Integral of Taylor expansions



Andrej,

On Thu, Apr 24, 2008 at 4:07 PM, Andrej Vodopivec
<andrej.vodopivec at gmail.com> wrote:
>
> On Thu, Apr 24, 2008 at 3:08 PM, marco restelli <mrestelli at gmail.com> wrote:
>  > Dear list,
>  >    I would like to use Taylor expansions to approximate integrals and
>  >  I see the following problem:
>  >
>  >  this trivial case works as expected, yielding   p(0) l
>  >  pT : taylor(p(s),s,0,0);
>  >  pT : ratsimp(pT);
>  >  pbar : integrate(pT,s,-l/2,l/2);
>  >
>  >  but when I take
>  >  pT : taylor(p(s),s,0,1);
>  >  pT : ratsimp(pT);
>  >  pbar : integrate(pT,s,-l/2,l/2);
>  >  maxima starts computing and never delivers any result. Does anyone
>  >  have a suggestion?
>  >
>
>  You can use the pdiff package:
>
>  (%i1) load(pdiff)$
>  (%i2) pT:taylor(p(s), s, 0, 1)$
>  (%i3) pT:ratsimp(pT)$
>  (%i4) pbar:integrate(pT,s,-I/2,I/2), ratsimp;
>  (%o4) p(0)*I

Yes, this works!

Thank you,
   Marco

>
>  HTH,
>
>  --
>  Andrej
>