fr.cnes.sirius.patrius.math.ode.events

Class EventState

java.lang.Object

fr.cnes.sirius.patrius.math.ode.events.EventState

public class EventState
extends Object

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.

Since:

1.2

Version:

$Id: EventState.java 18108 2017-10-04 06:45:27Z bignon $

Constructor Summary

Constructors

Constructor and Description
EventState(EventHandler handlerIn, double maxCheckIntervalIn, double convergenceIn, int maxIterationCountIn, UnivariateSolver solverIn) Simple constructor.

Method Summary

Modifier and Type	Method and Description
void	cancelStepAccepted() Cancel stepAccepted call (does not cancel event).
boolean	evaluateStep(double t, double[] y) Evaluate the impact of the proposed step on the event handler.
boolean	evaluateStep(StepInterpolator interpolator) Evaluate the impact of the proposed step on the event handler.
double	getConvergence() Get the convergence threshold for event localization.
EventHandler	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.
double	getPreviousEventTime() Get previous event time.
double	getT0() Getter for t0.
boolean	isPendingReset() Check if some reset is being triggered.
void	reinitializeBegin(StepInterpolator interpolator) Reinitialize the beginning of the step.
boolean	removeDetector() Check the current detector should be removed at the end of the current step current step.
boolean	reset(double t, double[] y) Let the event handler reset the state if it wants.
void	stepAccepted(double t, double[] y) Acknowledge the fact the step has been accepted by the integrator.
boolean	stop() Check if the integration should be stopped at the end of the current step.
void	storeState(double t, double[] y, boolean forceUpdate) Store event state with provided time and state.

Methods inherited from class java.lang.Object

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

Constructor Detail

EventState

public EventState(EventHandler handlerIn,
                  double maxCheckIntervalIn,
                  double convergenceIn,
                  int maxIterationCountIn,
                  UnivariateSolver solverIn)

Simple constructor.

Parameters:

handlerIn - event handler

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

convergenceIn - convergence threshold in the event time search

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

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

Method Detail

getEventHandler

public EventHandler getEventHandler()

Get the underlying event handler.

Returns:

underlying event handler

getMaxCheckInterval

public double getMaxCheckInterval()

Get the maximal time interval between events handler checks.

Returns:

maximal time interval between events handler checks

getConvergence

public double getConvergence()

Get the convergence threshold for event localization.

Returns:

convergence threshold for event localization

getMaxIterationCount

public int getMaxIterationCount()

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

Returns:

upper limit in the iteration count for event localization

reinitializeBegin

public void reinitializeBegin(StepInterpolator interpolator)

Reinitialize the beginning of the step.

Parameters:

interpolator - valid for the current step

Throws:

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

isPendingReset

public boolean isPendingReset()

Check if some reset is being triggered.

Returns:

true is some reset is being triggered

storeState

public void storeState(double t,
                       double[] y,
                       boolean forceUpdate)

Store event state with provided time and state.

Parameters:

t - current time

y - current state

forceUpdate - force update of event parameters

evaluateStep

public boolean evaluateStep(double t,
                            double[] y)

Evaluate the impact of the proposed step on the event handler. In that case, the step is of null size (the provided time should be equal to t0)

Parameters:

t - current time

y - current state

Returns:

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

evaluateStep

public boolean evaluateStep(StepInterpolator interpolator)

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:

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

NoBracketingException - 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

getPreviousEventTime

public double getPreviousEventTime()

Get previous event time.

Returns:

previous event time

stepAccepted

public void stepAccepted(double t,
                         double[] y)

Acknowledge the fact the step has been accepted by the integrator.

Parameters:

t - value of the independent time variable at the end of the step

y - array containing the current value of the state vector at the end of the step

cancelStepAccepted

public void cancelStepAccepted()

Cancel stepAccepted call (does not cancel event). This method is used only when some missed event have occurred: event search algorithm goes backward in time, rewriting the future: stepAccepted() call leading to this jump in the past needs to be canceled.

getT0

public double getT0()

Getter for t0.

Returns:

t0

stop

public boolean stop()

Check if the integration should be stopped at the end of the current step.

Returns:

true if the integration should be stopped

removeDetector

public boolean removeDetector()

Check the current detector should be removed at the end of the current step current step.

Returns:

true if the detector should be removed

reset

public boolean reset(double t,
                     double[] y)

Let the event handler reset the state if it wants.

Parameters:

t - value of the independent time variable at the beginning of the next step

y - array were to put the desired state vector at the beginning of the next step

Returns:

true if the integrator should reset the derivatives too