1 files changed, 62 insertions, 0 deletions
diff --git a/gsl-1.9/sys/fcmp.c b/gsl-1.9/sys/fcmp.c
new file mode 100644
index 0000000..444169d
--- /dev/null
+++ b/gsl-1.9/sys/fcmp.c
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+/* sys/gsl_compare.c
+ * 
+ * Copyright (C) 2002 Gert Van den Eynde
+ * 
+ * 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.
+ * 
+ * Based on fcmp 1.2.2 Copyright (c) 1998-2000 Theodore C. Belding
+ * University of Michigan Center for the Study of Complex Systems
+ * Ted.Belding@umich.edu
+ *
+ */
+
+#include <config.h>
+#include <gsl/gsl_sys.h>
+#include <math.h>
+
+int
+gsl_fcmp (const double x1, const double x2, const double epsilon)
+{
+  int exponent;
+  double delta, difference;
+
+  /* Find exponent of largest absolute value */
+
+  {
+    double max = (fabs (x1) > fabs (x2)) ? x1 : x2;
+
+    frexp (max, &exponent);
+  }
+
+  /* Form a neighborhood of size  2 * delta */
+
+  delta = ldexp (epsilon, exponent);
+
+  difference = x1 - x2;
+
+  if (difference > delta)       /* x1 > x2 */
+    {
+      return 1;
+    }
+  else if (difference < -delta) /* x1 < x2 */
+    {
+      return -1;
+    }
+  else                          /* -delta <= difference <= delta */
+    {
+      return 0;                 /* x1 ~=~ x2 */
+    }
+}
+