Class template runge_kutta_cash_karp54

Class template runge_kutta_cash_karp54_classic

boost::numeric::odeint::runge_kutta_cash_karp54_classic — The Runge-Kutta Cash-Karp method implemented without the generic Runge-Kutta algorithm.

Synopsis

// In header: <boost/numeric/odeint/stepper/runge_kutta_cash_karp54_classic.hpp>

template<typename State, typename Value = double, typename Deriv = State, 
         typename Time = Value, 
         typename Algebra = typename algebra_dispatcher< State >::algebra_type, 
         typename Operations = typename operations_dispatcher< State >::operations_type, 
         typename Resizer = initially_resizer> 
class runge_kutta_cash_karp54_classic : public explicit_error_stepper_base {
public:
  // types
  typedef explicit_error_stepper_base< runge_kutta_cash_karp54_classic< ... >,... > stepper_base_type;
  typedef stepper_base_type::state_type                                             state_type;       
  typedef stepper_base_type::value_type                                             value_type;       
  typedef stepper_base_type::deriv_type                                             deriv_type;       
  typedef stepper_base_type::time_type                                              time_type;        
  typedef stepper_base_type::algebra_type                                           algebra_type;     
  typedef stepper_base_type::operations_type                                        operations_type;  
  typedef stepper_base_type::resizer_type                                           resizer_type;     

  // construct/copy/destruct
  runge_kutta_cash_karp54_classic(const algebra_type & = algebra_type());

  // public member functions
  template<typename System, typename StateIn, typename DerivIn, 
           typename StateOut, typename Err> 
    void do_step_impl(System, const StateIn &, const DerivIn &, time_type, 
                      StateOut &, time_type, Err &);
  template<typename System, typename StateIn, typename DerivIn, 
           typename StateOut> 
    void do_step_impl(System, const StateIn &, const DerivIn &, time_type, 
                      StateOut &, time_type);
  template<typename StateIn> void adjust_size(const StateIn &);

  // private member functions
  template<typename StateIn> bool resize_impl(const StateIn &);
};

Description

The Runge-Kutta Cash-Karp method is one of the standard methods for solving ordinary differential equations, see en.wikipedia.org/wiki/Cash-Karp_method. The method is explicit and fulfills the Error Stepper concept. Step size control is provided but continuous output is not available for this method.

This class derives from explicit_error_stepper_base and inherits its interface via CRTP (current recurring template pattern). This class implements the method directly, hence the generic Runge-Kutta algorithm is not used.

Template Parameters

```
typename State
```
The state type.
```
typename Value = double
```
The value type.
```
typename Deriv = State
```
The type representing the time derivative of the state.
```
typename Time = Value
```
The time representing the independent variable - the time.

typename Algebra = typename algebra_dispatcher< State >::algebra_type

The algebra type.

typename Operations = typename operations_dispatcher< State >::operations_type

The operations type.

```
typename Resizer = initially_resizer
```
The resizer policy type.

`runge_kutta_cash_karp54_classic` public construct/copy/destruct

```
runge_kutta_cash_karp54_classic(const algebra_type & algebra = algebra_type());
```
Constructs the runge_kutta_cash_karp54_classic class. This constructor can be used as a default constructor if the algebra has a default constructor.

Parameters:

algebra

A copy of algebra is made and stored inside explicit_stepper_base.

`runge_kutta_cash_karp54_classic` public member functions

template<typename System, typename StateIn, typename DerivIn, 
         typename StateOut, typename Err> 
  void do_step_impl(System system, const StateIn & in, const DerivIn & dxdt, 
                    time_type t, StateOut & out, time_type dt, Err & xerr);

template<typename System, typename StateIn, typename DerivIn, 
         typename StateOut> 
  void do_step_impl(System system, const StateIn & in, const DerivIn & dxdt, 
                    time_type t, StateOut & out, time_type dt);

```
template<typename StateIn> void adjust_size(const StateIn & x);
```
Adjust the size of all temporaries in the stepper manually.

Parameters:

x

A state from which the size of the temporaries to be resized is deduced.

`runge_kutta_cash_karp54_classic` private member functions

template<typename StateIn> bool resize_impl(const StateIn & x);