/* sys/test.c * * Copyright (C) 1996, 1997, 1998, 1999, 2000, 2007 Brian Gough * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 3 of the License, or (at * your option) any later version. * * This program 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 * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ #include #include #include #include #include #include int main (void) { double y, y_expected; int e, e_expected; gsl_ieee_env_setup (); /* Test for expm1 */ y = gsl_expm1 (0.0); y_expected = 0.0; gsl_test_rel (y, y_expected, 1e-15, "gsl_expm1(0.0)"); y = gsl_expm1 (1e-10); y_expected = 1.000000000050000000002e-10; gsl_test_rel (y, y_expected, 1e-15, "gsl_expm1(1e-10)"); y = gsl_expm1 (-1e-10); y_expected = -9.999999999500000000017e-11; gsl_test_rel (y, y_expected, 1e-15, "gsl_expm1(-1e-10)"); y = gsl_expm1 (0.1); y_expected = 0.1051709180756476248117078264902; gsl_test_rel (y, y_expected, 1e-15, "gsl_expm1(0.1)"); y = gsl_expm1 (-0.1); y_expected = -0.09516258196404042683575094055356; gsl_test_rel (y, y_expected, 1e-15, "gsl_expm1(-0.1)"); y = gsl_expm1 (10.0); y_expected = 22025.465794806716516957900645284; gsl_test_rel (y, y_expected, 1e-15, "gsl_expm1(10.0)"); y = gsl_expm1 (-10.0); y_expected = -0.99995460007023751514846440848444; gsl_test_rel (y, y_expected, 1e-15, "gsl_expm1(-10.0)"); /* Test for log1p */ y = gsl_log1p (0.0); y_expected = 0.0; gsl_test_rel (y, y_expected, 1e-15, "gsl_log1p(0.0)"); y = gsl_log1p (1e-10); y_expected = 9.9999999995000000000333333333308e-11; gsl_test_rel (y, y_expected, 1e-15, "gsl_log1p(1e-10)"); y = gsl_log1p (0.1); y_expected = 0.095310179804324860043952123280765; gsl_test_rel (y, y_expected, 1e-15, "gsl_log1p(0.1)"); y = gsl_log1p (10.0); y_expected = 2.3978952727983705440619435779651; gsl_test_rel (y, y_expected, 1e-15, "gsl_log1p(10.0)"); /* Test for gsl_hypot */ y = gsl_hypot (0.0, 0.0); y_expected = 0.0; gsl_test_rel (y, y_expected, 1e-15, "gsl_hypot(0.0, 0.0)"); y = gsl_hypot (1e-10, 1e-10); y_expected = 1.414213562373095048801688e-10; gsl_test_rel (y, y_expected, 1e-15, "gsl_hypot(1e-10, 1e-10)"); y = gsl_hypot (1e-38, 1e-38); y_expected = 1.414213562373095048801688e-38; gsl_test_rel (y, y_expected, 1e-15, "gsl_hypot(1e-38, 1e-38)"); y = gsl_hypot (1e-10, -1.0); y_expected = 1.000000000000000000005; gsl_test_rel (y, y_expected, 1e-15, "gsl_hypot(1e-10, -1)"); y = gsl_hypot (-1.0, 1e-10); y_expected = 1.000000000000000000005; gsl_test_rel (y, y_expected, 1e-15, "gsl_hypot(-1, 1e-10)"); y = gsl_hypot (1e307, 1e301); y_expected = 1.000000000000499999999999e307; gsl_test_rel (y, y_expected, 1e-15, "gsl_hypot(1e307, 1e301)"); y = gsl_hypot (1e301, 