double gsl_sf_bessel_Y1(const double x) { EVAL_RESULT(gsl_sf_bessel_Y1_e(x, &result)); }
int gsl_sf_bessel_Yn_e(int n, const double x, gsl_sf_result * result) { int sign = 1; if(n < 0) { /* reduce to case n >= 0 */ n = -n; if(GSL_IS_ODD(n)) sign = -1; } /* CHECK_POINTER(result) */ if(n == 0) { int status = gsl_sf_bessel_Y0_e(x, result); result->val *= sign; return status; } else if(n == 1) { int status = gsl_sf_bessel_Y1_e(x, result); result->val *= sign; return status; } else { if(x <= 0.0) { DOMAIN_ERROR(result); } if(x < 5.0) { int status = bessel_Yn_small_x(n, x, result); result->val *= sign; return status; } else if(GSL_ROOT3_DBL_EPSILON * x > (n*n + 1.0)) { int status = gsl_sf_bessel_Ynu_asympx_e((double)n, x, result); result->val *= sign; return status; } else if(n > 50) { int status = gsl_sf_bessel_Ynu_asymp_Olver_e((double)n, x, result); result->val *= sign; return status; } else { double two_over_x = 2.0/x; gsl_sf_result r_by; gsl_sf_result r_bym; int stat_1 = gsl_sf_bessel_Y1_e(x, &r_by); int stat_0 = gsl_sf_bessel_Y0_e(x, &r_bym); double bym = r_bym.val; double by = r_by.val; double byp; int j; for(j=1; j<n; j++) { byp = j*two_over_x*by - bym; bym = by; by = byp; } result->val = sign * by; result->err = fabs(result->val) * (fabs(r_by.err/r_by.val) + fabs(r_bym.err/r_bym.val)); result->err += 2.0 * GSL_DBL_EPSILON * fabs(result->val); return GSL_ERROR_SELECT_2(stat_1, stat_0); } } }