Warning

This documents an unmaintained version of NetworkX. Please upgrade to a maintained version and see the current NetworkX documentation.

networkx.generators.duplication.duplication_divergence_graph

duplication_divergence_graph(n, p, seed=None)[source]

Returns an undirected graph using the duplication-divergence model.

A graph of n nodes is created by duplicating the initial nodes and retaining edges incident to the original nodes with a retention probability p.

Parameters:
  • n (int) – The desired number of nodes in the graph.
  • p (float) – The probability for retaining the edge of the replicated node.
  • seed (int, optional) – A seed for the random number generator of random (default=None).
Returns:

G

Return type:

Graph

Raises:

NetworkXError – If p is not a valid probability. If n is less than 2.

Notes

This algorithm appears in [1].

This implementation disallows the possibility of generating disconnected graphs.

References

[1]I. Ispolatov, P. L. Krapivsky, A. Yuryev, “Duplication-divergence model of protein interaction network”, Phys. Rev. E, 71, 061911, 2005.