path: root/tests/tlgamma.c

/* mpfr_tlgamma -- test file for lgamma function

Copyright 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
Contributed by the Arenaire and Cacao projects, INRIA.

This file is part of the GNU MPFR Library.

The GNU 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 GNU 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 GNU 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 int
mpfr_lgamma_nosign (mpfr_ptr y, mpfr_srcptr x, mp_rnd_t rnd)
{
  int inex, sign;

  inex = mpfr_lgamma (y, &sign, x, rnd);
  if (!MPFR_IS_SINGULAR (y))
    {
      MPFR_ASSERTN (sign == 1 || sign == -1);
      if (sign == -1 && (rnd == GMP_RNDN || rnd == GMP_RNDZ))
        {
          mpfr_neg (y, y, GMP_RNDN);
          inex = -inex;
          /* This is a way to check with the generic tests, that the value
             returned in the sign variable is consistent, but warning! The
             tested function depends on the rounding mode: it is
               * lgamma(x) = log(|Gamma(x)|) in GMP_RNDD and GMP_RNDU;
               * lgamma(x) * sign(Gamma(x)) in GMP_RNDN and GMP_RNDZ. */
        }
    }

  return inex;
}

#define TEST_FUNCTION mpfr_lgamma_nosign
#include "tgeneric.c"

static void
special (void)
{
  mpfr_t x, y;
  int inex;
  int sign;
  mp_exp_t emin, emax;

  mpfr_init (x);
  mpfr_init (y);

  mpfr_set_nan (x);
  mpfr_lgamma (y, &sign, x, GMP_RNDN);
  if (!mpfr_nan_p (y))
    {
      printf ("Error for lgamma(NaN)\n");
      exit (1);
    }

  mpfr_set_inf (x, -1);
  mpfr_lgamma (y, &sign, x, GMP_RNDN);
  if (!mpfr_inf_p (y) || mpfr_sgn (y) < 0)
    {
      printf ("Error for lgamma(-Inf)\n");
      exit (1);
    }

  mpfr_set_inf (x, 1);
  sign = -17;
  mpfr_lgamma (y, &sign, x, GMP_RNDN);
  if (!mpfr_inf_p (y) || mpfr_sgn (y) < 0 || sign != 1)
    {
      printf ("Error for lgamma(+Inf)\n");
      exit (1);
    }

  mpfr_set_ui (x, 0, GMP_RNDN);
  sign = -17;
  mpfr_lgamma (y, &sign, x, GMP_RNDN);
  if (!mpfr_inf_p (y) || mpfr_sgn (y) < 0 || sign != 1)
    {
      printf ("Error for lgamma(+0)\n");
      exit (1);
    }

  mpfr_set_ui (x, 0, GMP_RNDN);
  mpfr_neg (x, x, GMP_RNDN);
  sign = -17;
  mpfr_lgamma (y, &sign, x, GMP_RNDN);
  if (!mpfr_inf_p (y) || mpfr_sgn (y) < 0 || sign != -1)
    {
      printf ("Error for lgamma(-0)\n");
      exit (1);
    }

  mpfr_set_ui (x, 1, GMP_RNDN);
  sign = -17;
  mpfr_lgamma (y, &sign, x, GMP_RNDN);
  if (MPFR_IS_NAN (y) || mpfr_cmp_ui (y, 0) || MPFR_IS_NEG (y) || sign != 1)
    {
      printf ("Error for lgamma(1)\n");
      exit (1);
    }

  mpfr_set_si (x, -1, GMP_RNDN);
  mpfr_lgamma (y, &sign, x, GMP_RNDN);
  if (!mpfr_inf_p (y) || mpfr_sgn (y) < 0)
    {
      printf ("Error for lgamma(-1)\n");
      exit (1);
    }

  mpfr_set_ui (x, 2, GMP_RNDN);
  sign = -17;
  mpfr_lgamma (y, &sign, x, GMP_RNDN);
  if (MPFR_IS_NAN (y) || mpfr_cmp_ui (y, 0) || MPFR_IS_NEG (y) || sign != 1)
    {
      printf ("Error for lgamma(2)\n");
      exit (1);
    }

  mpfr_set_prec (x, 53);
  mpfr_set_prec (y, 53);

