dist/tests/tlog.c

/* Test file for mpfr_log.

Copyright 1999, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 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 3 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.LESSER.  If not, see
http://www.gnu.org/licenses/ or 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"

#ifdef CHECK_EXTERNAL
static int
test_log (mpfr_ptr a, mpfr_srcptr b, mpfr_rnd_t rnd_mode)
{
  int res;
  int ok = rnd_mode == MPFR_RNDN && mpfr_number_p (b) && mpfr_get_prec (a)>=53;
  if (ok)
    {
      mpfr_print_raw (b);
    }
  res = mpfr_log (a, b, rnd_mode);
  if (ok)
    {
      printf (" ");
      mpfr_print_raw (a);
      printf ("\n");
    }
  return res;
}
#else
#define test_log mpfr_log
#endif

static void
check2 (const char *as, mpfr_rnd_t rnd_mode, const char *res1s)
{
  mpfr_t ta, tres;

  mpfr_inits2 (53, ta, tres, (mpfr_ptr) 0);
  mpfr_set_str1 (ta, as);
  test_log (tres, ta, rnd_mode);

  if (mpfr_cmp_str1 (tres, res1s))
    {
      printf ("mpfr_log failed for    a=%s, rnd_mode=%s\n",
              as, mpfr_print_rnd_mode (rnd_mode));
      printf ("correct result is        %s\n mpfr_log gives          ",
              res1s);
      mpfr_out_str(stdout, 10, 0, tres, MPFR_RNDN);
      exit (1);
    }
  mpfr_clears (ta, tres, (mpfr_ptr) 0);
}

static void
check3 (double d, unsigned long prec, mpfr_rnd_t rnd)
{
  mpfr_t x, y;

  mpfr_init2 (x, prec);
  mpfr_init2 (y, prec);
  mpfr_set_d (x, d, rnd);
  test_log (y, x, rnd);
  mpfr_out_str (stdout, 10, 0, y, rnd);
  puts ("");
  mpfr_print_binary (y);
  puts ("");
  mpfr_clear (x);
  mpfr_clear (y);
}

/* examples from Jean-Michel Muller and Vincent Lefevre
   Cf http://www.ens-lyon.fr/~jmmuller/Intro-to-TMD.htm
*/

static void
check_worst_cases (void)
{
  check2("1.00089971802309629645", MPFR_RNDD, "8.99313519443722736088e-04");
  check2("1.00089971802309629645", MPFR_RNDN, "8.99313519443722844508e-04");
  check2("1.00089971802309629645", MPFR_RNDU, "8.99313519443722844508e-04");

  check2("1.01979300812244555452", MPFR_RNDD, "1.95996734891603630047e-02");
  check2("1.01979300812244555452", MPFR_RNDN, "1.95996734891603664741e-02");
  check2("1.01979300812244555452", MPFR_RNDU, "1.95996734891603664741e-02");

  check2("1.02900871924604464525", MPFR_RNDD, "2.85959303301472726744e-02");
  check2("1.02900871924604464525", MPFR_RNDN, "2.85959303301472761438e-02");
  check2("1.02900871924604464525", MPFR_RNDU, "2.85959303301472761438e-02");

  check2("1.27832870030418943585", MPFR_RNDD, "2.45553521871417795852e-01");
  check2("1.27832870030418943585", MPFR_RNDN, "2.45553521871417823608e-01");
  check2("1.27832870030418943585", MPFR_RNDU, "2.45553521871417823608e-01");

  check2("1.31706530746788241792", MPFR_RNDD, "2.75406009586277422674e-01");
  check2("1.31706530746788241792", MPFR_RNDN, "2.75406009586277478185e-01");
  check2("1.31706530746788241792", MPFR_RNDU, "2.75406009586277478185e-01");

  check2("1.47116981099449883885", MPFR_RNDD, "3.86057874110010412760e-01");
  check2("1.47116981099449883885", MPFR_RNDN, "3.86057874110010412760e-01");
  check2("1.47116981099449883885", MPFR_RNDU, "3.86057874110010468272e-01");

  check2("1.58405446812987782401", MPFR_RNDD, "4.59987679246663727639e-01");
  check2("1.58405446812987782401", MPFR_RNDN, "4.59987679246663783150e-01");
  check2("1.58405446812987782401", MPFR_RNDU, "4.59987679246663783150e-01");

