Re: [Bug-gsl] incorrect values by bessel_steed_array

[Brian Gough]

Hu Zhan writes:
 > When I use gsl_sf_bessel_jl_steed_array(LMAX, x, wrk) with a large LMAX,
 > e.g. LMAX = 80, the function returns wrong values at small l and x. My
 > system is Debian Linux with Opteron CPU.

Hi,

Thanks for the data.  I can't reproduce your output, the program works
fine on my system against gsl-1.6, the largest relative error is
O(1e-14) i.e. close to machine precision.

It looks like you have a machine- or compiler- specific problem. I'd
suggest running "make check" for the whole library to see if it throws
up any other problems.

-- 
regards

Brian Gough

bjg|debian> gcc -Wall steedtest.c -lgsl -lgslcblas -lm
bjg|debian> ./a.out 
bjg|debian> more jl0.txt 
0 1 1
0.1 0.998334 0.998334
0.2 0.993347 0.993347
0.3 0.985067 0.985067
0.4 0.973546 0.973546
0.5 0.958851 0.958851
0.6 0.941071 0.941071
0.7 0.920311 0.920311
0.8 0.896695 0.896695
....