/* Test file for mpfr_atan.

Copyright 2001, 2002, 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
Written by Paul Zimmermann, INRIA Lorraine.

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 St, Fifth Floor, Boston,
MA 02110-1301, USA. */

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

#include "mpfr-test.h"

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

  mpfr_init2 (x, 53);
  mpfr_init2 (y, 53);
  mpfr_init2 (z, 53);

  mpfr_set_str_binary (x, "1.0000100110000001100111100011001110101110100111011101");
  mpfr_set_str_binary (y, "1.1001101101110100101100110011011101101000011010111110e-1");
  mpfr_atan (z, x, GMP_RNDN);
  if (mpfr_cmp (y, z))
    {
      printf ("Error in mpfr_atan for prec=53, rnd=GMP_RNDN\n");
      printf ("x=");
      mpfr_out_str (stdout, 2, 0, x, GMP_RNDN);
      printf ("\nexpected ");
      mpfr_out_str (stdout, 2, 0, y, GMP_RNDN);
      printf ("\ngot      ");
      mpfr_out_str (stdout, 2, 0, z, GMP_RNDN);
      printf ("\n");
      exit (1);
    }

  /* atan(+Inf) = Pi/2 */
  for (r = 0; r < GMP_RND_MAX ; r++)
    {
      mpfr_set_inf (x, 1);
      mpfr_atan (y, x, (mp_rnd_t) r);
      mpfr_const_pi (x, (mp_rnd_t) r);
      mpfr_div_2exp (x, x, 1, (mp_rnd_t) r);
      if (mpfr_cmp (x, y))
        {
          printf ("Error: mpfr_atan(+Inf), rnd=%s\n",
                  mpfr_print_rnd_mode ((mp_rnd_t) r));
          exit (1);
        }
    }

  /* atan(-Inf) = - Pi/2 */
  for (r = 0; r < GMP_RND_MAX ; r++)
    {
      mpfr_set_inf (x, -1);
      mpfr_atan (y, x, (mp_rnd_t) r);
      mpfr_const_pi (x, MPFR_INVERT_RND((mp_rnd_t) r));
      mpfr_neg (x, x, (mp_rnd_t) r);
      mpfr_div_2exp (x, x, 1, (mp_rnd_t) r);
      if (mpfr_cmp (x, y))
        {
          printf ("Error: mpfr_atan(-Inf), rnd=%s\n",
                  mpfr_print_rnd_mode ((mp_rnd_t) r));
          exit (1);
        }
    }

  /* atan(NaN) = NaN */
  mpfr_set_nan (x);
  mpfr_atan (y, x, GMP_RNDN);
  if (!mpfr_nan_p (y))
    {
      printf ("Error: mpfr_atan(NaN) <> NaN\n");
      exit (1);
    }

  /* atan(+/-0) = +/-0 */
  mpfr_set_ui (x, 0, GMP_RNDN);
  MPFR_SET_NEG (y);
  mpfr_atan (y, x, GMP_RNDN);
  if (mpfr_cmp_ui (y, 0) || MPFR_IS_NEG (y))
    {
      printf ("Error: mpfr_atan (+0) <> +0\n");
      exit (1);
    }
  mpfr_atan (x, x, GMP_RNDN);
  if (mpfr_cmp_ui (x, 0) || MPFR_IS_NEG (x))
    {
      printf ("Error: mpfr_atan (+0) <> +0 (in place)\n");
      exit (1);
    }
  mpfr_neg (x, x, GMP_RNDN);
  MPFR_SET_POS (y);
  mpfr_atan (y, x, GMP_RNDN);
  if (mpfr_cmp_ui (y, 0) || MPFR_IS_POS (y))
    {
      printf ("Error: mpfr_atan (-0) <> -0\n");
      exit (1);
    }
  mpfr_atan (x, x, GMP_RNDN);
  if (mpfr_cmp_ui (x, 0) || MPFR_IS_POS (x))
    {
      printf ("Error: mpfr_atan (-0) <> -0 (in place)\n");
      exit (1);
    }

  mpfr_set_prec (x, 32);
  mpfr_set_prec (y, 32);

