy/linalg/linalg.py", line 561, in inv 
    140954 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    140955 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140956 File
    140957 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140958 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    140959 raise LinAlgError("Singular matrix") 
    140960 numpy.linalg.LinAlgError: Singular matrix 
    140961  
    140962 numpy.linalg.LinAlgError: Singular matrix 
    140963  
    140964 File
    140965 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140966 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    140967 raise LinAlgError("Singular matrix") 
    140968  
    140969 See log for complete Python traceback. 
    140970  
    140971 Traceback (most recent call last): 
    140972 File
    140973 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140974 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    140975 self.session.ui.mouse_modes.mouse_pause_tracking() 
    140976 File
    140977 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140978 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    140979 mouse_pause_tracking 
    140980 self._mouse_pause() 
    140981 File
    140982 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140983 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    140984 m.pause(self._mouse_pause_position) 
    140985 File
    140986 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140987 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    140988 p = self.view.picked_object(x, y) 
    140989 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140990 File
    140991 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140992 packages/chimerax/graphics/view.py", line 838, in picked_object 
    140993 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    140994 beyond, 
    140995 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    140996 File
    140997 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    140998 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    140999 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    141000 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141001 File
    141002 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141003 packages/chimerax/core/models.py", line 143, in first_intercept 
    141004 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    141005 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141006 File
    141007 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141008 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    141009 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    141010 exclude=exclude) 
    141011 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141012 File
    141013 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141014 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    141015 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    141016 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141017 File
    141018 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141019 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    141020 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    141021 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141022 File
    141023 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141024 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    141025 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    141026 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141027 File
    141028 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141029 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    141030 p = super().first_intercept(mxyz1, mxyz2) 
    141031 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141032 File
    141033 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141034 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    141035 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    141036 exclude=exclude) 
    141037 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141038 File
    141039 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141040 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    141041 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    141042 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141043 File
    141044 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141045 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    141046 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    141047 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141048 File
    141049 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141050 packages/chimerax/graphics/drawing.py", line 1108, in
    141051 _first_intercept_excluding_children 
    141052 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    141053 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141054 File
    141055 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141056 packages/chimerax/geometry/place.py", line 201, in inverse 
    141057 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    141058 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141059 File
    141060 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141061 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    141062 rinv[:, :] = matrix_inverse(r) 
    141063 ^^^^^^^^^^^^^^^^^ 
    141064 File
    141065 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141066 packages/numpy/linalg/linalg.py", line 561, in inv 
    141067 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    141068 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141069 File
    141070 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141071 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    141072 raise LinAlgError("Singular matrix") 
    141073 numpy.linalg.LinAlgError: Singular matrix 
    141074  
    141075 numpy.linalg.LinAlgError: Singular matrix 
    141076  
    141077 File
    141078 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141079 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    141080 raise LinAlgError("Singular matrix") 
