256 lines
11 KiB
Plaintext
256 lines
11 KiB
Plaintext
/*
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[auto_generated]
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boost/numeric/odeint/stepper/explicit_error_generic_rk.hpp
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[begin_description]
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Implementation of the generic Runge Kutta error stepper. Base class for many RK error steppers.
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[end_description]
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Copyright 2011-2013 Mario Mulansky
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Copyright 2011-2013 Karsten Ahnert
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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_EXPLICIT_ERROR_GENERIC_RK_HPP_INCLUDED
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#define BOOST_NUMERIC_ODEINT_STEPPER_EXPLICIT_ERROR_GENERIC_RK_HPP_INCLUDED
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#include <boost/numeric/odeint/stepper/base/explicit_error_stepper_base.hpp>
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#include <boost/numeric/odeint/algebra/default_operations.hpp>
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#include <boost/numeric/odeint/algebra/range_algebra.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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#include <boost/numeric/odeint/stepper/detail/generic_rk_algorithm.hpp>
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#include <boost/numeric/odeint/stepper/detail/generic_rk_call_algebra.hpp>
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#include <boost/numeric/odeint/stepper/detail/generic_rk_operations.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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namespace boost {
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namespace numeric {
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namespace odeint {
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template<
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size_t StageCount,
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size_t Order,
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size_t StepperOrder ,
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size_t ErrorOrder ,
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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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>
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#ifndef DOXYGEN_SKIP
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class explicit_error_generic_rk
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: public explicit_error_stepper_base<
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explicit_error_generic_rk< StageCount , Order , StepperOrder , ErrorOrder , State ,
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Value , Deriv , Time , Algebra , Operations , Resizer > ,
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Order , StepperOrder , ErrorOrder , State , Value , Deriv , Time , Algebra ,
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Operations , Resizer >
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#else
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class explicit_error_generic_rk : public explicit_error_stepper_base
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#endif
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{
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public:
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#ifndef DOXYGEN_SKIP
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typedef explicit_error_stepper_base<
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explicit_error_generic_rk< StageCount , Order , StepperOrder , ErrorOrder , State ,
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Value , Deriv , Time , Algebra , Operations , Resizer > ,
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Order , StepperOrder , ErrorOrder , State , Value , Deriv , Time , Algebra ,
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Operations , Resizer > stepper_base_type;
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#else
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typedef explicit_stepper_base< ... > stepper_base_type;
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#endif
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typedef typename stepper_base_type::state_type state_type;
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typedef typename stepper_base_type::wrapped_state_type wrapped_state_type;
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typedef typename stepper_base_type::value_type value_type;
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typedef typename stepper_base_type::deriv_type deriv_type;
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typedef typename stepper_base_type::wrapped_deriv_type wrapped_deriv_type;
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typedef typename stepper_base_type::time_type time_type;
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typedef typename stepper_base_type::algebra_type algebra_type;
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typedef typename stepper_base_type::operations_type operations_type;
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typedef typename stepper_base_type::resizer_type resizer_type;
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#ifndef DOXYGEN_SKIP
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typedef explicit_error_generic_rk< StageCount , Order , StepperOrder , ErrorOrder , State ,
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Value , Deriv , Time , Algebra , Operations , Resizer > stepper_type;
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#endif
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typedef detail::generic_rk_algorithm< StageCount , Value , Algebra , Operations > rk_algorithm_type;
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typedef typename rk_algorithm_type::coef_a_type coef_a_type;
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typedef typename rk_algorithm_type::coef_b_type coef_b_type;
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typedef typename rk_algorithm_type::coef_c_type coef_c_type;
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static const size_t stage_count = StageCount;
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private:
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public:
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// we use an explicit_generic_rk to do the normal rk step
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// and add a separate calculation of the error estimate afterwards
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explicit_error_generic_rk( const coef_a_type &a ,
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const coef_b_type &b ,
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const coef_b_type &b2 ,
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const coef_c_type &c ,
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const algebra_type &algebra = algebra_type() )
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: stepper_base_type( algebra ) , m_rk_algorithm( a , b , c ) , m_b2( b2 )
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{ }
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template< class System , class StateIn , class DerivIn , class StateOut , class Err >
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void do_step_impl( System system , const StateIn &in , const DerivIn &dxdt ,
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time_type t , StateOut &out , time_type dt , Err &xerr )
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{
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// normal step
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do_step_impl( system , in , dxdt , t , out , dt );
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// additionally, perform the error calculation
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detail::template generic_rk_call_algebra< StageCount , algebra_type >()( stepper_base_type::m_algebra ,
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xerr , dxdt , m_F , detail::generic_rk_scale_sum_err< StageCount , operations_type , value_type , time_type >( m_b2 , dt) );
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}
