[Chimera-users] Creating distances using the command line

[Elaine Meng]

Hi Iva,
You almost had it.   There is no dash ("-") and no spaces in the specification of each atom, so could be something like

distance #1:347.A at ca  #1:323.A at ca

...if they are really in model #1.  Or if there is only one model open anyway, you don't have to give the model number:

distance :347.A at ca  :323.A at ca

You can see what number your model is in the Model Panel (open from Favorites menu).  They start with #0 so maybe your model is #0, not #1.

The "distance" help page has a few example commands (you can also show this page with command "help distance"):
<https://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/midas/distance.html>

...and there are many more example atom specifications in the atom-spec help:
<https://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/midas/frameatom_spec.html>

I hope this helps,
Elaine
-----
Elaine C. Meng, Ph.D.                       
UCSF Chimera(X) team
Department of Pharmaceutical Chemistry
University of California, San Francisco

> On Apr 6, 2022, at 7:25 AM, Lucic, Iva via Chimera-users <chimera-users at cgl.ucsf.edu> wrote:
> 
> Hello,
> 
> I would like to measure distances between atoms in a structure by using the command line, and not manually by clicking on the atoms and then clicking on "create" button in the Structure Measurements tool.
> 
> I would like to map many distances on the same structure (I performed a crosslinking experiments, so I would now like to map the crosslinks on the structure of my protein of interest).
> 
> I tried something like distance #1 :347.A at ca - :323.A at ca and similar variations, hoping that I could get the distance between CA atoms of residues 347 and 323 of chain A (there are 12 chains in my protein) from model 1. But I couldn't find a good combination of commands to give me a distance.
> 
> I would highly appreciate any advice. Otherwise, I would have to map manually over 20 crosslinks for each chain... 
> 
> Thank you in advance,
> Iva