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... > > >> 2) Is there an example of graph property that holds after deleting any > >> vertex but not necessarily after deleting an edge? Or the converse? > > > Completeness, if you start with a complete graph, is preserved if you > > delete a vertex but not if you delete an edge. > > True. But it is propably not what one will generate orderly... > > -- > Jori Mäntysalo -- 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.
