add tests file for gamma

git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@1486 280ebfd0-de03-0410-8827-d642c229c3f4

1 files changed, 79 insertions, 0 deletions

diff --git a/tests/tgamma.c b/tests/tgamma.c
new file mode 100644
index 000000000..69e11ee95
--- /dev/null
+++ b/tests/tgamma.c
@@ -0,0 +1,79 @@
+/* mpfr_tgamma -- test file for gamma function
+
+Copyright (C) 2001 Free Software Foundation.
+
+This file is part of the MPFR Library, and was contributed by Mathieu Dutour.
+
+The MPFR Library is free software; you can redistribute it and/or modify
+it under the terms of the GNU Library General Public License as published by
+the Free Software Foundation; either version 2 of the License, or (at your
+option) any later version.
+
+The MPFR Library 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 Library General Public
+License for more details.
+
+You should have received a copy of the GNU Library General Public License
+along with the MPFR Library; see the file COPYING.LIB.  If not, write to
+the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+MA 02111-1307, USA. */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <gmp.h>
+#include <mpfr.h>
+
+int mpfr_gamma (mpfr_ptr, mpfr_srcptr, mp_rnd_t);
+
+int
+main (void)
+{
+  unsigned int prec, err, yprec, n;
+  mp_rnd_t rnd;
+  mpfr_t x, y, z;
+
+  mpfr_init (x);
+  mpfr_init (y);
+  mpfr_init (z);
+
+  for (prec = 1; prec <= 100; prec++)
+    {
+      mpfr_set_prec (x, prec);
+      mpfr_set_prec (z, prec);
+      yprec = prec + 10;
+
+      for (n=0; n<100; n++)
+	{
+	  mpfr_random (x);
+	  rnd = random () % 4;
+	  mpfr_set_prec (y, yprec);
+	  mpfr_gamma (y, x, rnd);
+	  err = (rnd == GMP_RNDN) ? yprec + 1 : yprec;
+	  if (mpfr_can_round (y, err, rnd, rnd, prec))
+	    {
+	      mpfr_round (y, rnd, prec);
+	      mpfr_gamma (z, x, rnd);
+	      if (mpfr_cmp (y, z))
+		{
+		  printf ("results differ for x=");
+		  mpfr_out_str (stdout, 2, prec, x, GMP_RNDN);
+		  printf (" prec=%u rnd_mode=%s\n", prec,
+			  mpfr_print_rnd_mode (rnd));
+		  printf ("   got ");
+		  mpfr_out_str (stdout, 2, prec, z, GMP_RNDN);
+		  putchar ('\n');
+		  printf ("   expected ");
+		  mpfr_out_str (stdout, 2, prec, y, GMP_RNDN);
+		  putchar ('\n');
+		}
+	    }
+	}
+    }
+
+  mpfr_clear (x);
+  mpfr_clear (y);
+  mpfr_clear (z);
+
+  return 0;
+}