IMHO we should start on making bliss (and nauty) available at is_isomorphic(), via an optional parameter. I have opened https://trac.sagemath.org/ticket/21313 to deal with this.
On Tuesday, August 23, 2016 at 5:45:42 AM UTC+1, [email protected] wrote: > > On Mon, 22 Aug 2016, Paul Leopardi wrote: > > > I am seeing a problem where "g.is_isomorphic(h)" is taking an > inordinately > > long time, where g and h are graphs, even though > > "g.automorphism_group().order() == h.automorphism_group().order()", and > > "g.canonical_label() == h.canonical_label()" both take a reasonable > time. > > Do you have Bliss installed? If so, then canonical_label() uses it, but > is_isomorphic() does not. > > > My main question for the moment is how do I specify graphs here in > > sage-support so that others can reproduce the problem? > > dig6_string() is only available do directed graphs, but a Graph made from > DiGraph is just a graph with directions forgotten. So you can say > > DiGraph(g).dig6_string() > > and on the other direction > > Graph(DiGraph('DOOOW?')) > > will give an undirected graph. We can then try to relabel your graph (like > g.relabel(lambda x: x+1) ) and check for isomorphism. > > -- > Jori Mäntysalo > -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
