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			421 lines
		
	
	
		
			15 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
|   | /* | ||
|  |  [auto_generated] | ||
|  |  boost/numeric/odeint/stepper/adams_bashforth.hpp | ||
|  | 
 | ||
|  |  [begin_description] | ||
|  |  Implementaton of the Adam-Bashforth method a multistep method used for the predictor step in the | ||
|  |  Adams-Bashforth-Moulton method. | ||
|  |  [end_description] | ||
|  | 
 | ||
|  |  Copyright 2011-2013 Karsten Ahnert | ||
|  |  Copyright 2011-2013 Mario Mulansky | ||
|  |  Copyright 2012 Christoph Koke | ||
|  |  Copyright 2013 Pascal Germroth | ||
|  | 
 | ||
|  |  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_ADAMS_BASHFORTH_HPP_INCLUDED | ||
|  | #define BOOST_NUMERIC_ODEINT_STEPPER_ADAMS_BASHFORTH_HPP_INCLUDED | ||
|  | 
 | ||
|  | #include <boost/static_assert.hpp> | ||
|  | 
 | ||
|  | #include <boost/numeric/odeint/util/bind.hpp> | ||
|  | #include <boost/numeric/odeint/util/unwrap_reference.hpp> | ||
|  | 
 | ||
|  | #include <boost/numeric/odeint/algebra/range_algebra.hpp> | ||
|  | #include <boost/numeric/odeint/algebra/default_operations.hpp> | ||
|  | #include <boost/numeric/odeint/algebra/algebra_dispatcher.hpp> | ||
|  | #include <boost/numeric/odeint/algebra/operations_dispatcher.hpp> | ||
|  | 
 | ||
|  | #include <boost/numeric/odeint/util/state_wrapper.hpp> | ||
|  | #include <boost/numeric/odeint/util/is_resizeable.hpp> | ||
|  | #include <boost/numeric/odeint/util/resizer.hpp> | ||
|  | 
 | ||
|  | #include <boost/numeric/odeint/stepper/stepper_categories.hpp> | ||
|  | #include <boost/numeric/odeint/stepper/runge_kutta4.hpp> | ||
|  | #include <boost/numeric/odeint/stepper/extrapolation_stepper.hpp> | ||
|  | 
 | ||
|  | #include <boost/numeric/odeint/stepper/base/algebra_stepper_base.hpp> | ||
|  | 
 | ||
|  | #include <boost/numeric/odeint/stepper/detail/adams_bashforth_coefficients.hpp> | ||
|  | #include <boost/numeric/odeint/stepper/detail/adams_bashforth_call_algebra.hpp> | ||
|  | #include <boost/numeric/odeint/stepper/detail/rotating_buffer.hpp> | ||
|  | 
 | ||
|  | #include <boost/mpl/arithmetic.hpp> | ||
|  | #include <boost/mpl/min_max.hpp> | ||
|  | #include <boost/mpl/equal_to.hpp> | ||
|  | 
 | ||
|  | namespace mpl = boost::mpl; | ||
|  | 
 | ||
|  | 
 | ||
|  | namespace boost { | ||
|  | namespace numeric { | ||
|  | namespace odeint { | ||
|  | 
 | ||
|  |     using mpl::int_; | ||
|  | 
 | ||
|  |     /* if N >= 4, returns the smallest even number > N, otherwise returns 4 */ | ||
|  |     template < int N > | ||
|  |     struct order_helper | ||
|  |         : mpl::max< typename mpl::eval_if< | ||
|  |                         mpl::equal_to< mpl::modulus< int_< N >, int_< 2 > >, | ||
|  |                                        int_< 0 > >, | ||
|  |                         int_< N >, int_< N + 1 > >::type, | ||
|  |                     int_< 4 > >::type | ||
|  |     { }; | ||
|  | 
 | ||
|  | template< | ||
|  | size_t Steps , | ||
|  | 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 , | ||
|  | class InitializingStepper = extrapolation_stepper< order_helper<Steps>::value,  | ||
|  |                                                    State, Value, Deriv, Time, | ||
|  |                                                    Algebra, Operations, Resizer > | ||
|  | > | ||
|  | class adams_bashforth : public algebra_stepper_base< Algebra , Operations > | ||
|  | { | ||
|  | 
 | ||
|  | #ifndef DOXYGEN_SKIP | ||
|  |     BOOST_STATIC_ASSERT(( Steps > 0 )); | ||
|  |     BOOST_STATIC_ASSERT(( Steps < 9 )); | ||
|  | #endif | ||
|  | 
 | ||
|  | public : | ||
|  | 
 | ||
|  |     typedef State state_type; | ||
