1 files changed, 101 insertions, 0 deletions
diff --git a/gsl-1.9/cheb/init.c b/gsl-1.9/cheb/init.c
new file mode 100644
index 0000000..9b42021
--- /dev/null
+++ b/gsl-1.9/cheb/init.c
@@ -0,0 +1,101 @@
+/* cheb/init.c
+ * 
+ * Copyright (C) 1996, 1997, 1998, 1999, 2000 Gerard Jungman
+ * 
+ * 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 <stdlib.h>
+#include <gsl/gsl_math.h>
+#include <gsl/gsl_errno.h>
+#include <gsl/gsl_chebyshev.h>
+
+/*-*-*-*-*-*-*-*-*-*-*-* Allocators *-*-*-*-*-*-*-*-*-*-*-*/
+
+gsl_cheb_series * 
+gsl_cheb_alloc(const size_t order)
+{
+  gsl_cheb_series * cs = (gsl_cheb_series *) malloc(sizeof(gsl_cheb_series));
+  
+  if(cs == 0) {
+    GSL_ERROR_VAL("failed to allocate gsl_cheb_series struct", GSL_ENOMEM, 0);
+  }
+  
+  cs->order    = order;
+  cs->order_sp = order;
+
+  cs->c = (double *) malloc((order+1) * sizeof(double));
+
+  if(cs->c == 0) {
+    GSL_ERROR_VAL("failed to allocate cheb coefficients", GSL_ENOMEM, 0);
+  }
+
+  cs->f = (double *) malloc((order+1) * sizeof(double));
+
+  if(cs->f == 0) {
+    GSL_ERROR_VAL("failed to allocate cheb function space", GSL_ENOMEM, 0);
+  }
+
+  return cs;
+}
+
+
+void gsl_cheb_free(gsl_cheb_series * cs)
+{
+  free(cs->f);
+  free(cs->c);
+  free(cs);
+}
+
+/*-*-*-*-*-*-*-*-*-*-*-* Initializer *-*-*-*-*-*-*-*-*-*-*-*/
+
+int gsl_cheb_init(gsl_cheb_series * cs, const gsl_function *func,
+                  const double a, const double b)
+{
+  size_t k, j;
+
+  if(a >= b) {
+    GSL_ERROR_VAL("null function interval [a,b]", GSL_EDOM, 0);
+  }
+  cs->a = a;
+  cs->b = b;
+  /* cs->err = 0.0; */
+
+  { 
+    double bma = 0.5 * (cs->b - cs->a);
+    double bpa = 0.5 * (cs->b + cs->a);
+    double fac = 2.0/(cs->order +1.0);
+
+    for(k = 0; k<=cs->order; k++) {
+      double y = cos(M_PI * (k+0.5)/(cs->order+1));
+      cs->f[k] = GSL_FN_EVAL(func, (y*bma + bpa));
+    }
+    
+    for(j = 0; j<=cs->order; j++) {
+      double sum = 0.0;
+      for(k = 0; k<=cs->order; k++) 
+        sum += cs->f[k]*cos(M_PI * j*(k+0.5)/(cs->order+1));
+      cs->c[j] = fac * sum;
+    }
+    
+  }
+  return GSL_SUCCESS;
+}
+
+
+
+
+