Re: [igraph] charachteristic of communites

[Tamas Nepusz]

> thanks Gabor for the answer , just to make sure my understanding (I meant
> for example a community consist of 12 nodes and zero edges
I think that "sensible" community detection algorithms should produce connected
communities where every node is reachable from every other (at least when the
network is undirected), so I think that if your community contains n vertices,
then it is very likely to contain at least n-1 edges. I don't have a formal
proof for this for any of the community detection algorithms in igraph, but
I think that at least the ones based on random walks (Infomap, walktrap) and/or
the merging of nodes into communities (fast greedy, walktrap) are very likely
to follow this rule.

T.