  /* test one random positive argument */
  mpfr_set_str_binary (x, "0.10000100001100101001001001011001");
  mpfr_atan (x, x, GMP_RNDN);
  mpfr_set_str_binary (y, "0.1111010000001111001111000000011E-1");
  if (mpfr_cmp (x, y))
    {
      printf ("Error in mpfr_atan (1)\n");
      exit (1);
    }

  /* test one random negative argument */
  mpfr_set_str_binary (x, "-0.1100001110110000010101011001011");
  mpfr_atan (x, x, GMP_RNDN);
  mpfr_set_str_binary (y, "-0.101001110001010010110001110001");
  if (mpfr_cmp (x, y))
    {
      printf ("Error in mpfr_atan (2)\n");
      mpfr_print_binary (x); printf ("\n");
      mpfr_print_binary (y); printf ("\n");
      exit (1);
    }

  mpfr_set_prec (x, 3);
  mpfr_set_prec (y, 192);
  mpfr_set_prec (z, 192);
  mpfr_set_str_binary (x, "-0.100e1");
  mpfr_atan (z, x, GMP_RNDD);
  mpfr_set_str_binary (y, "-0.110010010000111111011010101000100010000101101000110000100011010011000100110001100110001010001011100000001101110000011100110100010010100100000010010011100000100010001010011001111100110001110101");
  if (mpfr_cmp (z, y))
    {
      printf ("Error in mpfr_atan (3)\n");
      printf ("Expected "); mpfr_print_binary (y); printf ("\n");
      printf ("Got      "); mpfr_print_binary (z); printf ("\n");
      exit (1);
    }

  /* Test regression */
  mpfr_set_prec (x, 51);
  mpfr_set_prec (y, 51);
  mpfr_set_str_binary (x,
           "0.101100100000101111111010001111111000001000000000000E-11");
  i = mpfr_atan (y, x, GMP_RNDN);
  if (mpfr_cmp_str (y,
   "1.01100100000101111111001110011001010110100100000000e-12", 2, GMP_RNDN)
      || i >= 0)
    {
      printf ("Wrong Regression test (%d)\n", i);
      mpfr_dump (y);
      exit (1);
    }

  mpfr_set_si (x, -1, GMP_RNDN);
  mpfr_atan (x, x, GMP_RNDN);
  MPFR_ASSERTN (MPFR_IS_NEG (x));

  /* Test regression */
  mpfr_set_prec (x, 48);
  mpfr_set_prec (y, 48);
  mpfr_set_str_binary (x, "1.11001110010000011111100000010000000000000000000e-19");
  mpfr_atan (y, x, GMP_RNDD);
  if (mpfr_cmp_str (y, "0.111001110010000011111100000001111111110000010011E-18", 2, GMP_RNDN))
    {
      printf ("Error in mpfr_atan (4)\n");
      printf ("Input    1.11001110010000011111100000010000000000000000000e-19 [prec=48]\n");
      printf ("Expected 0.111001110010000011111100000001111111110000010011E-18\n");
      printf ("Got      "); mpfr_dump (y);
      exit (1);
    }

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

#define TEST_FUNCTION mpfr_atan
#define test_generic test_generic_atan
#define RAND_FUNCTION(x) (mpfr_random (x), mpfr_mul_2si (x, x, (randlimb () %1000-500), GMP_RNDN))
#include "tgeneric.c"

#define TEST_FUNCTION mpfr_atan2
#define TWO_ARGS
#define test_generic test_generic_atan2
#include "tgeneric.c"

