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. -- 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.
