Le mercredi 11 octobre 2017 16:36:07 UTC+2, Dima Pasechnik a écrit : > > > > On Wednesday, October 11, 2017 at 10:20:02 AM UTC+1, Jori Mäntysalo wrote: >> >> On Wed, 11 Oct 2017, David Joyner wrote: >> >> >> 1) list(graphs.nauty_geng(0)) gives empty list, whereas Sage knows a >> >> graph of 0 vertices. Can someone ask McKay to handle this special case >> >> too? >> >> > Wouldn't it be easier to simply catch that case in the nauty_geng >> method? >> >> Could be done, but needs some string processing, as the argument is given >> as a string to nauty. And anyways, isn't this a corner-case bug? >> > > it depends upon the definition of an empty graph, I guess... >
Many authors avoid the empty graph (see e.g., the excellent book "Graph Theory with Applications" by Bondy and Murty) as there are no consensus on its properties. Should it be considered connected ? biconnected ? hamiltonian ? minor-free ? transitively reduced ? -- 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 sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at https://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