|  |     typedef state_wrapper< state_type > wrapped_state_type; | ||
|  |     typedef Value value_type; | ||
|  |     typedef Deriv deriv_type; | ||
|  |     typedef state_wrapper< deriv_type > wrapped_deriv_type; | ||
|  |     typedef Time time_type; | ||
|  |     typedef Resizer resizer_type; | ||
|  |     typedef stepper_tag stepper_category; | ||
|  | 
 | ||
|  |     typedef InitializingStepper initializing_stepper_type; | ||
|  | 
 | ||
|  |     typedef algebra_stepper_base< Algebra , Operations > algebra_stepper_base_type; | ||
|  |     typedef typename algebra_stepper_base_type::algebra_type algebra_type; | ||
|  |     typedef typename algebra_stepper_base_type::operations_type operations_type; | ||
|  | #ifndef DOXYGEN_SKIP | ||
|  |     typedef adams_bashforth< Steps , State , Value , Deriv , Time , Algebra , Operations , Resizer , InitializingStepper > stepper_type; | ||
|  | #endif | ||
|  |     static const size_t steps = Steps; | ||
|  | 
 | ||
|  | 
 | ||
|  | 
 | ||
|  |     typedef unsigned short order_type; | ||
|  |     static const order_type order_value = steps; | ||
|  | 
 | ||
|  |     typedef detail::rotating_buffer< wrapped_deriv_type , steps > step_storage_type; | ||
|  | 
 | ||
|  | 
 | ||
|  |      | ||
|  |     order_type order( void ) const { return order_value; } | ||
|  | 
 | ||
|  |     adams_bashforth( const algebra_type &algebra = algebra_type() ) | ||
|  |     : algebra_stepper_base_type( algebra ) , | ||
|  |       m_step_storage() , m_resizer() , m_coefficients() , | ||
|  |       m_steps_initialized( 0 ) , m_initializing_stepper() | ||
|  |     { } | ||
|  | 
 | ||
|  | 
 | ||
|  | 
 | ||
|  |     /* | ||
|  |      * Version 1 : do_step( system , x , t , dt ); | ||
|  |      * | ||
|  |      * solves the forwarding problem | ||
|  |      */ | ||
|  |     template< class System , class StateInOut > | ||
|  |     void do_step( System system , StateInOut &x , time_type t , time_type dt ) | ||
|  |     { | ||
|  |         do_step( system , x , t , x , dt ); | ||
|  |     } | ||
|  | 
 | ||
|  |     /** | ||
|  |      * \brief Second version to solve the forwarding problem, can be called with Boost.Range as StateInOut. | ||
|  |      */ | ||
|  |     template< class System , class StateInOut > | ||
|  |     void do_step( System system , const StateInOut &x , time_type t , time_type dt ) | ||
|  |     { | ||
|  |         do_step( system , x , t , x , dt ); | ||
|  |     } | ||
|  | 
 | ||
|  | 
 | ||
|  | 
 | ||
|  |     /* | ||
|  |      * Version 2 : do_step( system , in , t , out , dt ); | ||
|  |      * | ||
|  |      * solves the forwarding problem | ||
|  |      */ | ||
|  | 
 | ||
|  |     template< class System , class StateIn , class StateOut > | ||
|  |     void do_step( System system , const StateIn &in , time_type t , StateOut &out , time_type dt ) | ||
|  |     { | ||
|  |         do_step_impl( system , in , t , out , dt ); | ||
|  |     } | ||
|  | 
 | ||
|  |     /** | ||
|  |      * \brief Second version to solve the forwarding problem, can be called with Boost.Range as StateOut. | ||
|  |      */ | ||
|  |     template< class System , class StateIn , class StateOut > | ||
|  |     void do_step( System system , const StateIn &in , time_type t , const StateOut &out , time_type dt ) | ||
|  |     { | ||
|  |         do_step_impl( system , in , t , out , dt ); | ||
|  |     } | ||
|  | 
 | ||
|  | 
 | ||
|  |     template< class StateType > | ||
|  |     void adjust_size( const StateType &x ) | ||
|  |     { | ||
|  |         resize_impl( x ); | ||
|  |     } | ||
|  | 
 | ||
|  |     const step_storage_type& step_storage( void ) const | ||
|  |     { | ||
|  |         return m_step_storage; | ||
