ceph/src/boost/libs/math/include/boost/math/special_functions/sin_pi.hpp

   1 //  Copyright (c) 2007 John Maddock
   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_SIN_PI_HPP
   7 #define BOOST_MATH_SIN_PI_HPP
   8
   9 #ifdef _MSC_VER
  10 #pragma once
  11 #endif
  12
  13 #include <boost/config/no_tr1/cmath.hpp>
  14 #include <boost/math/tools/config.hpp>
  15 #include <boost/math/special_functions/math_fwd.hpp>
  16 #include <boost/math/special_functions/trunc.hpp>
  17 #include <boost/math/tools/promotion.hpp>
  18 #include <boost/math/constants/constants.hpp>
  19
  20 namespace boost{ namespace math{ namespace detail{
  21
  22 template <class T, class Policy>
  23 T sin_pi_imp(T x, const Policy& pol)
  24 {
  25    BOOST_MATH_STD_USING // ADL of std names
  26    if(x < 0)
  27       return -sin_pi(-x);
  28    // sin of pi*x:
  29    bool invert;
  30    if(x < 0.5)
  31       return sin(constants::pi<T>() * x);
  32    if(x < 1)
  33    {
  34       invert = true;
  35       x = -x;
  36    }
  37    else
  38       invert = false;
  39
  40    T rem = floor(x);
  41    if(itrunc(rem, pol) & 1)
  42       invert = !invert;
  43    rem = x - rem;
  44    if(rem > 0.5f)
  45       rem = 1 - rem;
  46    if(rem == 0.5f)
  47       return static_cast<T>(invert ? -1 : 1);
  48
  49    rem = sin(constants::pi<T>() * rem);
  50    return invert ? T(-rem) : rem;
  51 }
  52
  53 } // namespace detail
  54
  55 template <class T, class Policy>
  56 inline typename tools::promote_args<T>::type sin_pi(T x, const Policy&)
  57 {
  58    typedef typename tools::promote_args<T>::type result_type;
  59    typedef typename policies::evaluation<result_type, Policy>::type value_type;
  60    typedef typename policies::normalise<
  61       Policy,
  62       policies::promote_float<false>,
  63       policies::promote_double<false>,
  64       policies::discrete_quantile<>,
  65       policies::assert_undefined<> >::type forwarding_policy;
  66    return policies::checked_narrowing_cast<result_type, forwarding_policy>(boost::math::detail::sin_pi_imp<value_type>(x, forwarding_policy()), "cos_pi");
  67 }
  68
  69 template <class T>
  70 inline typename tools::promote_args<T>::type sin_pi(T x)
  71 {
  72    return boost::math::sin_pi(x, policies::policy<>());
  73 }
  74
  75 } // namespace math
  76 } // namespace boost
  77 #endif
  78