Certain Piecewise expressions will recursively evaluate themselves ad infinitium for every call to .doit (), instead of recognizing the recursion. For example:
Sum (x**n, (n, -1, oo)).doit () = Piecewise((1/(x*(1 - x)), Abs(x) < 1), (Sum(x**n, (n, -1, oo)), True)) Piecewise((1/(x*(1 - x)), Abs(x) < 1), (Sum(x**n, (n, -1, oo)), True)).doit () = Piecewise((1/(x*(1 - x)), Abs(x) < 1), (Piecewise((1/(x*(1 - x)), Abs(x) < 1), (Sum(x**n, (n, -1, oo)), True)), True)) etc... Is this intended behavior? This would not be a problem and .doit () could be artificially restricted to one call but this seems to happen within SymPy itself, e.g. Sum (x**(n-1), (n, 0, oo)).doit () = Piecewise((1/(1 - x), Abs(x) < 1), (Piecewise((1/(1 - x), Abs(x) < 1), (Sum(x**n, (n, 0, oo)), True)), True))/x -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sympy+unsubscr...@googlegroups.com. To post to this group, send email to sympy@googlegroups.com. Visit this group at https://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/bb54a4aa-7634-46a4-bdce-fbee3bc1074e%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
