| /* |
| [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 |