  check2("1.67192331263391547047", MPFR_RNDD, "5.13974647961076613889e-01");
  check2("1.67192331263391547047", MPFR_RNDN, "5.13974647961076724911e-01");
  check2("1.67192331263391547047", MPFR_RNDU, "5.13974647961076724911e-01");

  check2("1.71101198068990645318", MPFR_RNDD, "5.37084997042120315669e-01");
  check2("1.71101198068990645318", MPFR_RNDN, "5.37084997042120315669e-01");
  check2("1.71101198068990645318", MPFR_RNDU, "5.37084997042120426691e-01");

  check2("1.72634853551388700588", MPFR_RNDD, "5.46008504786553605648e-01");
  check2("1.72634853551388700588", MPFR_RNDN, "5.46008504786553716670e-01");
  check2("1.72634853551388700588", MPFR_RNDU, "5.46008504786553716670e-01");

  check2("2.00028876593004323325", MPFR_RNDD, "6.93291553102749702475e-01");
  check2("2.00028876593004323325", MPFR_RNDN, "6.93291553102749813497e-01");
  check2("2.00028876593004323325", MPFR_RNDU, "6.93291553102749813497e-01");

  check2("6.27593230200363105808", MPFR_RNDD, "1.83672204800630312072");
  check2("6.27593230200363105808", MPFR_RNDN, "1.83672204800630334276");
  check2("6.27593230200363105808", MPFR_RNDU, "1.83672204800630334276");

  check2("7.47216682321367997588", MPFR_RNDD, "2.01118502712453661729");
  check2("7.47216682321367997588", MPFR_RNDN, "2.01118502712453706138");
  check2("7.47216682321367997588", MPFR_RNDU, "2.01118502712453706138");

  check2("9.34589857718275318632", MPFR_RNDD, "2.23493759221664944903");
  check2("9.34589857718275318632", MPFR_RNDN, "2.23493759221664989312");
  check2("9.34589857718275318632", MPFR_RNDU, "2.23493759221664989312");

  check2("10.6856587560831854944", MPFR_RNDD, "2.36890253928838445674");
  check2("10.6856587560831854944", MPFR_RNDN, "2.36890253928838445674");
  check2("10.6856587560831854944", MPFR_RNDU, "2.36890253928838490083");

  check2("12.4646345033981766903", MPFR_RNDD, "2.52289539471636015122");
  check2("12.4646345033981766903", MPFR_RNDN, "2.52289539471636015122");
  check2("12.4646345033981766903", MPFR_RNDU, "2.52289539471636059531");

  check2("17.0953275851761752335", MPFR_RNDD, "2.83880518553861849185");
  check2("17.0953275851761752335", MPFR_RNDN, "2.83880518553861893594");
  check2("17.0953275851761752335", MPFR_RNDU, "2.83880518553861893594");

  check2("19.8509496207496916043", MPFR_RNDD, "2.98825184582516722998");
  check2("19.8509496207496916043", MPFR_RNDN, "2.98825184582516722998");
  check2("19.8509496207496916043", MPFR_RNDU, "2.98825184582516767406");

  check2("23.9512076062771335216", MPFR_RNDD, "3.17601874455977206679");
  check2("23.9512076062771335216", MPFR_RNDN, "3.17601874455977206679");
  check2("23.9512076062771335216", MPFR_RNDU, "3.17601874455977251088");

  check2("428.315247165198229595", MPFR_RNDD, "6.05985948325268264369");
  check2("428.315247165198229595", MPFR_RNDN, "6.05985948325268353187");
  check2("428.315247165198229595", MPFR_RNDU, "6.05985948325268353187");
}

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

  emin = mpfr_get_emin ();
  emax = mpfr_get_emax ();

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

  /* Check special case: An overflow in const_pi could occurs! */
  set_emin (-125);
  set_emax (128);
  mpfr_set_prec (y, 24*2);
  mpfr_set_prec (x, 24);
  mpfr_set_str_binary (x, "0.111110101010101011110101E0");
  test_log (y, x, MPFR_RNDN);
  set_emin (emin);
  set_emax (emax);

  mpfr_set_prec (y, 53);
  mpfr_set_prec (x, 53);
  mpfr_set_ui (x, 3, MPFR_RNDD);
  test_log (y, x, MPFR_RNDD);
  if (mpfr_cmp_str1 (y, "1.09861228866810956"))
    {
      printf ("Error in mpfr_log(3) for MPFR_RNDD\n");
      exit (1);
    }

