[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Axiom-developer] Re: About Schaums.

From: Waldek Hebisch
Subject: Re: [Axiom-developer] Re: About Schaums.
Date: Wed, 7 May 2008 05:11:04 +0200 (CEST)

Martin Rubey wrote:
> root <address@hidden> writes:
> >   Axiom has a closed form for 2 integrals where Schaums has series.
> But at least one of them seems to be wrong. Since it seems that my message was
> overlooked, I repeat it here:
> address@hidden writes:
> >   14:668 SCHAUMS AND AXIOM DIFFER (Axiom has closed form)
> But I'm not so sure that it is correct, at least not for a=1 and x in 0..1.
> draw(D(integrate(asech(x)/x,x),x)-asech(x)/x, x=0..1)

Integral of 'asech(x)/x' is definitely wrong.  I belive that the
error is in 'lfextendedint':

    lfextendedint(f, x, g) ==
      empty?(l := varselect(kernels f, x)) => [x::F * f, 0]
      symbolIfCan(k := kmax(l))
        case SE =>
          map(multivariate(#1, k), extendedint(univariate(f, k),
                                               univariate(g, k)))

AFAICS we need stronger condition than 'case SE' (and extra code
to handle remaining cases).
                              Waldek Hebisch

reply via email to

[Prev in Thread] Current Thread [Next in Thread]