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template< class System , class StateIn , class DerivIn , class StateOut >
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void do_step_impl( System system , const StateIn &in , const DerivIn &dxdt ,
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time_type t , StateOut &out , time_type dt )
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{
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m_resizer.adjust_size( in , detail::bind( &stepper_type::template resize_impl< StateIn > , detail::ref( *this ) , detail::_1 ) );
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// actual calculation done in generic_rk.hpp
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m_rk_algorithm.do_step( stepper_base_type::m_algebra , system , in , dxdt , t , out , dt , m_x_tmp.m_v , m_F );
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}
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template< class StateIn >
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void adjust_size( const StateIn &x )
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{
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resize_impl( x );
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stepper_base_type::adjust_size( x );
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}
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private:
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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_x_tmp , x , typename is_resizeable<state_type>::type() );
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for( size_t i = 0 ; i < StageCount-1 ; ++i )
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{
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resized |= adjust_size_by_resizeability( m_F[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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rk_algorithm_type m_rk_algorithm;
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coef_b_type m_b2;
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resizer_type m_resizer;
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wrapped_state_type m_x_tmp;
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wrapped_deriv_type m_F[StageCount-1];
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};
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/********* DOXYGEN *********/
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/**
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* \class explicit_error_generic_rk
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* \brief A generic implementation of explicit Runge-Kutta algorithms with error estimation. This class is as a
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* base class for all explicit Runge-Kutta steppers with error estimation.
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*
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* This class implements the explicit Runge-Kutta algorithms with error estimation in a generic way.
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* The Butcher tableau is passed to the stepper which constructs the stepper scheme with the help of a
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* template-metaprogramming algorithm. ToDo : Add example!
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*
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* This class derives explicit_error_stepper_base which provides the stepper interface.
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*
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* \tparam StageCount The number of stages of the Runge-Kutta algorithm.
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* \tparam Order The order of a stepper if the stepper is used without error estimation.
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* \tparam StepperOrder The order of a step if the stepper is used with error estimation. Usually Order and StepperOrder have
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* the same value.
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* \tparam ErrorOrder The order of the error step if the stepper is used with error estimation.
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* \tparam State The type representing the state of the ODE.
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* \tparam Value The floating point type which is used in the computations.
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* \tparam Time The type representing the independent variable - the time - of the ODE.
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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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*/
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/**
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* \fn explicit_error_generic_rk::explicit_error_generic_rk( const coef_a_type &a , const coef_b_type &b , const coef_b_type &b2 , const coef_c_type &c , const algebra_type &algebra )
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* \brief Constructs the explicit_error_generik_rk class with the given parameters a, b, b2 and c. See examples section for details on the coefficients.
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*
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* \param a Triangular matrix of parameters b in the Butcher tableau.
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* \param b Last row of the butcher tableau.
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* \param b2 Parameters for lower-order evaluation to estimate the error.
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* \param c Parameters to calculate the time points in the Butcher tableau.
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* \param algebra A copy of algebra is made and stored inside explicit_stepper_base.
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*/
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/**
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* \fn explicit_error_generic_rk::do_step_impl( System system , const StateIn &in , const DerivIn &dxdt , time_type t , StateOut &out , time_type dt , Err &xerr )
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* \brief This method performs one step. The derivative `dxdt` of `in` at the time `t` is passed to the method.
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* The result is updated out-of-place, hence the input is in `in` and the output in `out`. Futhermore, an
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* estimation of the error is stored in `xerr`. `do_step_impl` is used by explicit_error_stepper_base.
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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 dxdt The derivative of x at t.
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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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* \param xerr The result of the error estimation is written in xerr.
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*/
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/**
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* \fn explicit_error_generic_rk::do_step_impl( System system , const StateIn &in , const DerivIn &dxdt , time_type t , StateOut &out , time_type dt )
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* \brief This method performs one step. The derivative `dxdt` of `in` at the time `t` is passed to the method.
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* The result is updated out-of-place, hence the input is in `in` and the output in `out`.
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* Access to this step functionality is provided by explicit_stepper_base and
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* `do_step_impl` should not be called directly.
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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 dxdt The derivative of x at t.
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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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* \fn explicit_error_generic_rk::adjust_size( const StateIn &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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#endif // BOOST_NUMERIC_ODEINT_STEPPER_EXPLICIT_ERROR_GENERIC_RK_HPP_INCLUDED
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