1 | // unit test file atanh.hpp for the special functions test suite |
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2 | |
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3 | // (C) Copyright Hubert Holin 2003. |
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4 | // Distributed under the Boost Software License, Version 1.0. (See |
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5 | // accompanying file LICENSE_1_0.txt or copy at |
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6 | // http://www.boost.org/LICENSE_1_0.txt) |
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7 | |
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8 | |
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9 | #include <functional> |
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10 | #include <iomanip> |
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11 | //#include <iostream> |
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12 | |
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13 | |
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14 | #include <boost/math/special_functions/atanh.hpp> |
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15 | |
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16 | |
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17 | #include <boost/test/unit_test.hpp> |
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18 | #include <boost/test/test_case_template.hpp> |
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19 | |
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20 | template<typename T> |
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21 | T atanh_error_evaluator(T x) |
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22 | { |
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23 | using ::std::abs; |
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24 | using ::std::tanh; |
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25 | using ::std::cosh; |
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26 | |
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27 | using ::std::numeric_limits; |
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28 | |
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29 | using ::boost::math::atanh; |
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30 | |
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31 | |
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32 | static T const epsilon = numeric_limits<float>::epsilon(); |
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33 | |
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34 | T y = tanh(x); |
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35 | T z = atanh(y); |
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36 | |
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37 | T absolute_error = abs(z-x); |
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38 | T relative_error = absolute_error/(cosh(x)*cosh(x)); |
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39 | T scaled_error = relative_error/epsilon; |
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40 | |
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41 | return(scaled_error); |
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42 | } |
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43 | |
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44 | |
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45 | BOOST_TEST_CASE_TEMPLATE_FUNCTION(atanh_test, T) |
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46 | { |
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47 | using ::std::abs; |
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48 | using ::std::tanh; |
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49 | using ::std::log; |
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50 | |
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51 | using ::std::numeric_limits; |
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52 | |
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53 | using ::boost::math::atanh; |
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54 | |
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55 | |
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56 | BOOST_MESSAGE("Testing atanh in the real domain for " |
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57 | << string_type_name<T>::_() << "."); |
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58 | |
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59 | BOOST_CHECK_PREDICATE(::std::less_equal<T>(), |
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60 | (abs(atanh<T>(static_cast<T>(0)))) |
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61 | (numeric_limits<T>::epsilon())); |
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62 | |
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63 | BOOST_CHECK_PREDICATE(::std::less_equal<T>(), |
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64 | (abs(atanh<T>(static_cast<T>(3)/5) - log(static_cast<T>(2)))) |
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65 | (numeric_limits<T>::epsilon())); |
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66 | |
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67 | BOOST_CHECK_PREDICATE(::std::less_equal<T>(), |
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68 | (abs(atanh<T>(static_cast<T>(-3)/5) + log(static_cast<T>(2)))) |
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69 | (numeric_limits<T>::epsilon())); |
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70 | |
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71 | for (int i = 0; i <= 100; i++) |
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72 | { |
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73 | T x = static_cast<T>(i-50)/static_cast<T>(5); |
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74 | T y = tanh(x); |
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75 | |
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76 | if ( |
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77 | (abs(y-static_cast<T>(1)) >= numeric_limits<T>::epsilon())&& |
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78 | (abs(y+static_cast<T>(1)) >= numeric_limits<T>::epsilon()) |
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79 | ) |
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80 | { |
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81 | BOOST_CHECK_PREDICATE(::std::less_equal<T>(), |
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82 | (atanh_error_evaluator(x)) |
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83 | (static_cast<T>(4))); |
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84 | } |
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85 | } |
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86 | } |
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87 | |
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88 | |
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89 | void atanh_manual_check() |
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90 | { |
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91 | using ::std::abs; |
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92 | using ::std::tanh; |
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93 | |
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94 | using ::std::numeric_limits; |
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95 | |
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96 | |
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97 | BOOST_MESSAGE(" "); |
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98 | BOOST_MESSAGE("atanh"); |
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99 | |
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100 | for (int i = 0; i <= 100; i++) |
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101 | { |
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102 | float xf = static_cast<float>(i-50)/static_cast<float>(5); |
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103 | double xd = static_cast<double>(i-50)/static_cast<double>(5); |
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104 | long double xl = |
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105 | static_cast<long double>(i-50)/static_cast<long double>(5); |
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106 | |
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107 | float yf = tanh(xf); |
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108 | double yd = tanh(xd); |
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109 | (void) &yd; // avoid "unused variable" warning |
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110 | long double yl = tanh(xl); |
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111 | (void) &yl; // avoid "unused variable" warning |
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112 | |
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113 | if ( |
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114 | std::numeric_limits<float>::has_infinity && |
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115 | std::numeric_limits<double>::has_infinity && |
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116 | std::numeric_limits<long double>::has_infinity |
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117 | ) |
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118 | { |
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119 | BOOST_MESSAGE( ::std::setw(15) |
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120 | << atanh_error_evaluator(xf) |
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121 | << ::std::setw(15) |
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122 | << atanh_error_evaluator(xd) |
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123 | << ::std::setw(15) |
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124 | << atanh_error_evaluator(xl)); |
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125 | } |
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126 | else |
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127 | { |
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128 | if ( |
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129 | (abs(yf-static_cast<float>(1)) < |
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130 | numeric_limits<float>::epsilon())|| |
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131 | (abs(yf+static_cast<float>(1)) < |
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132 | numeric_limits<float>::epsilon())|| |
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133 | (abs(yf-static_cast<double>(1)) < |
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134 | numeric_limits<double>::epsilon())|| |
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135 | (abs(yf+static_cast<double>(1)) < |
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136 | numeric_limits<double>::epsilon())|| |
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137 | (abs(yf-static_cast<long double>(1)) < |
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138 | numeric_limits<long double>::epsilon())|| |
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139 | (abs(yf+static_cast<long double>(1)) < |
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140 | numeric_limits<long double>::epsilon()) |
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141 | ) |
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142 | { |
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143 | BOOST_MESSAGE("Platform's numerics may lack precision."); |
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144 | } |
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145 | else |
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146 | { |
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147 | BOOST_MESSAGE( ::std::setw(15) |
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148 | << atanh_error_evaluator(xf) |
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149 | << ::std::setw(15) |
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150 | << atanh_error_evaluator(xd) |
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151 | << ::std::setw(15) |
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152 | << atanh_error_evaluator(xl)); |
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153 | } |
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154 | } |
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155 | } |
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156 | |
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157 | BOOST_MESSAGE(" "); |
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158 | } |
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159 | |
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