comparison DEPENDENCIES/generic/include/boost/numeric/odeint/stepper/runge_kutta4_classic.hpp @ 16:2665513ce2d3

Add boost headers

+/*
+ [auto_generated]
+ boost/numeric/odeint/stepper/runge_kutta4_classic.hpp
+
+ [begin_description]
+ Implementation for the classical Runge Kutta stepper.
+ [end_description]
+
+ Copyright 2009-2011 Karsten Ahnert
+ Copyright 2009-2011 Mario Mulansky
+
+ 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_RUNGE_KUTTA4_CLASSIC_HPP_INCLUDED
+#define BOOST_NUMERIC_ODEINT_STEPPER_RUNGE_KUTTA4_CLASSIC_HPP_INCLUDED
+
+
+
+#include <boost/numeric/odeint/stepper/base/explicit_stepper_base.hpp>
+#include <boost/numeric/odeint/algebra/range_algebra.hpp>
+#include <boost/numeric/odeint/algebra/default_operations.hpp>
+
+#include <boost/numeric/odeint/util/state_wrapper.hpp>
+#include <boost/numeric/odeint/util/is_resizeable.hpp>
+#include <boost/numeric/odeint/util/resizer.hpp>
+
+namespace boost {
+namespace numeric {
+namespace odeint {
+
+template<
+class State ,
+class Value = double ,
+class Deriv = State ,
+class Time = Value ,
+class Algebra = range_algebra ,
+class Operations = default_operations ,
+class Resizer = initially_resizer
+>
+#ifndef DOXYGEN_SKIP
+class runge_kutta4_classic
+: public explicit_stepper_base<
+  runge_kutta4_classic< State , Value , Deriv , Time , Algebra , Operations , Resizer > ,
+  4 , State , Value , Deriv , Time , Algebra , Operations , Resizer >
+#else
+class runge_kutta4_classic : public explicit_stepper_base
+#endif
+{
+
+public :
+
+    #ifndef DOXYGEN_SKIP
+    typedef explicit_stepper_base<
+    runge_kutta4_classic< State , Value , Deriv , Time , Algebra , Operations , Resizer > ,
+    4 , State , Value , Deriv , Time , Algebra , Operations , Resizer > stepper_base_type;
+    #else
+    typedef explicit_stepper_base< runge_kutta4_classic< ... > , ... > stepper_base_type;
+    #endif
+
+    typedef typename stepper_base_type::state_type state_type;
+    typedef typename stepper_base_type::value_type value_type;
+    typedef typename stepper_base_type::deriv_type deriv_type;
+    typedef typename stepper_base_type::time_type time_type;
+    typedef typename stepper_base_type::algebra_type algebra_type;
+    typedef typename stepper_base_type::operations_type operations_type;
+    typedef typename stepper_base_type::resizer_type resizer_type;
+
+    #ifndef DOXYGEN_SKIP
+    typedef typename stepper_base_type::stepper_type stepper_type;
+    typedef typename stepper_base_type::wrapped_state_type wrapped_state_type;
+    typedef typename stepper_base_type::wrapped_deriv_type wrapped_deriv_type;
+    #endif // DOXYGEN_SKIP
+
+
+
+    runge_kutta4_classic( const algebra_type &algebra = algebra_type() ) : stepper_base_type( algebra )
+    { }
+
+
+    template< class System , class StateIn , class DerivIn , class StateOut >
+    void do_step_impl( System system , const StateIn &in , const DerivIn &dxdt , time_type t , StateOut &out , time_type dt )
+    {
+        // ToDo : check if size of in,dxdt,out are equal?
