size_t integrate_adaptive(
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;
typename odeint::unwrap_reference< Stepper >::type &st = stepper;
const size_t max_attempts = 1000;
const char *error_string = "Integrate adaptive : Maximal number of iterations reached. A step size could not be found.";
size_t count = 0;
while( less_with_sign( start_time , end_time , dt ) )
{
obs( start_state , start_time );
if( less_with_sign( end_time , start_time + dt , dt ) )
{
dt = end_time - start_time;
}
size_t trials = 0;
controlled_step_result res = success;
do
{
res = st.try_step( system , start_state , start_time , dt );
++trials;
}
while( ( res == fail ) && ( trials < max_attempts ) );
if( trials == max_attempts ) throw std::overflow_error( error_string );
++count;
}
obs( start_state , start_time );
return count;
}
size_t integrate_adaptive(
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;
typename odeint::unwrap_reference< Stepper >::type &st = stepper;
failed_step_checker fail_checker; // to throw a runtime_error if step size adjustment fails
size_t count = 0;
while( less_with_sign( start_time , end_time , dt ) )
{
obs( start_state , start_time );
if( less_with_sign( end_time , static_cast<Time>(start_time + dt) , dt ) )
{
dt = end_time - start_time;
}
controlled_step_result res;
do
{
res = st.try_step( system , start_state , start_time , dt );
fail_checker(); // check number of failed steps
}
while( res == fail );
fail_checker.reset(); // if we reach here, the step was successful -> reset fail checker
++count;
}
obs( start_state , start_time );
return count;
}
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;
}
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 );
}
}
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 end point, only if we ended exactly on the end-point (or above due to finite precision)
obs( st.current_state() , end_time );
return time;
}
size_t integrate_adaptive(
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;
size_t count = 0;
st.initialize( start_state , start_time , dt );
while( less_with_sign( st.current_time() , end_time , st.current_time_step() ) )
{
while( less_eq_with_sign( static_cast<Time>(st.current_time() + st.current_time_step()) ,
end_time ,
st.current_time_step() ) )
{ //make sure we don't go beyond the end_time
obs( st.current_state() , st.current_time() );
st.do_step( system );
++count;
}
// calculate time step to arrive exactly at end time
st.initialize( st.current_state() , st.current_time() , end_time - st.current_time() );
}
obs( st.current_state() , st.current_time() );
// overwrite start_state with the final point
boost::numeric::odeint::copy( st.current_state() , start_state );
return count;
}
size_t integrate_times(
Stepper stepper , System system , State &start_state ,
TimeIterator start_time , TimeIterator end_time , Time dt ,
Observer observer , stepper_tag
)
{
typename odeint::unwrap_reference< Observer >::type &obs = observer;
typename odeint::unwrap_reference< Stepper >::type &st = stepper;
typedef typename unit_value_type<Time>::type time_type;
size_t steps = 0;
Time current_dt = dt;
while( true )
{
Time current_time = *start_time++;
obs( start_state , current_time );
if( start_time == end_time )
break;
while( less_with_sign( current_time , static_cast<time_type>(*start_time) , current_dt ) )
{
current_dt = min_abs( dt , *start_time - current_time );
st.do_step( system , start_state , current_time , current_dt );
current_time += current_dt;
steps++;
}
}
return steps;
}
size_t integrate_adaptive(
state_type &start_state ,
time_type start_time ,
time_type end_time ,
time_type dt )
{
const size_t max_attempts = 1000;
const char *error_string = "Integrate adaptive : Maximal number of iterations reached. A step size could not be found.";
size_t count = 0;
time_type next_interrupt_time=system.timer(start_state,start_time);
// time_type& next_sudden_change_time=system.next_sudden_change_time;
if(system.max_dt>0 && system.max_dt<EPSILON)
throw std::runtime_error("Maximum step size has been proposed to be zero!");
if(system.max_dt>0 && dt>system.max_dt) // Help C++ optimizer
dt=system.max_dt;
if(system.min_dt>0 && dt<system.max_dt) // Help C++ optimizer
dt=system.min_dt;
time_type force_point;
while(less_with_sign(start_time,end_time,dt))
{
if(std::abs(start_time-next_interrupt_time)<EPSILON)
next_interrupt_time=system.timer(start_state,start_time);
system.observer(start_state,start_time,dt);
