Re: [Boost-users] graph library : isomorphism.hpp vertex invariant parameter

On 6/13/07, Patrick A. La Fratta wrote:

Also, I believe the vertex_max_invariant named parameter needs to be set for the isomorphism function to work (mine doesn't seem to work without it set). I added the necessary change to my named_params.hpp, similar to the patches you gave, in order to set this. It seems to work fine now. thanks, Patrick

On 6/13/07, Patrick A. La Fratta wrote:

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Thanks for your help and the fix. Also, there is a comment in the

"isomorphism.hpp" file in the "match" function that says "this *HAS* to be a bug!". Does anyone know if there is a problem here that hasn't been addressed?

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- Patrick

Hi Patrick, Thanks - I'll add the named parameter for vertex_max_invariant to the patch as well. As for the "this has to be a bug comment" - I've seen that too. What I can say is that I've hit the isomorphism code pretty hard recently with several thousands of small graphs and it looks good to me. I use it in the planarity testing/embedding code that I have in the vault right now (http://tinyurl.com/2dltju) to verify non-planar graphs - any graph that isn't planar contains a subgraph that can be contracted and tested for isomorphism against either the complete graph on 5 vertices or the complete bipartite graph on 6 vertices (with 3 vertices in each bipartition). So, admittedly, I'm using it to test for isomorphism against two very special small graphs, but I've never seen it give incorrect results. Regards, Aaron