1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
|
// Copyright John Maddock 2008
// (C) Copyright Paul A. Bristow 2011 (added tests for changesign)
// Copyright Matt Borland 2024
// Use, modification and distribution are subject to the
// Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt
// or copy at http://www.boost.org/LICENSE_1_0.txt)
#include <boost/math/concepts/real_concept.hpp> // for real_concept
#include <boost/math/special_functions/sign.hpp>
#define BOOST_TEST_MAIN
#include <boost/test/unit_test.hpp> // Boost.Test
#include <boost/test/results_collector.hpp>
#include <boost/test/unit_test.hpp>
#include <boost/test/tools/floating_point_comparison.hpp>
#include <iostream>
using std::cout;
using std::endl;
using std::setprecision;
template <class RealType>
void test_spots(RealType /*T*/, const char* /*type_name*/)
{
// Basic sanity checks.
RealType a = 0;
RealType b = 1;
RealType c = -1;
BOOST_CHECK_EQUAL((boost::math::signbit)(a), 0);
BOOST_CHECK_EQUAL((boost::math::sign)(a), 0);
BOOST_CHECK_EQUAL((boost::math::changesign)(b), RealType(-1));
BOOST_CHECK_EQUAL((boost::math::changesign)(c), RealType(+1));
BOOST_CHECK_EQUAL((boost::math::changesign)(a), RealType(0));
// Compare to formula for changsign(x) = copysign(x, signbit(x) ? 1.0 : -1.0)
BOOST_CHECK_EQUAL((boost::math::changesign)(b),
(boost::math::copysign)(b, (boost::math::signbit)(b) ? RealType(1.) : RealType(-1.) ));
BOOST_CHECK_EQUAL((boost::math::copysign)(b, a), RealType(1));
BOOST_CHECK_EQUAL((boost::math::copysign)(c, a), RealType(1));
a = 1;
BOOST_CHECK_EQUAL((boost::math::signbit)(a), 0);
BOOST_CHECK_EQUAL((boost::math::sign)(a), 1);
BOOST_CHECK_EQUAL((boost::math::copysign)(b, a), RealType(1));
BOOST_CHECK_EQUAL((boost::math::copysign)(c, a), RealType(1));
a = -1;
BOOST_CHECK((boost::math::signbit)(a) != 0);
BOOST_CHECK_EQUAL((boost::math::sign)(a), -1);
BOOST_CHECK_EQUAL((boost::math::copysign)(b, a), RealType(-1));
BOOST_CHECK_EQUAL((boost::math::copysign)(c, a), RealType(-1));
a = boost::math::tools::max_value<RealType>();
BOOST_CHECK_EQUAL((boost::math::signbit)(a), 0);
BOOST_CHECK_EQUAL((boost::math::sign)(a), 1);
BOOST_CHECK_EQUAL((boost::math::copysign)(b, a), RealType(1));
BOOST_CHECK_EQUAL((boost::math::copysign)(c, a), RealType(1));
a = -boost::math::tools::max_value<RealType>();
BOOST_CHECK((boost::math::signbit)(a) != 0);
BOOST_CHECK_EQUAL((boost::math::sign)(a), -1);
BOOST_CHECK_EQUAL((boost::math::copysign)(b, a), RealType(-1));
BOOST_CHECK_EQUAL((boost::math::copysign)(c, a), RealType(-1));
if(std::numeric_limits<RealType>::has_infinity)
{
a = std::numeric_limits<RealType>::infinity();
BOOST_CHECK_EQUAL((boost::math::signbit)(a), 0);
BOOST_CHECK_EQUAL((boost::math::sign)(a), 1);
BOOST_CHECK_EQUAL((boost::math::copysign)(b, a), RealType(1));
BOOST_CHECK_EQUAL((boost::math::copysign)(c, a), RealType(1));
BOOST_CHECK_EQUAL((boost::math::changesign)(a), -a);
a = -std::numeric_limits<RealType>::infinity();
BOOST_CHECK((boost::math::signbit)(a) != 0);
BOOST_CHECK_EQUAL((boost::math::sign)(a), -1);
BOOST_CHECK_EQUAL((boost::math::copysign)(b, a), RealType(-1));
BOOST_CHECK_EQUAL((boost::math::copysign)(c, a), RealType(-1));
BOOST_CHECK_EQUAL((boost::math::changesign)(a), -a);
}
#if !defined(__SUNPRO_CC) && !defined(__INTEL_COMPILER)
if(std::numeric_limits<RealType>::has_quiet_NaN)
{
a = std::numeric_limits<RealType>::quiet_NaN();
BOOST_CHECK_EQUAL((boost::math::signbit)(a), 0);
BOOST_CHECK_EQUAL((boost::math::sign)(a), 1);
BOOST_CHECK_EQUAL((boost::math::copysign)(b, a), RealType(1));
BOOST_CHECK_EQUAL((boost::math::copysign)(c, a), RealType(1));
// BOOST_CHECK_EQUAL((boost::math::changesign)(a), -a); // NaN comparison fails always!
