This documents the development version of NetworkX. Documentation for the current release can be found here.
Returns the node expansion of the set
The node expansion is the quotient of the size of the node boundary of S and the cardinality of S. 
- GNetworkX graph
A collection of nodes in
The node expansion of the set
Vadhan, Salil P. “Pseudorandomness.” Foundations and Trends in Theoretical Computer Science 7.1–3 (2011): 1–336. <https://doi.org/10.1561/0400000010>