fr.cnes.sirius.patrius.events.utils

Class SignalPropagationWrapperDetector

java.lang.Object

fr.cnes.sirius.patrius.events.utils.SignalPropagationWrapperDetector

All Implemented Interfaces:

EventDetector, Serializable

public class SignalPropagationWrapperDetector
extends Object
implements EventDetector

Wrap a signal propagation event detector and compute the emitter & receiver dates of the occurred events.

The dates are store in Maps (accessible with a getter).
For N events occurred, the Maps describe N elements.

Since:

4.13

Author:

Thibaut BONIT

See Also:

AbstractSignalPropagationDetector, Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface fr.cnes.sirius.patrius.events.EventDetector

EventDetector.Action

Field Summary

Fields inherited from interface fr.cnes.sirius.patrius.events.EventDetector

DECREASING, INCREASING, INCREASING_DECREASING

Constructor Summary

Constructors

Constructor and Description
SignalPropagationWrapperDetector(AbstractSignalPropagationDetector eventDetector) Constructor.

Method Summary

Modifier and Type	Method and Description
EventDetector	copy() A copy of the detector.
EventDetector.Action	eventOccurred(SpacecraftState s, boolean increasing, boolean forward) Handle an event and choose what to do next.
boolean	filterEvent(SpacecraftState state, boolean increasing, boolean forward) Filter last event: returns true if the last event is a false detection, false otherwise.
double	g(SpacecraftState s) Compute the value of the switching function.
AbstractSignalPropagationDetector.DatationChoice	getDatationChoice() Specify if the datation choice corresponds to the emitter date or the receiver date.
List<AbsoluteDate>	getEmitterDatesList() Getter for the list of the emitter dates of the occurred events.
Map<AbsoluteDate,AbsoluteDate>	getEmitterDatesMap() Getter for the Map of the emitter (keys) & receiver (values) dates of the occurred events.
double	getMaxCheckInterval() Get maximal time interval between switching function checks.
int	getMaxIterationCount() Get maximal number of iterations in the event time search.
int	getNBOccurredEvents() Getter for the number of the occurred events.
List<AbsoluteDate>	getReceiverDatesList() Getter for the list of the receiver dates of the occurred events.
Map<AbsoluteDate,AbsoluteDate>	getReceiverDatesMap() Getter for the Map of the receiver (keys) & emitter (values) dates of the occurred events.
int	getSlopeSelection() Get the parameter in charge of the selection of detected events by the slope of the g-function.
double	getThreshold() Get the convergence threshold in the event time search.
AbstractSignalPropagationDetector	getWrappedDetector() Returns the underlying wrapped detector.
void	init(SpacecraftState s0, AbsoluteDate t) Initialize event handler at the start of a propagation.
SpacecraftState	resetState(SpacecraftState oldState) Reset the state (including additional states) prior to continue propagation.
boolean	shouldBeRemoved() This method is called after EventDetector.eventOccurred(fr.cnes.sirius.patrius.propagation.SpacecraftState, boolean, boolean) has been triggered.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

SignalPropagationWrapperDetector

public SignalPropagationWrapperDetector(AbstractSignalPropagationDetector eventDetector)

Constructor.

Parameters:

eventDetector - Wrapped signal propagation detector

Method Detail

init

public void init(SpacecraftState s0,
                 AbsoluteDate t)
          throws PatriusException

Initialize event handler at the start of a propagation.

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

Specified by:

init in interface EventDetector

Parameters:

s0 - initial state

t - target time for the integration

Throws:

PatriusException - thrown if initialization failed

g

public double g(SpacecraftState s)
         throws PatriusException

Compute the value of the switching function. This function must be continuous (at least in its roots neighborhood), as the integrator will need to find its roots to locate the events.

Specified by:

g in interface EventDetector

Parameters:

s - the current state information: date, kinematics, attitude for forces and events computation, mass provider, and additional states

Returns:

value of the switching function

Throws:

PatriusException - if some specific error occurs

eventOccurred

public EventDetector.Action eventOccurred(SpacecraftState s,
                                          boolean increasing,
                                          boolean forward)
                                   throws PatriusException

Handle an event and choose what to do next.

The scheduling between this method and the PatriusStepHandler method handleStep() is to call this method first and handleStep afterwards. This scheduling allows the propagator to pass true as the isLast parameter to the step handler to make it aware the step will be the last one if this method returns EventDetector.Action.STOP. As the interpolator may be used to navigate back throughout the last step (as OrekitStepNormalizer does for example), user code called by this method and user code called by step handlers may experience apparently out of order values of the independent time variable. As an example, if the same user object implements both this EventDetector interface and the OrekitFixedStepHandler interface, a forward integration may call its eventOccurred method with a state at 2000-01-01T00:00:10 first and call its handleStep method with a state at 2000-01-01T00:00:09 afterwards. Such out of order calls are limited to the size of the integration step for variable step handlers and to the size of the fixed step for fixed step handlers.

