summaryrefslogtreecommitdiff
path: root/boost/numeric/odeint/iterator/impl/const_step_iterator_impl.hpp
blob: e23474c7afbb74ec3f96af4206760a5cfffdd6f6 (plain)
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
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
/*
  [auto_generated]
  boost/numeric/odeint/iterator/detail/const_step_iterator_impl.hpp

  [begin_description]
  tba.
  [end_description]

  Copyright 2013 Karsten Ahnert
  Copyright 2013 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_ITERATOR_DETAIL_CONST_STEP_ITERATOR_IMPL_HPP_DEFINED
#define BOOST_NUMERIC_ODEINT_ITERATOR_DETAIL_CONST_STEP_ITERATOR_IMPL_HPP_DEFINED

#include <boost/numeric/odeint/iterator/detail/ode_iterator_base.hpp>
#include <boost/numeric/odeint/util/unit_helper.hpp>



namespace boost {
namespace numeric {
namespace odeint {


    template< class Iterator , class Stepper , class System , class State , typename Tag , class StepperTag >
    class const_step_iterator_impl;


    /*
     * Specilization for steppers and error steppers
     */
    template< class Iterator , class Stepper , class System , class State , typename Tag >
    class const_step_iterator_impl< Iterator , Stepper , System , State , Tag , stepper_tag >
        : public detail::ode_iterator_base< Iterator , Stepper , System , State , Tag >
    {
    private:

        typedef Stepper stepper_type;
        typedef System system_type;
        typedef typename boost::numeric::odeint::unwrap_reference< stepper_type >::type unwrapped_stepper_type;
        typedef State state_type;
        typedef typename traits::time_type< stepper_type >::type time_type;
        typedef typename traits::value_type< stepper_type >::type ode_value_type;
        #ifndef DOXYGEN_SKIP
        typedef detail::ode_iterator_base< Iterator , Stepper , System , State , Tag > base_type;
        #endif

    public:
   
        /**
         * \brief Constructs a const_step_iterator. This constructor should be used to construct the begin iterator.
         *
         * \param stepper The stepper to use during the iteration.
         * \param sys The system function (ODE) to solve.
         * \param s The initial state. const_step_iterator stores a reference of s and changes its value during the iteration.
         * \param t The initial time.
         * \param t_end The end time, at which the iteration should stop.
         * \param dt The initial time step.
         */
        const_step_iterator_impl( stepper_type stepper , system_type sys , state_type &s , time_type t , time_type t_end , time_type dt )
            : base_type( stepper , sys , t , dt ) , m_t_start( t ) , m_t_end( t_end ) , m_state( &s ) , m_step( 0 )
        {
            if( detail::less_with_sign( this->m_t_end , this->m_t , this->m_dt ) )
                this->m_at_end = true;
        }

        /**
         * \brief Constructs a const_step_iterator. This constructor should be used to construct the end iterator.
         *
         * \param stepper The stepper to use during the iteration.
         * \param sys The system function (ODE) to solve.
         * \param s The initial state. const_step_iterator stores a reference of s and changes its value during the iteration.
         */
        const_step_iterator_impl( stepper_type stepper , system_type sys , state_type& /* s */ )
            : base_type( stepper , sys ) { }

    protected:

        friend class boost::iterator_core_access;

        void increment()
        {
            if( detail::less_eq_with_sign( static_cast<time_type>(this->m_t+this->m_dt) ,
                                           this->m_t_end , this->m_dt ) )
            {
                unwrapped_stepper_type &stepper = this->m_stepper;
                stepper.do_step( this->m_system , *this->m_state , this->m_t , this->m_dt );
                // use integer to compute current time to reduce roundoff errors
                this->m_step++;
                this->m_t = this->m_t_start + static_cast< typename unit_value_type<time_type>::type >(this->m_step)*this->m_dt;
            } else {
                this->m_at_end = true;
            }
        }

    public:
        const state_type& get_state() const
        {
            return *m_state;
        }

    private:
        time_type m_t_start;
        time_type m_t_end;
        state_type* m_state;
        size_t m_step;

    };



