Returns True if the graph is distance regular, False otherwise.
A connected graph G is distance-regular if for any nodes x,y and any integers i,j=0,1,…,d (where d is the graph diameter), the number of vertices at distance i from x and distance j from y depends only on i,j and the graph distance between x and y, independently of the choice of x and y.
Parameters: G (Networkx graph (undirected)) – Returns: True if the graph is Distance Regular, False otherwise Return type: bool
>>> G=nx.hypercube_graph(6) >>> nx.is_distance_regular(G) True
For undirected and simple graphs only
 Brouwer, A. E.; Cohen, A. M.; and Neumaier, A. Distance-Regular Graphs. New York: Springer-Verlag, 1989.  Weisstein, Eric W. “Distance-Regular Graph.” http://mathworld.wolfram.com/Distance-RegularGraph.html