1 // (C) Copyright John Maddock 2005. 2 // Use, modification and distribution are subject to the 3 // Boost Software License, Version 1.0. (See accompanying file 4 // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) 5 6 #ifndef BOOST_MATH_COMPLEX_ATAN_INCLUDED 7 #define BOOST_MATH_COMPLEX_ATAN_INCLUDED 8 9 #ifndef BOOST_MATH_COMPLEX_DETAILS_INCLUDED 10 # include <boost/math/complex/details.hpp> 11 #endif 12 #ifndef BOOST_MATH_COMPLEX_ATANH_INCLUDED 13 # include <boost/math/complex/atanh.hpp> 14 #endif 15 16 namespace boost{ namespace math{ 17 18 template<class T> atan(const std::complex<T> & x)19std::complex<T> atan(const std::complex<T>& x) 20 { 21 // 22 // We're using the C99 definition here; atan(z) = -i atanh(iz): 23 // 24 if(x.real() == 0) 25 { 26 if(x.imag() == 1) 27 return std::complex<T>(0, std::numeric_limits<T>::has_infinity ? std::numeric_limits<T>::infinity() : static_cast<T>(HUGE_VAL)); 28 if(x.imag() == -1) 29 return std::complex<T>(0, std::numeric_limits<T>::has_infinity ? -std::numeric_limits<T>::infinity() : -static_cast<T>(HUGE_VAL)); 30 } 31 return ::boost::math::detail::mult_minus_i(::boost::math::atanh(::boost::math::detail::mult_i(x))); 32 } 33 34 } } // namespaces 35 36 #endif // BOOST_MATH_COMPLEX_ATAN_INCLUDED 37