integrate_const.hpp 5.51 KB
Newer Older
xuebingbing's avatar
xuebingbing committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163
/*
 [auto_generated]
 boost/numeric/odeint/integrate/detail/integrate_const.hpp

 [begin_description]
 integrate const implementation
 [end_description]

 Copyright 2012 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_CONST_HPP_INCLUDED
#define BOOST_NUMERIC_ODEINT_INTEGRATE_DETAIL_INTEGRATE_CONST_HPP_INCLUDED

#include <boost/numeric/odeint/util/unwrap_reference.hpp>
#include <boost/numeric/odeint/stepper/stepper_categories.hpp>
#include <boost/numeric/odeint/util/unit_helper.hpp>
#include <boost/numeric/odeint/integrate/detail/integrate_adaptive.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(
        Stepper stepper , System system , State &start_state ,
        Time &start_time , Time end_time , Time &dt ,
        Observer observer , controlled_stepper_tag
);


template< class Stepper , class System , class State , class Time , class Observer >
size_t integrate_const(
        Stepper stepper , System system , State &start_state ,
        Time start_time , Time end_time , Time dt ,
        Observer observer , stepper_tag 
)
{
    typename odeint::unwrap_reference< Observer >::type &obs = observer;
    typename odeint::unwrap_reference< Stepper >::type &st = stepper;
    
    Time time = start_time;
    int step = 0;
    // cast time+dt explicitely in case of expression templates (e.g. multiprecision)
    while( less_eq_with_sign( static_cast<Time>(time+dt) , end_time , dt ) )
    {
        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
        ++step;
        time = start_time + static_cast< typename unit_value_type<Time>::type >(step) * dt;
    }
    obs( start_state , time );

    return step;
}



template< class Stepper , class System , class State , class Time , class Observer >
size_t integrate_const(
        Stepper stepper , System system , State &start_state ,
        Time start_time , Time end_time , Time dt ,
        Observer observer , controlled_stepper_tag 
)
{
    typename odeint::unwrap_reference< Observer >::type &obs = observer;
    
    Time time = start_time;
    const Time time_step = dt;
    int real_steps = 0;
    int step = 0;
    
    while( less_eq_with_sign( static_cast<Time>(time+time_step) , end_time , dt ) )
    {
        obs( start_state , time );
        real_steps += detail::integrate_adaptive( stepper , system , start_state , 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
        step++;
        time = start_time + static_cast< typename unit_value_type<Time>::type >(step) * time_step;
    }
    obs( start_state , time );

    return real_steps;
}


template< class Stepper , class System , class State , class Time , class Observer >
size_t integrate_const(
        Stepper stepper , System system , State &start_state ,
        Time start_time , Time end_time , Time dt ,
        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;
    
    st.initialize( start_state , time , dt );
    obs( start_state , time );
    time += dt;

    int obs_step( 1 );
    int real_step( 0 );
    
    while( less_with_sign( static_cast<Time>(time+dt) , end_time , dt ) )
    {
        while( less_eq_with_sign( time , st.current_time() , dt ) )
        {
            st.calc_state( time , start_state );
            obs( start_state , time );
            ++obs_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 >(obs_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() ) )
        {
            while( less_eq_with_sign( st.current_time() , time , dt ) )
            {
                st.do_step( system );
                ++real_step;
            }
        }
        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() , end_time - st.current_time() );
            st.do_step( system );
            ++real_step;
        }
        
    }
    // last observation, if we are still in observation interval
    if( less_eq_with_sign( time , end_time , dt ) )
    {
        st.calc_state( time , start_state );
        obs( start_state , time );
    }
    
    return real_step;
}


} } } }

#endif