| /* integration/qk21.c |
| * |
| * Copyright (C) 1996, 1997, 1998, 1999, 2000 Brian Gough |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or (at |
| * your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, but |
| * WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. |
| */ |
| |
| #include <config.h> |
| #include <gsl/gsl_integration.h> |
| |
| /* Gauss quadrature weights and kronrod quadrature abscissae and |
| weights as evaluated with 80 decimal digit arithmetic by |
| L. W. Fullerton, Bell Labs, Nov. 1981. */ |
| |
| static const double xgk[11] = /* abscissae of the 21-point kronrod rule */ |
| { |
| 0.995657163025808080735527280689003, |
| 0.973906528517171720077964012084452, |
| 0.930157491355708226001207180059508, |
| 0.865063366688984510732096688423493, |
| 0.780817726586416897063717578345042, |
| 0.679409568299024406234327365114874, |
| 0.562757134668604683339000099272694, |
| 0.433395394129247190799265943165784, |
| 0.294392862701460198131126603103866, |
| 0.148874338981631210884826001129720, |
| 0.000000000000000000000000000000000 |
| }; |
| |
| /* xgk[1], xgk[3], ... abscissae of the 10-point gauss rule. |
| xgk[0], xgk[2], ... abscissae to optimally extend the 10-point gauss rule */ |
| |
| static const double wg[5] = /* weights of the 10-point gauss rule */ |
| { |
| 0.066671344308688137593568809893332, |
| 0.149451349150580593145776339657697, |
| 0.219086362515982043995534934228163, |
| 0.269266719309996355091226921569469, |
| 0.295524224714752870173892994651338 |
| }; |
| |
| static const double wgk[11] = /* weights of the 21-point kronrod rule */ |
| { |
| 0.011694638867371874278064396062192, |
| 0.032558162307964727478818972459390, |
| 0.054755896574351996031381300244580, |
| 0.075039674810919952767043140916190, |
| 0.093125454583697605535065465083366, |
| 0.109387158802297641899210590325805, |
| 0.123491976262065851077958109831074, |
| 0.134709217311473325928054001771707, |
| 0.142775938577060080797094273138717, |
| 0.147739104901338491374841515972068, |
| 0.149445554002916905664936468389821 |
| }; |
| |
| |
| void |
| gsl_integration_qk21 (const gsl_function * f, double a, double b, |
| double *result, double *abserr, |
| double *resabs, double *resasc) |
| { |
| double fv1[11], fv2[11]; |
| gsl_integration_qk (11, xgk, wg, wgk, fv1, fv2, f, a, b, result, abserr, resabs, resasc); |
| } |