[Chimera-users] Chimera-users Digest, Vol 38, Issue 12

[Eric Pettersen]

I've fixed the "reset" code so that it does work between all the  
positions you provided.  I'm sending it as an attachment in a  
separate mail (since this is going to the list).  It will also be in  
the snapshot release we are making next week.

As for 'reset' not being compatible with a stepwise approach,  
couldn't you put all your saved positions in a session and have your  
script work with a session file?

--Eric

On Jun 16, 2006, at 3:15 PM, Jonathan Hilmer wrote:

> Thanks to all for the quick responses on interpolation.
>
> Here's a quick example showing what I was concerned about:
>
> arrows.bld
> ------------------
> .color red
> .arrow 0 0 0 1 0 0
> .color green
> .arrow 0 0 0 0 1 0
> .color blue
> .arrow 0 0 0 0 0 1
> ------------------
>
> matrix2
> -----------------
> Model 0.0
> 	0.505641 0.433743 -0.745785 -2.58211
> 	-0.807506 0.542275 -0.232105 2.90884
> 	0.303746 0.719587 0.624446 -0.194334
> -----------------
>
> matrix3
> ----------------
> Model 0.0
> 	0.60158 -0.458982 0.653787 0.653219
> 	0.190507 -0.712397 -0.675423 5.48737
> 	0.775763 0.530872 -0.341124 0.0103466
> ----------------
>
> The first matrix is just unity.
>
> The 'reset'-based interpolation works great for going between 1 and 3
> or 1 and 2 in both directions, as well as 3 to 2, but fails from 2 to
> 3.  Since all this is new to me, I can't say for certain that this is
> due to gimbal lock, but that was my first guess.  I haven't had the
> opportunity yet to try out Tom's axis-angle approach, but that should
> rule out any Euler problems.  The other problem for me is that all my
> current methods are based upon a stepwise approach via commands
> (ungainly, but very functional when combined with shell scripts,
> imagemagick etc), and this is incompatible with the 'reset'
> interpolation.
>
> Perhaps it was misleading to mention the use of 'matrixset'.  I
> appreciate that it is more trouble to deal with external files, but if
> it is not possible to easily implement the interpolation I'm looking
> for dynamically within Chimera's Python (due to required math
> libraries, etc) then I would have to hard-code the interpolation
> matrices into the .py script file anway, defeating the purpose.
>
> Thanks for the help: I'd love to hear about any future development  
> in this area.
> _______________________________________________
> Chimera-users mailing list
> Chimera-users at cgl.ucsf.edu
> http://www.cgl.ucsf.edu/mailman/listinfo/chimera-users