Return dictionary representation of mixing matrix for degree.
Parameters :
G : graph
NetworkX graph object.
x: string (‘in’,’out’) :
The degree type for source node (directed graphs only).
y: string (‘in’,’out’) :
The degree type for target node (directed graphs only).
weight: string or None, optional (default=None) :
The edge attribute that holds the numerical value used
as a weight. If None, then each edge has weight 1.
The degree is the sum of the edge weights adjacent to the node.
normalized : bool (default=False)
Return counts if False or probabilities if True.
Returns :
d: dictionary :
Counts or joint probability of occurrence of degree pairs.