boost/numeric/odeint/stepper/explicit_error_generic_rk.hpp
/* [auto_generated] boost/numeric/odeint/stepper/explicit_error_generic_rk.hpp [begin_description] Implementation of the generic Runge Kutta error stepper. Base class for many RK error steppers. [end_description] Copyright 2011-2013 Mario Mulansky Copyright 2011-2013 Karsten Ahnert Copyright 2012 Christoph Koke 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_EXPLICIT_ERROR_GENERIC_RK_HPP_INCLUDED #define BOOST_NUMERIC_ODEINT_STEPPER_EXPLICIT_ERROR_GENERIC_RK_HPP_INCLUDED #include <boost/numeric/odeint/stepper/base/explicit_error_stepper_base.hpp> #include <boost/numeric/odeint/algebra/default_operations.hpp> #include <boost/numeric/odeint/algebra/range_algebra.hpp> #include <boost/numeric/odeint/algebra/algebra_dispatcher.hpp> #include <boost/numeric/odeint/algebra/operations_dispatcher.hpp> #include <boost/numeric/odeint/stepper/detail/generic_rk_algorithm.hpp> #include <boost/numeric/odeint/stepper/detail/generic_rk_call_algebra.hpp> #include <boost/numeric/odeint/stepper/detail/generic_rk_operations.hpp> #include <boost/numeric/odeint/util/state_wrapper.hpp> #include <boost/numeric/odeint/util/is_resizeable.hpp> #include <boost/numeric/odeint/util/resizer.hpp> namespace boost { namespace numeric { namespace odeint { template< size_t StageCount, size_t Order, size_t StepperOrder , size_t ErrorOrder , class State , class Value = double , class Deriv = State , class Time = Value , class Algebra = typename algebra_dispatcher< State >::algebra_type , class Operations = typename operations_dispatcher< State >::operations_type , class Resizer = initially_resizer > #ifndef DOXYGEN_SKIP class explicit_error_generic_rk : public explicit_error_stepper_base< explicit_error_generic_rk< StageCount , Order , StepperOrder , ErrorOrder , State , Value , Deriv , Time , Algebra , Operations , Resizer > , Order , StepperOrder , ErrorOrder , State , Value , Deriv , Time , Algebra , Operations , Resizer > #else class explicit_error_generic_rk : public explicit_error_stepper_base #endif { public: #ifndef DOXYGEN_SKIP typedef explicit_error_stepper_base< explicit_error_generic_rk< StageCount , Order , StepperOrder , ErrorOrder , State , Value , Deriv , Time , Algebra , Operations , Resizer > , Order , StepperOrder , ErrorOrder , State , Value , Deriv , Time , Algebra , Operations , Resizer > stepper_base_type; #else typedef explicit_stepper_base< ... > stepper_base_type; #endif typedef typename stepper_base_type::state_type state_type; typedef typename stepper_base_type::wrapped_state_type wrapped_state_type; typedef typename stepper_base_type::value_type value_type; typedef typename stepper_base_type::deriv_type deriv_type; typedef typename stepper_base_type::wrapped_deriv_type wrapped_deriv_type; typedef typename stepper_base_type::time_type time_type; typedef typename stepper_base_type::algebra_type algebra_type; typedef typename stepper_base_type::operations_type operations_type; typedef typename stepper_base_type::resizer_type resizer_type; #ifndef DOXYGEN_SKIP typedef explicit_error_generic_rk< StageCount , Order , StepperOrder , ErrorOrder , State , Value , Deriv , Time , Algebra , Operations , Resizer > stepper_type; #endif typedef detail::generic_rk_algorithm< StageCount , Value , Algebra , Operations > rk_algorithm_type; typedef typename rk_algorithm_type::coef_a_type coef_a_type; typedef typename rk_algorithm_type::coef_b_type coef_b_type; typedef typename rk_algorithm_type::coef_c_type coef_c_type; static const size_t stage_count = StageCount; private: public: // we use an explicit_generic_rk to do the normal rk step // and add a separate calculation of the error estimate afterwards explicit_error_generic_rk( const coef_a_type &a , const coef_b_type &b , const coef_b_type &b2 , const coef_c_type &c , const algebra_type &algebra = algebra_type() ) : stepper_base_type( algebra ) , m_rk_algorithm( a , b , c ) , m_b2( b2 ) { } template< class System , class StateIn , class DerivIn , class StateOut , class Err > void do_step_impl( System system , const StateIn &in , const DerivIn &dxdt , time_type t , StateOut &out , time_type dt , Err &xerr ) { // normal step do_step_impl( system , in , dxdt , t , out , dt ); // additionally, perform the error calculation detail::template generic_rk_call_algebra< StageCount , algebra_type >()( stepper_base_type::m_algebra , xerr , dxdt , m_F , detail::generic_rk_scale_sum_err< StageCount , operations_type , value_type , time_type >( m_b2 , dt) ); } template< class System , class StateIn , class DerivIn , class StateOut > void do_step_impl( System system , const StateIn &in , const DerivIn &dxdt , time_type t , StateOut &out , time_type dt ) { m_resizer.adjust_size( in , detail::bind( &stepper_type::template resize_impl< StateIn > , detail::ref( *this ) , detail::_1 ) ); // actual calculation done in generic_rk.hpp m_rk_algorithm.do_step( stepper_base_type::m_algebra , system , in , dxdt , t , out , dt , m_x_tmp.m_v , m_F ); } template< class StateIn > void adjust_size( const StateIn &x ) { resize_impl( x ); stepper_base_type::adjust_size( x ); } private: template< class StateIn > bool resize_impl( const StateIn &x ) { bool resized( false ); resized |= adjust_size_by_resizeability( m_x_tmp , x , typename is_resizeable<state_type>::type() ); for( size_t i = 0 ; i < StageCount-1 ; ++i ) { resized |= adjust_size_by_resizeability( m_F[i] , x , typename is_resizeable<deriv_type>::type() ); } return resized; } rk_algorithm_type m_rk_algorithm; coef_b_type m_b2; resizer_type m_resizer; wrapped_state_type m_x_tmp; wrapped_deriv_type m_F[StageCount-1]; }; /********* DOXYGEN *********/ /** * \class explicit_error_generic_rk * \brief A generic implementation of explicit Runge-Kutta algorithms with error estimation. This class is as a * base class for all explicit Runge-Kutta steppers with error estimation. * * This class implements the explicit Runge-Kutta algorithms with error estimation in a generic way. * The Butcher tableau is passed to the stepper which constructs the stepper scheme with the help of a * template-metaprogramming algorithm. ToDo : Add example! * * This class derives explicit_error_stepper_base which provides the stepper interface. * * \tparam StageCount The number of stages of the Runge-Kutta algorithm. * \tparam Order The order of a stepper if the stepper is used without error estimation. * \tparam StepperOrder The order of a step if the stepper is used with error estimation. Usually Order and StepperOrder have * the same value. * \tparam ErrorOrder The order of the error step if the stepper is used with error estimation. * \tparam State The type representing the state of the ODE. * \tparam Value The floating point type which is used in the computations. * \tparam Time The type representing the independent variable - the time - of the ODE. * \tparam Algebra The algebra type. * \tparam Operations The operations type. * \tparam Resizer The resizer policy type. */ /** * \fn explicit_error_generic_rk::explicit_error_generic_rk( const coef_a_type &a , const coef_b_type &b , const coef_b_type &b2 , const coef_c_type &c , const algebra_type &algebra ) * \brief Constructs the explicit_error_generik_rk class with the given parameters a, b, b2 and c. See examples section for details on the coefficients. * * \param a Triangular matrix of parameters b in the Butcher tableau. * \param b Last row of the butcher tableau. * \param b2 Parameters for lower-order evaluation to estimate the error. * \param c Parameters to calculate the time points in the Butcher tableau. * \param algebra A copy of algebra is made and stored inside explicit_stepper_base. */ /** * \fn explicit_error_generic_rk::do_step_impl( System system , const StateIn &in , const DerivIn &dxdt , time_type t , StateOut &out , time_type dt , Err &xerr ) * \brief This method performs one step. The derivative `dxdt` of `in` at the time `t` is passed to the method. * The result is updated out-of-place, hence the input is in `in` and the output in `out`. Futhermore, an * estimation of the error is stored in `xerr`. `do_step_impl` is used by explicit_error_stepper_base. * * \param system The system function to solve, hence the r.h.s. of the ODE. It must fulfill the * Simple System concept. * \param in The state of the ODE which should be solved. in is not modified in this method * \param dxdt The derivative of x at t. * \param t The value of the time, at which the step should be performed. * \param out The result of the step is written in out. * \param dt The step size. * \param xerr The result of the error estimation is written in xerr. */ /** * \fn explicit_error_generic_rk::do_step_impl( System system , const StateIn &in , const DerivIn &dxdt , time_type t , StateOut &out , time_type dt ) * \brief This method performs one step. The derivative `dxdt` of `in` at the time `t` is passed to the method. * The result is updated out-of-place, hence the input is in `in` and the output in `out`. * Access to this step functionality is provided by explicit_stepper_base and * `do_step_impl` should not be called directly. * * \param system The system function to solve, hence the r.h.s. of the ODE. It must fulfill the * Simple System concept. * \param in The state of the ODE which should be solved. in is not modified in this method * \param dxdt The derivative of x at t. * \param t The value of the time, at which the step should be performed. * \param out The result of the step is written in out. * \param dt The step size. */ /** * \fn explicit_error_generic_rk::adjust_size( const StateIn &x ) * \brief Adjust the size of all temporaries in the stepper manually. * \param x A state from which the size of the temporaries to be resized is deduced. */ } } } #endif // BOOST_NUMERIC_ODEINT_STEPPER_EXPLICIT_ERROR_GENERIC_RK_HPP_INCLUDED