Extracting an edge list with conditions from an igraph object in R

You can use the %--% selector to find edges that connect male nodes to female nodes. For example

E(g)[V(g)[gender=="M"] %--% V(g)[gender=="F"]]

The V(g)[gender=="M"] finds all the "male" nodes and V(g)[gender=="F"] finds all the female node and %--% finds all the edges between the two sets.

edges = get.edgelist(g)
edges[rowSums(apply(edges, 2, function(x) get.vertex.attribute(g, "gender", x)) == "M") == 1,]
#     [,1] [,2]
#[1,]    4    7
#[2,]    3    7
#[3,]    5    7
#[4,]    4    6