You could also check equality for all vertices with sage: ans, isom = G1.is_isomorphic(G2, certificate=True) sage: all(G1.spanning_trees_count(u) == G2.spanning_trees_count(isom[u]) for u in G1.vertices(sort=False)) True
On Sun, 18 Jun 2023 at 10:09, Dima Pasechnik <[email protected]> wrote: > > It could be an integer overflow somewhere in the determinant > computation, as the numbers are very, very big. > > By default, determinants are computed by flint, so it can be a bug there. > You can modify the code of spanning_trees_count() to allow passing of > the algorithm to compute determinant, and see if you can get it right. > > HTH > Dima > > On Sun, Jun 18, 2023 at 8:49 AM Georgi Guninski <[email protected]> wrote: > > > > On Sun, Jun 18, 2023 at 10:16 AM Emmanuel Briand > > <[email protected]> wrote: > > > > > > Have you taken into account the following? > > > > > > ignature: G1.spanning_trees_count(root_vertex=None) > > > Docstring: > > > Return the number of spanning trees in a graph. > > > > > > In the case of a digraph, counts the number of spanning out-trees > > > rooted in "root_vertex". Default is to set first vertex as root. > > > > > > > > > > Thanks, I should have RTFM. > > > > This still doesn't work for me: > > > > sage: > > G1.spanning_trees_count(root_vertex=None),G2.spanning_trees_count(root_ver > > ....: tex=None) > > (27202601182632270746156805986464038912000, > > 40803901773948406119235208979696058368000) > > > > > > Is it rigorous to set c1=G1.spanning_trees_count() > > and then do: > > > > sage: c1=G1.spanning_trees_count() > > sage: for i in range(G1.order()): > > ....: c2=G2.spanning_trees_count(i) > > ....: if c2==c1: print(i) > > ....: > > 6 > > > > I expect for isomorphic multi digraphs the loop to find equal c1,c2? > > > > -- > > You received this message because you are subscribed to the Google Groups > > "sage-devel" group. > > To unsubscribe from this group and stop receiving emails from it, send an > > email to [email protected]. > > To view this discussion on the web visit > > https://groups.google.com/d/msgid/sage-devel/CAGUWgD_Zkf7g2py2PxWkYA4PqBOW6Ws%2BW31JtsQF2nmO6JE9tg%40mail.gmail.com. > > -- > You received this message because you are subscribed to the Google Groups > "sage-devel" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/sage-devel/CAAWYfq2%2B_eejUwRr9M5%3DB%3Ddn36XMvU1hRbEQ_wwGu2obdWf2Kw%40mail.gmail.com. -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/sage-devel/CAGEwAAmK1t%3DHrcRG4QeeitLsU88XMuuRsY_w0sMG-iC6zQFC3g%40mail.gmail.com.
