/* integration/qk15.c

 * 

 * Copyright (C) 1996, 1997, 1998, 1999, 2000, 2007 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 3 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);

}