[igraph] Relative betweenness

[Moses Boudourides]

Hello,

My question concerns the betweenness igraph function. In a network, I
have two disjoint sets of vertices, A and B. I would like to compute
the measure of vertex betweenness of A on the basis of not all the
geodesics of the network (passing from A) but only the geodesics with
end vertices in B. I understand that the betweenness function has an
argument "v" as the set of vertices for which the vertex betweenness
will be calculated. But I'm not sure whether and how I could get the
betweenness of A with regards to geodesics stemming from B. Any ideas?

Best,

--Moses