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

Add boost headers

+/*
+ [auto_generated]
+ boost/numeric/odeint/stepper/euler.hpp
+
+ [begin_description]
+ Implementation of the classical explicit Euler stepper. This method is really simple and should only
+ be used for demonstration purposes.
+ [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_EULER_HPP_INCLUDED
+#define BOOST_NUMERIC_ODEINT_STEPPER_EULER_HPP_INCLUDED
+
+
+#include <boost/numeric/odeint/stepper/base/explicit_stepper_base.hpp>
+#include <boost/numeric/odeint/util/resizer.hpp>
+#include <boost/numeric/odeint/algebra/range_algebra.hpp>
+#include <boost/numeric/odeint/algebra/default_operations.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 euler
+: public explicit_stepper_base<
+  euler< State , Value , Deriv , Time , Algebra , Operations , Resizer > ,
+  1 , State , Value , Deriv , Time , Algebra , Operations , Resizer >
+#else
+class euler : public explicit_stepper_base
+#endif
+{
+public :
+
+    #ifndef DOXYGEN_SKIP
+    typedef explicit_stepper_base< euler< State , Value , Deriv , Time , Algebra , Operations , Resizer > , 1 , State , Value , Deriv , Time , Algebra , Operations , Resizer > stepper_base_type;
+    #else
+    typedef explicit_stepper_base< euler< ... > , ... > 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 
+
+
+    euler( 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 )
+    {
+        stepper_base_type::m_algebra.for_each3( out , in , dxdt ,
+                typename operations_type::template scale_sum2< value_type , time_type >( 1.0 , dt ) );
+
+    }
+
+    template< class StateOut , class StateIn1 , class StateIn2 >
+    void calc_state( StateOut &x , time_type t ,  const StateIn1 &old_state , time_type t_old , const StateIn2 &current_state , time_type t_new ) const
+    {
+        const time_type delta = t - t_old;
+        stepper_base_type::m_algebra.for_each3( x , old_state , stepper_base_type::m_dxdt.m_v ,
+                typename operations_type::template scale_sum2< value_type , time_type >( 1.0 , delta ) );
+    }
+
+    template< class StateType >
+    void adjust_size( const StateType &x )
+    {
+        stepper_base_type::adjust_size( x );
+    }
+};
+
+
+
+/********** DOXYGEN ***********/
+
+/**
+ * \class euler
+ * \brief An implementation of the Euler method.
+ *
+ * The Euler method is a very simply solver for ordinary differential equations. This method should not be used
+ * for real applications. It is only useful for demonstration purposes. Step size control is not provided but
+ * trivial continuous output is available.
+ * 
+ * This class derives from explicit_stepper_base and inherits its interface via CRTP (current recurring template pattern),
+ * 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 euler::euler( const algebra_type &algebra )
+     * \brief Constructs the euler class. This constructor can be used as a default
+     * constructor of the algebra has a default constructor.
+     * \param algebra A copy of algebra is made and stored inside explicit_stepper_base.
+     */
+    
+    /**
+     * \fn euler::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 euler::calc_state( StateOut &x , time_type t ,  const StateIn1 &old_state , time_type t_old , const StateIn2 &current_state , time_type t_new ) const
+     * \brief This method is used for continuous output and it calculates the state `x` at a time `t` from the 
+     * knowledge of two states `old_state` and `current_state` at time points `t_old` and `t_new`.
+     */
+
+    /**
+     * \fn euler::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_EULER_HPP_INCLUDED