Oh, indeed, sorry, my bad. I am afraid that this is this bug then: https://bugs.launchpad.net/igraph/+bug/1032819
Gabor On Wed, Sep 12, 2012 at 10:53 AM, Louis Aslett <[email protected]> wrote: > Thanks, yes that's what I meant in my rather imperfect rambling > definition! In the example I sent in the first mail, nodes 1 and 4 > are colour 1; nodes 2 and 3 are colour 2. My understanding is that > simply switching labels within colours is an isomorphism? > > Thanks, > > Louis > > > On 12 September 2012 14:49, Gábor Csárdi <[email protected]> wrote: >> Well, that's not the definition we used for color isomorphism. What we >> do is that in the mapping of the vertices, vertex 'v' can only be >> mapped to vertex 'w' if they have the same color. My understanding is >> that this is the "common" definition of isomorphism between colored >> graphs, but I might be wrong. >> >> Gabor >> >> On Wed, Sep 12, 2012 at 9:22 AM, Louis Aslett <[email protected]> wrote: >>> I might have misunderstood coloured graph isomorphisms, but from my >>> understanding the following two graphs should be isomorphic (code in >>> R). >>> >>> g1 <- graph.formula(1 -- 2:3, 2 -- 3, 3 -- 4) >>> g2 <- graph.formula(1 -- 2, 2 -- 3, 2:3 -- 4) >>> graph.count.isomorphisms.vf2(g1, g2, vertex.color1=c(1,2,2,1), >>> vertex.color2=c(1,2,2,1)) >>> >>> My understanding of coloured isomorphism is that two bijections are >>> looked for f and g, say, such that f applied to one colour or vertex >>> and g to the other results in equivalent adjacency to the original >>> graph. In this case, bijection f which switches 1 and 4, and another >>> g which switches 2 and 3 does the job (I think). However, the >>> function says there are no isomorphisms. >>> >>> Any thoughts (or corrections to my understanding of coloured >>> isomorphism) appreciated! >>> >>> Louis >>> >>> _______________________________________________ >>> igraph-help mailing list >>> [email protected] >>> https://lists.nongnu.org/mailman/listinfo/igraph-help >> >> >> >> -- >> Gabor Csardi <[email protected]> MTA KFKI RMKI >> >> _______________________________________________ >> igraph-help mailing list >> [email protected] >> https://lists.nongnu.org/mailman/listinfo/igraph-help > > _______________________________________________ > igraph-help mailing list > [email protected] > https://lists.nongnu.org/mailman/listinfo/igraph-help -- Gabor Csardi <[email protected]> MTA KFKI RMKI _______________________________________________ igraph-help mailing list [email protected] https://lists.nongnu.org/mailman/listinfo/igraph-help
