| /* integration/qk15.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[8] = /* abscissae of the 15-point kronrod rule */ |
| { |
| 0.991455371120812639206854697526329, |
| 0.949107912342758524526189684047851, |
| 0.864864423359769072789712788640926, |
| 0.741531185599394439863864773280788, |
| 0.586087235467691130294144838258730, |
| 0.405845151377397166906606412076961, |
| 0.207784955007898467600689403773245, |
| 0.000000000000000000000000000000000 |
| }; |
| |
| /* xgk[1], xgk[3], ... abscissae of the 7-point gauss rule. |
| xgk[0], xgk[2], ... abscissae to optimally extend the 7-point gauss rule */ |
| |
| static const double wg[4] = /* weights of the 7-point gauss rule */ |
| { |
| 0.129484966168869693270611432679082, |
| 0.279705391489276667901467771423780, |
| 0.381830050505118944950369775488975, |
| 0.417959183673469387755102040816327 |
| }; |
| |
| static const double wgk[8] = /* weights of the 15-point kronrod rule */ |
| { |
| 0.022935322010529224963732008058970, |
| 0.063092092629978553290700663189204, |
| 0.104790010322250183839876322541518, |
| 0.140653259715525918745189590510238, |
| 0.169004726639267902826583426598550, |
| 0.190350578064785409913256402421014, |
| 0.204432940075298892414161999234649, |
| 0.209482141084727828012999174891714 |
| }; |
| |
| void |
| gsl_integration_qk15 (const gsl_function * f, double a, double b, |
| double *result, double *abserr, |
| double *resabs, double *resasc) |
| { |
| double fv1[8], fv2[8]; |
| gsl_integration_qk (8, xgk, wg, wgk, fv1, fv2, f, a, b, result, abserr, resabs, resasc); |
| } |
| |