# boundary_expansion¶

boundary_expansion(G, S)[source]

Returns the boundary expansion of the set S.

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

Parameters: G (NetworkX graph) S (sequence) – A sequence of nodes in G. The boundary expansion of the set S. number

References

 [1] Vadhan, Salil P. “Pseudorandomness.” Foundations and Trends in Theoretical Computer Science 7.1–3 (2011): 1–336.