Sprout/sprout/complex/log.hpp

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