Consider the following:
g = RandomGraph[WattsStrogatzGraphDistribution[1000, 0.1, 5]] comm = FindGraphPartition[g, 2]; CommunityGraphPlot[g, comm]
FindGraphPartition[g,2] will find a partition of vertices such that the number of edges having endpoints in different parts is minimized. How can I get Mathematica to tell me the number of edges that connect these two groups? It seems like something I should be able to get at easily, but looking through the documentation I just can't find anything.