[Bug-gsl] gsl_sf_hyperg_1F1

[Weibin Li]

Hi, guys

I experienced bugs with gsl_sf_hyperg_1F1. The version  is gsl_1.12, but
the testing is also done with gsl_1.13, using a  mac with version 10.5.8
and hp-workstation with gnome_2.24.1.

#include<stdlib.h>
#include<stdio.h>
#include<math.h>
#include "gsl/gsl_sf_hyperg.h"

int main(int argc, char **argv)
{
 int ii;
 double Ri;
 double v0;
     
 gsl_sf_result r;
 for(ii = 10; ii< 140;ii++)
{
     Ri = 2013;
     v0 =38.86871 +ii*2.5e-10;

    gsl_sf_hyperg_1F1_e(1.0-v0,2,2.0*Ri/v0,&r);
    printf("%lg\t%14.13g\t%14.13g\n",v0,r.val,r.err);

 }
return 0;
}

The output of above code shows an extremely large error. by increasing
Ri, the relative error decreases. Is there any idea to fix this?

Thank you very much.

Best

Weibin