On Wed, Nov 9, 2011 at 10:33 AM, Richard Fateman
<fateman at eecs.berkeley.edu>wrote:
> On 11/9/2011 10:20 AM, Raymond Toy wrote:....
> ....
>
>
>
> The lack of bigfloat routines for all of the special functions is a
> different problem. I know that Barton's hypergeometric code could be used
> to evaluate them, but it seems unnecessarily slow to use hypergeometrics to
> evaluate these common special functions. It would, however, be a
> reasonable workaround for this lack of coverage.
>
> I think this is what Mathematica does for a whole bunch of stuff. I have
> reported bugs in their code where this scheme gives small but significant
> errors ... in particular some f(x) which mathematically should be real for
> real x but returns a complex value.
>
I guess that's the problem with using hypergeometrics. Any special
properties of the function are lost. I suppose you could try to fix up the
result of the hypergeometric, but I don't know how well that would work.
Ray