fs.surface.vertex.neighbors {fsbrain}

Compute vertex neighborhoods or the full adjacency list for a mesh using the Rvcg or igraph library.

Description

This is a faster replacement for mesh.vertex.neighbors that requires the optional dependency package 'igraph' or 'Rvcg'.

Usage

fs.surface.vertex.neighbors(
  surface,
  nodes = NULL,
  order = 1L,
  simplify = TRUE,
  include_self = FALSE
)

Arguments

surface

an fs.surface instance as returned by subject.surface, an existing igraph (which will be returned as-is) or a string which is interpreted as a path to a surface file.

nodes

the source vertex. Passed on to igraph::neighborhood. Can be a vector, in which case the neighborhoods for all these vertices are computed separately. If NULL, all graph vertices are used.

order

integer, the max graph distance of vertices to consider neighbors (number of neighborhood rings). Passed on to igraph::neighborhood

simplify

logical, whether to return only an integer vector if the 'nodes' parameter has length 1 (instead of a list where the first element is such a vector).

include_self

logical, whether to include vertices in their own neighborhood

Value

named list of integer vectors (see igraph::neighborhood), unless 'simplify' is TRUE, see there for details.

Note

If you intend to call several functions on the igraph, it is faster to construct it with fs.surface.to.igraph and keep it.

See Also

The fs.surface.as.adjacencylist function computes the 1-ring neighborhood for the whole graph.