1e307); y_expected = 1.000000000000499999999999e307; gsl_test_rel (y, y_expected, 1e-15, "gsl_hypot(1e301, 1e307)"); y = gsl_hypot (1e307, 1e307); y_expected = 1.414213562373095048801688e307; gsl_test_rel (y, y_expected, 1e-15, "gsl_hypot(1e307, 1e307)"); /* Test +-Inf, finite */ y = gsl_hypot (GSL_POSINF, 1.2); y_expected = GSL_POSINF; gsl_test_rel (y, y_expected, 1e-15, "gsl_hypot(GSL_POSINF, 1.2)"); y = gsl_hypot (GSL_NEGINF, 1.2); y_expected = GSL_POSINF; gsl_test_rel (y, y_expected, 1e-15, "gsl_hypot(GSL_NEGINF, 1.2)"); y = gsl_hypot (1.2, GSL_POSINF); y_expected = GSL_POSINF; gsl_test_rel (y, y_expected, 1e-15, "gsl_hypot(1.2, GSL_POSINF)"); y = gsl_hypot (1.2, GSL_NEGINF); y_expected = GSL_POSINF; gsl_test_rel (y, y_expected, 1e-15, "gsl_hypot(1.2, GSL_NEGINF)"); /* Test NaN, finite */ y = gsl_hypot (GSL_NAN, 1.2); y_expected = GSL_NAN; gsl_test_rel (y, y_expected, 1e-15, "gsl_hypot(GSL_NAN, 1.2)"); y = gsl_hypot (1.2, GSL_NAN); y_expected = GSL_NAN; gsl_test_rel (y, y_expected, 1e-15, "gsl_hypot(1.2, GSL_NAN)"); /* Test NaN, NaN */ y = gsl_hypot (GSL_NAN, GSL_NAN); y_expected = GSL_NAN; gsl_test_rel (y, y_expected, 1e-15, "gsl_hypot(GSL_NAN, GSL_NAN)"); /* Test +Inf, NaN */ y = gsl_hypot (GSL_POSINF, GSL_NAN); y_expected = GSL_POSINF; gsl_test_rel (y, y_expected, 1e-15, "gsl_hypot(GSL_POSINF, GSL_NAN)"); /* Test -Inf, NaN */ y = gsl_hypot (GSL_NEGINF, GSL_NAN); y_expected = GSL_POSINF; gsl_test_rel (y, y_expected, 1e-15, "gsl_hypot(GSL_NEGINF, GSL_NAN)"); /* Test NaN, +Inf */ y = gsl_hypot (GSL_NAN, GSL_POSINF); y_expected = GSL_POSINF; gsl_test_rel (y, y_expected, 1e-15, "gsl_hypot(GSL_NAN, GSL_POSINF)"); /* Test NaN, -Inf */ y = gsl_hypot (GSL_NAN, GSL_NEGINF); y_expected = GSL_POSINF; gsl_test_rel (y, y_expected, 1e-15, "gsl_hypot(GSL_NAN, GSL_NEGINF)"); /* Test for gsl_hypot3 */ y = gsl_hypot3 (0.0, 0.0, 0.0); y_expected = 0.0; gsl_test_rel (y, y_expected, 1e-15, "gsl_hypot3(0.0, 0.0, 0.0)"); y = gsl_hypot3 (1e-10, 1e-10, 1e-10); y_expected = 1.732050807568877293527446e-10; gsl_test_rel (y, y_expected, 1e-15, "gsl_hypot3(1e-10, 1e-10, 1e-10)"); y = gsl_hypot3 (1e-38, 1e-38, 1e-38); y_expected = 1.732050807568877293527446e-38; gsl_test_rel (y, y_expected, 1e-15, "gsl_hypot3(1e-38, 1e-38, 1e-38)"); y = gsl_hypot3 (1e-10, 1e-10, -1.0); y_expected = 1.000000000000000000099; gsl_test_rel (y, y_expected, 1e-15, "gsl_hypot3(1e-10, 1e-10, -1)"); y = gsl_hypot3 (1e-10, -1.0, 1e-10); y_expected = 1.000000000000000000099; gsl_test_rel (y, y_expected, 1e-15, "gsl_hypot3(1e-10, -1, 1e-10)"); y = gsl_hypot3 (-1.0, 1e-10, 1e-10); y_expected = 1.000000000000000000099; gsl_test_rel (y, y_expected, 1e-15, "gsl_hypot3(-1, 