On Wed, Apr 23, 2008 at 6:20 PM, Jason Grout <[EMAIL PROTECTED]> wrote:
> I have a need to enumerate all possible black and white colorings of a > graph, up to (colored) isomorphism. Is there a way to use some of the > NICE code to make this fast? It seems like I read somewhere that Robert > was going to generalize NICE to let you compute enumeration/canonical > things for more general combinatorial objects. > Jason, Is your graph highly symmetric? If not, then there's really no need to worry about isomorph rejection (the only isomorphism being switching the colors). If so, then McKay's method of "canonical augmentation" would be helpful. McKay has a paper called "Isomorph-free exhaustive generation" describing this that is available on his webpage. You can use NICE to do the actual isomorph testing, but you would need to build the general framework yourself. I don't think this could be done in general, since each type of combinatorial generation would need different routines, and the "framework" part would be just a few lines. Best wishes, Stephen --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
