/* [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 #include #include #include #include #include #include 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