From: linas@austin.ibm.com (Linas Vepstas)
To: Michael <comtech.usa@gmail.com>
Cc: gsl-discuss@sources.redhat.com, help-gsl@gnu.org,
gmp-discuss@swox.com, mpfr@loria.fr
Subject: Re: Does GSL or IMSL or GMP or MPFR have high precision hypergeometric function 2F1?
Date: Fri, 06 Jul 2007 17:29:00 -0000 [thread overview]
Message-ID: <20070706172856.GA4457@austin.ibm.com> (raw)
In-Reply-To: <b1f16d9d0707041652t6d1716b1g27462b58aff5131b@mail.gmail.com>
On Wed, Jul 04, 2007 at 07:52:21PM -0400, Michael wrote:
> Does GSL or IMSL or GMP or MPFR have high precision hypergeometric function 2F1?
>
> Hi all,
>
> I am looking for a high/multiple precision hypergeometric function
> 2F1(a, b, c, z) implementation. My application needs b and c to be
> very large, and it is beyond the range of double precision.
?
GSL only goes as far as double precision.
If b and c are "beyond the range of double precision", then one can get
a good approximation by computing 1F0 instead. This isn't what you need?
> More specifically, I hope I will be able to looking into the multiple
> precision implementation of the hypergeometric function 2F1(a, b, c,
> z) and change the power series
>
> a0+a1*z+a2*z^2+a3*z^3+...
>
> into
>
> a0+a1*z1+a2*z2+a3*z3+...
!? It is not hard to write code for this. Its maybe 50 lines
of code or so. I spent a (very) short afternoon writing 2F1 for GMP,
and then tweaking and tesing it. Its not "rocket science".
> The whole evaluation of the hypergeometric function has to be
> extremely fast for my application.
Heh. And how fast must that be?
--linas
prev parent reply other threads:[~2007-07-06 17:29 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-07-04 23:52 Michael
2007-07-06 17:29 ` Linas Vepstas [this message]
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