Package org.hipparchus.ode.events

Class DetectorBasedEventState

java.lang.Object

org.hipparchus.ode.events.DetectorBasedEventState

All Implemented Interfaces:

EventState

public class DetectorBasedEventState
extends Object
implements EventState

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.

Constructor Summary

Constructors

Constructor	Description
DetectorBasedEventState(ODEEventDetector detector)	Simple constructor.

Method Summary

Modifier and Type	Method	Description
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 handler.
ODEEventDetector	getEventDetector()	Get the underlying event detector.
double	getEventTime()	Get the occurrence time of the event triggered in the current step.
void	init(ODEStateAndDerivative s0, double t)	Initialize handler at the start of an integration.
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

DetectorBasedEventState

public DetectorBasedEventState(ODEEventDetector detector)

Simple constructor.

Parameters:

detector - event detector

Since:

3.0

Method Detail

getEventDetector

public ODEEventDetector getEventDetector()

Get the underlying event detector.

Returns:

underlying event detector

Since:

3.0

init

public void init(ODEStateAndDerivative s0,
                 double t)

Initialize handler at the start of an integration.

This method is called once at the start of the integration. It may be used by the handler to initialize some internal data if needed.

Specified by:

init in interface EventState

Parameters:

s0 - initial state

t - target time for the integration

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 handler.

Specified by:

evaluateStep in interface EventState

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:

MathIllegalArgumentException - if the event cannot be bracketed

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

getEventTime

public double getEventTime()

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

Specified by:

getEventTime in interface EventState

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 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(ODEEventDetector, ODEStateAndDerivative) if necessary.

Specified by:

doEvent in interface EventState

Parameters:

state - the state at the time of the event. This must be at the same time as the current value of EventState.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.