force_point=std::min(end_time,next_interrupt_time); // minimum
if(system.next_sudden_change_time-start_time>EPSILON)
force_point=std::min(force_point,system.next_sudden_change_time);
if(less_with_sign(force_point,start_time + dt , dt ) )
{
dt= force_point - start_time;
if(std::abs(dt)<EPSILON)
throw std::runtime_error("dt has been proposed to be zero!");
}
size_t trials = 0;
controlled_step_result res = success;
do
{
res = stepper.try_step( system , start_state , start_time , dt );
++trials;
}
while( ( res == fail ) && ( trials < max_attempts ) );
if( trials == max_attempts )
throw std::overflow_error(error_string);
++count;
}
system.observer( start_state , start_time, dt );
return count;
}
size_t integrate_adaptive(
Stepper stepper , System system , State &start_state ,
Time start_time , Time end_time , Time dt ,
Observer observer , stepper_tag
)
{
size_t steps = static_cast< size_t >( (end_time-start_time)/dt );
Time end = detail::integrate_n_steps( stepper , system , start_state , start_time ,
dt , steps , observer , stepper_tag() );
if( less_with_sign( end , end_time , dt ) )
{ //make a last step to end exactly at end_time
stepper.do_step( system , start_state , end , end_time - end );
steps++;
typename omplext_odeint::unwrap_reference< Observer >::type &obs = observer;
obs( start_state , end_time );
}
return steps;
}
size_t integrate_adaptive(
Stepper stepper , System system , State &start_state ,
Time start_time , Time end_time , Time dt ,
Observer observer , stepper_tag
)
{
size_t steps = detail::integrate_const( stepper , system , start_state , start_time ,
end_time , dt , observer , stepper_tag() );
typename odeint::unwrap_reference< Observer >::type &obs = observer;
typename odeint::unwrap_reference< Stepper >::type &st = stepper;
Time end = start_time + dt*steps;
if( less_with_sign( end , end_time , dt ) )
{ //make a last step to end exactly at end_time
st.do_step( system , start_state , end , end_time - end );
steps++;
obs( start_state , end_time );
}
return steps;
}
size_t integrate_times(
Stepper stepper , System system , State &start_state ,
TimeIterator start_time , TimeIterator end_time , Time dt ,
Observer observer , controlled_stepper_tag
)
{
typename odeint::unwrap_reference< Observer >::type &obs = observer;
typename odeint::unwrap_reference< Stepper >::type &st = stepper;
typedef typename unit_value_type<Time>::type time_type;
const size_t max_attempts = 1000;
const char *error_string = "Integrate adaptive : Maximal number of iterations reached. A step size could not be found.";
size_t steps = 0;
while( true )
{
size_t fail_steps = 0;
Time current_time = *start_time++;
obs( start_state , current_time );
if( start_time == end_time )
break;
while( less_with_sign( current_time , static_cast<time_type>(*start_time) , dt ) )
{
// adjust stepsize to end up exactly at the observation point
Time current_dt = min_abs( dt , *start_time - current_time );
if( st.try_step( system , start_state , current_time , current_dt ) == success )
{
++steps;
// continue with the original step size if dt was reduced due to observation
dt = max_abs( dt , current_dt );
}
else
{
++fail_steps;
dt = current_dt;
}
if( fail_steps == max_attempts ) throw std::overflow_error( error_string );
}
}
return steps;
}
size_t integrate_times(
Stepper stepper , System system , State &start_state ,
TimeIterator start_time , TimeIterator end_time , Time dt ,
Observer observer , controlled_stepper_tag
)
{
typename odeint::unwrap_reference< Observer >::type &obs = observer;
typename odeint::unwrap_reference< Stepper >::type &st = stepper;
typedef typename unit_value_type<Time>::type time_type;
failed_step_checker fail_checker; // to throw a runtime_error if step size adjustment fails
size_t steps = 0;
while( true )
{
Time current_time = *start_time++;
obs( start_state , current_time );
if( start_time == end_time )
break;
while( less_with_sign( current_time , static_cast<time_type>(*start_time) , dt ) )
{
// adjust stepsize to end up exactly at the observation point
Time current_dt = min_abs( dt , *start_time - current_time );
if( st.try_step( system , start_state , current_time , current_dt ) == success )
{
++steps;
// successful step -> reset the fail counter, see #173
fail_checker.reset();
// continue with the original step size if dt was reduced due to observation
dt = max_abs( dt , current_dt );
}
else
{
fail_checker(); // check for possible overflow of failed steps in step size adjustment
dt = current_dt;
}
}
}
return steps;
}
