triadic_census#

triadic_census(G, nodelist=None)[source]#

Determines the triadic census of a directed graph.

The triadic census is a count of how many of the 16 possible types of triads are present in a directed graph. If a list of nodes is passed, then only those triads are taken into account which have elements of nodelist in them.

Parameters:

Gdigraph: A NetworkX DiGraph
nodelistlist: List of nodes for which you want to calculate triadic census

Returns:

censusdict: Dictionary with triad type as keys and number of occurrences as values.

Raises:

ValueError: If nodelist contains duplicate nodes or nodes not in G. If you want to ignore this you can preprocess with set(nodelist) & G.nodes

See also

triad_graph

Notes

This algorithm has complexity \(O(m)\) where \(m\) is the number of edges in the graph.

References

[1]

Vladimir Batagelj and Andrej Mrvar, A subquadratic triad census algorithm for large sparse networks with small maximum degree, University of Ljubljana, http://vlado.fmf.uni-lj.si/pub/networks/doc/triads/triads.pdf