使用R中的igraph计算两个节点之间的公共节点

Question

Suppose I've generated an undirected graph(you can think about the graph of my friends on facebook). I would like to know, for each couple of nodes(taken two friends), the number of common "nodes" they have(the "mutual friends" of them). Is there a function in igraph that I can use?

Or in network or sna packages?

Thank you.

Answer 1

If v_1 and v_2 are the two nodes in the graph g, then:

cocitation(g, v_1)[v_2]

will give you the number of "mutual friends" they have. Obviously is the same of

cocitation(g, v_2)[v_1]