NetworkX

Previous topic

networkx.algorithms.centrality.closeness_centrality

Next topic

networkx.algorithms.centrality.edge_betweenness_centrality

networkx.algorithms.centrality.betweenness_centrality

networkx.algorithms.centrality.betweenness_centrality(G, normalized=True, weight=None, endpoints=False)

Compute the shortest-path betweenness centrality for nodes.

Betweenness centrality of a node v is the sum of the fraction of all-pairs shortest paths that pass through v:

c_B(v) =\sum_{s,t \in V} \frac{\sigma(s, t|v)}{\sigma(s, t)}

where V is the set of nodes, \sigma(s, t) is the number of shortest (s, t)-paths, and \sigma(s, t|v) is the number of those paths passing through some node v other than s, t. If s = t, \sigma(s, t) = 1, and if v \in {s, t}, \sigma(s, t|v) = 0 [R87].

Parameters :

G : graph

A NetworkX graph

normalized : bool, optional

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

weight : None, True or string, optional

If None, all edge weights are considered equal. If True, edge attribute ‘weight’ is used as weight of each edge. Otherwise holds the name of the edge attribute used as weight.

endpoints : bool, optional

If True include the endpoints in the shortest path counts.

Returns :

nodes : dictionary

Dictionary of nodes with betweenness centrality as the value.

Notes

The algorithm is from Ulrik Brandes [R86]. See [R87] for details on algorithms for variations and related metrics.

For weighted graphs the edge weights must be greater than zero. Zero edge weights can produce an infinite number of equal length paths between pairs of nodes.

References

[R86](1, 2) A Faster Algorithm for Betweenness Centrality. Ulrik Brandes, Journal of Mathematical Sociology 25(2):163-177, 2001. http://www.inf.uni-konstanz.de/algo/publications/b-fabc-01.pdf
[R87](1, 2, 3) Ulrik Brandes: On Variants of Shortest-Path Betweenness Centrality and their Generic Computation. Social Networks 30(2):136-145, 2008. http://www.inf.uni-konstanz.de/algo/publications/b-vspbc-08.pdf