// Copyright (c) 2007 John Maddock // Use, modification and distribution are subject to 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 BOOST_MATH_SIN_PI_HPP #define BOOST_MATH_SIN_PI_HPP #ifdef _MSC_VER #pragma once #endif #include <boost/config/no_tr1/cmath.hpp> #include <boost/math/tools/config.hpp> #include <boost/math/special_functions/math_fwd.hpp> #include <boost/math/special_functions/trunc.hpp> #include <boost/math/tools/promotion.hpp> #include <boost/math/constants/constants.hpp> namespace boost{ namespace math{ namespace detail{ template <class T, class Policy> inline T sin_pi_imp(T x, const Policy& pol) { BOOST_MATH_STD_USING // ADL of std names if(x < 0) return -sin_pi_imp(T(-x), pol); // sin of pi*x: bool invert; if(x < 0.5) return sin(constants::pi<T>() * x); if(x < 1) { invert = true; x = -x; } else invert = false; T rem = floor(x); if(iconvert(rem, pol) & 1) invert = !invert; rem = x - rem; if(rem > 0.5f) rem = 1 - rem; if(rem == 0.5f) return static_cast<T>(invert ? -1 : 1); rem = sin(constants::pi<T>() * rem); return invert ? T(-rem) : rem; } } // namespace detail template <class T, class Policy> inline typename tools::promote_args<T>::type sin_pi(T x, const Policy&) { typedef typename tools::promote_args<T>::type result_type; typedef typename policies::evaluation<result_type, Policy>::type value_type; typedef typename policies::normalise< Policy, policies::promote_float<false>, policies::promote_double<false>, policies::discrete_quantile<>, policies::assert_undefined<>, // We want to ignore overflows since the result is in [-1,1] and the // check slows the code down considerably. policies::overflow_error<policies::ignore_error> >::type forwarding_policy; return policies::checked_narrowing_cast<result_type, forwarding_policy>(boost::math::detail::sin_pi_imp<value_type>(x, forwarding_policy()), "sin_pi"); } template <class T> inline typename tools::promote_args<T>::type sin_pi(T x) { return boost::math::sin_pi(x, policies::policy<>()); } } // namespace math } // namespace boost #endif