|  |     } | ||
|  | 
 | ||
|  |     step_storage_type& step_storage( void ) | ||
|  |     { | ||
|  |         return m_step_storage; | ||
|  |     } | ||
|  | 
 | ||
|  |     template< class ExplicitStepper , class System , class StateIn > | ||
|  |     void initialize( ExplicitStepper explicit_stepper , System system , StateIn &x , time_type &t , time_type dt ) | ||
|  |     { | ||
|  |         typename odeint::unwrap_reference< ExplicitStepper >::type &stepper = explicit_stepper; | ||
|  |         typename odeint::unwrap_reference< System >::type &sys = system; | ||
|  | 
 | ||
|  |         m_resizer.adjust_size( x , detail::bind( &stepper_type::template resize_impl<StateIn> , detail::ref( *this ) , detail::_1 ) ); | ||
|  | 
 | ||
|  |         for( size_t i=0 ; i+1<steps ; ++i ) | ||
|  |         { | ||
|  |             if( i != 0 ) m_step_storage.rotate(); | ||
|  |             sys( x , m_step_storage[0].m_v , t ); | ||
|  |             stepper.do_step_dxdt_impl( system, x, m_step_storage[0].m_v, t, | ||
|  |                                        dt ); | ||
|  |             t += dt; | ||
|  |         } | ||
|  |         m_steps_initialized = steps; | ||
|  |     } | ||
|  | 
 | ||
|  |     template< class System , class StateIn > | ||
|  |     void initialize( System system , StateIn &x , time_type &t , time_type dt ) | ||
|  |     { | ||
|  |         initialize( detail::ref( m_initializing_stepper ) , system , x , t , dt ); | ||
|  |     } | ||
|  | 
 | ||
|  |     void reset( void ) | ||
|  |     { | ||
|  |         m_steps_initialized = 0; | ||
|  |     } | ||
|  | 
 | ||
|  |     bool is_initialized( void ) const | ||
|  |     { | ||
|  |         return m_steps_initialized >= ( steps - 1 ); | ||
|  |     } | ||
|  | 
 | ||
|  |     const initializing_stepper_type& initializing_stepper( void ) const { return m_initializing_stepper; } | ||
|  | 
 | ||
|  |     initializing_stepper_type& initializing_stepper( void ) { return m_initializing_stepper; } | ||
|  | 
 | ||
|  | private: | ||
|  | 
 | ||
|  |     template< class System , class StateIn , class StateOut > | ||
|  |     void do_step_impl( System system , const StateIn &in , time_type t , StateOut &out , time_type dt ) | ||
|  |     { | ||
|  |         typename odeint::unwrap_reference< System >::type &sys = system; | ||
|  |         if( m_resizer.adjust_size( in , detail::bind( &stepper_type::template resize_impl<StateIn> , detail::ref( *this ) , detail::_1 ) ) ) | ||
|  |         { | ||
|  |             m_steps_initialized = 0; | ||
|  |         } | ||
|  | 
 | ||
|  |         if( m_steps_initialized + 1 < steps ) | ||
|  |         { | ||
|  |             if( m_steps_initialized != 0 ) m_step_storage.rotate(); | ||
|  |             sys( in , m_step_storage[0].m_v , t ); | ||
|  |             m_initializing_stepper.do_step_dxdt_impl( | ||
|  |                 system, in, m_step_storage[0].m_v, t, out, dt ); | ||
|  |             ++m_steps_initialized; | ||
|  |         } | ||
|  |         else | ||
|  |         { | ||
|  |             m_step_storage.rotate(); | ||
|  |             sys( in , m_step_storage[0].m_v , t ); | ||
|  |             detail::adams_bashforth_call_algebra< steps , algebra_type , operations_type >()( this->m_algebra , in , out , m_step_storage , m_coefficients , dt ); | ||
|  |         } | ||
|  |     } | ||
|  | 
 | ||
|  | 
 | ||
|  |     template< class StateIn > | ||
|  |     bool resize_impl( const StateIn &x ) | ||
|  |     { | ||
|  |         bool resized( false ); | ||
|  |         for( size_t i=0 ; i<steps ; ++i ) | ||
|  |         { | ||
|  |             resized |= adjust_size_by_resizeability( m_step_storage[i] , x , typename is_resizeable<deriv_type>::type() ); | ||
