1 files changed, 77 insertions, 0 deletions
diff --git a/gsl-1.9/integration/qk21.c b/gsl-1.9/integration/qk21.c
new file mode 100644
index 0000000..8c5d27f
--- /dev/null
+++ b/gsl-1.9/integration/qk21.c
@@ -0,0 +1,77 @@
+/* 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);
+}