[SciPy-user] high precision bessel’s functions

Robert Kern robert.kern@gmail....
Sun Dec 7 16:19:01 CST 2008


On Sun, Dec 7, 2008 at 13:39, Leonid Chaichenets
<chaichenets@int.uni-karlsruhe.de> wrote:
> Hello,
>
> im looking for a high precision (more than float/double) implementation of
> the hankel2 function.
>
> My actual problem is, that i need to evaluate hankel2 of a realatively high
> order (7.5) on a short path in the complex plane. Most of the precision is
> lost, as the values are of high magnitude (10^6) and vary in the 6th decimal
> place only. The roundoff errors then propagate through the calculation and
> become significant.
>
> Does anyone know an implementation of hankel2 with more precision? Can maybe
> the scaled bessel functions (scipy.special.hankel2e) be used for that
> (unfortunatly I couldnt find enough documentation on them)?

mpmath has Bessel functions. You should be able to construct the
Hankel functions from those.

http://code.google.com/p/mpmath/

-- 
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless
enigma that is made terrible by our own mad attempt to interpret it as
though it had an underlying truth."
  -- Umberto Eco


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