477 lines
15 KiB
Plaintext
477 lines
15 KiB
Plaintext
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/*
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[auto_generated]
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boost/numeric/odeint/stepper/dense_output_runge_kutta.hpp
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[begin_description]
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Implementation of the Dense-output stepper for all steppers. Note, that this class does
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not computes the result but serves as an interface.
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[end_description]
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Copyright 2011-2013 Karsten Ahnert
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Copyright 2011-2015 Mario Mulansky
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Copyright 2012 Christoph Koke
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Distributed under the Boost Software License, Version 1.0.
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(See accompanying file LICENSE_1_0.txt or
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copy at http://www.boost.org/LICENSE_1_0.txt)
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*/
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#ifndef BOOST_NUMERIC_ODEINT_STEPPER_DENSE_OUTPUT_RUNGE_KUTTA_HPP_INCLUDED
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#define BOOST_NUMERIC_ODEINT_STEPPER_DENSE_OUTPUT_RUNGE_KUTTA_HPP_INCLUDED
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#include <utility>
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#include <stdexcept>
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#include <boost/throw_exception.hpp>
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#include <boost/numeric/odeint/util/bind.hpp>
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#include <boost/numeric/odeint/util/copy.hpp>
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#include <boost/numeric/odeint/util/state_wrapper.hpp>
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#include <boost/numeric/odeint/util/is_resizeable.hpp>
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#include <boost/numeric/odeint/util/resizer.hpp>
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#include <boost/numeric/odeint/stepper/controlled_step_result.hpp>
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#include <boost/numeric/odeint/stepper/stepper_categories.hpp>
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#include <boost/numeric/odeint/integrate/max_step_checker.hpp>
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namespace boost {
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namespace numeric {
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namespace odeint {
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template< class Stepper , class StepperCategory = typename Stepper::stepper_category >
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class dense_output_runge_kutta;
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/**
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* \brief The class representing dense-output Runge-Kutta steppers.
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* \note In this stepper, the initialize method has to be called before using
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* the do_step method.
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*
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* The dense-output functionality allows to interpolate the solution between
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* subsequent integration points using intermediate results obtained during the
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* computation. This version works based on a normal stepper without step-size
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* control.
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*
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*
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* \tparam Stepper The stepper type of the underlying algorithm.
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*/
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template< class Stepper >
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class dense_output_runge_kutta< Stepper , stepper_tag >
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{
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public:
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/*
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* We do not need all typedefs.
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*/
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typedef Stepper stepper_type;
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typedef typename stepper_type::state_type state_type;
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typedef typename stepper_type::wrapped_state_type wrapped_state_type;
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typedef typename stepper_type::value_type value_type;
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typedef typename stepper_type::deriv_type deriv_type;
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typedef typename stepper_type::wrapped_deriv_type wrapped_deriv_type;
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typedef typename stepper_type::time_type time_type;
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typedef typename stepper_type::algebra_type algebra_type;
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typedef typename stepper_type::operations_type operations_type;
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typedef typename stepper_type::resizer_type resizer_type;
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typedef dense_output_stepper_tag stepper_category;
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typedef dense_output_runge_kutta< Stepper > dense_output_stepper_type;
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/**
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* \brief Constructs the dense_output_runge_kutta class. An instance of the
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* underlying stepper can be provided.
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* \param stepper An instance of the underlying stepper.
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*/
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dense_output_runge_kutta( const stepper_type &stepper = stepper_type() )
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: m_stepper( stepper ) , m_resizer() ,
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m_x1() , m_x2() , m_current_state_x1( true ) ,
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m_t() , m_t_old() , m_dt()
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{ }
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/**
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* \brief Initializes the stepper. Has to be called before do_step can be
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* used to set the initial conditions and the step size.
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* \param x0 The initial state of the ODE which should be solved.
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* \param t0 The initial time, at which the step should be performed.
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* \param dt0 The step size.
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*/
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template< class StateType >
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void initialize( const StateType &x0 , time_type t0 , time_type dt0 )
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{
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m_resizer.adjust_size( x0 , detail::bind( &dense_output_stepper_type::template resize_impl< StateType > , detail::ref( *this ) , detail::_1 ) );
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boost::numeric::odeint::copy( x0 , get_current_state() );
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m_t = t0;
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m_dt = dt0;
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}
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/**
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* \brief Does one time step.