|  |         } | ||
|  |         return resized; | ||
|  |     } | ||
|  | 
 | ||
|  |     step_storage_type m_step_storage; | ||
|  |     resizer_type m_resizer; | ||
|  |     detail::adams_bashforth_coefficients< value_type , steps > m_coefficients; | ||
|  |     size_t m_steps_initialized; | ||
|  |     initializing_stepper_type m_initializing_stepper; | ||
|  | 
 | ||
|  | }; | ||
|  | 
 | ||
|  | 
 | ||
|  | /***** DOXYGEN *****/ | ||
|  | 
 | ||
|  | /** | ||
|  |  * \class adams_bashforth | ||
|  |  * \brief The Adams-Bashforth multistep algorithm. | ||
|  |  * | ||
|  |  * The Adams-Bashforth method is a multi-step algorithm with configurable step | ||
|  |  * number. The step number is specified as template parameter Steps and it  | ||
|  |  * then uses the result from the previous Steps steps. See also | ||
|  |  * <a href="http://en.wikipedia.org/wiki/Linear_multistep_method">en.wikipedia.org/wiki/Linear_multistep_method</a>. | ||
|  |  * Currently, a maximum of Steps=8 is supported. | ||
|  |  * The method is explicit and fulfills the Stepper concept. Step size control | ||
|  |  * or continuous output are not provided. | ||
|  |  *  | ||
|  |  * This class derives from algebra_base and inherits its interface via | ||
|  |  * CRTP (current recurring template pattern). For more details see | ||
|  |  * algebra_stepper_base. | ||
|  |  * | ||
|  |  * \tparam Steps The number of steps (maximal 8). | ||
|  |  * \tparam State The state type. | ||
|  |  * \tparam Value The value type. | ||
|  |  * \tparam Deriv The type representing the time derivative of the state. | ||
|  |  * \tparam Time The time representing the independent variable - the time. | ||
|  |  * \tparam Algebra The algebra type. | ||
|  |  * \tparam Operations The operations type. | ||
|  |  * \tparam Resizer The resizer policy type. | ||
|  |  * \tparam InitializingStepper The stepper for the first two steps. | ||
|  |  */ | ||
|  | 
 | ||
|  |     /** | ||
|  |      * \fn adams_bashforth::adams_bashforth( const algebra_type &algebra ) | ||
|  |      * \brief Constructs the adams_bashforth class. 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. | ||
|  |      */ | ||
|  | 
 | ||
|  |     /** | ||
|  |      * \fn order_type adams_bashforth::order( void ) const | ||
|  |      * \brief Returns the order of the algorithm, which is equal to the number of steps. | ||
|  |      * \return order of the method. | ||
|  |      */ | ||
|  | 
 | ||
|  |     /** | ||
|  |      * \fn void adams_bashforth::do_step( System system , StateInOut &x , time_type t , time_type dt ) | ||
|  |      * \brief This method performs one step. It transforms the result in-place. | ||
|  |      * | ||
|  |      * \param system The system function to solve, hence the r.h.s. of the ordinary differential equation. It must fulfill the | ||
|  |      *               Simple System concept. | ||
|  |      * \param x The state of the ODE which should be solved. After calling do_step the result is updated in x. | ||
|  |      * \param t The value of the time, at which the step should be performed. | ||
|  |      * \param dt The step size. | ||
|  |      */ | ||
|  | 
 | ||
|  |     /** | ||
|  |      * \fn void adams_bashforth::do_step( System system , const StateIn &in , time_type t , StateOut &out , time_type dt ) | ||
|  |      * \brief The method performs one step with the stepper passed by Stepper. The state of the ODE is updated out-of-place. | ||
|  |      * | ||
|  |      * \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 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 void adams_bashforth::adjust_size( const StateType &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. | ||
