1 files changed, 189 insertions, 0 deletions
diff --git a/gsl-1.9/combination/combination.c b/gsl-1.9/combination/combination.c
new file mode 100644
index 0000000..6f8c817
--- /dev/null
+++ b/gsl-1.9/combination/combination.c
@@ -0,0 +1,189 @@
+/* combination/combination.c
+ * based on permutation/permutation.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 <gsl/gsl_errno.h>
+#include <gsl/gsl_combination.h>
+
+size_t
+gsl_combination_n (const gsl_combination * c)
+{
+  return c->n ;
+}
+
+size_t
+gsl_combination_k (const gsl_combination * c)
+{
+  return c->k ;
+}
+
+size_t *
+gsl_combination_data (const gsl_combination * c)
+{
+  return c->data ;
+}
+
+#ifndef HIDE_INLINE_STATIC
+size_t
+gsl_combination_get (const gsl_combination * c, const size_t i)
+{
+  if (gsl_check_range)
+    {
+      if (i >= c->k)            /* size_t is unsigned, can't be negative */
+        {
+          GSL_ERROR_VAL ("index out of range", GSL_EINVAL, 0);
+        }
+    }
+
+  return c->data[i];
+}
+#endif
+
+
+int
+gsl_combination_valid (gsl_combination * c)
+{
+  const size_t n = c->n ;
+  const size_t k = c->k ;
+
+  size_t i, j ;
+
+  if( k > n )
+    {
+      GSL_ERROR("combination has k greater than n", GSL_FAILURE) ;
+    }
+  for (i = 0; i < k; i++) 
+    {
+      const size_t ci = c->data[i];
+
+      if (ci >= n)
+        {
+          GSL_ERROR("combination index outside range", GSL_FAILURE) ;
+        }
+
+      for (j = 0; j < i; j++)
+        {
+          if (c->data[j] == ci)
+            {
+              GSL_ERROR("duplicate combination index", GSL_FAILURE) ;
+            }
+          if (c->data[j] > ci)
+            {
+              GSL_ERROR("combination indices not in increasing order",
+                        GSL_FAILURE) ;
+            }
+        }
+    }
+  
+  return GSL_SUCCESS;
+}
+
+
+int
+gsl_combination_next (gsl_combination * c)
+{
+  /* Replaces c with the next combination (in the standard lexicographical
+   * ordering).  Returns GSL_FAILURE if there is no next combination.
+   */
+  const size_t n = c->n;
+  const size_t k = c->k;
+  size_t *data = c->data;
+  size_t i;
+
+  if(k == 0)
+    {
+      return GSL_FAILURE;
+    }
+  i = k - 1;
+
+  while(i > 0 && data[i] == n - k + i)
+    {
+      i--;
+    }
+  if(i == 0 && data[i] == n - k)
+    {
+      return GSL_FAILURE;
+    }
+  data[i]++;
+  for(; i < k - 1; i++)
+    {
+      data[i + 1] = data[i] + 1;
+    }
+  return GSL_SUCCESS;
+}
+
+int
+gsl_combination_prev (gsl_combination * c)
+{
+  /* Replaces c with the previous combination (in the standard
+   * lexicographical ordering).  Returns GSL_FAILURE if there is no
+   * previous combination.
+   */
+  const size_t n = c->n;
+  const size_t k = c->k;
+  size_t *data = c->data;
+  size_t i;
+
+  if(k == 0)
+    {
+      return GSL_FAILURE;
+    }
+  i = k - 1;
+
+  while(i > 0 && data[i] == data[i-1] + 1)
+    {
+      i--;
+    }
+  if(i == 0 && data[i] == 0)
+    {
+      return GSL_FAILURE;
+    }
+  data[i++]--;
+  for(; i < k; i++)
+    {
+      data[i] = n - k + i;
+    }
+  return GSL_SUCCESS;
+}
+
+int
+gsl_combination_memcpy (gsl_combination * dest, const gsl_combination * src)
+{
+   const size_t src_n = src->n;
+   const size_t src_k = src->k;
+   const size_t dest_n = dest->n;
+   const size_t dest_k = dest->k;
+
+   if (src_n != dest_n || src_k != dest_k)
+     {
+       GSL_ERROR ("combination lengths are not equal", GSL_EBADLEN);
+     }
+   
+   {
+     size_t j;
+     
+     for (j = 0; j < src_k; j++)
+       {
+         dest->data[j] = src->data[j];
+       }
+   }
+   
+   return GSL_SUCCESS;
+}