// (C) Copyright John Maddock 2006. | |
// 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_SPECIAL_HERMITE_HPP | |
#define BOOST_MATH_SPECIAL_HERMITE_HPP | |
#ifdef _MSC_VER | |
#pragma once | |
#endif | |
#include <boost/math/special_functions/math_fwd.hpp> | |
#include <boost/math/tools/config.hpp> | |
#include <boost/math/policies/error_handling.hpp> | |
namespace boost{ | |
namespace math{ | |
// Recurrance relation for Hermite polynomials: | |
template <class T1, class T2, class T3> | |
inline typename tools::promote_args<T1, T2, T3>::type | |
hermite_next(unsigned n, T1 x, T2 Hn, T3 Hnm1) | |
{ | |
return (2 * x * Hn - 2 * n * Hnm1); | |
} | |
namespace detail{ | |
// Implement Hermite polynomials via recurrance: | |
template <class T> | |
T hermite_imp(unsigned n, T x) | |
{ | |
T p0 = 1; | |
T p1 = 2 * x; | |
if(n == 0) | |
return p0; | |
unsigned c = 1; | |
while(c < n) | |
{ | |
std::swap(p0, p1); | |
p1 = hermite_next(c, x, p0, p1); | |
++c; | |
} | |
return p1; | |
} | |
} // namespace detail | |
template <class T, class Policy> | |
inline typename tools::promote_args<T>::type | |
hermite(unsigned n, T x, const Policy&) | |
{ | |
typedef typename tools::promote_args<T>::type result_type; | |
typedef typename policies::evaluation<result_type, Policy>::type value_type; | |
return policies::checked_narrowing_cast<result_type, Policy>(detail::hermite_imp(n, static_cast<value_type>(x)), "boost::math::hermite<%1%>(unsigned, %1%)"); | |
} | |
template <class T> | |
inline typename tools::promote_args<T>::type | |
hermite(unsigned n, T x) | |
{ | |
return boost::math::hermite(n, x, policies::policy<>()); | |
} | |
} // namespace math | |
} // namespace boost | |
#endif // BOOST_MATH_SPECIAL_HERMITE_HPP | |