#define CHECK_X1 "1.0762904832837976166"
#define CHECK_Y1 "-0.039418362817587634939"

  mpfr_set_str (x, CHECK_X1, 10, GMP_RNDN);
  sign = -17;
  mpfr_lgamma (y, &sign, x, GMP_RNDN);
  mpfr_set_str (x, CHECK_Y1, 10, GMP_RNDN);
  if (mpfr_equal_p (y, x) == 0 || sign != 1)
    {
      printf ("mpfr_lgamma("CHECK_X1") is wrong:\n"
              "expected ");
      mpfr_print_binary (x); putchar ('\n');
      printf ("got      ");
      mpfr_print_binary (y); putchar ('\n');
      exit (1);
    }

#define CHECK_X2 "9.23709516716202383435e-01"
#define CHECK_Y2 "0.049010669407893718563"
  mpfr_set_str (x, CHECK_X2, 10, GMP_RNDN);
  sign = -17;
  mpfr_lgamma (y, &sign, x, GMP_RNDN);
  mpfr_set_str (x, CHECK_Y2, 10, GMP_RNDN);
  if (mpfr_equal_p (y, x) == 0 || sign != 1)
    {
      printf ("mpfr_lgamma("CHECK_X2") is wrong:\n"
              "expected ");
      mpfr_print_binary (x); putchar ('\n');
      printf ("got      ");
      mpfr_print_binary (y); putchar ('\n');
      exit (1);
    }

  mpfr_set_prec (x, 8);
  mpfr_set_prec (y, 175);
  mpfr_set_ui (x, 33, GMP_RNDN);
  sign = -17;
  mpfr_lgamma (y, &sign, x, GMP_RNDU);
  mpfr_set_prec (x, 175);
  mpfr_set_str_binary (x, "0.1010001100011101101011001101110010100001000001000001110011000001101100001111001001000101011011100100010101011110100111110101010100010011010010000101010111001100011000101111E7");
  if (mpfr_equal_p (x, y) == 0 || sign != 1)
    {
      printf ("Error in mpfr_lgamma (1)\n");
      exit (1);
    }

  mpfr_set_prec (x, 21);
  mpfr_set_prec (y, 8);
  mpfr_set_ui (y, 120, GMP_RNDN);
  sign = -17;
  mpfr_lgamma (x, &sign, y, GMP_RNDZ);
  mpfr_set_prec (y, 21);
  mpfr_set_str_binary (y, "0.111000101000001100101E9");
  if (mpfr_equal_p (x, y) == 0 || sign != 1)
    {
      printf ("Error in mpfr_lgamma (120)\n");
      printf ("Expected "); mpfr_print_binary (y); puts ("");
      printf ("Got      "); mpfr_print_binary (x); puts ("");
      exit (1);
    }

  mpfr_set_prec (x, 3);
  mpfr_set_prec (y, 206);
  mpfr_set_str_binary (x, "0.110e10");
  sign = -17;
  inex = mpfr_lgamma (y, &sign, x, GMP_RNDN);
  mpfr_set_prec (x, 206);
  mpfr_set_str_binary (x, "0.10000111011000000011100010101001100110001110000111100011000100100110110010001011011110101001111011110110000001010100111011010000000011100110110101100111000111010011110010000100010111101010001101000110101001E13");
  if (mpfr_equal_p (x, y) == 0 || sign != 1)
    {
      printf ("Error in mpfr_lgamma (768)\n");
      exit (1);
    }
  if (inex >= 0)
    {
      printf ("Wrong flag for mpfr_lgamma (768)\n");
      exit (1);
    }

  mpfr_set_prec (x, 4);
  mpfr_set_prec (y, 4);
  mpfr_set_str_binary (x, "0.1100E-66");
  sign = -17;
  mpfr_lgamma (y, &sign, x, GMP_RNDN);
  mpfr_set_str_binary (x, "0.1100E6");
  if (mpfr_equal_p (x, y) == 0 || sign != 1)
    {
      printf ("Error for lgamma(0.1100E-66)\n");
      printf ("Expected ");
      mpfr_dump (x);
      printf ("Got      ");
      mpfr_dump (y);
      exit (1);
    }

