Hi Nathann, Whoo hoo. First of all, you put my wrong e-mail address and I am not reading sage-devel all the time. Second of all, I did not write the poset code. As far as I know, it was written by Peter Jipsen and Franco Saliola. I used the poset code in the new class LinearExtensions in combinat/posets/linear_extensions.py
Anne On Tuesday, September 30, 2014 4:45:28 AM UTC-7, Nathann Cohen wrote: > > Hello, > > > Let's for sanity's sake suppose that == among all vertex labels of > > FinitePosets is an equivalence relation. Let's moreover suppose that > > hashing respects this equivalence relation. > > Thanks, > > > Then the problem seems to be that in the unique representation > > (an_integer_labelled_hasse_diagram, list_of_vertex_labels) > > of FinitePoset the internal mapping from vertex labels to integers is > > exposed. > > > > It seems to me that this can be fixed by > > A) getting rid of the exposure of the internal mapping, > > or > > B) by making the internal mapping unique given the Hasse diagram > > labelled using the actual vertex labels. > > > > Option A probably involves using a vertex label labelled Hasse diagram > > in the unique representation. The issue then becomes implementing that. > > I will rewrite it by making Poset.__init__ only depend on a hasse diagram > represented by a labelled digraph (which will then be translated internally > into an integer-labelled HasseDiagram). This way the key is the labelled > hasse diagram, which is the only thing that makes sense. > > Nicolas told me that this "_elements" thing was only used by Anne > Schilling in her markov-related code. So I will create some > AnneSchillingPoset class with list of elements, keys and everything she > needs and get us a real Poset class. And I hope everything will hold > together afterwards. > > Thank you for your message, though. Asking a design question only earned > me answers about "what is equality", and "can you provide a bug report > which is not the bug report you provided". > > Now, all I have to do is write somebody else's code. > > Nathann > -- 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 http://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