    141081  
    141082 See log for complete Python traceback. 
    141083  
    141084 Traceback (most recent call last): 
    141085 File
    141086 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141087 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    141088 self.session.ui.mouse_modes.mouse_pause_tracking() 
    141089 File
    141090 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141091 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    141092 mouse_pause_tracking 
    141093 self._mouse_pause() 
    141094 File
    141095 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141096 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    141097 m.pause(self._mouse_pause_position) 
    141098 File
    141099 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141100 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    141101 p = self.view.picked_object(x, y) 
    141102 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141103 File
    141104 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141105 packages/chimerax/graphics/view.py", line 838, in picked_object 
    141106 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    141107 beyond, 
    141108 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141109 File
    141110 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141111 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    141112 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    141113 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141114 File
    141115 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141116 packages/chimerax/core/models.py", line 143, in first_intercept 
    141117 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    141118 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141119 File
    141120 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141121 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    141122 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    141123 exclude=exclude) 
    141124 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141125 File
    141126 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141127 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    141128 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    141129 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141130 File
    141131 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141132 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    141133 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    141134 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141135 File
    141136 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141137 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    141138 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    141139 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141140 File
    141141 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141142 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    141143 p = super().first_intercept(mxyz1, mxyz2) 
    141144 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141145 File
    141146 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141147 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    141148 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    141149 exclude=exclude) 
    141150 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141151 File
    141152 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141153 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    141154 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    141155 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141156 File
    141157 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141158 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    141159 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    141160 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141161 File
    141162 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141163 packages/chimerax/graphics/drawing.py", line 1108, in
    141164 _first_intercept_excluding_children 
    141165 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    141166 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141167 File
    141168 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141169 packages/chimerax/geometry/place.py", line 201, in inverse 
    141170 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    141171 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141172 File
    141173 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141174 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    141175 rinv[:, :] = matrix_inverse(r) 
    141176 ^^^^^^^^^^^^^^^^^ 
    141177 File
    141178 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141179 packages/numpy/linalg/linalg.py", line 561, in inv 
    141180 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    141181 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141182 File
    141183 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141184 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    141185 raise LinAlgError("Singular matrix") 
    141186 numpy.linalg.LinAlgError: Singular matrix 
    141187  
    141188 numpy.linalg.LinAlgError: Singular matrix 
    141189  
    141190 File
    141191 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141192 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    141193 raise LinAlgError("Singular matrix") 
    141194  
    141195 See log for complete Python traceback. 
    141196  
    141197 Traceback (most recent call last): 
    141198 File
    141199 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141200 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    141201 self.session.ui.mouse_modes.mouse_pause_tracking() 
    141202 File
    141203 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141204 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    141205 mouse_pause_tracking 
    141206 self._mouse_pause() 
    141207 File
    141208 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141209 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    141210 m.pause(self._mouse_pause_position) 
    141211 File
    141212 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141213 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    141214 p = self.view.picked_object(x, y) 
    141215 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141216 File
    141217 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141218 packages/chimerax/graphics/view.py", line 838, in picked_object 
    141219 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    141220 beyond, 
    141221 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141222 File
    141223 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141224 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    141225 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    141226 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141227 File
    141228 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141229 packages/chimerax/core/models.py", line 143, in first_intercept 
    141230 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    141231 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141232 File
    141233 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141234 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    141235 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    141236 exclude=exclude) 
    141237 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141238 File
    141239 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141240 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    141241 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    141242 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141243 File
    141244 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141245 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    141246 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    141247 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141248 File
    141249 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141250 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    141251 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    141252 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141253 File
    141254 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141255 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    141256 p = super().first_intercept(mxyz1, mxyz2) 
    141257 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141258 File
    141259 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141260 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    141261 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    141262 exclude=exclude) 
    141263 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141264 File
    141265 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141266 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    141267 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    141268 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141269 File
    141270 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141271 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    141272 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    141273 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141274 File
    141275 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141276 packages/chimerax/graphics/drawing.py", line 1108, in
    141277 _first_intercept_excluding_children 
    141278 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    141279 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141280 File
    141281 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141282 packages/chimerax/geometry/place.py", line 201, in inverse 
    141283 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    141284 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141285 File
    141286 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141287 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    141288 rinv[:, :] = matrix_inverse(r) 
    141289 ^^^^^^^^^^^^^^^^^ 
    141290 File
    141291 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141292 packages/numpy/linalg/linalg.py", line 561, in inv 
    141293 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    141294 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141295 File
    141296 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141297 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    141298 raise LinAlgError("Singular matrix") 
    141299 numpy.linalg.LinAlgError: Singular matrix 
    141300  
    141301 numpy.linalg.LinAlgError: Singular matrix 
    141302  
    141303 File
    141304 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141305 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    141306 raise LinAlgError("Singular matrix") 
