Status: Accepted Owner: smichr Labels: Type-Defect Priority-Medium Assumptions
New issue 1585 by smichr: expression expanded indiscriminantly http://code.google.com/p/sympy/issues/detail?id=1585 When two terms appear under an exponent they get split apart into an expression which is not always true, e.g. >>> x=var('x');neg=Symbol('neg',negative=True) >>> eq=(x/neg)**-S.Half; eq 1/(x**(1/2)*(1/neg)**(1/2)) If you subs -2 and -3 in for x and neg, respectively and evaluate... >>> N(_.subs({x:-2,neg:-3})) -1.22474487139159 the answer you get is off by a sign: it should be 1.22... I've been able to track a few of these sorts of problems down, but I can't see where the x and neg are split from each other and how to control that. I'm guessing this is an assumptions issue and have marked it as such. /c -- You received this message because you are listed in the owner or CC fields of this issue, or because you starred this issue. You may adjust your issue notification preferences at: http://code.google.com/hosting/settings --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "sympy-issues" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/sympy-issues?hl=en -~----------~----~----~----~------~----~------~--~---
