| /* |
| [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 |