Why does it matter what the exact translation is -- the exact origin? Why not just arbitrarily assign (0,0,0) to A0'?
Bob Timothy Driscoll wrote: >On May 11, 2007, at 2:09 PM, Bob Hanson wrote: > > > >>>original >>> ATOM 1 ATOM 2 d(2-1) M*d >>>x 3.95 3.86 -0.08 -1.25 >>>y 38.05 36.58 -1.48 0.59 >>>z 17.44 17.32 -0.11 0.53 >>> >>> >>>transformed >>> ATOM 1 ATOM 2 d(2-1) >>>x 52.94 51.69 -1.25 >>>y 50.01 50.6 0.59 >>>z 89.41 89.95 0.53 >>> >>> >>>that's good, but now I'm stuck. unapplying the translation does not >>>get me to the transformed coords. this makes me think that... >>> >>> >>> >>> >>Since M*(a2-a1) = (a2'-a1'), you simply add ATOM 1 coordinates now to >>that and get the transformed coordinates. >> >>That is, calling A an initial coordinate, A' its transformed >>coordinate, >>A0 the coordinate (3.95, 38.05, 17.44) and A0' (52.94, 50.01, 89.41), >>you have: >> >>A' = A0' + M*(A - A0) >> >>I think it probably doesn't matter what you use for A0'. >> >>Maybe I've lost the purpose of doing all this.... >> >> >> > >ack, but I won't know A0' when I do this for real. > >I'm trying to get from the original coords and the matrix, to the >transformed coordinates. (in this particular case, I do know the >transformed coordinates, but only because I'm trying to work out the >equations. normally I will not know them in advance.) > > > >tim > > ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ Jmol-users mailing list Jmol-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/jmol-users
