1 files changed, 126 insertions, 0 deletions
diff --git a/gsl-1.9/combination/init.c b/gsl-1.9/combination/init.c
new file mode 100644
index 0000000..6bac2d4
--- /dev/null
+++ b/gsl-1.9/combination/init.c
@@ -0,0 +1,126 @@
+/* combination/init.c
+ * based on permutation/init.c by Brian Gough
+ * 
+ * Copyright (C) 2001 Szymon Jaroszewicz
+ * 
+ * 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_errno.h>
+#include <gsl/gsl_combination.h>
+
+gsl_combination *
+gsl_combination_alloc (const size_t n, const size_t k)
+{
+  gsl_combination * c;
+
+  if (n == 0)
+    {
+      GSL_ERROR_VAL ("combination parameter n must be positive integer",
+                        GSL_EDOM, 0);
+    }
+  if (k > n)
+    {
+      GSL_ERROR_VAL ("combination length k must be an integer less than or equal to n",
+                        GSL_EDOM, 0);
+    }
+  c = (gsl_combination *) malloc (sizeof (gsl_combination));
+
+  if (c == 0)
+    {
+      GSL_ERROR_VAL ("failed to allocate space for combination struct",
+                        GSL_ENOMEM, 0);
+    }
+
+  if (k > 0)
+    {
+      c->data = (size_t *) malloc (k * sizeof (size_t));
+
+      if (c->data == 0)
+        {
+          free (c);             /* exception in constructor, avoid memory leak */
+
+          GSL_ERROR_VAL ("failed to allocate space for combination data",
+                         GSL_ENOMEM, 0);
+        }
+    }
+  else
+    {
+      c->data = 0;
+    }
+
+  c->n = n;
+  c->k = k;
+
+  return c;
+}
+
+gsl_combination *
+gsl_combination_calloc (const size_t n, const size_t k)
+{
+  size_t i;
+
+  gsl_combination * c =  gsl_combination_alloc (n, k);
+
+  if (c == 0)
+    return 0;
+
+  /* initialize combination to identity */
+
+  for (i = 0; i < k; i++)
+    {
+      c->data[i] = i;
+    }
+
+  return c;
+}
+
+void
+gsl_combination_init_first (gsl_combination * c)
+{
+  const size_t k = c->k ;
+  size_t i;
+
+  /* initialize combination to identity */
+
+  for (i = 0; i < k; i++)
+    {
+      c->data[i] = i;
+    }
+}
+
+void
+gsl_combination_init_last (gsl_combination * c)
+{
+  const size_t k = c->k ;
+  size_t i;
+  size_t n = c->n;
+
+  /* initialize combination to identity */
+
+  for (i = 0; i < k; i++)
+    {
+      c->data[i] = n - k + i;
+    }
+}
+
+void
+gsl_combination_free (gsl_combination * c)
+{
+  if (c->k > 0) free (c->data);
+  free (c);
+}