  /* check large precision */
  mpfr_set_prec (x, 3322);
  mpfr_set_prec (y, 3322);
  mpfr_set_ui (x, 3, MPFR_RNDN);
  mpfr_sqrt (x, x, MPFR_RNDN);
  test_log (y, x, MPFR_RNDN);

  /* negative argument */
  mpfr_set_si (x, -1, MPFR_RNDN);
  test_log (y, x, MPFR_RNDN);
  MPFR_ASSERTN(mpfr_nan_p (y));

  /* infinite loop when  */
  set_emax (128);
  mpfr_set_prec (x, 251);
  mpfr_set_prec (y, 251);
  mpfr_set_str_binary (x, "0.10010111000000000001101E8");
  /* x = 4947981/32768, log(x) ~ 5.017282... */
  test_log (y, x, MPFR_RNDN);

  set_emax (emax);

  mpfr_set_ui (x, 0, MPFR_RNDN);
  inex = test_log (y, x, MPFR_RNDN);
  MPFR_ASSERTN (inex == 0);
  MPFR_ASSERTN (mpfr_inf_p (y));
  MPFR_ASSERTN (mpfr_sgn (y) < 0);

  mpfr_set_ui (x, 0, MPFR_RNDN);
  mpfr_neg (x, x, MPFR_RNDN);
  inex = test_log (y, x, MPFR_RNDN);
  MPFR_ASSERTN (inex == 0);
  MPFR_ASSERTN (mpfr_inf_p (y));
  MPFR_ASSERTN (mpfr_sgn (y) < 0);

  mpfr_clear (x);
  mpfr_clear (y);
}

static void
x_near_one (void)
{
  mpfr_t x, y;
  int inex;

  mpfr_init2 (x, 32);
  mpfr_init2 (y, 16);

  mpfr_set_ui (x, 1, MPFR_RNDN);
  mpfr_nextbelow (x);
  inex = mpfr_log (y, x, MPFR_RNDD);
  if (mpfr_cmp_str (y, "-0.1000000000000001E-31", 2, MPFR_RNDN)
      || inex >= 0)
    {
      printf ("Failure in x_near_one, got inex = %d and\ny = ", inex);
      mpfr_dump (y);
    }

  mpfr_clears (x, y, (mpfr_ptr) 0);
}

#define TEST_FUNCTION test_log
#define TEST_RANDOM_POS 8
#include "tgeneric.c"

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

  if (argc==4)
    {   /* tlog x prec rnd */
      check3 (atof(argv[1]), atoi(argv[2]), (mpfr_rnd_t) atoi(argv[3]));
      goto done;
    }

  special ();
  check_worst_cases();

  check2("1.01979300812244555452", MPFR_RNDN, "1.95996734891603664741e-02");
  check2("10.0",MPFR_RNDU,"2.30258509299404590110e+00");
  check2("6.0",MPFR_RNDU,"1.79175946922805517936");
  check2("1.0",MPFR_RNDZ,"0.0");
  check2("62.0",MPFR_RNDU,"4.12713438504509166905");
  check2("0.5",MPFR_RNDZ,"-6.93147180559945286226e-01");
  check2("3.0",MPFR_RNDZ,"1.09861228866810956006e+00");
  check2("234375765.0",MPFR_RNDU,"1.92724362186836231104e+01");
  check2("8.0",MPFR_RNDZ,"2.07944154167983574765e+00");
  check2("44.0",MPFR_RNDU,"3.78418963391826146392e+00");
  check2("1.01979300812244555452", MPFR_RNDN, "1.95996734891603664741e-02");

  /* bugs found by Vincent Lefe`vre */
  check2("0.99999599881598921769", MPFR_RNDN, "-0.0000040011920155404072924737977900999652547398000024259090423583984375");
  check2("9.99995576063808955247e-01",MPFR_RNDZ,"-4.42394597667932383816e-06");
  check2("9.99993687357856209097e-01",MPFR_RNDN,"-6.31266206860017342601e-06");
  check2("9.99995223520736886691e-01",MPFR_RNDN,"-4.77649067052670982220e-06");
  check2("9.99993025794720935551e-01",MPFR_RNDN,"-6.97422959894716163837e-06");
  check2("9.99987549017837484833e-01",MPFR_RNDN,"-1.24510596766369924330e-05");
  check2("9.99985901426543311032e-01",MPFR_RNDN,"-1.40986728425098585229e-05");
  check2("9.99986053947420794330e-01",MPFR_RNDN, "-0.000013946149826301084938555592540598837558718514628708362579345703125");
  check2("9.99971938247442126979e-01",MPFR_RNDN,"-2.80621462962173414790e-05");