#define TEST_FUNCTION mpfr_atan2
#define TWO_ARGS
#define RAND_FUNCTION(x) (mpfr_random (x), MPFR_SET_NEG (x))
#define test_generic test_generic_atan2_neg
#include "tgeneric.c"

static void
special_overflow (void)
{
  mpfr_t x, y;

  set_emin (-125);
  set_emax (128);
  mpfr_init2 (x, 24);
  mpfr_init2 (y, 48);
  mpfr_set_str_binary (x, "0.101101010001001101111010E0");
  mpfr_atan (y, x, GMP_RNDN);
  if (mpfr_cmp_str (y, "0.100111011001100111000010111101000111010101011110E0",
                    2, GMP_RNDN))
    {
      printf("Special Overflow error.\n");
      mpfr_dump (y);
      exit (1);
    }
  mpfr_clear (y);
  mpfr_clear (x);
  set_emin (MPFR_EMIN_MIN);
  set_emax (MPFR_EMAX_MAX);
}

static void
special_atan2 (void)
{
  mpfr_t x, y, z;

  mpfr_inits2 (4, x, y, z, NULL);

  /* Anything with NAN should be set to NAN */
  mpfr_set_ui (y, 0, GMP_RNDN);
  mpfr_set_nan (x);
  mpfr_atan2 (z, y, x, GMP_RNDN);
  MPFR_ASSERTN (MPFR_IS_NAN (z));
  mpfr_swap (x, y);
  mpfr_atan2 (z, y, x, GMP_RNDN);
  MPFR_ASSERTN (MPFR_IS_NAN (z));

  /* 0+ 0+ --> 0+ */
  mpfr_set_ui (y, 0, GMP_RNDN);
  mpfr_atan2 (z, y, x, GMP_RNDN);
  MPFR_ASSERTN (MPFR_IS_ZERO (z) && MPFR_IS_POS (z));
  /* 0- 0+ --> 0- */
  MPFR_CHANGE_SIGN (y);
  mpfr_atan2 (z, y, x, GMP_RNDN);
  MPFR_ASSERTN (MPFR_IS_ZERO (z) && MPFR_IS_NEG (z));
  /* 0- 0- --> -PI */
  MPFR_CHANGE_SIGN (x);
  mpfr_atan2 (z, y, x, GMP_RNDN);
  MPFR_ASSERTN (mpfr_cmp_str (z, "-3.1415", 10, GMP_RNDN) == 0);
  /* 0+ 0- --> +PI */
  MPFR_CHANGE_SIGN (y);
  mpfr_atan2 (z, y, x, GMP_RNDN);
  MPFR_ASSERTN (mpfr_cmp_str (z, "3.1415", 10, GMP_RNDN) == 0);
  /* 0+ -1 --> PI */
  mpfr_set_si (x, -1, GMP_RNDN);
  mpfr_atan2 (z, y, x, GMP_RNDN);
  MPFR_ASSERTN (mpfr_cmp_str (z, "3.1415", 10, GMP_RNDN) == 0);
  /* 0- -1 --> -PI */
  MPFR_CHANGE_SIGN (y);
  mpfr_atan2 (z, y, x, GMP_RNDN);
  MPFR_ASSERTN (mpfr_cmp_str (z, "-3.1415", 10, GMP_RNDN) == 0);
  /* 0- +1 --> 0- */
  mpfr_set_ui (x, 1, GMP_RNDN);
  mpfr_atan2 (z, y, x, GMP_RNDN);
  MPFR_ASSERTN (MPFR_IS_ZERO (z) && MPFR_IS_NEG (z));
  /* 0+ +1 --> 0+ */
  MPFR_CHANGE_SIGN (y);
  mpfr_atan2 (z, y, x, GMP_RNDN);
  MPFR_ASSERTN (MPFR_IS_ZERO (z) && MPFR_IS_POS (z));
  /* +1 0+ --> PI/2 */
  mpfr_swap (x, y);
  mpfr_atan2 (z, y, x, GMP_RNDN);
  MPFR_ASSERTN (mpfr_cmp_str (z, "1.57075", 10, GMP_RNDN) == 0);
  /* +1 0- --> PI/2 */
  MPFR_CHANGE_SIGN (x);
  mpfr_atan2 (z, y, x, GMP_RNDN);
  MPFR_ASSERTN (mpfr_cmp_str (z, "1.57075", 10, GMP_RNDN) == 0);
  /* -1 0- --> -PI/2 */
  MPFR_CHANGE_SIGN (y);
  mpfr_atan2 (z, y, x, GMP_RNDN);
  MPFR_ASSERTN (mpfr_cmp_str (z, "-1.57075", 10, GMP_RNDN) == 0);
  /* -1 0+ --> -PI/2 */
  MPFR_CHANGE_SIGN (x);
  mpfr_atan2 (z, y, x, GMP_RNDN);
  MPFR_ASSERTN (mpfr_cmp_str (z, "-1.57075", 10, GMP_RNDN) == 0);

