Hi,
I would appreciate if some one could help me to speed up this piece of code :
what I am trying to do is to calculate the number of edges on the boundary of community S but it is really slow.
numberofedge<-function(graph,community)
{
cs <- data.frame(combn(unique(membership(community)),2)) #----considering a combination of communities two by two
cx <- sapply(cs, function(x) { #calculating edges in between two communities
es<-E(graph)[V(graph)[membership(community)==x[1]] %--%
V(graph)[membership(community)==x[2]]]
length(es)})
y=cbind(t(cs),cx)
i=1
CS=array( data="" = length(unique(membership(community))))
while (i<length(y[,1])+1){ # calculating the edges on the boundary for each community
CS[y[i,1]]=CS[y[i,1]]+y[i,3]
CS[y[i,2]]=CS[y[i,2]]+y[i,3]
i=i+1
}
regards
F..A