From: John Stone (johns_at_ks.uiuc.edu)
Date: Fri Oct 24 2003 - 19:11:25 CDT

Markus,
  While I don't have an example script for you, depending on what angles
you're looking for, couldn't you just take the acos() of the dot product
of each of the axis vectors (assuming they are unit vectors) to get
the angles? Or am I misunderstanding?

I suspect a picture of the angles that you're trying to calculate would
be helpful in this instance, thus the lack of response by others so far...
If you're just trying to calculate the angles, then try doing what I mention
above and see if it works for you. If that's not what you're looking for,
then I think you'll have to give a more detailed description of what you're
trying to calculate.

Thanks,
  John Stone
  vmd_at_ks.uiuc.edu
 

On Wed, Oct 22, 2003 at 02:37:44PM +0200, Markus Laub wrote:
> I would like to calculate angles between two subunits of a protein. The
> idea is to calculate the principal axes of inertia for each molecule
> and then calculate the angles between the x, y and z-axes.
>
> Because I'm not familar with programmimg I was looking for some scripts
> in the VMD Script Library and found one from Paul Grayson called
> "orient" which calculates and draws the principle axes of inertia for
> molecules. That works well but was is missing is the calculation of the
> angles. Is there anybody out there who can help me with this problem?
> Or to be more fortright who can put together a script which makes the
> necessary calculations.
>
>
> Greetings,
>
>
> MArkus
>
>
>
>
>
>
>
>
>
>

-- 
NIH Resource for Macromolecular Modeling and Bioinformatics
Beckman Institute for Advanced Science and Technology
University of Illinois, 405 N. Mathews Ave, Urbana, IL 61801
Email: johns_at_ks.uiuc.edu                 Phone: 217-244-3349              
  WWW: http://www.ks.uiuc.edu/~johns/      Fax: 217-244-6078