Hi, On 23 May 2011 20:50, Aaron S. Meurer <asmeu...@gmail.com> wrote:
> > On May 23, 2011, at 12:49 PM, Mateusz Paprocki wrote: > > Hi, > > On 23 May 2011 20:46, Aaron S. Meurer <asmeu...@gmail.com> wrote: > >> >> On May 23, 2011, at 12:40 PM, Chris Smith wrote: >> >> > Aaron S. Meurer wrote: >> >>> On May 22, 2011, at 9:31 PM, Renato Coutinho wrote: >> >>> >> >>>> On Mon, May 23, 2011 at 12:28 AM, Mateusz Paprocki >> >>>> <matt...@gmail.com> wrote: >> >>>>> Hi, >> >>>>> >> >>>>> On 23 May 2011 05:18, smichr <smi...@gmail.com> wrote: >> >>>>>> >> >>>>>> Will list(e.free_symbols) be OS independent? >> >>>>> >> >>>>> .free_symbols is implemented using sets so it is platform (hash) >> >>>>> dependent (I mean order of elements). >> >>>> >> >>>> But sets don't have any ordering (except for printing or iterating, >> >>>> but you shouldn't use it). I think sorted(list(e.free_symbols)) >> >>>> should >> >>>> be safe. >> >>>> >> >>>> Cheers, >> >>>> Renato >> >>> >> >>> No, sorted uses __le__, which for symbols uses the hash, so that too >> >>> will be platform dependent (granted it's better than list(set), >> >>> which might return a different thing within the same session). >> >>> >> >>> Why do you need to have a list instead of a set? >> >>> >> > If you have `solve([x+y-3,x-y-1])` you need an unambiguous way to return >> the tuples if you aren't going to return the results with the symbols. You >> could get set([Tuple(1, 2)]) or set([Tuple(2, 1)]) so you need a way to >> internally send back something unambiguous. >> > >> >> I think it should just return the result with the symbols. >> > > Or use sorted_key to get hash independent ordering. > > > Even then, it isn't clear at all to the user what refers to what. I think > we should return a dictionary. > I agree. Most other systems return some kind of mapping, e.g. equations, rules. > > Aaron Meurer > > > >> >> Aaron Meurer >> >> -- >> You received this message because you are subscribed to the Google Groups >> "sympy" group. >> To post to this group, send email to sympy@googlegroups.com. >> To unsubscribe from this group, send email to >> sympy+unsubscr...@googlegroups.com. >> For more options, visit this group at >> http://groups.google.com/group/sympy?hl=en. >> >> > Mateusz > > -- > You received this message because you are subscribed to the Google Groups > "sympy" group. > To post to this group, send email to sympy@googlegroups.com. > To unsubscribe from this group, send email to > sympy+unsubscr...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/sympy?hl=en. > > > -- > You received this message because you are subscribed to the Google Groups > "sympy" group. > To post to this group, send email to sympy@googlegroups.com. > To unsubscribe from this group, send email to > sympy+unsubscr...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/sympy?hl=en. > Mateusz -- You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to sympy@googlegroups.com. To unsubscribe from this group, send email to sympy+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sympy?hl=en.
