Barton Willis wrote:
> -----maxima-bounces at math.utexas.edu wrote: -----
>
>
>> There is hgfred, but that is primarily meant to transform hypergeometric
>> functions to "simpler" forms. It's not really meant for numerical
>> evaluation. Barton has done some work in this area, but I can't remember
>> what's done.
>>
>
> Earlier this year, I played with numerical evaluation of the hypergeometic
> functions. This code isn't even ready for share/contrib. I stopped working
> on it for many reasons--mostly I was hoping that somebody else would
> do it right.
>
> My code uses a running error to sum the power series. When the running
> error
> bound is too large (subtractive cancellation), it tries again with a larger
> value for fpprec. There are no special cases for 1F1, 2F1, etc --- all the
> hypergeometrics use the same code. As I recall, the articles I located for
> good methods for the hypergeometrics didn't seem all that great to me. But
> obviously, somebody knows good fast ways. If you search our mailing list,
> you'll find a recursion for 2F1 (I think)--as I recall, I found some ranges
> where this code was inaccurate, but I forgotten the details.
>
> For now, if you need numerical evaluation of the hypergeometrics, you are
> on your own. One possibility might be GSL:
>
> http://www.gnu.org/software/gsl/
>
> Barton
>
>
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>
I looked at incorporating a gsl/lisp interface into Maxima earlier this
year. There is one available that works with a couple of lisp's; but
not all that Maxima supports. Since the interest is low I didn't follow
up and try to expand the interface to the other lisp versions; and it
would have only been a numerical version not including the symbolic
transformations that Maxima generically supports. Right now I don't
have the time
RayR