The OddGraph (special case of a Kneser graph) has vertices that are sets, but this seems to lead to the computation of the girth reporting it has no cycles. The code for computing the girth looks like a fairly straight-forward depth-first search. Does something about the nature of the vertices have to change? They look hashable to me, so it may not be that simple. Any ideas?
Rob sage: P = graphs.PetersenGraph() sage: P.girth() 5 sage: K = graphs.OddGraph(3) sage: K.is_isomorphic(P) True sage: K.girth() +Infinity sage: H = copy(K) sage: H.relabel() sage: H.girth() 5 sage: type(K.vertices()[0]) <class 'sage.sets.set.Set_object_enumerated_with_category'> -- 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
