It's a bug in ratint. The bug should be fixed, but regardless, didn't we make it so that integrate automatically pull out common coefficients before it calls the algorithms?
Aaron Meurer On Fri, Nov 29, 2013 at 9:07 AM, Ondřej Čertík <[email protected]> wrote: > Hi Leryra, > > On Thu, Nov 28, 2013 at 3:16 PM, Leryra <[email protected]> wrote: >> Hi there ! >> >> I'm using Sympy in an extensive way to do some work on slow blow up >> solutions of the critical wave equation, >> The thing is that I stumbled accross this : >> integrate(-3*sqrt(3)*(a**8 - 5*a**6 + 10*a**4 - 406*a**2 + >> 224)/(4*a**2*(a**6 + 6*a**5 + 15*a**4 + 20*a**3 + 15*a**2 + 6*a + 1)),a) >> >> And I can't get why sympy throw me some "PolynomialError: 1/(16*_t**2 + >> 72*sqrt(3)*_t + 243) contains an element of the generators set" >> >> Could someone explain me this error ? Those are "just polynomials" and the >> integral doesn't look so ugly.. It has some log, but still... > > I think you found a bug. If you try the integral without the sqrt(3) > at the beginning, it works: > >>>> integrate(-3*(a**8 - 5*a**6 + 10*a**4 - 406*a**2 + 224)/(4*a**2*(a**6 + >>>> 6*a**5 + 15*a**4 + 20*a**3 + 15*a**2 + 6*a + 1)),a) > 5 4 3 2 > 3⋅a 40620⋅a + 182640⋅a + 317590⋅a + 259775⋅a + 89869⋅a + 6720 > - ─── + ───────────────────────────────────────────────────────────── + 1008⋅l > 4 6 5 4 3 2 > 40⋅a + 200⋅a + 400⋅a + 400⋅a + 200⋅a + 40⋅a > > > 2007⋅log(a + 1) > og(a) - ─────────────── > 2 > > > > So we need to figure out what's going on and fix it. > > Ondrej > >> >> -- >> 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 http://groups.google.com/group/sympy. >> For more options, visit https://groups.google.com/groups/opt_out. > > -- > 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 http://groups.google.com/group/sympy. > For more options, visit https://groups.google.com/groups/opt_out. -- 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 http://groups.google.com/group/sympy. For more options, visit https://groups.google.com/groups/opt_out.
