org.hipparchus.ode.events

Class EventState

java.lang.Object

org.hipparchus.ode.events.EventState

All Implemented Interfaces:

EventHandlerConfiguration

public class EventState
extends Object
implements EventHandlerConfiguration

This class handles the state for one event handler during integration steps.

Each time the integrator proposes a step, the event handler switching function should be checked. This class handles the state of one handler during one integration step, with references to the state at the end of the preceding step. This information is used to decide if the handler should trigger an event or not during the proposed step.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	EventState.EventOccurrence Class to hold the data related to an event occurrence that is needed to decide how to modify integration.

Constructor Summary

Constructors

Constructor and Description
EventState(ODEEventHandler handler, double maxCheckInterval, double convergence, int maxIterationCount, BracketedUnivariateSolver<UnivariateFunction> solver) Simple constructor.

Method Summary

Modifier and Type	Method and Description
EventState.EventOccurrence	doEvent(ODEStateAndDerivative state) Notify the user's listener of the event.
boolean	evaluateStep(ODEStateInterpolator interpolator) Evaluate the impact of the proposed step on the event handler.
double	getConvergence() Get the convergence threshold for event localization.
ODEEventHandler	getEventHandler() Get the underlying event handler.
double	getEventTime() Get the occurrence time of the event triggered in the current step.
double	getMaxCheckInterval() Get the maximal time interval between events handler checks.
int	getMaxIterationCount() Get the upper limit in the iteration count for event localization.
BracketedUnivariateSolver<UnivariateFunction>	getSolver() Get the root-finding algorithm to use to detect state events.
void	reinitializeBegin(ODEStateInterpolator interpolator) Reinitialize the beginning of the step.
boolean	tryAdvance(ODEStateAndDerivative state, ODEStateInterpolator interpolator) Try to accept the current history up to the given time.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

EventState

public EventState(ODEEventHandler handler,
                  double maxCheckInterval,
                  double convergence,
                  int maxIterationCount,
                  BracketedUnivariateSolver<UnivariateFunction> solver)

Simple constructor.

Parameters:

handler - event handler

maxCheckInterval - maximal time interval between switching function checks (this interval prevents missing sign changes in case the integration steps becomes very large)

convergence - convergence threshold in the event time search

maxIterationCount - upper limit of the iteration count in the event time search

solver - Root-finding algorithm to use to detect state events

Method Detail

getEventHandler

public ODEEventHandler getEventHandler()

Get the underlying event handler.

Specified by:

getEventHandler in interface EventHandlerConfiguration

Returns:

underlying event handler

getMaxCheckInterval

public double getMaxCheckInterval()

Get the maximal time interval between events handler checks.

Specified by:

getMaxCheckInterval in interface EventHandlerConfiguration

Returns:

maximal time interval between events handler checks

getConvergence

public double getConvergence()

Get the convergence threshold for event localization.

Specified by:

getConvergence in interface EventHandlerConfiguration

Returns:

convergence threshold for event localization

getMaxIterationCount

public int getMaxIterationCount()

Get the upper limit in the iteration count for event localization.

Specified by:

getMaxIterationCount in interface EventHandlerConfiguration

Returns:

upper limit in the iteration count for event localization

getSolver

public BracketedUnivariateSolver<UnivariateFunction> getSolver()

Get the root-finding algorithm to use to detect state events.

Specified by:

getSolver in interface EventHandlerConfiguration

Returns:

root-finding algorithm to use to detect state events

reinitializeBegin

public void reinitializeBegin(ODEStateInterpolator interpolator)
                       throws MathIllegalStateException

Reinitialize the beginning of the step.

Parameters:

interpolator - valid for the current step

Throws:

MathIllegalStateException - if the interpolator throws one because the number of functions evaluations is exceeded

evaluateStep

public boolean evaluateStep(ODEStateInterpolator interpolator)
                     throws MathIllegalArgumentException,
                            MathIllegalStateException

Evaluate the impact of the proposed step on the event handler.

Parameters:

interpolator - step interpolator for the proposed step

Returns:

true if the event handler triggers an event before the end of the proposed step

Throws:

MathIllegalStateException - if the interpolator throws one because the number of functions evaluations is exceeded

MathIllegalArgumentException - if the event cannot be bracketed

getEventTime

public double getEventTime()

Get the occurrence time of the event triggered in the current step.

Returns:

occurrence time of the event triggered in the current step or infinity if no events are triggered

tryAdvance

public boolean tryAdvance(ODEStateAndDerivative state,
                          ODEStateInterpolator interpolator)

Try to accept the current history up to the given time.

It is not necessary to call this method before calling doEvent(ODEStateAndDerivative) with the same state. It is necessary to call this method before you call doEvent(ODEStateAndDerivative) on some other event detector.

Parameters:

state - to try to accept.

interpolator - to use to find the new root, if any.

Returns:

if the event detector has an event it has not detected before that is on or before the same time as state. In other words false means continue on while true means stop and handle my event first.

doEvent

public EventState.EventOccurrence doEvent(ODEStateAndDerivative state)

Notify the user's listener of the event. The event occurs wholly within this method call including a call to ODEEventHandler.resetState(ODEStateAndDerivative) if necessary.

Parameters:

state - the state at the time of the event. This must be at the same time as the current value of getEventTime().

Returns:

the user's requested action and the new state if the action is Action.RESET_STATE. Otherwise the new state is state. The stop time indicates what time propagation should stop if the action is Action.STOP. This guarantees the integration will stop on or after the root, so that integration may be restarted safely.