41 lines
1.1 KiB
C++
41 lines
1.1 KiB
C++
#ifndef UTILITYMATHFUNCTIONS_H
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#define UTILITYMATHFUNCTIONS_H
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/// \cond
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// C headers
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// C++ headers
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#include <cmath>
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#include <limits>
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// 3rd party headers
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/// \endcond
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namespace utils
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{
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namespace math
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{
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/**
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* @brief doublesEqual compares two doubles for equality, using a value for number of smallest
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* places to ignore
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*
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* This is derived from the example on cppreference.com: https://en.cppreference.com/w/cpp/types/numeric_limits/epsilon
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* The default ulp of 4 with a numeric_limits<double>::epsilon() of ~2e-16, so ulp of 4 yields 12
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* significant figures. A ulp of 10 yields 6 significant figures.
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* @param a the first double to compare
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* @param b the second double to compare
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* @param ulp number of smallest decimal places to ignore
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* @return
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*/
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template<typename T>
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bool floatingPointEqual(T a, T b, int ulp = 4)
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{
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return std::fabs(a - b) <= std::numeric_limits<T>::epsilon() * std::fabs(a + b) * ulp
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// unless the result is subnormal
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|| std::fabs(a - b) < std::numeric_limits<T>::min();
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}
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} // namespace math
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} // namespace utils
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#endif // UTILITYMATHFUNCTIONS_H
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