Compute MNI talairach coordinates from RAS coords.
talairachras.to.ras(tal_ras_coords, talairach)
the Talairach RAS coordinates for the given RAS coordinates. They are based on a linear transform.
coordinate matrix in Talairach RAS space
the 4x4 numerical talairach matrix, or a character string which will be interpreted as the path to an xfm file containing the matrix (typically `$SUBJECTS_DIR/$subject/mri/transforms/talairach.xfm`).