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boost::numeric::odeint::runge_kutta4_classic — The classical RungeKutta stepper of fourth order.
// In header: <boost/numeric/odeint/stepper/runge_kutta4_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_kutta4_classic : public explicit_stepper_base { public: // types typedef explicit_stepper_base< runge_kutta4_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_kutta4_classic(const algebra_type & = algebra_type()); // public member functions 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 StateType> void adjust_size(const StateType &); // private member functions template<typename StateIn> bool resize_impl(const StateIn &); };
The RungeKutta method of fourth order is one standard method for solving ordinary differential equations and is widely used, see also en.wikipedia.org/wiki/RungeKutta_methods The method is explicit and fulfills the Stepper concept. Step size control or continuous output are not provided. This class implements the method directly, hence the generic RungeKutta algorithm is not used.
This class derives from explicit_stepper_base and inherits its interface via CRTP (current recurring template pattern). For more details see explicit_stepper_base.
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_kutta4_classic
public
construct/copy/destructrunge_kutta4_classic(const algebra_type & algebra = algebra_type());Constructs the
runge_kutta4_classic
class. This constructor can be used as a default constructor if the algebra has a default constructor.
Parameters: 

runge_kutta4_classic
public member functionstemplate<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);This method performs one step. The derivative
dxdt
of in
at the time t
is passed to the method. The result is updated out of place, hence the input is in in
and the output in out
. Access to this step functionality is provided by explicit_stepper_base and do_step_impl
should not be called directly.
Parameters: 

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