mirror of
https://github.com/ecency/ecency-mobile.git
synced 2024-12-23 13:22:02 +03:00
84 lines
3.2 KiB
C++
84 lines
3.2 KiB
C++
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
// Copyright 2013 Nikhar Agrawal
|
|
// Copyright 2013 Christopher Kormanyos
|
|
// Copyright 2014 John Maddock
|
|
// Copyright 2013 Paul Bristow
|
|
// Distributed under 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_POLYGAMMA_2013_07_30_HPP_
|
|
#define _BOOST_POLYGAMMA_2013_07_30_HPP_
|
|
|
|
#include <boost/math/special_functions/factorials.hpp>
|
|
#include <boost/math/special_functions/detail/polygamma.hpp>
|
|
#include <boost/math/special_functions/trigamma.hpp>
|
|
|
|
namespace boost { namespace math {
|
|
|
|
|
|
template<class T, class Policy>
|
|
inline typename tools::promote_args<T>::type polygamma(const int n, T x, const Policy& pol)
|
|
{
|
|
//
|
|
// Filter off special cases right at the start:
|
|
//
|
|
if(n == 0)
|
|
return boost::math::digamma(x, pol);
|
|
if(n == 1)
|
|
return boost::math::trigamma(x, pol);
|
|
//
|
|
// We've found some standard library functions to misbehave if any FPU exception flags
|
|
// are set prior to their call, this code will clear those flags, then reset them
|
|
// on exit:
|
|
//
|
|
BOOST_FPU_EXCEPTION_GUARD
|
|
//
|
|
// The type of the result - the common type of T and U after
|
|
// any integer types have been promoted to double:
|
|
//
|
|
typedef typename tools::promote_args<T>::type result_type;
|
|
//
|
|
// The type used for the calculation. This may be a wider type than
|
|
// the result in order to ensure full precision:
|
|
//
|
|
typedef typename policies::evaluation<result_type, Policy>::type value_type;
|
|
//
|
|
// The type of the policy to forward to the actual implementation.
|
|
// We disable promotion of float and double as that's [possibly]
|
|
// happened already in the line above. Also reset to the default
|
|
// any policies we don't use (reduces code bloat if we're called
|
|
// multiple times with differing policies we don't actually use).
|
|
// Also normalise the type, again to reduce code bloat in case we're
|
|
// called multiple times with functionally identical policies that happen
|
|
// to be different types.
|
|
//
|
|
typedef typename policies::normalise<
|
|
Policy,
|
|
policies::promote_float<false>,
|
|
policies::promote_double<false>,
|
|
policies::discrete_quantile<>,
|
|
policies::assert_undefined<> >::type forwarding_policy;
|
|
//
|
|
// Whew. Now we can make the actual call to the implementation.
|
|
// Arguments are explicitly cast to the evaluation type, and the result
|
|
// passed through checked_narrowing_cast which handles things like overflow
|
|
// according to the policy passed:
|
|
//
|
|
return policies::checked_narrowing_cast<result_type, forwarding_policy>(
|
|
detail::polygamma_imp(n, static_cast<value_type>(x), forwarding_policy()),
|
|
"boost::math::polygamma<%1%>(int, %1%)");
|
|
}
|
|
|
|
template<class T>
|
|
inline typename tools::promote_args<T>::type polygamma(const int n, T x)
|
|
{
|
|
return boost::math::polygamma(n, x, policies::policy<>());
|
|
}
|
|
|
|
} } // namespace boost::math
|
|
|
|
#endif // _BOOST_BERNOULLI_2013_05_30_HPP_
|
|
|