So, there is no way to do it using subs and/or some manipulations? real_root(-1, 3) is of no help, because I can have arbitrary expression.
On Wednesday, November 4, 2015 at 6:29:29 PM UTC+2, Aaron Meurer wrote: > > You need to use real_root, like > > In [3]: real_root(-1, 3) > Out[3]: -1 > > In [4]: real_root(-1, 3)**2 > Out[4]: 1 > > SymPy, like most math libraries, uses complex roots (i.e., principal > roots) because they have nicer mathematical properties. > > Aaron Meurer > > On Wed, Nov 4, 2015 at 3:30 AM, Paul Royik <distan...@gmail.com > <javascript:>> wrote: > > I have the following expresssion: > > > > f=x**(Rational(2,3)) > > > > How can I get 1, when substituting (-1) instead of complex number? > > For now, I got complex number when run f.subs(x,-1).evalf() > > > > -- > > 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+un...@googlegroups.com <javascript:>. > > To post to this group, send email to sy...@googlegroups.com > <javascript:>. > > Visit this group at http://groups.google.com/group/sympy. > > To view this discussion on the web visit > > > https://groups.google.com/d/msgid/sympy/662a2085-1030-42d5-bbde-feb524fd246c%40googlegroups.com. > > > > 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 sympy+unsubscr...@googlegroups.com. To post to this group, send email to sympy@googlegroups.com. Visit this group at http://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/c88261c0-3449-4d7a-abf8-8d28ebdca59d%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
