| // 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/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> |
| T sin_pi_imp(T x, const Policy& pol) |
| { |
| BOOST_MATH_STD_USING // ADL of std names |
| if(x < 0) |
| return -sin_pi(-x); |
| // 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(itrunc(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& pol) |
| { |
| typedef typename tools::promote_args<T>::type result_type; |
| return boost::math::detail::sin_pi_imp<result_type>(x, pol); |
| } |
| |
| 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 |
| |