Re: [igraph] using colors when counting isomorphisms (also indexing)

[Gábor Csárdi]

Hi, thanks for your report, answers are below.

On Thu, Mar 7, 2013 at 2:41 PM, Jason Cory Brunson <address@hidden> wrote:

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V(g1)$color <- rep(1:2, length = vcount(g1))

V(g2)$color <- rep(1:2, length = vcount(g2))
graph.count.isomorphisms.vf2(g1, g2)
[1] 2

It seems to me that there should be four isomorphisms: two mapping node 1 to node 1 and two mapping node 1 to node 3.

This is a bug that was already fixed. I guess you are using an old igraph version. Including your R and igraph version and platform (e.g. output of sessionInfo()) in your bug report is a good idea. Please upgrade and try it again.

 

Any help reconciling this issue would be greatly appreciated!

Also, the indices of the vertices returned by graph.get.isomorphisms are 1 less than they should be (possibly a relic of previous versions when graphs begin with vertex 0?):

You are right, this is another bug. I'll submit a bug report for it, and will fix it soon. 

Thanks, Best Regards

G.

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