From: Thomas C. Bishop (bishop_at_latech.edu)
Date: Thu Oct 03 2013 - 12:42:02 CDT

The magnitude of the cross product provides information about the sine of the angle between the vectors
but seems there must be an easy way that only involves scalars :-)

TOm

On 10/03/2013 11:37 AM, Axel Kohlmeyer wrote:
On Thu, Oct 3, 2013 at 5:40 PM, Peterson J <peterson.jjjj@gmail.com> wrote:
Hello VMD Users,

I am trying to calculate the angle between two domains of my protein. I have
calculated the inertia for both domains which provided me the center of mass
and the principal axes of each domain. But I have a problem calculating the
angle using the two principal axes. The 'measure angle' asks for three atom
indices.

How do I measure it?
how do you compute the angle between two vectors?

axel.

Thanks

Peter