Dear all,
I'm using community_multilevel to detect communities, and then use subgraphs() method on the resulting VertexClustering object to create a list of subgraphs corresponding to detected communities.
For these subgraphs, what happens to the edges that connect members of different communities? Are they preserved? If so, how does igraph decide which community/subgraph they should belong to?
For a made-up example, consider this graph:
http://socialqihealthcare.files.wordpress.com/2012/08/simple-social-graph-structure.png, let's just assume that nodes 1, 2, 3, 4, B are in one community/subgraph, and nodes 6, 7, 8, 9, A are in the other. How does igraph place the edges B-6, B-7, B-8 and B-9? And how does igraph take them into account when it comes to calculating various network metrics of the subgraphs such as density, clustering, etc?
Thanks.