1 /*
2 [auto_generated]
3 boost/numeric/odeint/integrate/detail/integrate_n_steps.hpp
4
5 [begin_description]
6 integrate steps implementation
7 [end_description]
8
9 Copyright 2012-2015 Mario Mulansky
10 Copyright 2012 Christoph Koke
11 Copyright 2012 Karsten Ahnert
12
13 Distributed under the Boost Software License, Version 1.0.
14 (See accompanying file LICENSE_1_0.txt or
15 copy at http://www.boost.org/LICENSE_1_0.txt)
16 */
17
18 #ifndef BOOST_NUMERIC_ODEINT_INTEGRATE_DETAIL_INTEGRATE_N_STEPS_HPP_INCLUDED
19 #define BOOST_NUMERIC_ODEINT_INTEGRATE_DETAIL_INTEGRATE_N_STEPS_HPP_INCLUDED
20
21 #include <boost/numeric/odeint/util/unwrap_reference.hpp>
22 #include <boost/numeric/odeint/stepper/stepper_categories.hpp>
23 #include <boost/numeric/odeint/integrate/detail/integrate_adaptive.hpp>
24 #include <boost/numeric/odeint/util/unit_helper.hpp>
25
26 #include <boost/numeric/odeint/util/detail/less_with_sign.hpp>
27
28 namespace boost {
29 namespace numeric {
30 namespace odeint {
31 namespace detail {
32
33 // forward declaration
34 template< class Stepper , class System , class State , class Time , class Observer >
35 size_t integrate_adaptive_checked(
36 Stepper stepper , System system , State &start_state ,
37 Time &start_time , Time end_time , Time &dt ,
38 Observer observer, controlled_stepper_tag
39 );
40
41
42 /* basic version */
43 template< class Stepper , class System , class State , class Time , class Observer>
integrate_n_steps(Stepper stepper,System system,State & start_state,Time start_time,Time dt,size_t num_of_steps,Observer observer,stepper_tag)44 Time integrate_n_steps(
45 Stepper stepper , System system , State &start_state ,
46 Time start_time , Time dt , size_t num_of_steps ,
47 Observer observer , stepper_tag )
48 {
49 typename odeint::unwrap_reference< Observer >::type &obs = observer;
50 typename odeint::unwrap_reference< Stepper >::type &st = stepper;
51
52 Time time = start_time;
53
54 for( size_t step = 0; step < num_of_steps ; ++step )
55 {
56 obs( start_state , time );
57 st.do_step( system , start_state , time , dt );
58 // direct computation of the time avoids error propagation happening when using time += dt
59 // we need clumsy type analysis to get boost units working here
60 time = start_time + static_cast< typename unit_value_type<Time>::type >( step+1 ) * dt;
61 }
62 obs( start_state , time );
63
64 return time;
65 }
66
67
68 /* controlled version */
69 template< class Stepper , class System , class State , class Time , class Observer >
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)70 Time integrate_n_steps(
71 Stepper stepper , System system , State &start_state ,
72 Time start_time , Time dt , size_t num_of_steps ,
73 Observer observer , controlled_stepper_tag )
74 {
75 typename odeint::unwrap_reference< Observer >::type &obs = observer;
76
77 Time time = start_time;
78 Time time_step = dt;
79
80 for( size_t step = 0; step < num_of_steps ; ++step )
81 {
82 obs( start_state , time );
83 // integrate_adaptive_checked uses the given checker to throw if an overflow occurs
84 detail::integrate_adaptive(stepper, system, start_state, time, static_cast<Time>(time + time_step), dt,
85 null_observer(), controlled_stepper_tag());
86 // direct computation of the time avoids error propagation happening when using time += dt
87 // we need clumsy type analysis to get boost units working here
88 time = start_time + static_cast< typename unit_value_type<Time>::type >(step+1) * time_step;
89 }
90 obs( start_state , time );
91
92 return time;
93 }
94
95
96 /* dense output version */
97 template< class Stepper , class System , class State , class Time , class Observer >
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)98 Time integrate_n_steps(
99 Stepper stepper , System system , State &start_state ,
100 Time start_time , Time dt , size_t num_of_steps ,
101 Observer observer , dense_output_stepper_tag )
102 {
103 typename odeint::unwrap_reference< Observer >::type &obs = observer;
104 typename odeint::unwrap_reference< Stepper >::type &st = stepper;
105
106 Time time = start_time;
107 const Time end_time = start_time + static_cast< typename unit_value_type<Time>::type >(num_of_steps) * dt;
108
109 st.initialize( start_state , time , dt );
110
111 size_t step = 0;
112
113 while( step < num_of_steps )
114 {
115 while( less_with_sign( time , st.current_time() , st.current_time_step() ) )
116 {
117 st.calc_state( time , start_state );
118 obs( start_state , time );
119 ++step;
120 // direct computation of the time avoids error propagation happening when using time += dt
121 // we need clumsy type analysis to get boost units working here
122 time = start_time + static_cast< typename unit_value_type<Time>::type >(step) * dt;
123 }
124
125 // we have not reached the end, do another real step
126 if( less_with_sign( static_cast<Time>(st.current_time()+st.current_time_step()) ,
127 end_time ,
128 st.current_time_step() ) )
129 {
130 st.do_step( system );
131 }
132 else if( less_with_sign( st.current_time() , end_time , st.current_time_step() ) )
133 { // do the last step ending exactly on the end point
134 st.initialize( st.current_state() , st.current_time() , static_cast<Time>(end_time - st.current_time()) );
135 st.do_step( system );
136 }
137 }
138
139 // make sure we really end exactly where we should end
140 while( st.current_time() < end_time )
141 {
142 if( less_with_sign( end_time ,
143 static_cast<Time>(st.current_time()+st.current_time_step()) ,
144 st.current_time_step() ) )
145 st.initialize( st.current_state() , st.current_time() , static_cast<Time>(end_time - st.current_time()) );
146 st.do_step( system );
147 }
148
149 // observation at final point
150 obs( st.current_state() , end_time );
151
152 return time;
153 }
154
155
156 }
157 }
158 }
159 }
160
161 #endif /* BOOST_NUMERIC_ODEINT_INTEGRATE_DETAIL_INTEGRATE_N_STEPS_HPP_INCLUDED */
162