Simllar problem with the Gray graph: sage: Gamma = graphs.GrayGraph() sage: G.diameter() 8 (it should be 6)
G = graphs.LCFGraph(54, [-25,7,-7,13,-13,25], 9) sage: G.diameter() 6 seems to be the Gray graph On Fri, Oct 2, 2015 at 5:47 PM, David Joyner <[email protected]> wrote: > On Fri, Oct 2, 2015 at 5:44 PM, David Joyner <[email protected]> wrote: >> Hi all: >> >> Several online sources (including a page on Royle's website) give the >> girth of the Foster graph to be 10, but Sage gives 6: >> >> sage: Gamma = graphs.FosterGraph() >> sage: G.girth() >> 6 >> >> Is there a bug in girth? >> >> - David > > I might have found an answer to my own question: > > sage: G = graphs.LCFGraph(90, [17,-9,37,-37,9,-17], 15) > sage: G.is_vertex_transitive() > True > sage: G.is_hamiltonian() > True > sage: G.chromatic_number() > 2 > sage: G.is_bipartite() > True > sage: len(G.vertices()) > 90 > sage: len(G.edges()) > 135 > sage: G.girth() > 10 > > These suggest that G is the true Foster graph -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
