That's great - I hadn't consider that. Thank you. On 6 September 2016 at 02:05, Aaron Meurer <[email protected]> wrote:
> When you enter 1/4, Python evaluates this as a float. That's why all your > expressions have floating point numbers. Use Rational(1, 4), or root(-1, > 4). If you do that, then expand_complex() will give you the answer you > want. See also http://docs.sympy.org/latest/tutorial/gotchas.html. > > Aaron Meurer > > On Mon, Sep 5, 2016 at 7:51 PM, Richard Fateman <[email protected]> wrote: > >> There are 4 values for (-1)^(1/4) and there are 2 values for sqrt(-I). >> >> the Maxima program has a command cabs() that returns 1/2 for this >> expression. >> Figure out what cabs does, and you are set. :) >> >> >> >> On Sunday, September 4, 2016 at 9:16:31 AM UTC-7, bsdz wrote: >>> >>> Hi >>> >>> Can anyone recommend a way to simplify following expression? >>> >>> (-1)**(1/4)*sqrt(-I)/2 >>> >>> I would like it to return 1/2 although various methods return different >>> equivalent expressions. >>> >>> i.e. >>> >>> - sp.N(_) = 0.5 # note: I don't wish to evaluate it, here >>> - sp.expand_complex(_) = 0.353553390593274*sqrt(2) >>> - sp.simplify(_) = 0.353553390593274*sqrt(-I)*(1 + I) >>> - sp.powsimp(_) = sqrt(-I)*(0.353553390593274 + 0.353553390593274*I) >>> >>> Thanks >>> Blair >>> >> -- >> 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 [email protected]. >> To post to this group, send email to [email protected]. >> Visit this group at https://groups.google.com/group/sympy. >> To view this discussion on the web visit https://groups.google.com/d/ms >> gid/sympy/6ea958be-131f-4f46-96b6-2d1c80ce5e9b%40googlegroups.com >> <https://groups.google.com/d/msgid/sympy/6ea958be-131f-4f46-96b6-2d1c80ce5e9b%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> For more options, visit https://groups.google.com/d/optout. >> > > -- > You received this message because you are subscribed to a topic in the > Google Groups "sympy" group. > To unsubscribe from this topic, visit https://groups.google.com/d/ > topic/sympy/zlwrXe6d-2g/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > [email protected]. > To post to this group, send email to [email protected]. > 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/CAKgW%3D6K9KkMOS8sa137k0eZuwHWoE_-FHTgAAwgkrD5ebOmtJQ%40mail. > gmail.com > <https://groups.google.com/d/msgid/sympy/CAKgW%3D6K9KkMOS8sa137k0eZuwHWoE_-FHTgAAwgkrD5ebOmtJQ%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > > For more options, visit https://groups.google.com/d/optout. > -- 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 [email protected]. To post to this group, send email to [email protected]. 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/CAAiKHosv3D3hYBj%2B9X1T0nE8x%2BMizwoA%3D7cCLS6Oos4pQBYM6Q%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
