Helloooooooooooooo everybody !!! I spent many hours fighting with Posets under Sage. I enjoyed it a lot, but I can already tell that it gets on Florent's and Nicolas' nerves, and so I was thinking of whether I should put an end to it. For their sake.
Here's the problem. With comments. ------------------------------- Building the poset from a DiGraph defined on integers : sage: g = DiGraph([(1,2),(1,3),(2,4),(3,4)]) sage: p = Poset(g) Is 3 in the poset ? sage: 3 in p True Of course it is ! sage: list(p) [1, 2, 3, 4] sage: 3 in list(p) False Not it is not ! So what the hell is this list [1,2,3,4] that we get as a result to list(p) ? sage: map(type,list(p)) [<class 'sage.combinat.posets.elements.FinitePoset_with_category.element_class'>, <class 'sage.combinat.posets.elements.FinitePoset_with_category.element_class'>, <class 'sage.combinat.posets.elements.FinitePoset_with_category.element_class'>, <class 'sage.combinat.posets.elements.FinitePoset_with_category.element_class'>] O_O;;; sage: p.cover_relations() [[1, 2], [1, 3], [2, 4], [3, 4]] sage: [1,3] in p.cover_relations() False sage: (1,3) in p.cover_relations() False And of course : sage: p.hasse_diagraph() == g False ------------------------ WELL. I personally consider that this behaviour is totally crazy, and I often say so (very loud, and very frequently. Just come eat with us anyday at lunch and I will probably complain about that, or about LaTeX). This being said, I also heard that it may possibly make sense in a very sick logic, and that the correction of some code may actually depend on that. I personally think that having this as the default behaviour of Poset is *madness*. I personally *ONLY* use Posets with he flag "facade = True" when I do not forget it, and lose half an hour when I do forget it. What would you think of making it the default behaviour of Poset ? This way, normal people could use a Poset without having to know what a facade is. Without having to hear about parents, elements, the .value() method and all. I mean. Why the hell should this stay the default behaviour ? Thank you for listening. Very soon, I hope to convince you that the way Poset.relabel is written is an insult to computer science. I think I may already have convinced Florent Hivert of the sin this method is. Nathann -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To post to this group, send email to sage-devel@googlegroups.com. To unsubscribe from this group, send email to sage-devel+unsubscr...@googlegroups.com. Visit this group at http://groups.google.com/group/sage-devel?hl=en.
