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Diffstat (limited to 'boost/numeric/odeint/stepper/explicit_error_generic_rk.hpp')
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diff --git a/boost/numeric/odeint/stepper/explicit_error_generic_rk.hpp b/boost/numeric/odeint/stepper/explicit_error_generic_rk.hpp new file mode 100644 index 0000000000..3c59810b69 --- /dev/null +++ b/boost/numeric/odeint/stepper/explicit_error_generic_rk.hpp @@ -0,0 +1,255 @@ +/* + [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 |