surfaceras.to.talairach {freesurferformats}

Compute Talairach RAS for surface RAS (e.g., vertex coordinates).

Description

Compute Talairach RAS for surface RAS (e.g., vertex coordinates).

Usage

surfaceras.to.talairach(
  sras_coords,
  talairach,
  header_cras,
  first_voxel_RAS = c(1, 1, 1)
)

Arguments

sras_coords

nx3 numerical vector, the input surface RAS coordinates. Could be the vertex coordinates of an 'fs.surface' instance, or the RAS coords from a surface label. Use the orig surfaces.

talairach

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').

header_cras

an MGH header instance from which to extract the cras (center RAS), or the cras vector, i.e., a numerical vector of length 3

first_voxel_RAS

the RAS of the first voxel, see mghheader.centervoxelRAS.from.firstvoxelRAS for details. Ignored if 'header_cras' is a vector.

Value

The Talairach RAS coordinates for the vertices of the orig surfaces (or coords in surface RAS space). Based on linear transform.