Hello, I just wanted to point out a little bug I've run into recently with the graph.adjacency function.
start with m <- matrix(c(0,1,1,0),nrow=2) then graph.adjacency(m, mode="undirected")
works fine, but g <- graph.adjacency(m, mode="undirected",weighted=TRUE) doubles every non-loop edges in g. For example get.adjacency(g) would output 0 2 2 0
instead of 0 1 1 0 This problem occurs for any symmetric m. I run up-to-date versions of igraph and R on both Linux and Windows systems.
Anyway, congratulations for igraph. It is a great and powerful software I use constantly.