/usr/include/boost/math/special_functions
Edit: /usr/include/boost/math/special_functions/cos_pi.hpp (2328B)
// 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_COS_PI_HPP
#define BOOST_MATH_COS_PI_HPP
#ifdef _MSC_VER
#pragma once
#endif
#include
#include
#include
#include
#include
#include
namespace boost{ namespace math{ namespace detail{
template
T cos_pi_imp(T x, const Policy& pol)
{
BOOST_MATH_STD_USING // ADL of std names
// cos of pi*x:
bool invert = false;
if(fabs(x) < 0.25)
return cos(constants::pi() * x);
if(x < 0)
{
x = -x;
}
T rem = floor(x);
if(iconvert(rem, pol) & 1)
invert = !invert;
rem = x - rem;
if(rem > 0.5f)
{
rem = 1 - rem;
invert = !invert;
}
if(rem == 0.5f)
return 0;
if(rem > 0.25f)
{
rem = 0.5f - rem;
rem = sin(constants::pi() * rem);
}
else
rem = cos(constants::pi() * rem);
return invert ? T(-rem) : rem;
}
} // namespace detail
template
inline typename tools::promote_args::type cos_pi(T x, const Policy&)
{
typedef typename tools::promote_args::type result_type;
typedef typename policies::evaluation::type value_type;
typedef typename policies::normalise<
Policy,
policies::promote_float,
policies::promote_double,
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 >::type forwarding_policy;
return policies::checked_narrowing_cast(boost::math::detail::cos_pi_imp(x, forwarding_policy()), "cos_pi");
}
template
inline typename tools::promote_args::type cos_pi(T x)
{
return boost::math::cos_pi(x, policies::policy<>());
}
} // namespace math
} // namespace boost
#endif