If you can calculate the transformation between the 2, the rotation (kappa) that relates them is found using the formula:
2 cosine (kappa) + 1 = Trace (transformation) where Trace = sum of diagonal elements. Doug -----Original Message----- From: CCP4 bulletin board [mailto:ccp...@jiscmail.ac.uk] On Behalf Of James Stroud Sent: Tuesday, February 03, 2009 3:57 PM To: CCP4BB@JISCMAIL.AC.UK Subject: Re: [ccp4bb] Obtaining relationships between two cross rotation solutions? I forgot to mention that I think the only fail-safe direct approach will involve converting both rotations into quaternions, "subtracting" (inv(A)*B) said quaternions, then converting the difference into an axis-angle pair. James On Feb 3, 2009, at 9:47 AM, Francis E Reyes wrote: > I have trouble with visualizing things in three dimensions so I'm > trying to figure out the relationship between two cross rotation > functions (given as theta1, theta2, theta3). > > > Is there a program or webapp that'll tell me whether two rotation > solutions are related by a 180/90/60/whathaveyou axis? > > e.g. > > The space group is P4(1) > The top few cross rotation solutions are: > ! index, theta1, theta2, theta3, RF-function (EPSIlon= 0.25) > 1 173.333 2.630 186.481 0.0907 > 3 353.426 180.000 353.426 0.0879 > 7 98.807 147.925 67.347 0.0608 > 8 279.440 30.322 292.587 0.0602 > 10 292.696 168.784 294.156 0.0562 > 12 233.216 30.322 246.364 0.0511 > > > Is index 1,3 related how about 7,8?? What is the relationship > between the pair 1,3 and 7,8 ? > > Thanks > > FR > > --------------------------------------------- > Francis Reyes M.Sc. > 215 UCB > University of Colorado at Boulder > > gpg --keyserver pgp.mit.edu --recv-keys 67BA8D5D > > 8AE2 F2F4 90F7 9640 28BC 686F 78FD 6669 67BA 8D5D
