
From:  Tamas Nepusz 
Subject:  Re: [igraph] going from a directed to an undirected graph 
Date:  Sun, 9 Mar 2008 21:44:25 +0100 
Dear Alisa,
My problem is that when I used the as.undirected function with the "collapse" parameter, I wiped out the secondary connection. Is there any way to replace each pair of directed edges with one undirected edge (i.e. not the "each" parameter) without removing multiple edges? Suggestions?I assume you are using the R interface of igraph. Try utilizing the simplify() and count.multiple() calls. A possible solution is listed in the documentation:
E(g)$weight < count.multiple(g) g < simplify(g) E(g)$weightsimplify eliminates all multiple edges, so you'll have at most one edge from a>b or b>a. However, its associated weight attribute will contain the number of edges that were collapsed into this single edge.
 T.
[Prev in Thread]  Current Thread  [Next in Thread] 