# flow_hierarchy¶

flow_hierarchy(G, weight=None)[source]

Returns the flow hierarchy of a directed network.

Flow hierarchy is defined as the fraction of edges not participating in cycles in a directed graph [1].

Parameters: G (DiGraph or MultiDiGraph) – A directed graph weight (key,optional (default=None)) – Attribute to use for node weights. If None the weight defaults to 1. h – Flow heirarchy value float

Notes

The algorithm described in [1] computes the flow hierarchy through exponentiation of the adjacency matrix. This function implements an alternative approach that finds strongly connected components. An edge is in a cycle if and only if it is in a strongly connected component, which can be found in O(m) time using Tarjan’s algorithm.

References

 [1] (1, 2) Luo, J.; Magee, C.L. (2011), Detecting evolving patterns of self-organizing networks by flow hierarchy measurement, Complexity, Volume 16 Issue 6 53-61. DOI: 10.1002/cplx.20368 http://web.mit.edu/~cmagee/www/documents/28-DetectingEvolvingPatterns_FlowHierarchy.pdf