  mpfr_set_prec (x, 256);
  mpfr_set_prec (y, 32);
  mpfr_set_si_2exp (x, -1, 200, GMP_RNDN);
  mpfr_add_ui (x, x, 1, GMP_RNDN);
  mpfr_div_2ui (x, x, 1, GMP_RNDN);
  sign = -17;
  mpfr_lgamma (y, &sign, x, GMP_RNDN);
  mpfr_set_prec (x, 32);
  mpfr_set_str_binary (x, "-0.10001000111011111011000010100010E207");
  if (mpfr_equal_p (x, y) == 0 || sign != 1)
    {
      printf ("Error for lgamma(-2^199+0.5)\n");
      printf ("Got        ");
      mpfr_dump (y);
      printf ("instead of ");
      mpfr_dump (x);
      exit (1);
    }

  mpfr_set_prec (x, 256);
  mpfr_set_prec (y, 32);
  mpfr_set_si_2exp (x, -1, 200, GMP_RNDN);
  mpfr_sub_ui (x, x, 1, GMP_RNDN);
  mpfr_div_2ui (x, x, 1, GMP_RNDN);
  sign = -17;
  mpfr_lgamma (y, &sign, x, GMP_RNDN);
  mpfr_set_prec (x, 32);
  mpfr_set_str_binary (x, "-0.10001000111011111011000010100010E207");
  if (mpfr_equal_p (x, y) == 0 || sign != -1)
    {
      printf ("Error for lgamma(-2^199-0.5)\n");
      printf ("Got        ");
      mpfr_dump (y);
      printf ("with sign %d instead of ", sign);
      mpfr_dump (x);
      printf ("with sign -1.\n");
      exit (1);
    }

  mpfr_set_prec (x, 10);
  mpfr_set_prec (y, 10);
  mpfr_set_str_binary (x, "-0.1101111000E-3");
  inex = mpfr_lgamma (y, &sign, x, GMP_RNDN);
  mpfr_set_str_binary (x, "10.01001011");
  if (mpfr_equal_p (x, y) == 0 || sign != -1 || inex >= 0)
    {
      printf ("Error for lgamma(-0.1101111000E-3)\n");
      printf ("Got        ");
      mpfr_dump (y);
      printf ("instead of ");
      mpfr_dump (x);
      printf ("with sign %d instead of -1 (inex=%d).\n", sign, inex);
      exit (1);
    }

  mpfr_set_prec (x, 18);
  mpfr_set_prec (y, 28);
  mpfr_set_str_binary (x, "-1.10001101010001101e-196");
  inex = mpfr_lgamma (y, &sign, x, GMP_RNDN);
  mpfr_set_prec (x, 28);
  mpfr_set_str_binary (x, "0.100001110110101011011010011E8");
  MPFR_ASSERTN (mpfr_equal_p (x, y) && inex < 0);

  /* values reported by Kaveh Ghazi on 14 Jul 2007, where mpfr_lgamma()
     takes forever */
#define VAL1 "-0.11100001001010110111001010001001001011110100110000110E-55"
#define OUT1 "100110.01000000010111001110110101110101001001100110111"
#define VAL2 "-0.11100001001010110111001010001001001011110011111111100E-55"
#define OUT2 "100110.0100000001011100111011010111010100100110011111"
#define VAL3 "-0.11100001001010110111001010001001001001110101101010100E-55"
#define OUT3 "100110.01000000010111001110110101110101001011110111011"
#define VAL4 "-0.10001111110110110100100100000000001111110001001001011E-57"
#define OUT4 "101000.0001010111110011101101000101111111010001100011"
#define VAL5 "-0.10001111110110110100100100000000001111011111100001000E-57"
#define OUT5 "101000.00010101111100111011010001011111110100111000001"
#define VAL6 "-0.10001111110110110100100100000000001111011101100011001E-57"
#define OUT6 "101000.0001010111110011101101000101111111010011101111"

  mpfr_set_prec (x, 53);
  mpfr_set_prec (y, 53);

  mpfr_set_str_binary (x, VAL1);
  mpfr_lgamma (y, &sign, x, GMP_RNDN);
  mpfr_set_str_binary (x, OUT1);
  MPFR_ASSERTN(sign == -1 && mpfr_equal_p(x, y));