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* \note initialize has to be called before using this method to set the
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* initial conditions x,t and the stepsize.
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* \param system The system function to solve, hence the r.h.s. of the ordinary differential equation. It must fulfill the
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* Simple System concept.
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* \return Pair with start and end time of the integration step.
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*/
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template< class System >
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std::pair< time_type , time_type > do_step( System system )
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{
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m_stepper.do_step( system , get_current_state() , m_t , get_old_state() , m_dt );
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m_t_old = m_t;
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m_t += m_dt;
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toggle_current_state();
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return std::make_pair( m_t_old , m_dt );
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}
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/*
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* The next two overloads are needed to solve the forwarding problem
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*/
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/**
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* \brief Calculates the solution at an intermediate point.
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* \param t The time at which the solution should be calculated, has to be
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* in the current time interval.
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* \param x The output variable where the result is written into.
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*/
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template< class StateOut >
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void calc_state( time_type t , StateOut &x ) const
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{
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if( t == current_time() )
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{
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boost::numeric::odeint::copy( get_current_state() , x );
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}
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m_stepper.calc_state( x , t , get_old_state() , m_t_old , get_current_state() , m_t );
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}
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/**
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* \brief Calculates the solution at an intermediate point. Solves the forwarding problem
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* \param t The time at which the solution should be calculated, has to be
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* in the current time interval.
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* \param x The output variable where the result is written into, can be a boost range.
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*/
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template< class StateOut >
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void calc_state( time_type t , const StateOut &x ) const
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{
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m_stepper.calc_state( x , t , get_old_state() , m_t_old , get_current_state() , m_t );
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}
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/**
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* \brief Adjust the size of all temporaries in the stepper manually.
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* \param x A state from which the size of the temporaries to be resized is deduced.
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*/
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template< class StateType >
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void adjust_size( const StateType &x )
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{
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resize_impl( x );
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m_stepper.stepper().resize( x );
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}
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/**
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* \brief Returns the current state of the solution.
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* \return The current state of the solution x(t).
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*/
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const state_type& current_state( void ) const
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{
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return get_current_state();
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}
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/**
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* \brief Returns the current time of the solution.
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* \return The current time of the solution t.
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*/
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time_type current_time( void ) const
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{
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return m_t;
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}
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/**
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* \brief Returns the last state of the solution.
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* \return The last state of the solution x(t-dt).
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*/
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const state_type& previous_state( void ) const
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{
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return get_old_state();
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}
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/**
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* \brief Returns the last time of the solution.
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* \return The last time of the solution t-dt.
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*/
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time_type previous_time( void ) const
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{
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return m_t_old;
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}
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/**
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* \brief Returns the current time step.
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* \return dt.
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*/
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time_type current_time_step( void ) const
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{
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return m_dt;
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}
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private:
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state_type& get_current_state( void )
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{
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return m_current_state_x1 ? m_x1.m_v : m_x2.m_v ;
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}
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const state_type& get_current_state( void ) const
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{
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return m_current_state_x1 ? m_x1.m_v : m_x2.m_v ;
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}
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state_type& get_old_state( void )
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{
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return m_current_state_x1 ? m_x2.m_v : m_x1.m_v ;
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}
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const state_type& get_old_state( void ) const
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{
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return m_current_state_x1 ? m_x2.m_v : m_x1.m_v ;
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}
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void toggle_current_state( void )
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{
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m_current_state_x1 = ! m_current_state_x1;
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}
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template< class StateIn >
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bool resize_impl( const StateIn &x )
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{
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bool resized = false;
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resized |= adjust_size_by_resizeability( m_x1 , x , typename is_resizeable<state_type>::type() );
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resized |= adjust_size_by_resizeability( m_x2 , x , typename is_resizeable<state_type>::type() );
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return resized;
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}
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stepper_type m_stepper;
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resizer_type m_resizer;
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wrapped_state_type m_x1 , m_x2;
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bool m_current_state_x1; // if true, the current state is m_x1
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time_type m_t , m_t_old , m_dt;
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};
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/**
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* \brief The class representing dense-output Runge-Kutta steppers with FSAL property.
