Robert Miller <rlmills...@gmail.com> writes: >> BTW, shouldn't the generator of the automorphism group be presented >> as "(0,2)(1,3)"? > > Good luck ever convincing the right systems that this should happen: > GAP's permutation groups don't allow you to permute on the letter 0. > See the translation option of automorphism_group on that... This has > been a pain in the butt since day 1. Your "0" is probably the "4". > >> >> sage: foo.edges() >> >> [(0, 1, 2), (0, 2, 1), (2, 3, 3)] >> >> sage: bar.edges() >> >> [(0, 1, 1), (0, 2, 2), (2, 3, 3)] >> >> sage: bar.is_isomorphic(foo, edge_labels = True) >> >> True > > Which version of Sage are you using?
I tried this in a Sage 3.1.1 and in Sage 3.1.2 > The edge_labels option should return True if and only if there is a > label-preserving isomorphism, as it does in your example in Sage > 3.2.2: > > ---------------------------------------------------------------------- > | Sage Version 3.2.2, Release Date: 2008-12-18 | > | Type notebook() for the GUI, and license() for information. | > ---------------------------------------------------------------------- > sage: foo = Graph() > sage: bar = Graph() > sage: foo.add_edges([(0,1,2),(0,2,1),(2,3,3)]) > sage: bar.add_edges([(0,1,1),(0,2,2),(2,3,3)]) > sage: foo.edges() > [(0, 1, 2), (0, 2, 1), (2, 3, 3)] > sage: bar.edges() > [(0, 1, 1), (0, 2, 2), (2, 3, 3)] > sage: bar.is_isomorphic(foo, edge_labels=True) > False Great! I'll upgrade and hopefully everything will be fine. Thanks. >> 2 1 3 >> 1 ----- 0 ----- 2 ----- 3 >> >> OTOH bar looks like this: >> >> 1 2 3 >> 1 ----- 0 ----- 2 ----- 3 > > You probably know, but you can do: > > sage: foo.plot(edge_labels=True) > Yeah, I know that but I kinda like ascii art :). Thanks, Nikos --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