  /* -1 +INF --> -0 */
  MPFR_SET_INF (x);
  mpfr_atan2 (z, y, x, GMP_RNDN);
  MPFR_ASSERTN (MPFR_IS_ZERO (z) && MPFR_IS_NEG (z));
  /* +1 +INF --> +0 */
  MPFR_CHANGE_SIGN (y);
  mpfr_atan2 (z, y, x, GMP_RNDN);
  MPFR_ASSERTN (MPFR_IS_ZERO (z) && MPFR_IS_POS (z));
  /* +1 -INF --> +PI */
  MPFR_CHANGE_SIGN (x);
  mpfr_atan2 (z, y, x, GMP_RNDN);
  MPFR_ASSERTN (mpfr_cmp_str (z, "3.1415", 10, GMP_RNDN) == 0);
  /* -1 -INF --> -PI */
  MPFR_CHANGE_SIGN (y);
  mpfr_atan2 (z, y, x, GMP_RNDN);
  MPFR_ASSERTN (mpfr_cmp_str (z, "-3.1415", 10, GMP_RNDN) == 0);
  /* -INF -1 --> -PI/2 */
  mpfr_swap (x, y);
  mpfr_atan2 (z, y, x, GMP_RNDN);
  MPFR_ASSERTN (mpfr_cmp_str (z, "-1.57075", 10, GMP_RNDN) == 0);
  /* +INF -1  --> PI/2 */
  MPFR_CHANGE_SIGN (y);
  mpfr_atan2 (z, y, x, GMP_RNDN);
  MPFR_ASSERTN (mpfr_cmp_str (z, "1.57075", 10, GMP_RNDN) == 0);
  /* +INF -INF --> 3*PI/4 */
  MPFR_SET_INF (x);
  mpfr_atan2 (z, y, x, GMP_RNDN);
  MPFR_ASSERTN (mpfr_cmp_str (z, "2.356194490192344928", 10, GMP_RNDN) == 0);
  /* +INF +INF --> PI/4 */
  MPFR_CHANGE_SIGN (x);
  mpfr_atan2 (z, y, x, GMP_RNDN);
  MPFR_ASSERTN (mpfr_cmp_str (z, "0.785375", 10, GMP_RNDN) == 0);
  /* -INF +INF --> -PI/4 */
  MPFR_CHANGE_SIGN (y);
  mpfr_atan2 (z, y, x, GMP_RNDN);
  MPFR_ASSERTN (mpfr_cmp_str (z, "-0.785375", 10, GMP_RNDN) == 0);
  /* -INF -INF --> -3*PI/4 */
  MPFR_CHANGE_SIGN (x);
  mpfr_atan2 (z, y, x, GMP_RNDN);
  MPFR_ASSERTN (mpfr_cmp_str (z, "-2.356194490192344928", 10, GMP_RNDN) == 0);

  mpfr_clears (x, y, z, NULL);
}

int
main (int argc, char *argv[])
{
  tests_start_mpfr ();

  special_overflow ();
  special ();
  special_atan2 ();

  test_generic_atan  (2, 200, 17);
  test_generic_atan2 (2, 200, 17);
  test_generic_atan2_neg (2, 200, 17);

  tests_end_mpfr ();
  return 0;
}