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Note

This documents the development version of NetworkX. Documentation for the current release can be found here.

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networkx.generators.joint_degree_seq.is_valid_joint_degree¶

is_valid_joint_degree(joint_degrees)[source]¶

Checks whether the given joint degree dictionary is realizable.

A joint degree dictionary is a dictionary of dictionaries, in which entry joint_degrees[k][l] is an integer representing the number of edges joining nodes of degree k with nodes of degree l. Such a dictionary is realizable as a simple graph if and only if the following conditions are satisfied.

each entry must be an integer,
the total number of nodes of degree k, computed by sum(joint_degrees[k].values()) / k, must be an integer,
the total number of edges joining nodes of degree k with nodes of degree l cannot exceed the total number of possible edges,
each diagonal entry joint_degrees[k][k] must be even (this is a convention assumed by the joint_degree_graph() function).

Parameters: joint_degrees (dictionary of dictionary of integers) – A joint degree dictionary in which entry joint_degrees[k][l] is the number of edges joining nodes of degree k with nodes of degree l.
Returns: Whether the given joint degree dictionary is realizable as a simple graph.
Return type: bool

References

1: M. Gjoka, M. Kurant, A. Markopoulou, “2.5K Graphs: from Sampling to Generation”, IEEE Infocom, 2013.
2: I. Stanton, A. Pinar, “Constructing and sampling graphs with a prescribed joint degree distribution”, Journal of Experimental Algorithmics, 2012.