Integral of Taylor expansions



On Thu, Apr 24, 2008 at 3:51 PM, marco restelli <mrestelli at gmail.com> wrote:
> On Thu, Apr 24, 2008 at 3:39 PM, Richard Fateman
>  <fateman at cs.berkeley.edu> wrote:
>  > you haven't given enough info, but maybe you should try without ratsimp.
>  >  The taylor series should be integrable as a polynomial in s.
>  >   RJF
>  >
>
>  Richard,
>    thank you for the suggestion. Unfortunately, avoiding ratsimp
>  doesn't help: I have the same behavior with
>
>
>  pT : taylor(p(s),s,0,0);
>
> pbar : integrate(pT,s,-l/2,l/2);
>
>  (which works) and
>
>
>  pT : taylor(p(s),s,0,1);
>
> pbar : integrate(pT,s,-l/2,l/2);
>
>  (which doesn't). I am using Maxima 5.14.0. Please, let me know if
>  there is any additional information I could provide.
>
>  Best,
>    Marco

Ok, here is some additional information:

(%i2) build_info();

Maxima version: 5.14.0
Maxima build date: 10:41 2/1/2008
host type: x86_64-pc-linux-gnu
lisp-implementation-type: GNU Common Lisp (GCL)
lisp-implementation-version: GCL 2.6.7

Marco

>
>
>
>  >
>  >
>  >
>  >  > -----Original Message-----
>  >  > From: maxima-bounces at math.utexas.edu
>  >  > [mailto:maxima-bounces at math.utexas.edu] On Behalf Of marco restelli
>  >  > Sent: Thursday, April 24, 2008 6:09 AM
>  >  > To: maxima at math.utexas.edu
>  >  > Subject: Integral of Taylor expansions
>  >  >
>  >  > 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?
>  >  >
>  >  > Thank you!
>  >  >    Marco
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