  /* other bugs found by Vincent Lefe`vre */
  check2("1.18615436389927785905e+77",MPFR_RNDN,"1.77469768607706015473e+02");
  check2("9.48868723578399476187e+77",MPFR_RNDZ,"1.79549152432275803903e+02");
  check2("2.31822210096938820854e+89",MPFR_RNDN,"2.05770873832573869322e+02");

  /* further bugs found by Vincent Lefe`vre */
  check2("9.99999989485669482647e-01",MPFR_RNDZ,"-1.05143305726283042331e-08");
  check2("9.99999989237970177136e-01",MPFR_RNDZ,"-1.07620298807745377934e-08");
  check2("9.99999989239339082125e-01",MPFR_RNDN,"-1.07606609757704445430e-08");

  check2("7.3890560989306504",MPFR_RNDU,"2.0000000000000004"); /* exp(2.0) */
  check2("7.3890560989306495",MPFR_RNDU,"2.0"); /* exp(2.0) */
  check2("7.53428236571286402512e+34",MPFR_RNDZ,"8.03073567492226345621e+01");
  check2("6.18784121531737948160e+19",MPFR_RNDZ,"4.55717030391710693493e+01");
  check2("1.02560267603047283735e+00",MPFR_RNDD,"2.52804164149448735987e-02");
  check2("7.53428236571286402512e+34",MPFR_RNDZ,"8.03073567492226345621e+01");
  check2("1.42470900831881198052e+49",MPFR_RNDZ,"113.180637144887668910087086260318756103515625");

  check2("1.08013816255293777466e+11",MPFR_RNDN,"2.54055249841782604392e+01");
  check2("6.72783635300509015581e-37",MPFR_RNDU,"-8.32893948416799503320e+01");
  check2("2.25904918906057891180e-52",MPFR_RNDU,"-1.18919480823735682406e+02");
  check2("1.48901209246462951085e+00",MPFR_RNDD,"3.98112874867437460668e-01");
  check2("1.70322470467612341327e-01",MPFR_RNDN,"-1.77006175364294615626");
  check2("1.94572026316065240791e+01",MPFR_RNDD,"2.96821731676437838842");
  check2("4.01419512207026418764e+04",MPFR_RNDD,"1.06001772315501128218e+01");
  check2("9.47077365236487591672e-04",MPFR_RNDZ,"-6.96212977303956748187e+00");
  check2("3.95906157687589643802e-109",MPFR_RNDD,"-2.49605768114704119399e+02");
  check2("2.73874914516503004113e-02",MPFR_RNDD,"-3.59766888618655977794e+00");
  check2("9.18989072589566467669e-17",MPFR_RNDZ,"-3.69258425351464083519e+01");
  check2("7706036453608191045959753324430048151991964994788917248.0",MPFR_RNDZ,"126.3815989984199177342816255986690521240234375");
  check2("1.74827399630587801934e-23",MPFR_RNDZ,"-5.24008281254547156891e+01");
  check2("4.35302958401482307665e+22",MPFR_RNDD,"5.21277441046519527390e+01");
  check2("9.70791868689332915209e+00",MPFR_RNDD,"2.27294191194272210410e+00");
  check2("2.22183639799464011100e-01",MPFR_RNDN,"-1.50425103275253957413e+00");
  check2("2.27313466156682375540e+00",MPFR_RNDD,"8.21159787095675608448e-01");
  check2("6.58057413965851156767e-01",MPFR_RNDZ,"-4.18463096196088235600e-01");
  check2 ("7.34302197248998461006e+43",MPFR_RNDZ,"101.0049094695131799426235374994575977325439453125");
  check2("6.09969788341579732815e+00",MPFR_RNDD,"1.80823924264386204363e+00");

  x_near_one ();

  test_generic (2, 100, 40);

  data_check ("data/log", mpfr_log, "mpfr_log");
  bad_cases (mpfr_log, mpfr_exp, "mpfr_log", 256, -30, 30, 4, 128, 800, 50);

 done:
  tests_end_mpfr ();
  return 0;
}