networkx.algorithms.distance_regular.is_strongly_regular

is_strongly_regular(G)[source]

Returns True if and only if the given graph is strongly regular.

An undirected graph is strongly regular if

  • it is regular,

  • each pair of adjacent vertices has the same number of neighbors in common,

  • each pair of nonadjacent vertices has the same number of neighbors in common.

Each strongly regular graph is a distance-regular graph. Conversely, if a distance-regular graph has diameter two, then it is a strongly regular graph. For more information on distance-regular graphs, see is_distance_regular().

Parameters
GNetworkX graph

An undirected graph.

Returns
bool

Whether G is strongly regular.

Examples

The cycle graph on five vertices is strongly regular. It is two-regular, each pair of adjacent vertices has no shared neighbors, and each pair of nonadjacent vertices has one shared neighbor:

>>> G = nx.cycle_graph(5)
>>> nx.is_strongly_regular(G)
True