test.c

来自「math library from gnu」· C语言 代码 · 共 594 行 · 第 1/2 页

  y = gsl_ldexp (1.0, 2);
  y_expected = 4.000000;
  gsl_test_rel (y, y_expected, 1e-15, "gsl_ldexp(1.0,2)");

  y = gsl_ldexp (0.0, 2);
  y_expected = 0.0;
  gsl_test_rel (y, y_expected, 1e-15, "gsl_ldexp(0.0,2)");

  y = gsl_ldexp (9.999999999999998890e-01, 1024);
  y_expected = GSL_DBL_MAX;
  gsl_test_rel (y, y_expected, 1e-15, "gsl_ldexp DBL_MAX");

  y = gsl_ldexp (1e308, -2000);
  y_expected = 8.7098098162172166755761e-295;
  gsl_test_rel (y, y_expected, 1e-15, "gsl_ldexp(1e308,-2000)");

  y = gsl_ldexp (GSL_DBL_MIN, 2000);
  y_expected = 2.554675596204441378334779940e294;
  gsl_test_rel (y, y_expected, 1e-15, "gsl_ldexp(DBL_MIN,2000)");

  /* Test subnormals */

  {
    int i = 0;
    volatile double x = GSL_DBL_MIN;
    y_expected = 2.554675596204441378334779940e294;
    
    while ((x /= 2) > 0)
      {
        i++ ;
        y = gsl_ldexp (x, 2000 + i);
        gsl_test_rel (y, y_expected, 1e-15, "gsl_ldexp(DBL_MIN/2**%d,%d)",i,2000+i);
      }
  }


  /* Test for frexp */

  y = gsl_frexp (0.0, &e);
  y_expected = 0;
  e_expected = 0;
  gsl_test_rel (y, y_expected, 1e-15, "gsl_frexp(0) fraction");
  gsl_test_int (e, e_expected, "gsl_frexp(0) exponent");

  y = gsl_frexp (M_PI, &e);
  y_expected = M_PI_4;
  e_expected = 2;
  gsl_test_rel (y, y_expected, 1e-15, "gsl_frexp(pi) fraction");
  gsl_test_int (e, e_expected, "gsl_frexp(pi) exponent");

  y = gsl_frexp (2.0, &e);
  y_expected = 0.5;
  e_expected = 2;
  gsl_test_rel (y, y_expected, 1e-15, "gsl_frexp(2.0) fraction");
  gsl_test_int (e, e_expected, "gsl_frexp(2.0) exponent");

  y = gsl_frexp (1.0 / 4.0, &e);
  y_expected = 0.5;
  e_expected = -1;
  gsl_test_rel (y, y_expected, 1e-15, "gsl_frexp(0.25) fraction");
  gsl_test_int (e, e_expected, "gsl_frexp(0.25) exponent");

  y = gsl_frexp (1.0 / 4.0 - 4.0 * GSL_DBL_EPSILON, &e);
  y_expected = 0.999999999999996447;
  e_expected = -2;
  gsl_test_rel (y, y_expected, 1e-15, "gsl_frexp(0.25-eps) fraction");
  gsl_test_int (e, e_expected, "gsl_frexp(0.25-eps) exponent");

  y = gsl_frexp (GSL_DBL_MAX, &e);
  y_expected = 9.999999999999998890e-01;
  e_expected = 1024;
  gsl_test_rel (y, y_expected, 1e-15, "gsl_frexp(DBL_MAX) fraction");
  gsl_test_int (e, e_expected, "gsl_frexp(DBL_MAX) exponent");

  y = gsl_frexp (-GSL_DBL_MAX, &e);
  y_expected = -9.999999999999998890e-01;
  e_expected = 1024;
  gsl_test_rel (y, y_expected, 1e-15, "gsl_frexp(-DBL_MAX) fraction");
  gsl_test_int (e, e_expected, "gsl_frexp(-DBL_MAX) exponent");

  y = gsl_frexp (GSL_DBL_MIN, &e);
  y_expected = 0.5;
  e_expected = -1021;
  gsl_test_rel (y, y_expected, 1e-15, "gsl_frexp(DBL_MIN) fraction");
  gsl_test_int (e, e_expected, "gsl_frexp(DBL_MIN) exponent");

  y = gsl_frexp (-GSL_DBL_MIN, &e);
  y_expected = -0.5;
  e_expected = -1021;
  gsl_test_rel (y, y_expected, 1e-15, "gsl_frexp(-DBL_MIN) fraction");
  gsl_test_int (e, e_expected, "gsl_frexp(-DBL_MIN) exponent");

  /* Test subnormals */

  {
    int i = 0;
    volatile double x = GSL_DBL_MIN;
    y_expected = 0.5;
    e_expected = -1021;
    
    while ((x /= 2) > 0)
      {
        e_expected--;
        i++ ;
        
        y = gsl_frexp (x, &e);
        gsl_test_rel (y, y_expected, 1e-15, "gsl_frexp(DBL_MIN/2**%d) fraction",i);
        gsl_test_int (e, e_expected, "gsl_frexp(DBL_MIN/2**%d) exponent", i);
      }
  }


  /* Test for approximate floating point comparison */
  {
    double x, y;
    int i;

    x = M_PI;
    y = 22.0 / 7.0;

