triad.census {igraph}R Documentation

Triad census, subgraphs with three vertices

Description

This function counts the different subgraphs of three vertices in a graph.

Usage

triad.census(graph)

Arguments

graph The input graph, it should be directed. An undirected graph results a warning, and undefined results.

Details

Triad census was defined by David and Leinhardt (see References below). Every triple of vertices (A, B, C) are classified into the 16 possible states:

This functions uses the RANDESU motif finder algorithm to find and count the subgraphs, see graph.motifs.

Value

A numeric vector, the subgraph counts, in the order given in the above description.

Author(s)

Gabor Csardi csardi@rmki.kfki.hu

References

See also Davis, J.A. and Leinhardt, S. (1972). The Structure of Positive Interpersonal Relations in Small Groups. In J. Berger (Ed.), Sociological Theories in Progress, Volume 2, 218-251. Boston: Houghton Mifflin.

See Also

dyad.census for classifying binary relationships, graph.motifs for the underlying implementation.

Examples

g <- erdos.renyi.game(15, 45, type="gnm", dir=TRUE)
triad.census(g)

[Package igraph version 0.5.2 Index]