On Friday, 6 January 2012 22:57:24 UTC+8, David Joyner wrote: > > On Fri, Jan 6, 2012 at 9:43 AM, Jason Grout <jason...@creativetrax.com> > wrote: > > Hi all, > > > > Is there an easy way to ask if two graphs are isomorphic, respecting some > > coloring or labeling of the vertices? I see the is_isomorphic function > lets > > > I don't know if this is easy or not but here is an idea: > First, suppose you have 2 colors, red and blue. Compute the automorphism > gp of > the graph, then look at the stabilizer of the red vertices. Done. > this might be horribly inefficient.
> Next, if you have more colors, you compute the stablizer of each > individual color, then take the intersection of all the stabilizers you > get. > and this is even worse... > > > you respect edge labels, so I guess I could attach a new vertex to, say, > all > > "blue" vertices, and label each of the edges to this new vertex as > "blue", > > then ask for edge-preserving isomorphism checking. But it would be nice > if > > there was a way to do this without modifying the graph, etc. > > > > Thanks, > > > > Jason > > > > -- > > To post to this group, send an email to sage-...@googlegroups.com > > To unsubscribe from this group, send an email to > > sage-devel+...@googlegroups.com > > For more options, visit this group at > > http://groups.google.com/group/sage-devel > > URL: http://www.sagemath.org > > -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
