boost/numeric/odeint/stepper/symplectic_rkn_sb3a_mclachlan.hpp
/*
[auto_generated]
boost/numeric/odeint/stepper/symplectic_rkn_sb3a_mclachlan.hpp
[begin_description]
Implementation of the symplectic MacLachlan stepper for separable Hamiltonian system.
[end_description]
Copyright 2011-2013 Karsten Ahnert
Copyright 2011-2013 Mario Mulansky
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_NUMERIC_ODEINT_STEPPER_SYMPLECTIC_RKN_SB3A_MCLACHLAN_HPP_INCLUDED
#define BOOST_NUMERIC_ODEINT_STEPPER_SYMPLECTIC_RKN_SB3A_MCLACHLAN_HPP_INCLUDED
#include <boost/numeric/odeint/stepper/base/symplectic_rkn_stepper_base.hpp>
#include <boost/numeric/odeint/algebra/range_algebra.hpp>
#include <boost/numeric/odeint/algebra/default_operations.hpp>
#include <boost/numeric/odeint/algebra/algebra_dispatcher.hpp>
#include <boost/numeric/odeint/algebra/operations_dispatcher.hpp>
#include <boost/numeric/odeint/util/resizer.hpp>
#include <boost/array.hpp>
namespace boost {
namespace numeric {
namespace odeint {
#ifndef DOXYGEN_SKIP
namespace detail {
namespace symplectic_rkn_sb3a_mclachlan {
/*
exp( a1 t A ) exp( b1 t B )
exp( a2 t A ) exp( b2 t B )
exp( a3 t A ) exp( b3 t B ) exp( a3 t A )
exp( b2 t B ) exp( a2 t A )
exp( b1 t B ) exp( a1 t A )
*/
template< class Value >
struct coef_a_type : public boost::array< Value , 6 >
{
coef_a_type( void )
{
(*this)[0] = static_cast< Value >( 0.40518861839525227722 );
(*this)[1] = static_cast< Value >( -0.28714404081652408900 );
(*this)[2] = static_cast< Value >( 1 ) / static_cast< Value >( 2 ) - ( (*this)[0] + (*this)[1] );
(*this)[3] = (*this)[2];
(*this)[4] = (*this)[1];
(*this)[5] = (*this)[0];
}
};
template< class Value >
struct coef_b_type : public boost::array< Value , 6 >
{
coef_b_type( void )
{
(*this)[0] = static_cast< Value >( -3 ) / static_cast< Value >( 73 );
(*this)[1] = static_cast< Value >( 17 ) / static_cast< Value >( 59 );
(*this)[2] = static_cast< Value >( 1 ) - static_cast< Value >( 2 ) * ( (*this)[0] + (*this)[1] );
(*this)[3] = (*this)[1];
(*this)[4] = (*this)[0];
(*this)[5] = static_cast< Value >( 0 );
}
};
} // namespace symplectic_rkn_sb3a_mclachlan
} // namespace detail
#endif // DOXYGEN_SKIP
template<
class Coor ,
class Momentum = Coor ,
class Value = double ,
class CoorDeriv = Coor ,
class MomentumDeriv = Coor ,
class Time = Value ,
class Algebra = typename algebra_dispatcher< Coor >::algebra_type ,
class Operations = typename operations_dispatcher< Coor >::operations_type ,
class Resizer = initially_resizer
>
#ifndef DOXYGEN_SKIP
class symplectic_rkn_sb3a_mclachlan :
public symplectic_nystroem_stepper_base
<
6 , 4 ,
Coor , Momentum , Value , CoorDeriv , MomentumDeriv , Time , Algebra , Operations , Resizer
>
#else
class symplectic_rkn_sb3a_mclachlan : public symplectic_nystroem_stepper_base
#endif
{
public:
#ifndef DOXYGEN_SKIP
typedef symplectic_nystroem_stepper_base
<
6 , 4 ,
Coor , Momentum , Value , CoorDeriv , MomentumDeriv , Time , Algebra , Operations , Resizer
> stepper_base_type;
#endif
typedef typename stepper_base_type::algebra_type algebra_type;
typedef typename stepper_base_type::value_type value_type;
symplectic_rkn_sb3a_mclachlan( const algebra_type &algebra = algebra_type() )
: stepper_base_type(
detail::symplectic_rkn_sb3a_mclachlan::coef_a_type< value_type >() ,
detail::symplectic_rkn_sb3a_mclachlan::coef_b_type< value_type >() ,
algebra )
{ }
};
/************* DOXYGEN ***********/
/**
* \class symplectic_rkn_sb3a_mclachlan
* \brief Implement of the symmetric B3A method of Runge-Kutta-Nystroem method of sixth order.
*
* The method is of fourth order and has six stages. It is described HERE. This method cannot be used
* with multiprecision types since the coefficients are not defined analytically.
*
* ToDo Add reference to the paper.
*
* \tparam Order The order of the stepper.
* \tparam Coor The type representing the coordinates q.
* \tparam Momentum The type representing the coordinates p.
* \tparam Value The basic value type. Should be something like float, double or a high-precision type.
* \tparam CoorDeriv The type representing the time derivative of the coordinate dq/dt.
* \tparam MomemtnumDeriv The type representing the time derivative of the momentum dp/dt.
* \tparam Time The type representing the time t.
* \tparam Algebra The algebra.
* \tparam Operations The operations.
* \tparam Resizer The resizer policy.
*/
/**
* \fn symplectic_rkn_sb3a_mclachlan::symplectic_rkn_sb3a_mclachlan( const algebra_type &algebra )
* \brief Constructs the symplectic_rkn_sb3a_mclachlan. This constructor can be used as a default
* constructor if the algebra has a default constructor.
* \param algebra A copy of algebra is made and stored inside explicit_stepper_base.
*/
} // namespace odeint
} // namespace numeric
} // namespace boost
#endif // BOOST_NUMERIC_ODEINT_STEPPER_SYMPLECTIC_RKN_SB3A_MCLACHLAN_HPP_INCLUDED