整理

include/boost/numeric/odeint/integrate/detail/integrate_n_steps.hpp

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+/*
+ [auto_generated]
+ boost/numeric/odeint/integrate/detail/integrate_n_steps.hpp
+
+ [begin_description]
+ integrate steps implementation
+ [end_description]
+
+ Copyright 2012-2015 Mario Mulansky
+ Copyright 2012 Christoph Koke
+ Copyright 2012 Karsten Ahnert
+
+ 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_INTEGRATE_DETAIL_INTEGRATE_N_STEPS_HPP_INCLUDED
+#define BOOST_NUMERIC_ODEINT_INTEGRATE_DETAIL_INTEGRATE_N_STEPS_HPP_INCLUDED
+
+#include <boost/numeric/odeint/util/unwrap_reference.hpp>
+#include <boost/numeric/odeint/stepper/stepper_categories.hpp>
+#include <boost/numeric/odeint/integrate/detail/integrate_adaptive.hpp>
+#include <boost/numeric/odeint/util/unit_helper.hpp>
+
+#include <boost/numeric/odeint/util/detail/less_with_sign.hpp>
+
+namespace boost {
+namespace numeric {
+namespace odeint {
+namespace detail {
+
+// forward declaration
+template< class Stepper , class System , class State , class Time , class Observer >
+size_t integrate_adaptive_checked(
+        Stepper stepper , System system , State &start_state ,
+        Time &start_time , Time end_time , Time &dt ,
+        Observer observer, controlled_stepper_tag
+);
+
+
+/* basic version */
+template< class Stepper , class System , class State , class Time , class Observer>
+Time integrate_n_steps(
+        Stepper stepper , System system , State &start_state ,
+        Time start_time , Time dt , size_t num_of_steps ,
+        Observer observer , stepper_tag )
+{
+    typename odeint::unwrap_reference< Observer >::type &obs = observer;
+    typename odeint::unwrap_reference< Stepper >::type &st = stepper;
+
+    Time time = start_time;
+
+    for( size_t step = 0; step < num_of_steps ; ++step )
+    {
+        obs( start_state , time );
+        st.do_step( system , start_state , time , dt );
+        // direct computation of the time avoids error propagation happening when using time += dt
+        // we need clumsy type analysis to get boost units working here
+        time = start_time + static_cast< typename unit_value_type<Time>::type >( step+1 ) * dt;
+    }
+    obs( start_state , time );
+
+    return time;
+}
+
+
+/* controlled version */
+template< class Stepper , class System , class State , class Time , class Observer >
+Time integrate_n_steps(
+        Stepper stepper , System system , State &start_state ,
+        Time start_time , Time dt , size_t num_of_steps ,
+        Observer observer , controlled_stepper_tag )
+{
+    typename odeint::unwrap_reference< Observer >::type &obs = observer;
+
+    Time time = start_time;
+    Time time_step = dt;
+
+    for( size_t step = 0; step < num_of_steps ; ++step )
+    {
+        obs( start_state , time );
+        // integrate_adaptive_checked uses the given checker to throw if an overflow occurs
+        detail::integrate_adaptive(stepper, system, start_state, time, static_cast<Time>(time + time_step), dt,
+                                   null_observer(), controlled_stepper_tag());
+        // direct computation of the time avoids error propagation happening when using time += dt
+        // we need clumsy type analysis to get boost units working here
+        time = start_time + static_cast< typename unit_value_type<Time>::type >(step+1) * time_step;
+    }
+    obs( start_state , time );
+
+    return time;
+}
+
+
+/* dense output version */
+template< class Stepper , class System , class State , class Time , class Observer >
+Time integrate_n_steps(
+        Stepper stepper , System system , State &start_state ,
+        Time start_time , Time dt , size_t num_of_steps ,
+        Observer observer , dense_output_stepper_tag )
+{
+    typename odeint::unwrap_reference< Observer >::type &obs = observer;
+    typename odeint::unwrap_reference< Stepper >::type &st = stepper;
+
+    Time time = start_time;
+    const Time end_time = start_time + static_cast< typename unit_value_type<Time>::type >(num_of_steps) * dt;
+
+    st.initialize( start_state , time , dt );
+
+    size_t step = 0;
+
+    while( step < num_of_steps )
+    {
+        while( less_with_sign( time , st.current_time() , st.current_time_step() ) )
+        {
+            st.calc_state( time , start_state );
+            obs( start_state , time );
+            ++step;
+            // direct computation of the time avoids error propagation happening when using time += dt
+            // we need clumsy type analysis to get boost units working here
+            time = start_time + static_cast< typename unit_value_type<Time>::type >(step) * dt;
+        }
+
+        // we have not reached the end, do another real step
+        if( less_with_sign( static_cast<Time>(st.current_time()+st.current_time_step()) ,
+                            end_time ,
+                            st.current_time_step() ) )
+        {
+            st.do_step( system );
+        }
+        else if( less_with_sign( st.current_time() , end_time , st.current_time_step() ) )
+        { // do the last step ending exactly on the end point
+            st.initialize( st.current_state() , st.current_time() , static_cast<Time>(end_time - st.current_time()) );
+            st.do_step( system );
+        }
+    }
+
+    // make sure we really end exactly where we should end
+    while( st.current_time() < end_time )
+    {
+        if( less_with_sign( end_time ,
+                            static_cast<Time>(st.current_time()+st.current_time_step()) ,
+                            st.current_time_step() ) )
+            st.initialize( st.current_state() , st.current_time() , static_cast<Time>(end_time - st.current_time()) );
+        st.do_step( system );
+    }
+
+    // observation at final point
+    obs( st.current_state() , end_time );
+
+    return time;
+}
+
+
+}
+}
+}
+}
+
+#endif /* BOOST_NUMERIC_ODEINT_INTEGRATE_DETAIL_INTEGRATE_N_STEPS_HPP_INCLUDED */