On Fri, Jan 17, 2014 at 11:24 AM, F. B. <franz.bona...@gmail.com> wrote:
>
>
> On Friday, January 17, 2014 1:51:22 AM UTC+1, Aaron Meurer wrote:
>>
>> it seems it is not true if p > 0.5.
>>
>
> No, this distribution is symmetric under { p ---> 1 - p, k ---> n - k }
> substitution, it has surely to converge for 0 <= p <= 1The result is still correct. It doesn't mean that it diverges when those conditions are false, only that it knows that it does when they are true (i.e., they are not sharp conditions). The same is true when integrate() returns a Piecewise. We'll have to see if the conditions for this integral can be improved. Any idea what the full convergence conditions should be? Aaron Meurer > >> The summation module is just fine for this problem, though. It >> computed the answer. There are many problems that it can't compute, >> and for those we do need improvement. I don't know how many of them >> come up in statistics. The so-called hypergeometric summations will be >> the best in the current system, due to the meijerg algorithm. >> > > Is there any list of papers/algorithms about summations? > >> > >> > Even worse with a slight modification: >> > >> >>>> summation(binomial_dist*k, (k, 0, n)) >> > TypeError: unsupported operand type(s) for *: 'NoneType' and 'Add' >> >> Well this is obviously a bug. Can you report it? > > > In any case, this again surely converges for p < 1, the mean (p n) is always > finite. > > https://github.com/sympy/sympy/issues/2787 > > -- > 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. > 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 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. For more options, visit https://groups.google.com/groups/opt_out.