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*
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* The interface is the same as for dense_output_runge_kutta< Stepper , stepper_tag >.
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* This class provides dense output functionality based on methods with step size controlled
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*
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*
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* \tparam Stepper The stepper type of the underlying algorithm.
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*/
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template< class Stepper >
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class dense_output_runge_kutta< Stepper , explicit_controlled_stepper_fsal_tag >
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{
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public:
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/*
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* We do not need all typedefs.
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*/
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typedef Stepper controlled_stepper_type;
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typedef typename controlled_stepper_type::stepper_type stepper_type;
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typedef typename stepper_type::state_type state_type;
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typedef typename stepper_type::wrapped_state_type wrapped_state_type;
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typedef typename stepper_type::value_type value_type;
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typedef typename stepper_type::deriv_type deriv_type;
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typedef typename stepper_type::wrapped_deriv_type wrapped_deriv_type;
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typedef typename stepper_type::time_type time_type;
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typedef typename stepper_type::algebra_type algebra_type;
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typedef typename stepper_type::operations_type operations_type;
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typedef typename stepper_type::resizer_type resizer_type;
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typedef dense_output_stepper_tag stepper_category;
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typedef dense_output_runge_kutta< Stepper > dense_output_stepper_type;
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dense_output_runge_kutta( const controlled_stepper_type &stepper = controlled_stepper_type() )
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: m_stepper( stepper ) , m_resizer() ,
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m_current_state_x1( true ) ,
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m_x1() , m_x2() , m_dxdt1() , m_dxdt2() ,
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m_t() , m_t_old() , m_dt() ,
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m_is_deriv_initialized( false )
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{ }
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template< class StateType >
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void initialize( const StateType &x0 , time_type t0 , time_type dt0 )
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{
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m_resizer.adjust_size( x0 , detail::bind( &dense_output_stepper_type::template resize< StateType > , detail::ref( *this ) , detail::_1 ) );
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boost::numeric::odeint::copy( x0 , get_current_state() );
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m_t = t0;
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m_dt = dt0;
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m_is_deriv_initialized = false;
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}
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template< class System >
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std::pair< time_type , time_type > do_step( System system )
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{
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if( !m_is_deriv_initialized )
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{
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typename odeint::unwrap_reference< System >::type &sys = system;
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sys( get_current_state() , get_current_deriv() , m_t );
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m_is_deriv_initialized = true;
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}
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failed_step_checker fail_checker; // to throw a runtime_error if step size adjustment fails
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controlled_step_result res = fail;
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m_t_old = m_t;
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do
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{
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res = m_stepper.try_step( system , get_current_state() , get_current_deriv() , m_t ,
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get_old_state() , get_old_deriv() , m_dt );
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fail_checker(); // check for overflow of failed steps
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}
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while( res == fail );
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toggle_current_state();
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return std::make_pair( m_t_old , m_t );
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}
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/*
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* The two overloads are needed in order to solve the forwarding problem.
