Re: [ccp4bb] Obtaining relationships between two cross rotation solutions?

2009-02-04 Thread Eleanor Dodson
I presume theta1 theta2theta3 are eulerian angles? When theta2 ~ 0, you can onlyy define theta1+theta2 so solution 1 is effectively the identity; theta1+theta3 = 360 (ie 0) theta2~0. theta3 not defined - that generates the identity matrix. When theta2 ~ 180, you can onlyy define theta1-t

Re: [ccp4bb] Obtaining relationships between two cross rotation solutions?

2009-02-03 Thread Doug Ohlendorf
...@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

Re: [ccp4bb] Obtaining relationships between two cross rotation solutions?

2009-02-03 Thread James Stroud
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

Re: [ccp4bb] Obtaining relationships between two cross rotation solutions?

2009-02-03 Thread James Stroud
Transform a molecule according to the two transformations in which you are interested and then use dyndom to see the hinge axis that relates the two transformed molecules. On Feb 3, 2009, at 9:47 AM, Francis E Reyes wrote: I have trouble with visualizing things in three dimensions so I'm

[ccp4bb] Obtaining relationships between two cross rotation solutions?

2009-02-03 Thread Francis E Reyes
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/whathaveyo