[SciPy-dev] Bessel functions from Boost

[Fredrik Johansson]

On Mon, Feb 9, 2009 at 10:20 AM, Ondrej Certik <ondrej at certik.cz> wrote:
>
> Right. For double precision I think mpmath is not so fast. Fredrik, is
> it difficult to make mpmath fast even for double precision?

Fast and accurate machine floating-point implementations require
entirely different algorithms. One also needs to piece together
multiple algorithms to handle cases where, in arbitrary-precision
arithmetic, increasing some parameter is sufficient.

I can see a use for a pure-Python double precision special functions
library. I don't think mpmath should be it, at least not for now;
getting the arbitrary-precision algorithms right is enough work.
Should someone be interested in writing such a library, they could use
mpmath to test accuracy against, and even to generate Chebyshev
approximations and the like.

Fredrik