grp: Group vertices by adjacencies

In rje42/MixedGraphs: Mixed Graphs and Graphical Models

Group vertices by adjacencies

Description

Generic functions for finding groups based on edge adjacencies, e.g. neighbourhoods, districts or ancestral sets.

Usage

grp(graph, v, etype, inclusive = TRUE, dir = 0, sort = 1, force = FALSE)

grp2(v, edges, dir, inclusive, sort = 1)

groups(graph, etype, sort = 1)

Arguments

graph	an object of class mixedgraph
v	vertices to group
etype	edge types to group by (defaults to all)
inclusive	logical indicating whether v should be included in output group.
dir	integer(s) indicating if direction should be considered: 0 = undirected, 1 = from row to column; -1 = from column to row.
sort	integer: 1 for unique but unsorted, 2 for sorted (0 for possibly repeated and unsorted).
force	logical - should invalid v be ignored?
edges	an adjMatrix or adjList

Details

grp() finds all vertices that can be reached from vertices in v by edges of the specified type, and in the specified direction. For example, we can find all the ancestors of v by using type="directed" and dir=-1 (i.e. go back up the edges).

groups() finds equivalence classes in a graph based on being connected by such a path (i.e. the connected components with respect to the specified edge types).

If any v is not a vertex of graph, an error is returned, unless force=TRUE.

grp2 is a faster version of the function for a single adjMatrix or adjList.

Functions

• grp2(): Faster routine for single adjMatrix or adjList

• groups(): find connected components

See Also

adj for single edge adjacencies.

rje42/MixedGraphs documentation built on March 29, 2025, 11:47 p.m.