#include <stdio.h>
#include <gsl/gsl_sf_coulomb.h>


int main( int argc, char *argv[] )
{
  int l = 20;
  double eta = -100.;

  /* Method 1: obtain F directly */
  {
    printf("Method 1: obtain F directly\n");
    gsl_sf_result F, Fp, G, Gp;
    double exp_F, exp_G;
    for(double rho=0.01; rho<20.; rho+=0.01)
    {
      printf("%f\t",rho);
      for(int i=0; i<=l; i++)
      {
        gsl_sf_coulomb_wave_FG_e(eta, rho, i, 0, &F, &Fp, &G, &Gp, &exp_F, &exp_G);
        printf("%e\t",F.val);
      }
      printf("\n");
    }
  }

  /* Method 2: obtain F from recurrence */
  {
    printf("Method 2: obtain F from recurrence\n");
    double F[1+l], exp_F[1+l];
    for(double rho=0.01; rho<20.; rho+=0.01)
    {
      gsl_sf_coulomb_wave_F_array(0., l, eta, rho, F, exp_F);
      printf("%f\t",rho);
      for(int i=0; i<=l; i++)
      {
        printf("%e\t",F[i]);
      }
      printf("\n");
    }
  }
}