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; }