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2013-01-03 03:39:18 -0500 answered a question Arbitrary precision BesselY

Didn't know about mpmath. It seems to provide all I need.

Many thanks Frank

2013-01-03 03:38:25 -0500 received badge  Scholar (source)
2013-01-03 03:38:25 -0500 marked best answer Arbitrary precision BesselY

Try:

sage: import mpmath  
sage: mpmath.bessely?

(mpmath is multiprecision package)

2013-01-03 02:52:57 -0500 asked a question Arbitrary precision BesselY

Hi, I consider using Sage for some calculations which contain Bessel functions of complex arguments. Since I have to mix Bessel functions with very small and very large arguments I require precision higher than 15 digits.

Unfortunately, I recognized that BesselY is not implemented in PARI. But BesselJ and BesselH1 are. My physicists understanding of math tells me, I could just use "(BesselH1-BesselJ)/i". But I am surprised that this has not been discussed before (at least I couldn't find it), since this would allow a quick implementation of BesselY. Am I missing something that's obvious for math experts? Or can I just use above definition to get an arbitrary precision BesselY?

Many thanks Frank