Status: Accepted Owner: robert.kern Labels: Type-Defect Priority-Medium WrongResult
New issue 1263 by robert.kern: Invalid movement of roots across fractions http://code.google.com/p/sympy/issues/detail?id=1263 These came up while implementing the Wester tests. Basically, sqrt(1/z) is being treated as equal to 1/sqrt(z)m but they are not in the case where z is on the negative real axis. For example, if z=-1, then sqrt(1/-1) == sqrt(-1) == I, but 1/sqrt(-1) == 1/I == -I. @XFAIL def test_K8(): z = Symbol('z', complex=True) # WrongResult! assert simplify(sqrt(1/z) - 1/sqrt(z)) != 0 z = symbols('z', complex=True, negative=False) assert simplify(sqrt(1/z) - 1/sqrt(z)) == 0 def test_K9(): z = Symbol('z', real=True, positive=True) assert simplify(sqrt(1/z) - 1/sqrt(z)) == 0 @XFAIL def test_K10(): # WrongResult! z = Symbol('z', real=True, negative=True) assert simplify(sqrt(1/z) + 1/sqrt(z)) == 0 -- 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 -~----------~----~----~----~------~----~------~--~---
