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is_graphical

is_graphical(sequence, method='eg')[source]

Returns True if sequence is a valid degree sequence.

A degree sequence is valid if some graph can realize it.

Parameters :

sequence : list or iterable container

A sequence of integer node degrees

method : “eg” | “hh”

The method used to validate the degree sequence. “eg” corresponds to the Erdős-Gallai algorithm, and “hh” to the Havel-Hakimi algorithm.

Returns :

valid : bool

True if the sequence is a valid degree sequence and False if not.

References

Erdős-Gallai
[EG1960], [choudum1986]
Havel-Hakimi
[havel1955], [hakimi1962], [CL1996]

Examples

>>> G = nx.path_graph(4)
>>> sequence = G.degree().values()
>>> nx.is_valid_degree_sequence(sequence)
True