My suggestion would be to continue with the matrixify solution and write functions to fix up the expression tree as need be. The whole issue of making Add/Mul/Pow extensible is separate but the logic can be transferred pretty easily.
-- Andy On Wed, Jul 13, 2011 at 1:44 PM, Aaron Meurer <asmeu...@gmail.com> wrote: > On Wed, Jul 13, 2011 at 1:19 PM, Ronan Lamy <ronan.l...@gmail.com> wrote: >> Le mercredi 13 juillet 2011 à 10:51 -0700, Brian Granger a écrit : >>> Matthew, >>> >>> Arron has provided a fantastic summary of the issues involve. The >>> summary is that even if you subclass Add/Mul/Pow, sympy will end up >>> creating expressions that don't use your subclasses everywhere. This >>> can't be fixed without changing the core, which is outside the scope >>> of your project. I know I sound like a broken record, but you should >>> resist the temptation to define your own Add/Mul/Pow classes. >> >> I'm not convinced. What other solution is there? >> >> Also, creating Add/Mul/Pow subclasses looks like the obvious way of >> extending sympy, so we want to make it work at some point. Creating >> MatrixAdd, etc. will help a lot with that by highlighting all the places >> where we assume things like a + b == Add(a, b). So if Matthew thinks he >> can make it work without too much pain, compared to the alternatives, >> then I think he should go for it. > > Well, the dispatch solution only works for op.whatever, but as we > know, reduce(op.whatever, list_of_args) is asymptotically less > efficient than Whatever(*list_of_args). > > Actually, half of the problem isn't so much making Add/Mul/etc. work > with dispatch rules, but making it *efficiently* work with dispatch > rules. > > 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. >> >> > > -- > 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.
