[R] igraph: Turn multiple edges into weights

[Gábor Csárdi]

On Tue, Aug 14, 2012 at 5:09 PM, Jonas Michaelis
<jonas.michaelis at gmail.com> wrote:
> Dear all,
>
>
> I have some network data - about 300 vertices and several thousand edges. I
> am looking for a way to turn multiple edges into weights of the edges. I
> looked around and - surprisingly? - haven't found anything. Is there an
> easy way to do this?

simplify() by default sums the edge weights, so just set all weights
to 1, and call simplify().

E.g.

## A graph with multiple edges
g <- graph.formula(A:A:A -- B:C:D, A -- B, simplify=FALSE)
str(g)
E(g)$weight <- 1
g2 <- simplify(g, remove.loops=FALSE)
str(g2, e=TRUE)

Best,
Gabor

>
> Best, Jonas
>
>         [[alternative HTML version deleted]]
>
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-- 
Gabor Csardi <csardi at rmki.kfki.hu>     MTA KFKI RMKI