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_ACOSH_INCLUDED 7 #define BOOST_MATH_COMPLEX_ACOSH_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/acos.hpp> 14 #endif 15 16 namespace boost{ namespace math{ 17 18 template<class T> acosh(const std::complex<T> & z)19inline std::complex<T> acosh(const std::complex<T>& z) 20 { 21 // 22 // We use the relation acosh(z) = +-i acos(z) 23 // Choosing the sign of multiplier to give real(acosh(z)) >= 0 24 // as well as compatibility with C99. 25 // 26 std::complex<T> result = boost::math::acos(z); 27 if(!(boost::math::isnan)(result.imag()) && signbit(result.imag())) 28 return detail::mult_i(result); 29 return detail::mult_minus_i(result); 30 } 31 32 } } // namespaces 33 34 #endif // BOOST_MATH_COMPLEX_ACOSH_INCLUDED 35