    /*
     * Specilization for dense output stepper
     */
    /**
     * \brief ODE Iterator with constant step size. The value type of this iterator is the state type of the stepper.
     *
     * Implements an ODE iterator solving the ODE with constant steps. Uses dense-output steppers.
     * const_step_iterator is a model of single-pass iterator.
     *
     * The value type of this iterator is the state type of the stepper. Hence one can only access the state and not the current time.
     *
     * \tparam Stepper The stepper type which should be used during the iteration.
     * \tparam System The type of the system function (ODE) which should be solved.
     */
    template< class Iterator , class Stepper , class System , class State , typename Tag >
    class const_step_iterator_impl< Iterator , Stepper , System , State , Tag , dense_output_stepper_tag >
        : public detail::ode_iterator_base< Iterator , Stepper , System , State , Tag >
    {
    private:

        typedef Stepper stepper_type;
        typedef System system_type;
        typedef typename boost::numeric::odeint::unwrap_reference< stepper_type >::type unwrapped_stepper_type;
        typedef State state_type;
        typedef typename traits::time_type< stepper_type >::type time_type;
        typedef typename traits::value_type< stepper_type >::type ode_value_type;
        #ifndef DOXYGEN_SKIP
        typedef detail::ode_iterator_base< Iterator , Stepper , System , State , Tag > base_type;
        #endif

    public:

        /**
         * \brief Constructs a const_step_iterator. This constructor should be used to construct the begin iterator.
         *
         * \param stepper The stepper to use during the iteration.
         * \param sys The system function (ODE) to solve.
         * \param s The initial state. const_step_iterator stores a reference of s and changes its value during the iteration.
         * \param t The initial time.
         * \param t_end The end time, at which the iteration should stop.
         * \param dt The initial time step.
         */
        const_step_iterator_impl( stepper_type stepper , system_type sys , state_type &s , time_type t , time_type t_end , time_type dt )
            : base_type( stepper , sys , t , dt ) , m_t_start( t ) , m_t_end( t_end ) , m_state( &s ) , m_step( 0 )
        {
            if( detail::less_eq_with_sign( this->m_t , this->m_t_end , this->m_dt ) )
            {
                unwrapped_stepper_type &st = this->m_stepper;
                st.initialize( * ( this->m_state ) , this->m_t , this->m_dt );
            } else {
                this->m_at_end = true;
            }
        }

        /**
         * \brief Constructs a const_step_iterator. This constructor should be used to construct the end iterator.
         *
         * \param stepper The stepper to use during the iteration.
         * \param sys The system function (ODE) to solve.
         * \param s The initial state. const_step_iterator stores a reference of s and changes its value during the iteration.
         */
        const_step_iterator_impl( stepper_type stepper , system_type sys , state_type &s )
            : base_type( stepper , sys ) , m_state( &s )
        {
        }



    protected:

        friend class boost::iterator_core_access;

        void increment( void )
        {
            if( detail::less_eq_with_sign( static_cast<time_type>(this->m_t+this->m_dt) ,
                                           this->m_t_end , this->m_dt ) )
            {
                unwrapped_stepper_type &stepper = this->m_stepper;
                // use integer to compute current time to reduce roundoff errors
                this->m_step++;
                this->m_t = this->m_t_start + static_cast< typename unit_value_type<time_type>::type >(this->m_step)*this->m_dt;
                while( detail::less_with_sign( stepper.current_time() , this->m_t ,
                       stepper.current_time_step() ) )
                {
                    stepper.do_step( this->m_system );
                }
                stepper.calc_state( this->m_t , *( this->m_state ) );
            } else {
                this->m_at_end = true;
            }
        }

    public:
        const state_type& get_state() const
        {
            return *m_state;
        }

    private:
        time_type m_t_start;
        time_type m_t_end;
        state_type* m_state;
        size_t m_step;
    };

} // namespace odeint
} // namespace numeric
} // namespace boost


#endif // BOOST_NUMERIC_ODEINT_ITERATOR_DETAIL_CONST_STEP_ITERATOR_IMPL_HPP_DEFINED