BOOST_CHECK((boost::math::signbit)((boost::math::changesign)(a)) != 0);
a = -std::numeric_limits<RealType>::quiet_NaN();
BOOST_CHECK((boost::math::signbit)(a) != 0);
BOOST_CHECK_EQUAL((boost::math::sign)(a), -1);
BOOST_CHECK_EQUAL((boost::math::copysign)(b, a), RealType(-1));
BOOST_CHECK_EQUAL((boost::math::copysign)(c, a), RealType(-1));
//BOOST_CHECK_EQUAL((boost::math::changesign)(a), -a); // NaN comparison fails always!
BOOST_CHECK_EQUAL((boost::math::signbit)((boost::math::changesign)(a)), 0);
}
#endif
//
// Try some extreme values:
//
a = boost::math::tools::min_value<RealType>();
b = -a;
c = -1;
BOOST_CHECK((boost::math::signbit)(a) == 0);
BOOST_CHECK_EQUAL((boost::math::sign)(a), 1);
BOOST_CHECK_EQUAL((boost::math::copysign)(c, a), RealType(1));
BOOST_CHECK((boost::math::signbit)(b) != 0);
BOOST_CHECK_EQUAL((boost::math::sign)(b), -1);
c = 1;
BOOST_CHECK_EQUAL((boost::math::copysign)(c, b), RealType(-1));
//
// try denormalised values:
//
a /= 4;
if(a != 0)
{
b = -a;
c = -1;
BOOST_CHECK((boost::math::signbit)(a) == 0);
BOOST_CHECK_EQUAL((boost::math::sign)(a), 1);
BOOST_CHECK_EQUAL((boost::math::copysign)(c, a), RealType(1));
BOOST_CHECK((boost::math::signbit)(b) != 0);
BOOST_CHECK_EQUAL((boost::math::sign)(b), -1);
c = 1;
BOOST_CHECK_EQUAL((boost::math::copysign)(c, b), RealType(-1));
}
a = boost::math::tools::max_value<RealType>() / 2;
b = -a;
c = -1;
BOOST_CHECK((boost::math::signbit)(a) == 0);
BOOST_CHECK_EQUAL((boost::math::sign)(a), 1);
BOOST_CHECK_EQUAL((boost::math::copysign)(c, a), RealType(1));
BOOST_CHECK((boost::math::signbit)(b) != 0);
BOOST_CHECK_EQUAL((boost::math::sign)(b), -1);
c = 1;
BOOST_CHECK_EQUAL((boost::math::copysign)(c, b), RealType(-1));
}
BOOST_AUTO_TEST_CASE( test_main )
{
// Basic sanity-check spot values.
// (Parameter value, arbitrarily zero, only communicates the floating point type).
test_spots(0.0F, "float"); // Test float. OK at decdigits = 0 tolerance = 0.0001 %
test_spots(0.0, "double"); // Test double. OK at decdigits 7, tolerance = 1e07 %
// long double support for the sign functions is considered "core" so we always test it
// even when long double support is turned off via BOOST_MATH_NO_LONG_DOUBLE_MATH_FUNCTIONS
#ifndef BOOST_MATH_NO_LONG_DOUBLE_MATH_FUNCTIONS
test_spots(0.0L, "long double"); // Test long double.
#endif
#ifndef BOOST_MATH_NO_REAL_CONCEPT_TESTS
test_spots(boost::math::concepts::real_concept(0), "real_concept"); // Test real_concept.
#endif
} // BOOST_AUTO_TEST_CASE( test_main )
|
