path: root/tests/thypot.c

/* Test file for mpfr_hypot.

Copyright 2001, 2002, 2003, 2004, 2005 Free Software Foundation.
Adapted from tarctan.c.

This file is part of the MPFR Library.

The MPFR Library is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 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 Lesser General Public
License for more details.

You should have received a copy of the GNU Lesser General Public License
along with the MPFR Library; see the file COPYING.LIB.  If not, write to
the Free Software Foundation, Inc., 51 Franklin Place, Fifth Floor, Boston,
MA 02110-1301, USA. */

#include <stdio.h>
#include <limits.h>
#include <stdlib.h>

#include "mpfr-test.h"

#define TEST_FUNCTION mpfr_hypot

static void
special (void)
{
  mpfr_t x, y, z;

  mpfr_init (x);
  mpfr_init (y);
  mpfr_init (z);

  mpfr_set_nan (x);
  mpfr_hypot (z, x, y, GMP_RNDN);
  MPFR_ASSERTN(mpfr_nan_p (z));

  mpfr_set_inf (x, 1);
  mpfr_set_inf (y, -1);
  mpfr_hypot (z, x, y, GMP_RNDN);
  MPFR_ASSERTN(mpfr_inf_p (z) && mpfr_sgn (z) > 0);

  mpfr_set_inf (x, -1);
  mpfr_set_nan (y);
  mpfr_hypot (z, x, y, GMP_RNDN);
  MPFR_ASSERTN(mpfr_inf_p (z) && mpfr_sgn (z) > 0);

  mpfr_set_nan (x);
  mpfr_set_inf (y, -1);
  mpfr_hypot (z, x, y, GMP_RNDN);
  MPFR_ASSERTN(mpfr_inf_p (z) && mpfr_sgn (z) > 0);

  mpfr_clear (x);
  mpfr_clear (y);
  mpfr_clear (z);
}

static void
test_large (void)
{
  mpfr_t x, y, z, t;

  mpfr_init (x);
  mpfr_init (y);
  mpfr_init (z);
  mpfr_init (t);

  mpfr_set_ui (x, 21, GMP_RNDN);
  mpfr_set_ui (y, 28, GMP_RNDN);
  mpfr_set_ui (z, 35, GMP_RNDN);

  mpfr_mul_2ui (x, x, MPFR_EMAX_DEFAULT-6, GMP_RNDN);
  mpfr_mul_2ui (y, y, MPFR_EMAX_DEFAULT-6, GMP_RNDN);
  mpfr_mul_2ui (z, z, MPFR_EMAX_DEFAULT-6, GMP_RNDN);

  mpfr_hypot (t, x, y, GMP_RNDN);
  if (mpfr_cmp (z, t))
    {
      printf ("Error in test_large: got\n");
      mpfr_out_str (stdout, 2, 0, t, GMP_RNDN);
      printf ("\ninstead of\n");
      mpfr_out_str (stdout, 2, 0, z, GMP_RNDN);
      printf ("\n");
      exit (1);
    }

  mpfr_set_prec (x, 53);
  mpfr_set_prec (t, 53);
  mpfr_set_prec (y, 53);
  mpfr_set_str_binary (x, "0.11101100011110000011101000010101010011001101000001100E-1021");
  mpfr_set_str_binary (t, "0.11111001010011000001110110001101011100001000010010100E-1021");
  mpfr_hypot (y, x, t, GMP_RNDN);

  mpfr_set_prec (x, 240);
  mpfr_set_prec (y, 22);
  mpfr_set_prec (t, 2);
  mpfr_set_str_binary (x, "0.100111011010010010110100000100000001100010011100110101101111111101011110111011011101010110100101111000111100010100110000100101011110111011100110100110100101110101101100011000001100000001111101110100100100011011011010110111100110010101000111e-7");
  mpfr_set_str_binary (y, "0.1111000010000011000111e-10");
  mpfr_hypot (t, x, y, GMP_RNDN);
  mpfr_set_str_binary (y, "0.11E-7");
  if (mpfr_cmp (t, y))
    {
      printf ("Error in mpfr_hypot (1)\n");
      exit (1);
    }

  mpfr_clear (x);
  mpfr_clear (y);
  mpfr_clear (z);
  mpfr_clear (t);
}

static void
test_large_small (void)
{
  mpfr_t x, y, z;
  int inexact;

  mpfr_init2 (x, 3);
  mpfr_init2 (y, 2);
  mpfr_init2 (z, 2);

  mpfr_set_ui_2exp (x, 1, mpfr_get_emax () / 2, GMP_RNDN);
  mpfr_set_ui_2exp (y, 1, -1, GMP_RNDN);
  inexact = mpfr_hypot (z, x, y, GMP_RNDN);
  if (inexact >= 0 || mpfr_cmp (x, z))
    {
      printf ("Error 1 in test_large_small\n");
      exit (1);
    }