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*/
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template< class StateOut >
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void calc_state( time_type t , StateOut &x ) const
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{
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m_stepper.stepper().calc_state( t , x , get_old_state() , get_old_deriv() , m_t_old ,
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get_current_state() , get_current_deriv() , m_t );
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}
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template< class StateOut >
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void calc_state( time_type t , const StateOut &x ) const
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{
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m_stepper.stepper().calc_state( t , x , get_old_state() , get_old_deriv() , m_t_old ,
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get_current_state() , get_current_deriv() , m_t );
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}
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template< class StateIn >
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bool resize( const StateIn &x )
|
||
|
|
{
|
||
|
|
bool resized = false;
|
||
|
|
resized |= adjust_size_by_resizeability( m_x1 , x , typename is_resizeable<state_type>::type() );
|
||
|
|
resized |= adjust_size_by_resizeability( m_x2 , x , typename is_resizeable<state_type>::type() );
|
||
|
|
resized |= adjust_size_by_resizeability( m_dxdt1 , x , typename is_resizeable<deriv_type>::type() );
|
||
|
|
resized |= adjust_size_by_resizeability( m_dxdt2 , x , typename is_resizeable<deriv_type>::type() );
|
||
|
|
return resized;
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
template< class StateType >
|
||
|
|
void adjust_size( const StateType &x )
|
||
|
|
{
|
||
|
|
resize( x );
|
||
|
|
m_stepper.stepper().resize( x );
|
||
|
|
}
|
||
|
|
|
||
|
|
const state_type& current_state( void ) const
|
||
|
|
{
|
||
|
|
return get_current_state();
|
||
|
|
}
|
||
|
|
|
||
|
|
time_type current_time( void ) const
|
||
|
|
{
|
||
|
|
return m_t;
|
||
|
|
}
|
||
|
|
|
||
|
|
const state_type& previous_state( void ) const
|
||
|
|
{
|
||
|
|
return get_old_state();
|
||
|
|
}
|
||
|
|
|
||
|
|
time_type previous_time( void ) const
|
||
|
|
{
|
||
|
|
return m_t_old;
|
||
|
|
}
|
||
|
|
|
||
|
|
time_type current_time_step( void ) const
|
||
|
|
{
|
||
|
|
return m_dt;
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
private:
|
||
|
|
|
||
|
|
state_type& get_current_state( void )
|
||
|
|
{
|
||
|
|
return m_current_state_x1 ? m_x1.m_v : m_x2.m_v ;
|
||
|
|
}
|
||
|
|
|
||
|
|
const state_type& get_current_state( void ) const
|
||
|
|
{
|
||
|
|
return m_current_state_x1 ? m_x1.m_v : m_x2.m_v ;
|
||
|
|
}
|
||
|
|
|
||
|
|
state_type& get_old_state( void )
|
||
|
|
{
|
||
|
|
return m_current_state_x1 ? m_x2.m_v : m_x1.m_v ;
|
||
|
|
}
|
||
|
|
|
||
|
|
const state_type& get_old_state( void ) const
|
||
|
|
{
|
||
|
|
return m_current_state_x1 ? m_x2.m_v : m_x1.m_v ;
|
||
|
|
}
|
||
|
|
|
||
|
|
deriv_type& get_current_deriv( void )
|
||
|
|
{
|
||
|
|
return m_current_state_x1 ? m_dxdt1.m_v : m_dxdt2.m_v ;
|
||
|
|
}
|
||
|
|
|
||
|
|
const deriv_type& get_current_deriv( void ) const
|
||
|
|
{
|
||
|
|
return m_current_state_x1 ? m_dxdt1.m_v : m_dxdt2.m_v ;
|
||
|
|
}
|
||
|
|
|
||
|
|
deriv_type& get_old_deriv( void )
|
||
|
|
{
|
||
|
|
return m_current_state_x1 ? m_dxdt2.m_v : m_dxdt1.m_v ;
|
||
|
|
}
|
||
|
|
|
||
|
|
const deriv_type& get_old_deriv( void ) const
|
||
|
|
{
|
||
|
|
return m_current_state_x1 ? m_dxdt2.m_v : m_dxdt1.m_v ;
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
void toggle_current_state( void )
|
||
|
|
{
|
||
|
|
m_current_state_x1 = ! m_current_state_x1;
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
controlled_stepper_type m_stepper;
|
||
|
|
resizer_type m_resizer;
|
||
|
|
bool m_current_state_x1;
|
||
|
|
wrapped_state_type m_x1 , m_x2;
|
||
|
|
wrapped_deriv_type m_dxdt1 , m_dxdt2;
|
||
|
|
time_type m_t , m_t_old , m_dt;
|
||
|
|
bool m_is_deriv_initialized;
|
||
|
|
|
||
|
|
};
|
||
|
|
|
||
|
|
} // namespace odeint
|
||
|
|
} // namespace numeric
|
||
|
|
} // namespace boost
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
#endif // BOOST_NUMERIC_ODEINT_STEPPER_DENSE_OUTPUT_RUNGE_KUTTA_HPP_INCLUDED
|