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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.degree_seq.havel_hakimi_graph

havel_hakimi_graph(deg_sequence, create_using=None)[source]

Returns a simple graph with given degree sequence constructed using the Havel-Hakimi algorithm.

Parameters

  • deg_sequence (list of integers) – Each integer corresponds to the degree of a node (need not be sorted).

  • create_using (NetworkX graph constructor, optional (default=nx.Graph)) – Graph type to create. If graph instance, then cleared before populated. Directed graphs are not allowed.

Raises

NetworkXException – For a non-graphical degree sequence (i.e. one not realizable by some simple graph).

Notes

The Havel-Hakimi algorithm constructs a simple graph by successively connecting the node of highest degree to other nodes of highest degree, resorting remaining nodes by degree, and repeating the process. The resulting graph has a high degree-associativity. Nodes are labeled 1,.., len(deg_sequence), corresponding to their position in deg_sequence.

The basic algorithm is from Hakimi 1 and was generalized by Kleitman and Wang 2.

References

1

Hakimi S., On Realizability of a Set of Integers as Degrees of the Vertices of a Linear Graph. I, Journal of SIAM, 10(3), pp. 496-506 (1962)

2

Kleitman D.J. and Wang D.L. Algorithms for Constructing Graphs and Digraphs with Given Valences and Factors Discrete Mathematics, 6(1), pp. 79-88 (1973)