[Chimera-users] Orientation and quaternion

[Thomas Goddard]

Hi Damien,

   You can measure the relative orientation of the two models with the 
"measure rotation" command:

	measure rot #0 #1

which produces output in the reply log (Favorites / Reply Log) like

Position of 2gbp.pdb (#1) relative to 1a0m.pdb (#0) coordinates:
   Matrix rotation and translation
      0.90028335   0.21178251  -0.38031310  38.41870000
      0.30675800   0.31121759   0.89946825 -28.00030000
      0.30885177  -0.92644038   0.21521804  53.80560000
   Axis  -0.93447169  -0.35270388   0.04860698
   Axis point   0.00000000  15.26078714  51.99569332
   Rotation angle (degrees)  77.68070000
   Shift along axis -23.41004496

Also it draws the rotation axis on the screen (append "show false" to 
suppress that).

The rotation is shown as a matrix and as axis/angle in the output.  You 
can compute the quaternion equivalent of the rotation if you need that:

	(sin(a/2)*axis, cos(a/2))

where a is the angle.

The "measure" command is only in Chimera 1.4 so get a daily build to use it.

http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/measure.html#rotation

	Tom


-------- Original Message --------
Subject: [Chimera-users] Orientation and quaternion
From: Damien Larivière <damien.lariviere at fourmentinguilbert.org>
To: chimera-users at cgl.ucsf.edu
Date: 8/6/09 11:11 AM

> Dear all,
> 
> In the attached image, two copies of the FtsZ protein (pdb 1FSZ) are 
> displayed in Chimera.
> 
> I would like to know the orientation of one copy with respect to the 
> other one. Is there a way to get this information ? Is it possible to 
> get a quaternion instead of a set of Euler angles ?
> 
> My best regards
> 
> Damien
> 
> 
> 
> ------------------------------------------------------------------------
> 
> 
> ------------------------------------------------------------------------
> 
> _______________________________________________
> Chimera-users mailing list
> Chimera-users at cgl.ucsf.edu
> http://www.cgl.ucsf.edu/mailman/listinfo/chimera-users