1 files changed, 60 insertions, 0 deletions
diff --git a/gsl-1.9/sys/ldfrexp.c b/gsl-1.9/sys/ldfrexp.c
new file mode 100644
index 0000000..c5ba3a6
--- /dev/null
+++ b/gsl-1.9/sys/ldfrexp.c
@@ -0,0 +1,60 @@
+/* sys/ldfrexp.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.
+ */
+
+#include <config.h>
+#include <math.h>
+#include <gsl/gsl_math.h>
+
+double
+gsl_ldexp (const double x, const int e)
+{
+  double p2 = pow (2.0, (double)e);
+  return x * p2;
+}
+
+double
+gsl_frexp (const double x, int *e)
+{
+  if (x == 0.0)
+    {
+      *e = 0;
+      return 0.0;
+    }
+  else
+    {
+      double ex = ceil (log (fabs (x)) / M_LN2);
+      int ei = (int) ex;
+      double f = gsl_ldexp (x, -ei);
+
+      while (fabs (f) >= 1.0)
+        {
+          ei++;
+          f /= 2.0;
+        }
+      
+      while (fabs (f) < 0.5)
+        {
+          ei--;
+          f *= 2.0;
+        }
+
+      *e = ei;
+      return f;
+    }
+}