surfaceras.to.ras {freesurferformats}

Translate surface RAS coordinates, as used in surface vertices and surface labels, to volume RAS.

Description

Translate surface RAS coordinates, as used in surface vertices and surface labels, to volume RAS.

Usage

surfaceras.to.ras(
  header_cras,
  sras_coords,
  first_voxel_RAS = c(1, 1, 1),
  invert_transform = FALSE
)

Arguments

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

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.

first_voxel_RAS

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

invert_transform

logical, whether to invert the transform. Do not use this, call link{ras.to.surfaceras} instead.

Value

the RAS coords for the input sras_coords

Note

The RAS can be computed from Surface RAS by adding the center RAS coordinates, i.e., it is nothing but a translation.