[PyMOL] Script for Torsion angles

[Martin H. <ma...@bl...>]

Dear List
Does anyone have a script to calculate torsion angles lying around?
Ideally, i would like to be able to enter x1, x2, x3, x4 and get the 
(smaller) angle between the two normals of the planes defined by x1, x2, 
x3 and x2, x3, x4, respectively. For some odd reason the measurment 
wizard in my PyMOL install does not display torsion angles..!?

Kind regards and thanks for any feedback.
Martin