1e-10, 1e-10)"); y = gsl_hypot3 (1e307, 1e301, 1e301); y_expected = 1.0000000000009999999999995e307; gsl_test_rel (y, y_expected, 1e-15, "gsl_hypot3(1e307, 1e301, 1e301)"); y = gsl_hypot3 (1e307, 1e307, 1e307); y_expected = 1.732050807568877293527446e307; gsl_test_rel (y, y_expected, 1e-15, "gsl_hypot3(1e307, 1e307, 1e307)"); y = gsl_hypot3 (1e307, 1e-307, 1e-307); y_expected = 1.0e307; gsl_test_rel (y, y_expected, 1e-15, "gsl_hypot3(1e307, 1e-307, 1e-307)"); /* Test for acosh */ y = gsl_acosh (1.0); y_expected = 0.0; gsl_test_rel (y, y_expected, 1e-15, "gsl_acosh(1.0)"); y = gsl_acosh (1.1); y_expected = 4.435682543851151891329110663525e-1; gsl_test_rel (y, y_expected, 1e-15, "gsl_acosh(1.1)"); y = gsl_acosh (10.0); y_expected = 2.9932228461263808979126677137742e0; gsl_test_rel (y, y_expected, 1e-15, "gsl_acosh(10.0)"); y = gsl_acosh (1e10); y_expected = 2.3718998110500402149594646668302e1; gsl_test_rel (y, y_expected, 1e-15, "gsl_acosh(1e10)"); /* Test for asinh */ y = gsl_asinh (0.0); y_expected = 0.0; gsl_test_rel (y, y_expected, 1e-15, "gsl_asinh(0.0)"); y = gsl_asinh (1e-10); y_expected = 9.9999999999999999999833333333346e-11; gsl_test_rel (y, y_expected, 1e-15, "gsl_asinh(1e-10)"); y = gsl_asinh (-1e-10); y_expected = -9.9999999999999999999833333333346e-11; gsl_test_rel (y, y_expected, 1e-15, "gsl_asinh(1e-10)"); y = gsl_asinh (0.1); y_expected = 9.983407889920756332730312470477e-2; gsl_test_rel (y, y_expected, 1e-15, "gsl_asinh(0.1)"); y = gsl_asinh (-0.1); y_expected = -9.983407889920756332730312470477e-2; gsl_test_rel (y, y_expected, 1e-15, "gsl_asinh(-0.1)"); y = gsl_asinh (1.0); y_expected = 8.8137358701954302523260932497979e-1; gsl_test_rel (y, y_expected, 1e-15, "gsl_asinh(1.0)"); y = gsl_asinh (-1.0); y_expected = -8.8137358701954302523260932497979e-1; gsl_test_rel (y, y_expected, 1e-15, "gsl_asinh(-1.0)"); y = gsl_asinh (10.0); y_expected = 2.9982229502979697388465955375965e0; gsl_test_rel (y, y_expected, 1e-15, "gsl_asinh(10)"); y = gsl_asinh (-10.0); y_expected = -2.9982229502979697388465955375965e0; gsl_test_rel (y, y_expected, 1e-15, "gsl_asinh(-10)"); y = gsl_asinh (1e10); y_expected = 2.3718998110500402149599646668302e1; gsl_test_rel (y, y_expected, 1e-15, "gsl_asinh(1e10)"); y = gsl_asinh (-1e10); y_expected = -2.3718998110500402149599646668302e1; gsl_test_rel (y, y_expected, 1e-15, "gsl_asinh(-1e10)"); /* Test for atanh */ y = gsl_atanh (0.0); y_expected = 0.0; gsl_test_rel (y, y_expected, 1e-15, "gsl_atanh(0.0)"); y = gsl_atanh (1e-20); y_expected = 1e-20; gsl_test_rel (y, y_expected, 1e-15, "gsl_atanh(1e-20)"); y = gsl_atanh (-1e-20); y_expected = -1e-20; gsl_test_rel (y, y_expected, 