Dear Phil, Because question keep popping up in the bullitin board about conversion from a rotation matrix into rotation angles, I decided to take the relevant subroutines from an old program from Groningen and make a jiffy to do these conversions. It is a small fortran program and does not need any additional libraries or subroutines. The program will take a rotation matrix and translation vector and print all kind of rotation angles and also the component of the translation vector parallel to the rotation axis, which is the number you want. All other components of the translation vector can be made zero by choosing the right position of the rotation axis.
Best regards, Herman Schreuder -----Original Message----- From: CCP4 bulletin board [mailto:[EMAIL PROTECTED] On Behalf Of Phil Evans Sent: Tuesday, July 29, 2008 10:11 AM To: [email protected] Subject: [ccp4bb] Rotation axis If I've go a superposition transformation (x' = Rx + t), as it happens from a superposition in ccp4mg, how do I get the position & direction of the rotation axis (to draw in a picture)? I know that any (orthonormal) transformation can be represented as a rotation about an axis + a screw translation along that axis I'm sure I've done this before ... thanks Phil
rotax.f
Description: rotax.f
