mirror of
https://github.com/bolero-MURAKAMI/Sprout.git
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70 lines
3.7 KiB
C++
70 lines
3.7 KiB
C++
/*=============================================================================
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Copyright (c) 2011-2014 Bolero MURAKAMI
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https://github.com/bolero-MURAKAMI/Sprout
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Distributed under the Boost Software License, Version 1.0. (See accompanying
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file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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=============================================================================*/
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#ifndef SPROUT_COMPLEX_LOG_HPP
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#define SPROUT_COMPLEX_LOG_HPP
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#include <sprout/config.hpp>
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#include <sprout/limits.hpp>
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#include <sprout/math/constants.hpp>
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#include <sprout/math/isnan.hpp>
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#include <sprout/math/isinf.hpp>
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#include <sprout/math/copysign.hpp>
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#include <sprout/math/signbit.hpp>
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#include <sprout/math/log.hpp>
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#include <sprout/complex/complex.hpp>
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#include <sprout/complex/abs.hpp>
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#include <sprout/complex/arg.hpp>
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namespace sprout {
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//
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// log
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//
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// G.6.3.2 The clog functions
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// clog(conj(z)) = conj(clog(z)).
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// clog(-0 + i0) returns -<2D>‡+ ip and raises the <20>e<EFBFBD>edivide-by-zero<72>f<EFBFBD>f floating-point exception.
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// clog(+0 + i0) returns -<2D>‡+ i0 and raises the <20>e<EFBFBD>edivide-by-zero<72>f<EFBFBD>f floating-point exception.
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// clog(x + i<>‡) returns +<2B>‡+ ip /2, for finite x.
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// clog(x + iNaN) returns NaN + iNaN and optionally raises the <20>e<EFBFBD>einvalid<69>f<EFBFBD>f floating-point exception, for finite x.
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// clog(-<2D>‡+ iy) returns +<2B>‡+ ip , for finite positive-signed y.
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// clog(+<2B>‡+ iy) returns +<2B>‡+ i0, for finite positive-signed y.
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// clog(-<2D>‡+ i<>‡) returns +<2B>‡+ i3p /4.
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// clog(+<2B>‡+ i<>‡) returns +<2B>‡+ ip /4.
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// clog(<28>}<7D>‡+ iNaN) returns +<2B>‡+ iNaN.
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// clog(NaN + iy) returns NaN + iNaN and optionally raises the <20>e<EFBFBD>einvalid<69>f<EFBFBD>f floating-point exception, for finite y.
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// clog(NaN + i<>‡) returns +<2B>‡+ iNaN.
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// clog(NaN + iNaN) returns NaN + iNaN.
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//
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template<typename T>
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inline SPROUT_CONSTEXPR sprout::complex<T>
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log(sprout::complex<T> const& x) {
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typedef sprout::complex<T> type;
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return sprout::math::isnan(x.real())
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? sprout::math::isnan(x.imag()) ? type(sprout::numeric_limits<T>::quiet_NaN(), x.real())
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: sprout::math::isinf(x.imag()) ? type(sprout::numeric_limits<T>::infinity(), x.real())
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: type(sprout::numeric_limits<T>::quiet_NaN(), x.real())
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: sprout::math::isnan(x.imag())
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? sprout::math::isinf(x.real()) ? type(sprout::numeric_limits<T>::infinity(), x.imag())
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: type(sprout::numeric_limits<T>::quiet_NaN(), x.imag())
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: x.real() == sprout::numeric_limits<T>::infinity()
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? x.imag() == sprout::numeric_limits<T>::infinity() ? type(sprout::numeric_limits<T>::infinity(), sprout::math::quarter_pi<T>())
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: x.imag() == -sprout::numeric_limits<T>::infinity() ? type(sprout::numeric_limits<T>::infinity(), -sprout::math::quarter_pi<T>())
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: type(sprout::numeric_limits<T>::infinity(), (x.imag() == 0 ? x.imag() : sprout::math::copysign(T(0), x.imag())))
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: x.real() == -sprout::numeric_limits<T>::infinity()
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? x.imag() == sprout::numeric_limits<T>::infinity() ? type(sprout::numeric_limits<T>::infinity(), sprout::math::three_quarters_pi<T>())
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: x.imag() == -sprout::numeric_limits<T>::infinity() ? type(sprout::numeric_limits<T>::infinity(), -sprout::math::three_quarters_pi<T>())
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: type(sprout::numeric_limits<T>::infinity(), sprout::math::copysign(sprout::math::pi<T>(), x.imag()))
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: sprout::math::isinf(x.imag()) ? type(sprout::numeric_limits<T>::infinity(), sprout::math::copysign(sprout::math::half_pi<T>(), x.imag()))
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: x.real() == 0 && x.imag() == 0
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? sprout::math::signbit(x.real()) ? type(-sprout::numeric_limits<T>::infinity(), sprout::math::copysign(sprout::math::pi<T>(), x.imag()))
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: type(-sprout::numeric_limits<T>::infinity(), x.imag())
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: type(sprout::math::log(sprout::abs(x)), sprout::arg(x))
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;
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}
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} // namespace sprout
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#endif // #ifndef SPROUT_COMPLEX_LOG_HPP
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