  mpfr_set_str_binary (x, VAL2);
  mpfr_lgamma (y, &sign, x, GMP_RNDN);
  mpfr_set_str_binary (x, OUT2);
  MPFR_ASSERTN(sign == -1 && mpfr_equal_p (x, y));

  mpfr_set_str_binary (x, VAL3);
  mpfr_lgamma (y, &sign, x, GMP_RNDN);
  mpfr_set_str_binary (x, OUT3);
  MPFR_ASSERTN(sign == -1 && mpfr_equal_p (x, y));

  mpfr_set_str_binary (x, VAL4);
  mpfr_lgamma (y, &sign, x, GMP_RNDN);
  mpfr_set_str_binary (x, OUT4);
  MPFR_ASSERTN(sign == -1 && mpfr_equal_p (x, y));

  mpfr_set_str_binary (x, VAL5);
  mpfr_lgamma (y, &sign, x, GMP_RNDN);
  mpfr_set_str_binary (x, OUT5);
  MPFR_ASSERTN(sign == -1 && mpfr_equal_p (x, y));

  mpfr_set_str_binary (x, VAL6);
  mpfr_lgamma (y, &sign, x, GMP_RNDN);
  mpfr_set_str_binary (x, OUT6);
  MPFR_ASSERTN(sign == -1 && mpfr_equal_p (x, y));

  /* further test from Kaveh Ghazi */
  mpfr_set_str_binary (x, "-0.10011010101001010010001110010111010111011101010111001E-53");
  mpfr_lgamma (y, &sign, x, GMP_RNDN);
  mpfr_set_str_binary (x, "100101.00111101101010000000101010111010001111001101111");
  MPFR_ASSERTN(sign == -1 && mpfr_equal_p (x, y));

  /* bug found by Kevin Rauch on 26 Oct 2007 */
  emin = mpfr_get_emin ();
  emax = mpfr_get_emax ();
  mpfr_set_emin (-1000000000);
  mpfr_set_emax (1000000000);
  mpfr_set_ui (x, 1, GMP_RNDN);
  mpfr_lgamma (x, &sign, x, GMP_RNDN);
  MPFR_ASSERTN(mpfr_get_emin () == -1000000000);
  MPFR_ASSERTN(mpfr_get_emax () == 1000000000);
  mpfr_set_emin (emin);
  mpfr_set_emax (emax);

  /* two other bugs reported by Kevin Rauch on 27 Oct 2007 */
  mpfr_set_prec (x, 128);
  mpfr_set_prec (y, 128);
  mpfr_set_str_binary (x, "0.11000110011110111111110010100110000000000000000000000000000000000000000000000000000000000000000001000011000110100100110111101010E-765689");
  inex = mpfr_lgamma (y, &sign, x, GMP_RNDN);
  mpfr_set_str_binary (x, "10000001100100101111011011010000111010001001110000111010011000101001011111011111110011011010110100101111110111001001010100011101E-108");
  MPFR_ASSERTN(inex < 0 && mpfr_cmp (y, x) == 0 && sign > 0);

  mpfr_set_prec (x, 128);
  mpfr_set_prec (y, 256);
  mpfr_set_str_binary (x, "0.1011111111111111100000111011111E-31871");
  inex = mpfr_lgamma (y, &sign, x, GMP_RNDN);
  mpfr_set_prec (x, 256);
  mpfr_set_str (x, "AC9729B83707E6797612D0D76DAF42B1240A677FF1B6E3783FD4E53037143B1P-237", 16, GMP_RNDN);
  MPFR_ASSERTN(inex < 0 && mpfr_cmp (y, x) == 0 && sign > 0);

  mpfr_clear (x);
  mpfr_clear (y);
}

static int
mpfr_lgamma1 (mpfr_ptr y, mpfr_srcptr x, mp_rnd_t r)
{
  int sign;

  return mpfr_lgamma (y, &sign, x, r);
}

int
main (void)
{
  tests_start_mpfr ();

  special ();
  test_generic (2, 100, 2);

  data_check ("data/lgamma", mpfr_lgamma1, "mpfr_lgamma");

  tests_end_mpfr ();
  return 0;
}