[Chimera-users] Principal axis of inertia

[Elaine Meng]

Hi JD,
Take a look at the new Axes tool (under Tools... Structure Analysis  
in recent builds of Chimera):
http://www.cgl.ucsf.edu/chimera/docs/ContributedSoftware/ 
structuremeas/structuremeas.html#axes

It can show protein helix axes, but you can also calculate an axis  
for any set of selected atoms.  Then you can perform other  
measurements such as distance to axis, crossing angle between two  
axes, etc.

However, I am not sure whether this computed axis is what you need -  
it is not exactly an axis of inertia (doesn't depend on the atomic  
weights of the atoms, for example).
Best,
Elaine
-----
Elaine C. Meng, Ph.D.                          meng at cgl.ucsf.edu
UCSF Computer Graphics Lab and Babbitt Lab
Department of Pharmaceutical Chemistry
University of California, San Francisco
                      http://www.cgl.ucsf.edu/home/meng/index.html


On Mar 19, 2008, at 8:40 AM, Jean-Didier Maréchal wrote:

> Hi everyone,
> I was wondering if there is a method available to calculate the
> principal axis of inertia of a protein (or a part of a protein) in
> chimera?
>
> If not what would be the easiest way to move forward?
> All the best,
> JD