Hi, I have two graphs, g1 and g2 (defined below), for which g1.is_isomorphic(g2) fails, but I know that they are isomorphic, and I can apply a relabelling of the vertices of g1 so that g1.is_isomorphic(g2) evaluates to True (see the code at the end of this email).
Have I set up something incorrectly? At first I wondered if vertices have to be in the range 0..n (mine are on 1..n) but adding an isolated vertex '0' doesn't change the behaviour of my code. Any ideas? -- Carlo Hamalainen http://carlo-hamalainen.net # This file is at http://carlo-hamalainen.net/sagetmp/graphiso.sage g1 = graphs.EmptyGraph() g2 = graphs.EmptyGraph() g1.add_edges([(1, 17, None), (1, 21, None), (1, 25, None), (2, 17, None), (2, 22, None), (2, 26, None), (3, 17, None), (3, 23, None), (3, 27, None), (4, 17, None), (4, 24, None), (4, 28, None), (5, 18, None), (5, 21, None), (5, 26, None), (6, 18, None), (6, 22, None), (6, 27, None), (7, 18, None), (7, 23, None), (7, 28, None), (8, 18, None), (8, 24, None), (8, 25, None), (9, 19, None), (9, 21, None), (9, 27, None), (10, 19, None), (10, 22, None), (10, 28, None), (11, 19, None), (11, 23, None), (11, 25, None), (12, 19, None), (12, 24, None), (12, 26, None), (13, 20, None), (13, 21, None), (13, 28, None), (14, 20, None), (14, 22, None), (14, 25, None), (15, 20, None), (15, 23, None), (15, 26, None), (16, 20, None), (16, 24, None), (16, 27, None), (17, 29, None), (18, 29, None), (19, 29, None), (20, 29, None), (21, 30, None), (22, 30, None), (23, 30, None), (24, 30, None), (25, 31, None), (26, 31, None), (27, 31, None), (28, 31, None)]) g2.add_edges([(1, 17, None), (1, 21, None), (1, 28, None), (2, 17, None), (2, 22, None), (2, 25, None), (3, 17, None), (3, 23, None), (3, 26, None), (4, 17, None), (4, 24, None), (4, 27, None), (5, 18, None), (5, 21, None), (5, 26, None), (6, 18, None), (6, 22, None), (6, 27, None), (7, 18, None), (7, 23, None), (7, 28, None), (8, 18, None), (8, 24, None), (8, 25, None), (9, 19, None), (9, 21, None), (9, 27, None), (10, 19, None), (10, 22, None), (10, 28, None), (11, 19, None), (11, 23, None), (11, 25, None), (12, 19, None), (12, 24, None), (12, 26, None), (13, 20, None), (13, 21, None), (13, 25, None), (14, 20, None), (14, 22, None), (14, 26, None), (15, 20, None), (15, 23, None), (15, 27, None), (16, 20, None), (16, 24, None), (16, 28, None), (17, 29, None), (18, 29, None), (19, 29, None), (20, 29, None), (21, 30, None), (22, 30, None), (23, 30, None), (24, 30, None), (25, 31, None), (26, 31, None), (27, 31, None), (28, 31, None)]) perm = {0:0, 1: 13, 2: 14, 3: 15, 4: 16, 5: 5, 6: 6, 7: 7, 8: 8, 9: 9, 10: 10, 11: 11, 12: 12, 13: 1, 14: 2, 15: 3, 16: 4, 17: 20, 18: 18, 19: 19, 20: 17, 21: 21, 22: 22, 23: 23, 24: 24, 25: 25, 26: 26, 27: 27, 28: 28, 29: 29, 30: 30, 31: 31} # This says no: print g1.is_isomorphic(g2) # But I can find a vertex relabelling... g1.relabel(perm) # ... and this says yes: print g1.is_isomorphic(g2) --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-support@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-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
