> I have a few comments: > * The call to expand() is slow and unnecessary. At this stage, all > that's needed is to call _eval_expand_multinomial(deep=False). So > instead of: > + return 1 / Pow(base, -exp.p).expand(deep=deep, **hints) > we should have: > + return 1 / Pow(base, > -exp.p)._eval_expand_multinomial(deep=False)
Yes, I think you are right. I will prepare a patch that changes it to what you have and makes sure that all the tests pass. > > * This line suggests that it would be helpful to create an 'inverse' > property - less work is needed to create this inverse than for a generic > Pow instance. Could you elaborate on what you mean here? Do you mean an inverse property to Pow instances which have a integer exponent? Perhaps 'reciprocal' instead of 'inverse'? > * There should be more tests for negative exponents, basically > duplicating all existing tests with positive exponents Yes, I agree. > *I don't see the point of the third test: it's only testing that (x > +y)**2*(x+y)**-4 == (x+y)**-2 which isn't related to expand. Yes, you are right, it isn't testing expand but I guess it probably doesn't hurt to keep it in either. ~Luke --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "sympy-patches" group. To post to this group, send email to sympy-patches@googlegroups.com To unsubscribe from this group, send email to sympy-patches+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sympy-patches?hl=en -~----------~----~----~----~------~----~------~--~---
