Return the biadjacency matrix of the bipartite graph G.
Let be a bipartite graph with node sets and . The biadjacency matrix [1] is the x matrix in which if, and only if, . If the parameter is not and matches the name of an edge attribute, its value is used instead of 1.
Parameters :  G : graph
row_order : list of nodes
column_order : list, optional
weight : string or None, optional (default=’weight’)
dtype : NumPy data type, optional


Returns :  B : numpy matrix

See also
to_numpy_matrix, adjacency_matrix
Notes
No attempt is made to check that the input graph is bipartite.
For directed bipartite graphs only successors are considered as neighbors. To obtain an adjacency matrix with ones (or weight values) for both predecessors and successors you have to generate two biadjacency matrices where the rows of one of them are the columns of the other, and then add one to the transpose of the other.
References
[1] http://en.wikipedia.org/wiki/Adjacency_matrix#Adjacency_matrix_of_a_bipartite_graph