Dear Freesurfers
I want to apply the transform matrix talairach.xfm, to a set of discrete points. (in order to get mni coordinate and use template brain). These are electrodes, with coordinates in the brain.mgz space. Here is what I did following the advices from the Coordinates systems page : get Norig and Torig using mri_info, then apply the transform: VOX_coor_tr = (tr_mat*Norig*inv(Torig)*VOX_coor)'; with tr_mat = [talairach.xfm;0 0 0 1]; and VOX_coor = [(n electrodes by 3 coordinates))' ; ones(1,length(VOX_coor))]; Looking at the result, it looks like something is wrong. Electrodes are few centimeters too lateral and anterior/frontal. I have been struggling with this problem for sometime and I am hoping that someone could help.
Thanks,
Manuel