[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Bug-gsl] bug in gsl_sf_coulomb_wave_FG_e (gsl 1.14 compiled with gc

From: Brian Gough
Subject: Re: [Bug-gsl] bug in gsl_sf_coulomb_wave_FG_e (gsl 1.14 compiled with gcc 4.5.0)
Date: Sun, 29 Aug 2010 14:12:28 +0100
User-agent: Wanderlust/2.15.6 (Almost Unreal) Emacs/23.2 Mule/6.0 (HANACHIRUSATO)

At Fri, 27 Aug 2010 13:36:08 -0400,
Alexey A. Illarionov wrote:
> It looks like that these values are incorrect since both F and Fp should 
> be very small (correct me if I'm wrong since I'm not familiar with Pari 
> and gsl test system). If you need verify the values than its better to 
> use bessel function series.
> For eta == 0. and integer lambda coulomb function are just 
> bessel-ricatti functions, i.e. spherical_bessel functions times argument
> F_l(x) = j_l (x) * x
> G_l(x) = n_l (x) * x
> Thus
> F_l(x) = 1/(2l+1)!! x^(l+1) [1 - x^2/(2l+3)/2 + ...]
> G_l(x) = (2l+1)!!/(2l+1) x^(-l) [1 + x^2/(2l-1)/2 + ...]
> I think Abramowitz, Stegun should have the complete expressions.

Thanks that is much better, the calculation of the integral was not
reliable.  I've committed the new test values.

reply via email to

[Prev in Thread] Current Thread [Next in Thread]