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