subject.descriptor.geodesic.average.distance: Compute mean geodesic distance descriptor for a subject.

In fsbrain: Managing and Visualizing Brain Surface Data

Compute mean geodesic distance descriptor for a subject.

Description

For all vertices: compute the mean pseudo-geodesic distance from this vertex to all others in the same hemisphere. Computes |V|^2 geodesic distances.

Usage

subject.descriptor.geodesic.average.distance(
  subjects_dir,
  subject_id,
  surface = "white",
  hemi = "both",
  ...
)

Arguments

subjects_dir	string. The FreeSurfer SUBJECTS_DIR, i.e., a directory containing the data for all your subjects, each in a subdir named after the subject identifier.
subject_id	string. The subject identifier.
surface	string. The display surface. E.g., "white", "pial", or "inflated". Defaults to "white".
hemi	string, one of 'lh', 'rh', or 'both'. The hemisphere name. Used to construct the names of the label data files to be loaded.
...	extra parameters passed on to geodesic.average.distance. Ignored if 'cortex_only' is TRUE.

Value

a hemilist containing vectors with the descriptor data for the requested hemisphere(s). The length of the vectors is the number of vertices in the surface, and the value for a vertex is the mean geodesic distance to all other vertices for this vertex.

Note

This takes quite a while for full-resolution meshes. Use down-sampled versions to quickly try it (see example).

Examples

## Not run: 
  download_fsaverage3(TRUE);
  sjd = fsaverage.path();
  dist = subject.descriptor.geodesic.average.distance(sjd,
    "fsaverage3", surface = "white", hemi = "both");
  vis.data.on.subject(sjd, "fsaverage3", morph_data_lh = dist$lh);

## End(Not run)

fsbrain documentation built on July 9, 2023, 7:12 p.m.