1e-15, "gsl_atanh(-1e-20)"); y = gsl_atanh (0.1); y_expected = 1.0033534773107558063572655206004e-1; gsl_test_rel (y, y_expected, 1e-15, "gsl_atanh(0.1)"); y = gsl_atanh (-0.1); y_expected = -1.0033534773107558063572655206004e-1; gsl_test_rel (y, y_expected, 1e-15, "gsl_atanh(-0.1)"); y = gsl_atanh (0.9); y_expected = 1.4722194895832202300045137159439e0; gsl_test_rel (y, y_expected, 1e-15, "gsl_atanh(0.9)"); y = gsl_atanh (-0.9); y_expected = -1.4722194895832202300045137159439e0; gsl_test_rel (y, y_expected, 1e-15, "gsl_atanh(0.9)"); /* Test for pow_int */ y = gsl_pow_2 (-3.14); y_expected = pow (-3.14, 2.0); gsl_test_rel (y, y_expected, 1e-15, "gsl_pow_2(-3.14)"); y = gsl_pow_3 (-3.14); y_expected = pow (-3.14, 3.0); gsl_test_rel (y, y_expected, 1e-15, "gsl_pow_3(-3.14)"); y = gsl_pow_4 (-3.14); y_expected = pow (-3.14, 4.0); gsl_test_rel (y, y_expected, 1e-15, "gsl_pow_4(-3.14)"); y = gsl_pow_5 (-3.14); y_expected = pow (-3.14, 5.0); gsl_test_rel (y, y_expected, 1e-15, "gsl_pow_5(-3.14)"); y = gsl_pow_6 (-3.14); y_expected = pow (-3.14, 6.0); gsl_test_rel (y, y_expected, 1e-15, "gsl_pow_6(-3.14)"); y = gsl_pow_7 (-3.14); y_expected = pow (-3.14, 7.0); gsl_test_rel (y, y_expected, 1e-15, "gsl_pow_7(-3.14)"); y = gsl_pow_8 (-3.14); y_expected = pow (-3.14, 8.0); gsl_test_rel (y, y_expected, 1e-15, "gsl_pow_8(-3.14)"); y = gsl_pow_9 (-3.14); y_expected = pow (-3.14, 9.0); gsl_test_rel (y, y_expected, 1e-15, "gsl_pow_9(-3.14)"); { int n; for (n = -9; n < 10; n++) { y = gsl_pow_int (-3.14, n); y_expected = pow (-3.14, n); gsl_test_rel (y, y_expected, 1e-15, "gsl_pow_int(-3.14,%d)", n); } } { unsigned int n; for (n = 0; n < 10; n++) { y = gsl_pow_uint (-3.14, n); y_expected = pow (-3.14, n); gsl_test_rel (y, y_expected, 1e-15, "gsl_pow_uint(-3.14,%d)", n); } } /* Test case for n at INT_MAX, INT_MIN */ { double u = 1.0000001; int n = INT_MAX; y = gsl_pow_int (u, n); y_expected = pow (u, n); gsl_test_rel (y, y_expected, 1e-6, "gsl_pow_int(%.7f,%d)", u, n); n = INT_MIN; y = gsl_pow_int (u, n); y_expected = pow (u, n); gsl_test_rel (y, y_expected, 1e-6, "gsl_pow_int(%.7f,%d)", u, n); } /* Test for ldexp */ y = gsl_ldexp (M_PI, -2); y_expected = M_PI_4; gsl_test_rel (y, y_expected, 1e-15, "gsl_ldexp(pi,-2)"); 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; x /= 2; while (x > 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); x /= 2; } } /* 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; x /= 2; while (x > 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); x /= 2; } } /* 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) != 0; 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 ()); }