+
+        static const value_type val1 = static_cast< value_type >( 1 );
+
+        m_resizer.adjust_size( in , detail::bind( &stepper_type::template resize_impl< StateIn > , detail::ref( *this ) , detail::_1 ) );
+
+        typename odeint::unwrap_reference< System >::type &sys = system;
+
+        const time_type dh = dt / static_cast< value_type >( 2 );
+        const time_type th = t + dh;
+
+        // dt * dxdt = k1
+        // m_x_tmp = x + dh*dxdt
+        stepper_base_type::m_algebra.for_each3( m_x_tmp.m_v , in , dxdt ,
+                typename operations_type::template scale_sum2< value_type , time_type >( val1 , dh ) );
+
+
+        // dt * m_dxt = k2
+        sys( m_x_tmp.m_v , m_dxt.m_v , th );
+
+        // m_x_tmp = x + dh*m_dxt
+        stepper_base_type::m_algebra.for_each3( m_x_tmp.m_v , in , m_dxt.m_v ,
+                typename operations_type::template scale_sum2< value_type , time_type >( val1 , dh ) );
+
+
+        // dt * m_dxm = k3
+        sys( m_x_tmp.m_v , m_dxm.m_v , th );
+        //m_x_tmp = x + dt*m_dxm
+        stepper_base_type::m_algebra.for_each3( m_x_tmp.m_v , in , m_dxm.m_v ,
+                typename operations_type::template scale_sum2< value_type , time_type >( val1 , dt ) );
+
+
+        // dt * m_dxh = k4
+        sys( m_x_tmp.m_v , m_dxh.m_v , t + dt );
+        //x += dt/6 * ( m_dxdt + m_dxt + val2*m_dxm )
+        time_type dt6 = dt / static_cast< value_type >( 6 );
+        time_type dt3 = dt / static_cast< value_type >( 3 );
+        stepper_base_type::m_algebra.for_each6( out , in , dxdt , m_dxt.m_v , m_dxm.m_v , m_dxh.m_v ,
+                typename operations_type::template scale_sum5< value_type , time_type , time_type , time_type , time_type >( 1.0 , dt6 , dt3 , dt3 , dt6 ) );
+    }
+
+    template< class StateType >
+    void adjust_size( const StateType &x )
+    {
+        resize_impl( x );
+        stepper_base_type::adjust_size( x );
+    }
+
+private:
+
+    template< class StateIn >
+    bool resize_impl( const StateIn &x )
+    {
+        bool resized = false;
+        resized |= adjust_size_by_resizeability( m_x_tmp , x , typename is_resizeable<state_type>::type() );
+        resized |= adjust_size_by_resizeability( m_dxm , x , typename is_resizeable<deriv_type>::type() );
+        resized |= adjust_size_by_resizeability( m_dxt , x , typename is_resizeable<deriv_type>::type() );
+        resized |= adjust_size_by_resizeability( m_dxh , x , typename is_resizeable<deriv_type>::type() );
+        return resized;
+    }
+
+
+    resizer_type m_resizer;
+
+    wrapped_deriv_type m_dxt;
+    wrapped_deriv_type m_dxm;
+    wrapped_deriv_type m_dxh;
+    wrapped_state_type m_x_tmp;
+
+};
+
+
+/********* DOXYGEN *********/
+
+/**
+ * \class runge_kutta4_classic
+ * \brief The classical Runge-Kutta stepper of fourth order.
+ *
+ * The Runge-Kutta method of fourth order is one standard method for
+ * solving ordinary differential equations and is widely used, see also
+ * <a href="http://en.wikipedia.org/wiki/Runge%E2%80%93Kutta_methods">en.wikipedia.org/wiki/Runge-Kutta_methods</a>
+ * 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 Runge-Kutta 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.
+ *
+ * \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.
+ */
+
+    /**
+     * \fn runge_kutta4_classic::runge_kutta4_classic( const algebra_type &algebra )
+     * \brief Constructs the runge_kutta4_classic 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 inside explicit_stepper_base.
+     */
+
+
+    /**
+     * \fn runge_kutta4_classic::do_step_impl( System system , const StateIn &in , const DerivIn &dxdt , time_type t , StateOut &out , time_type dt )
+     * \brief 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.
+     *
+     * \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 dxdt The derivative of x at t.
+     * \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 runge_kutta4_classic::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.
+     */
+
+} // odeint
+} // numeric
+} // boost
+
+
+#endif // BOOST_NUMERIC_ODEINT_STEPPER_RUNGE_KUTTA4_CLASSIC_HPP_INCLUDED