Compute the degree centrality for nodes in a bipartite network.
The degree centrality for a node is the fraction of nodes connected to it.
Parameters :  G : graph
nodes : list or container


Returns :  centrality : dictionary

See also
betweenness_centrality, closeness_centrality, sets, is_bipartite
Notes
The nodes input parameter must conatin all nodes in one bipartite node set, but the dictionary returned contains all nodes from both bipartite node sets.
For unipartite networks, the degree centrality values are normalized by dividing by the maximum possible degree (which is where is the number of nodes in G).
In the bipartite case, the maximum possible degree of a node in a bipartite node set is the number of nodes in the opposite node set [R120]. The degree centrality for a node in the bipartite sets with nodes and with nodes is
where is the degree of node .
References
[R120]  (1, 2) Borgatti, S.P. and Halgin, D. In press. “Analyzing Affiliation Networks”. In Carrington, P. and Scott, J. (eds) The Sage Handbook of Social Network Analysis. Sage Publications. http://www.steveborgatti.com/papers/bhaffiliations.pdf 