Compute geodesic path from a source vertex to one or more target vertices.

Usage

geodesic.path(surface, source_vertex, target_vertices)

Arguments

surface: an rgl::tmesh3d or freesurferformats::fs.surface instance. Can be a character string, which will be loaded as a surface file if it exists.
source_vertex: a scalar positive integer, the source vertex index in the mesh
target_vertices: single integer or vector of integers, the target vertices to which to compute the paths from the source_vertex.

Value

list of integer vectors, the paths

Note

This can take a bit for very large graphs. This requires the optional dependency package 'Rvcg'. The backtracking is currently done in R, which is not optimal from a performance perspective. If you have a recent Rvcg version with the Rvcg::vcgGeodesicPath function, that one will be used instead, and the performance will be better.

Examples

if (FALSE) { # \dontrun{
  sjd = fsaverage.path(TRUE);
  surface = subject.surface(sjd, 'fsaverage3',
    surface = "white", hemi = "lh");
  p = geodesic.path(surface, 5, c(10, 20));
  vis.subject.morph.native(sjd, 'fsaverage3', 'thickness', views='si');
  vis.paths.along.verts(surface$vertices, p$paths, color=c("red", "yellow"));
} # }