node_expansion#

node_expansion(G, S)[source]#

Returns the node expansion of the set S.

The node expansion is the quotient of the size of the node boundary of S and the cardinality of S. [1]

Parameters:
GNetworkX graph
Scollection

A collection of nodes in G.

Returns:
number

The node expansion of the set S.

References

[1]

Vadhan, Salil P. “Pseudorandomness.” Foundations and Trends in Theoretical Computer Science 7.1–3 (2011): 1–336. <https://doi.org/10.1561/0400000010>