Triad Census

Counts the 16 types of triads in a directed network using MAN notation. An edge is a cell with a positive weight; the weight values are otherwise ignored, so a zero or negative weight is no edge.

Usage

triad_census(x)

Arguments

x

A matrix, igraph object, or cograph_network.

Value

A data frame with one row per MAN triad type (16 rows), in the order listed under Details, and the columns type (the MAN code) and count (the number of triads of that type). The counts sum to choose(n, 3) for n nodes.

Details

The triad census is defined only for directed networks. Matrix input is read as directed. An undirected igraph or cograph_network input raises an error.

A MAN code gives the number of mutual (reciprocated) dyads, the number of asymmetric dyads and the number of null (absent) dyads of a triad, followed by a letter that separates types with the same counts. The 16 triad types, in the order of the result, are 003, 012, 102, 021D, 021U, 021C, 111D, 111U, 030T, 030C, 201, 120D, 120U, 120C, 210 and 300.

See also

motifs() for the unified API, motif_census()

Other motifs: extract_motifs(), extract_triads(), get_edge_list(), motif_census(), motifs(), subgraphs()

Examples

cograph::triad_census(regulation_net)
#>    type count
#> 1   003     7
#> 2   012    27
#> 3   102     2
#> 4  021D     9
#> 5  021U    11
#> 6  021C    29
#> 7  111D     9
#> 8  111U     7
#> 9  030T    11
#> 10 030C     2
#> 11  201     0
#> 12 120D     2
#> 13 120U     1
#> 14 120C     3
#> 15  210     0
#> 16  300     0