|  |      */ | ||
|  | 
 | ||
|  | 
 | ||
|  |     /** | ||
|  |      * \fn const step_storage_type& adams_bashforth::step_storage( void ) const | ||
|  |      * \brief Returns the storage of intermediate results. | ||
|  |      * \return The storage of intermediate results. | ||
|  |      */ | ||
|  | 
 | ||
|  |     /** | ||
|  |      * \fn step_storage_type& adams_bashforth::step_storage( void ) | ||
|  |      * \brief Returns the storage of intermediate results. | ||
|  |      * \return The storage of intermediate results. | ||
|  |      */ | ||
|  | 
 | ||
|  |     /** | ||
|  |      * \fn void adams_bashforth::initialize( ExplicitStepper explicit_stepper , System system , StateIn &x , time_type &t , time_type dt ) | ||
|  |      * \brief Initialized the stepper. Does Steps-1 steps with the explicit_stepper to fill the buffer. | ||
|  |      * \param explicit_stepper the stepper used to fill the buffer of previous step results | ||
|  |      * \param system The system function to solve, hence the r.h.s. of the ordinary differential equation. It must fulfill the | ||
|  |      *               Simple System concept. | ||
|  |      * \param x The state of the ODE which should be solved. After calling do_step the result is updated in x. | ||
|  |      * \param t The value of the time, at which the step should be performed. | ||
|  |      * \param dt The step size. | ||
|  |      */ | ||
|  | 
 | ||
|  |     /** | ||
|  |      * \fn void adams_bashforth::initialize( System system , StateIn &x , time_type &t , time_type dt ) | ||
|  |      * \brief Initialized the stepper. Does Steps-1 steps with an internal instance of InitializingStepper to fill the buffer. | ||
|  |      * \note The state x and time t are updated to the values after Steps-1 initial steps. | ||
|  |      * \param system The system function to solve, hence the r.h.s. of the ordinary differential equation. It must fulfill the | ||
|  |      *               Simple System concept. | ||
|  |      * \param x The initial state of the ODE which should be solved, updated in this method. | ||
|  |      * \param t The initial value of the time, updated in this method. | ||
|  |      * \param dt The step size. | ||
|  |      */ | ||
|  | 
 | ||
|  |     /** | ||
|  |      * \fn void adams_bashforth::reset( void ) | ||
|  |      * \brief Resets the internal buffer of the stepper. | ||
|  |      */ | ||
|  | 
 | ||
|  |     /** | ||
|  |      * \fn bool adams_bashforth::is_initialized( void ) const | ||
|  |      * \brief Returns true if the stepper has been initialized. | ||
|  |      * \return bool true if stepper is initialized, false otherwise | ||
|  |      */ | ||
|  | 
 | ||
|  |     /** | ||
|  |      * \fn const initializing_stepper_type& adams_bashforth::initializing_stepper( void ) const | ||
|  |      * \brief Returns the internal initializing stepper instance. | ||
|  |      * \return initializing_stepper | ||
|  |      */ | ||
|  | 
 | ||
|  |     /** | ||
|  |      * \fn const initializing_stepper_type& adams_bashforth::initializing_stepper( void ) const | ||
|  |      * \brief Returns the internal initializing stepper instance. | ||
|  |      * \return initializing_stepper | ||
|  |      */ | ||
|  | 
 | ||
|  |     /** | ||
|  |      * \fn initializing_stepper_type& adams_bashforth::initializing_stepper( void ) | ||
|  |      * \brief Returns the internal initializing stepper instance. | ||
|  |      * \return initializing_stepper | ||
|  |      */ | ||
|  | 
 | ||
|  | } // odeint | ||
|  | } // numeric | ||
|  | } // boost | ||
|  | 
 | ||
|  | 
 | ||
|  | 
 | ||
|  | #endif // BOOST_NUMERIC_ODEINT_STEPPER_ADAMS_BASHFORTH_HPP_INCLUDED |