    141307  
    141308 See log for complete Python traceback. 
    141309  
    141310 Traceback (most recent call last): 
    141311 File
    141312 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141313 packages/chimerax/core/updateloop.py", line 151, in _redraw_timer_callback 
    141314 self.session.ui.mouse_modes.mouse_pause_tracking() 
    141315 File
    141316 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141317 packages/chimerax/mouse_modes/mousemodes.py", line 504, in
    141318 mouse_pause_tracking 
    141319 self._mouse_pause() 
    141320 File
    141321 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141322 packages/chimerax/mouse_modes/mousemodes.py", line 645, in _mouse_pause 
    141323 m.pause(self._mouse_pause_position) 
    141324 File
    141325 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141326 packages/chimerax/mouse_modes/std_modes.py", line 803, in pause 
    141327 p = self.view.picked_object(x, y) 
    141328 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141329 File
    141330 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141331 packages/chimerax/graphics/view.py", line 838, in picked_object 
    141332 p = self.picked_object_on_segment(xyz1, xyz2, exclude = exclude, beyond =
    141333 beyond, 
    141334 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141335 File
    141336 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141337 packages/chimerax/graphics/view.py", line 870, in picked_object_on_segment 
    141338 p = self.drawing.first_intercept(xyz1, xyz2, exclude=exclude) 
    141339 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141340 File
    141341 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141342 packages/chimerax/core/models.py", line 143, in first_intercept 
    141343 pick = super().first_intercept(mxyz1, mxyz2, exclude=exclude) 
    141344 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141345 File
    141346 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141347 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    141348 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    141349 exclude=exclude) 
    141350 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141351 File
    141352 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141353 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    141354 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    141355 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141356 File
    141357 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141358 packages/chimerax/atomic/structure.py", line 703, in first_intercept 
    141359 ppicks = self._position_intercepts(self.positions[pn], mxyz1, mxyz2, exclude) 
    141360 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141361 File
    141362 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141363 packages/chimerax/atomic/structure.py", line 736, in _position_intercepts 
    141364 p = d.first_intercept(xyz1, xyz2, exclude=exclude) 
    141365 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141366 File
    141367 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141368 packages/chimerax/atomic/ribbon.py", line 715, in first_intercept 
    141369 p = super().first_intercept(mxyz1, mxyz2) 
    141370 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141371 File
    141372 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141373 packages/chimerax/graphics/drawing.py", line 1069, in first_intercept 
    141374 p = self.first_intercept_children(self.child_drawings(), mxyz1, mxyz2,
    141375 exclude=exclude) 
    141376 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141377 File
    141378 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141379 packages/chimerax/graphics/drawing.py", line 1086, in first_intercept_children 
    141380 p = d.first_intercept(cxyz1, cxyz2, exclude=exclude) 
    141381 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141382 File
    141383 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141384 packages/chimerax/graphics/drawing.py", line 1064, in first_intercept 
    141385 p = self._first_intercept_excluding_children(mxyz1, mxyz2) 
    141386 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141387 File
    141388 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141389 packages/chimerax/graphics/drawing.py", line 1108, in
    141390 _first_intercept_excluding_children 
    141391 cxyz1, cxyz2 = self.positions[i].inverse() * (mxyz1, mxyz2) 
    141392 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141393 File
    141394 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141395 packages/chimerax/geometry/place.py", line 201, in inverse 
    141396 self._inverse = Place(m34.invert_matrix(self._matrix)) 
    141397 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141398 File
    141399 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141400 packages/chimerax/geometry/matrix.py", line 141, in invert_matrix 
    141401 rinv[:, :] = matrix_inverse(r) 
    141402 ^^^^^^^^^^^^^^^^^ 
    141403 File
    141404 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141405 packages/numpy/linalg/linalg.py", line 561, in inv 
    141406 ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj) 
    141407 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    141408 File
    141409 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141410 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    141411 raise LinAlgError("Singular matrix") 
    141412 numpy.linalg.LinAlgError: Singular matrix 
    141413  
    141414 numpy.linalg.LinAlgError: Singular matrix 
    141415  
    141416 File
    141417 "/Applications/ChimeraX-1.8.app/Contents/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-
    141418 packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular 
    141419 raise LinAlgError("Singular matrix") 
    141420  
    141421 See log for complete Python traceback. 
    141422  
     2353[deleted to fit within ticket limits]
     2354
    1414232355Traceback (most recent call last): 
    1414242356File