  mpfr_mul_ui (x, x, 5, GMP_RNDN);
  inexact = mpfr_hypot (z, x, y, GMP_RNDN);
  if (mpfr_cmp (x, z) >= 0)
    {
      printf ("Error 2 in test_large_small\n");
      printf ("x = ");
      mpfr_out_str (stdout, 2, 0, x, GMP_RNDN);
      printf ("\n");
      printf ("y = ");
      mpfr_out_str (stdout, 2, 0, y, GMP_RNDN);
      printf ("\n");
      printf ("z = ");
      mpfr_out_str (stdout, 2, 0, z, GMP_RNDN);
      printf (" (in precision 2) instead of\n    ");
      mpfr_out_str (stdout, 2, 2, x, GMP_RNDU);
      printf ("\n");
      exit (1);
    }

  mpfr_clear (x);
  mpfr_clear (y);
  mpfr_clear (z);
}

int
main (int argc, char *argv[])
{
  unsigned int prec, err, yprec, n, p0 = 2, p1 = 100, N = 100;
  mp_rnd_t rnd;
  mpfr_t x1, x2, y, z, t;
  int inexact, compare, compare2;

  tests_start_mpfr ();

  special ();

  mpfr_init (x1);
  mpfr_init (x2);
  mpfr_init (y);
  mpfr_init (z);
  mpfr_init (t);

  /* thypot prec - perform one random computation with precision prec */
  if (argc >= 2)
    {
      p0 = p1 = atoi (argv[1]);
      N = 1;
    }

  for (prec = p0; prec <= p1; prec++)
    {
      mpfr_set_prec (x1, prec);
      mpfr_set_prec (x2, prec);
      mpfr_set_prec (z, prec);
      mpfr_set_prec (t, prec);
      yprec = prec + 10;

      for (n=0; n<N; n++)
        {
          mpfr_random(x1);
          mpfr_random(x2);
          if (randlimb () % 2)
            mpfr_neg (x1, x1, GMP_RNDN);
          if (randlimb () % 2)
            mpfr_neg (x2, x2, GMP_RNDN);
          rnd = (mp_rnd_t) RND_RAND ();
          mpfr_set_prec (y, yprec);

          compare =TEST_FUNCTION (y, x1,x2, rnd);
          err = (rnd == GMP_RNDN) ? yprec + 1 : yprec;
          if (mpfr_can_round (y, err, rnd, rnd, prec))
            {
              mpfr_set (t, y, rnd);
              inexact = TEST_FUNCTION (z, x1,x2, rnd);
              if (mpfr_cmp (t, z))
                {
                  printf ("results differ for x1=");
                  mpfr_out_str (stdout, 2, prec, x1, GMP_RNDN);
                  printf ("\n and x2=");
                  mpfr_out_str (stdout, 2, prec, x2, GMP_RNDN);
                  printf (" \n prec=%u rnd_mode=%s\n", prec,
                          mpfr_print_rnd_mode (rnd));
                  printf ("   got ");
                  mpfr_out_str (stdout, 2, prec, z, GMP_RNDN);
                  puts ("");
                  printf ("   expected ");
                  mpfr_out_str (stdout, 2, prec, t, GMP_RNDN);
                  puts ("");
                  printf ("   approximation was ");
                  mpfr_print_binary (y);
                  puts ("");
                  exit (1);
                }
              compare2 = mpfr_cmp (t, y);
              /* if rounding to nearest, cannot know the sign of t - f(x)
                 because of composed rounding: y = o(f(x)) and t = o(y) */
              if ((rnd != GMP_RNDN) && (compare * compare2 >= 0))
                compare = compare + compare2;
              else
                compare = inexact; /* cannot determine sign(t-f(x)) */
              if (((inexact == 0) && (compare != 0)) ||
                  ((inexact > 0) && (compare <= 0)) ||
                  ((inexact < 0) && (compare >= 0)))
                {
                  printf ("Wrong inexact flag for rnd=%s: expected %d, got %d"
                          "\n", mpfr_print_rnd_mode (rnd), compare, inexact);
                  printf ("x1="); mpfr_print_binary (x1); puts ("");
                  printf ("x2="); mpfr_print_binary (x2); puts ("");
                  printf ("t="); mpfr_print_binary (t); puts ("");
                  exit (1);
                }
            }
        }
    }

  mpfr_clear (x1);
  mpfr_clear (x2);
  mpfr_clear (y);
  mpfr_clear (z);
  mpfr_clear (t);

  test_large ();
  test_large_small ();

  tests_end_mpfr ();
  return 0;
}