double GetCoulombNormalization(double Z, int l, double k)
{
double eta = Z / k;
gsl_sf_result C;
int error = gsl_sf_coulomb_CL_e(l, eta, &C);
return C.val;
}
void coulomb_CL(double *L, double *eta, int *len, double *val, double *err, int *status)
{
int i;
gsl_sf_result result;
gsl_set_error_handler_off();
for(i = 0; i< *len ; i++){
status[i] = gsl_sf_coulomb_CL_e(L[i], eta[i], &result) ;
val[i] = result.val;
err[i] = result.err;
}
}
/* cl[0] .. cl[kmax] = C_{lam_min}(eta) .. C_{lam_min+kmax}(eta)
*/
int
gsl_sf_coulomb_CL_array(double lam_min, int kmax, double eta, double * cl)
{
int k;
gsl_sf_result cl_0;
gsl_sf_coulomb_CL_e(lam_min, eta, &cl_0);
cl[0] = cl_0.val;
for(k=1; k<=kmax; k++) {
double L = lam_min + k;
cl[k] = cl[k-1] * sqrt(L*L + eta*eta)/(L*(2.0*L+1.0));
}
return GSL_SUCCESS;
}
/**
* C++ version of gsl_sf_coulomb_CL_e().
* @param L A real value
* @param eta A real value
* @param result The result as a @c gsl::sf::result object
* @return Error code on failure
*/
inline int CL_e( double L, double eta, result& result ){
return gsl_sf_coulomb_CL_e( L, eta, &result ); }
