Subject: integrate ( exp (x^3), x, 0, 1) still wrong
From: Raymond Toy
Date: Wed, 16 May 2012 08:40:04 -0700
On Sat, May 12, 2012 at 7:32 AM, Raymond Toy <toy.raymond at gmail.com> wrote:
> >
> > --------------------------------------------------
> > case exp(x^5) over (1,2)
> > domain:complex greatly improves answer
> > but large incorrect imaginary part
> > and real part only accurate to two sig. figures.
>
> Yes, that's a problem. gamma_incomplete(1/5,-32) is not very accurate.
> This can probably solved, but I'm not sure. Using bigfloats with 32
> digits gives a much better answer.
>
>
I've updated the evaluation for gamma_incomplete(, and
gamma_incomplete1/5,-32) should give about 15 digits now. The bigfloat
version should give about fpprec precision too. (Previously, for large
negative x, it was getting less and less accurate.)
Ray