On 29 Nov., 23:42, smichr <[email protected]> wrote: > In the calculation of roots_binomial a value of zeta is being > calculated using Euler's formulation and expanded(complex=True). Is > there a reason to do the expanding and is there a reason not to use > the more compact "roots of -1" formulation? > > Also, after computing the root an expand(power_base=False) is done > > If the (-1) formulation and no expanding is done, a much more compact > (and faster) result is attained. Is that expanding necessary? > > compare > > h[2] >>> solve((x-1)**3 - 3) > [1 - (-3)**(1/3), 1 + I*(-3)**(1/3)*3**(1/2)/2 + (-3)**(1/3)/2, > 1 - I*(-3)**(1/3)*3**(1/2)/2 + (-3)**(1/3)/2] > > to the unexpanded Euler representation: > > [1 + 3**(1/3), 1 + 3**(1/3)*exp(2*pi*I/3), 1 + 3**(1/3)*exp(4*pi*I/ > 3)] > > or the "roots of -1" representation > > [1 + 3**(1/3), 1 + (-1)**(2/3)*3**(1/3), 1 - (-3)**(1/3)]
I really like the "roots of -1" representation, because it is so compact. Anyonre can expand it if he wants. But, aren't there multiple possibilities for a complex root of -1? Vinzent -- You received this message because you are subscribed to the Google Groups "sympy" 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?hl=en.
