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current_flow_betweenness_centrality

current_flow_betweenness_centrality(G, normalized=True, weight='weight', dtype=<type 'float'>, solver='lu')

Compute current-flow betweenness centrality for nodes.

Current-flow betweenness centrality uses an electrical current model for information spreading in contrast to betweenness centrality which uses shortest paths.

Current-flow betweenness centrality is also known as random-walk betweenness centrality [R127].

Parameters :

G : graph

A NetworkX graph

normalized : bool, optional (default=True)

If True the betweenness values are normalized by b=b/(n-1)(n-2) where n is the number of nodes in G.

weight : string or None, optional (default=’weight’)

Key for edge data used as the edge weight. If None, then use 1 as each edge weight.

dtype: data type (float) :

Default data type for internal matrices. Set to np.float32 for lower memory consumption.

solver: string (default=’lu’) :

Type of linear solver to use for computing the flow matrix. Options are “full” (uses most memory), “lu” (recommended), and “cg” (uses least memory).

Returns :

nodes : dictionary

Dictionary of nodes with betweenness centrality as the value.

Notes

Current-flow betweenness can be computed in O(I(n-1)+mn \log n) time [R126], where I(n-1) is the time needed to compute the inverse Laplacian. For a full matrix this is O(n^3) but using sparse methods you can achieve O(nm{\sqrt k}) where k is the Laplacian matrix condition number.

The space required is O(nw) where `w is the width of the sparse Laplacian matrix. Worse case is w=n for O(n^2).

If the edges have a ‘weight’ attribute they will be used as weights in this algorithm. Unspecified weights are set to 1.

References

[R126](1, 2) Centrality Measures Based on Current Flow. Ulrik Brandes and Daniel Fleischer, Proc. 22nd Symp. Theoretical Aspects of Computer Science (STACS ‘05). LNCS 3404, pp. 533-544. Springer-Verlag, 2005. http://www.inf.uni-konstanz.de/algo/publications/bf-cmbcf-05.pdf
[R127](1, 2) A measure of betweenness centrality based on random walks, M. E. J. Newman, Social Networks 27, 39-54 (2005).