To go back and forth from the SPARX (`psi_S,theta_S, phi_S `)convention and what Chimera records( `psi_C, theta_C, phi_C` ):

1. I took the tripod, saved to BRIX, and loaded into Chimera

2. Noting the original positions of the tripods legs,

3. For each of these rotations, a, I noted the transformation recorded in Chimera as b.

4.

for each of the rotations, a, with `R_alpha` and `R_beta` unknown but fixed.

The general solution to these sort of problems is not so easy.

But in this particular case, the problem is not quite so hard and I found (with a certain amount of guesswork):

Notice that `R_beta`is its own inverse `R_beta = R_beta^(-1)` . So a = `R_beta` b `R_beta` and b = `R_beta` a `R_beta`


SparxWiki/Chimera-Brix_issue (last edited 2013-07-01 13:12:53 by localhost)