    /* test the basic function */

    for (i = 0; i < 10; i++)
      {
        double tol = pow (10, -i);
        int res = gsl_fcmp (x, y, tol);
        gsl_test_int (res, -(i >= 4), "gsl_fcmp(%.5f,%.5f,%g)", x, y, tol);
      }

    for (i = 0; i < 10; i++)
      {
        double tol = pow (10, -i);
        int res = gsl_fcmp (y, x, tol);
        gsl_test_int (res, (i >= 4), "gsl_fcmp(%.5f,%.5f,%g)", y, x, tol);
      }
  }
    

#if HAVE_IEEE_COMPARISONS
  /* Test for isinf, isnan, finite */

  {
    double zero, one, inf, nan;
    int s;

    zero = 0.0;
    one = 1.0;
    inf = exp (1.0e10);
    nan = inf / inf;

    s = gsl_isinf (zero);
    gsl_test_int (s, 0, "gsl_isinf(0)");

    s = gsl_isinf (one);
    gsl_test_int (s, 0, "gsl_isinf(1)");

    s = gsl_isinf (inf);
    gsl_test_int (s, 1, "gsl_isinf(inf)");

    s = gsl_isinf (-inf);  
    gsl_test_int (s, -1, "gsl_isinf(-inf)");

    s = gsl_isinf (nan);
    gsl_test_int (s, 0, "gsl_isinf(nan)");


    s = gsl_isnan (zero);
    gsl_test_int (s, 0, "gsl_isnan(0)");

    s = gsl_isnan (one);
    gsl_test_int (s, 0, "gsl_isnan(1)");

    s = gsl_isnan (inf);
    gsl_test_int (s, 0, "gsl_isnan(inf)");

    s = gsl_isnan (-inf);
    gsl_test_int (s, 0, "gsl_isnan(-inf)");

    s = gsl_isnan (nan);
    gsl_test_int (s, 1, "gsl_isnan(nan)");


    s = gsl_finite (zero);
    gsl_test_int (s, 1, "gsl_finite(0)");

    s = gsl_finite (one);
    gsl_test_int (s, 1, "gsl_finite(1)");

    s = gsl_finite (inf);
    gsl_test_int (s, 0, "gsl_finite(inf)");

    s = gsl_finite (-inf);
    gsl_test_int (s, 0, "gsl_finite(-inf)");

    s = gsl_finite (nan);
    gsl_test_int (s, 0, "gsl_finite(nan)");
  }
#endif


  {
    double x = gsl_fdiv (2.0, 3.0);
    gsl_test_rel (x, 2.0 / 3.0, 4 * GSL_DBL_EPSILON, "gsl_fdiv(2,3)");
  }


  /* Test constants in gsl_math.h */

  {
    double x = log(M_E);
    gsl_test_rel (x, 1.0, 4 * GSL_DBL_EPSILON, "ln(M_E)");
  }
  
  {
    double x=pow(2.0,M_LOG2E);
    gsl_test_rel (x, exp(1.0), 4 * GSL_DBL_EPSILON, "2^M_LOG2E");
  }
 
  {
    double x=pow(10.0,M_LOG10E);
    gsl_test_rel (x, exp(1.0), 4 * GSL_DBL_EPSILON, "10^M_LOG10E");
  }

  {
    double x=pow(M_SQRT2, 2.0);
    gsl_test_rel (x, 2.0, 4 * GSL_DBL_EPSILON, "M_SQRT2^2");
  }    

  {
    double x=pow(M_SQRT1_2, 2.0);
    gsl_test_rel (x, 1.0/2.0, 4 * GSL_DBL_EPSILON, "M_SQRT1_2");
  }    

  {
    double x=pow(M_SQRT3, 2.0);
    gsl_test_rel (x, 3.0, 4 * GSL_DBL_EPSILON, "M_SQRT3^2");
  }    

  {
    double x = M_PI;
    gsl_test_rel (x, 3.1415926535897932384626433832795, 4 * GSL_DBL_EPSILON, "M_PI");
  }    

  {
    double x = 2 * M_PI_2;
    gsl_test_rel (x, M_PI, 4 * GSL_DBL_EPSILON, "2*M_PI_2");
  }    

  {
    double x = 4 * M_PI_4;
    gsl_test_rel (x, M_PI, 4 * GSL_DBL_EPSILON, "4*M_PI_4");
  }    

  {
    double x = pow(M_SQRTPI, 2.0);
    gsl_test_rel (x, M_PI, 4 * GSL_DBL_EPSILON, "M_SQRTPI^2");
  }    

  {
    double x = pow(M_2_SQRTPI, 2.0);
    gsl_test_rel (x, 4/M_PI, 4 * GSL_DBL_EPSILON, "M_SQRTPI^2");
  }    

  {
    double x = M_1_PI;
    gsl_test_rel (x, 1/M_PI, 4 * GSL_DBL_EPSILON, "M_1_SQRTPI");
  }    

  {
    double x = M_2_PI;
    gsl_test_rel (x, 2.0/M_PI, 4 * GSL_DBL_EPSILON, "M_2_PI");
  }    

  {
    double x = exp(M_LN10);
    gsl_test_rel (x, 10, 4 * GSL_DBL_EPSILON, "exp(M_LN10)");
  }    

  {
    double x = exp(M_LN2);
    gsl_test_rel (x, 2, 4 * GSL_DBL_EPSILON, "exp(M_LN2)");
  }    

  {
    double x = exp(M_LNPI);
    gsl_test_rel (x, M_PI, 4 * GSL_DBL_EPSILON, "exp(M_LNPI)");
  }    

  {
    double x = M_EULER;
    gsl_test_rel (x, 0.5772156649015328606065120900824, 4 * GSL_DBL_EPSILON, "M_EULER");
  }    

  exit (gsl_test_summary ());
}