Specified by:

eventOccurred in interface EventDetector

Parameters:

s - the current state information: date, kinematics, attitude for forces and events computation, mass provider, and additional states

increasing - if true, the value of the switching function increases when times increases around event (note that increase is measured with respect to physical time, not with respect to propagation which may go backward in time)

forward - if true, the integration variable (time) increases during integration.

Returns:

one of EventDetector.Action.STOP, EventDetector.Action.RESET_STATE, EventDetector.Action.RESET_DERIVATIVES, EventDetector.Action.CONTINUE

Throws:

PatriusException - if some specific error occurs

shouldBeRemoved

public boolean shouldBeRemoved()

This method is called after EventDetector.eventOccurred(fr.cnes.sirius.patrius.propagation.SpacecraftState, boolean, boolean) has been triggered. It returns true if the current detector should be removed after first event detection. WARNING: this method can be called only once a event has been triggered. Before, the value is not available.

Specified by:

shouldBeRemoved in interface EventDetector

Returns:

true if the current detector should be removed after first event detection

resetState

public SpacecraftState resetState(SpacecraftState oldState)
                           throws PatriusException

Reset the state (including additional states) prior to continue propagation.

This method is called after the step handler has returned and before the next step is started, but only when EventDetector.eventOccurred(fr.cnes.sirius.patrius.propagation.SpacecraftState, boolean, boolean) has itself returned the EventDetector.Action.RESET_STATE indicator. It allows the user to reset the state for the next step, without perturbing the step handler of the finishing step. If the EventDetector.eventOccurred(fr.cnes.sirius.patrius.propagation.SpacecraftState, boolean, boolean) never returns the EventDetector.Action.RESET_STATE indicator, this function will never be called, and it is safe to simply return null.

Specified by:

resetState in interface EventDetector

Parameters:

oldState - old state

Returns:

new state

Throws:

PatriusException - if the state cannot be reseted

filterEvent

public boolean filterEvent(SpacecraftState state,
                           boolean increasing,
                           boolean forward)
                    throws PatriusException

Filter last event: returns true if the last event is a false detection, false otherwise.

This method is called right before EventDetector.eventOccurred(SpacecraftState, boolean, boolean) method.

This may be useful in order to filter some events in particular when angles are at stake (see for example LocalTimeAngleDetector).

Specified by:

filterEvent in interface EventDetector

Parameters:

state - state at last event occurrence

increasing - if true, the value of the switching function increases when times increases around event (note that increase is measured with respect to physical time, not with respect to propagation which may go backward in time)

forward - if true, the integration variable (time) increases during integration.

Returns:

true if the last event is a false detection, false otherwise

Throws:

PatriusException - thrown if computation failed for some reasons

getThreshold

public double getThreshold()

Get the convergence threshold in the event time search.

Specified by:

getThreshold in interface EventDetector

Returns:

convergence threshold (s)

getMaxCheckInterval

public double getMaxCheckInterval()

Get maximal time interval between switching function checks.

Specified by:

getMaxCheckInterval in interface EventDetector

Returns:

maximal time interval (s) between switching function checks

getMaxIterationCount

public int getMaxIterationCount()

Get maximal number of iterations in the event time search.

Specified by:

getMaxIterationCount in interface EventDetector

Returns:

maximal number of iterations in the event time search

getSlopeSelection

public int getSlopeSelection()

Get the parameter in charge of the selection of detected events by the slope of the g-function.

Specified by:

getSlopeSelection in interface EventDetector

Returns:

EventDetector.INCREASING (0): events related to the increasing g-function;
EventDetector.DECREASING (1): events related to the decreasing g-function;
EventDetector.INCREASING_DECREASING (2): events related to both increasing and decreasing g-function.

copy

public EventDetector copy()

A copy of the detector. By default copy is deep. If not, detector javadoc will specify which attribute is not fully copied. In that case, the attribute reference is passed.

Specified by:

copy in interface EventDetector

Returns:

a copy of the detector.

getNBOccurredEvents

public int getNBOccurredEvents()

Getter for the number of the occurred events.

Returns:

the number of the occurred events

getEmitterDatesMap

public Map<AbsoluteDate,AbsoluteDate> getEmitterDatesMap()

Getter for the Map of the emitter (keys) & receiver (values) dates of the occurred events.

For N events occurred, the Map describes N elements.

Returns:

the Map of the emitter (keys) & receiver (values) dates

getEmitterDatesList

public List<AbsoluteDate> getEmitterDatesList()

Getter for the list of the emitter dates of the occurred events.

For N events occurred, the List describes N elements.

Returns:

the list of the emitter dates

getReceiverDatesMap

public Map<AbsoluteDate,AbsoluteDate> getReceiverDatesMap()

Getter for the Map of the receiver (keys) & emitter (values) dates of the occurred events.

For N events occurred, the Map describes N elements.

Returns:

the Map of the receiver (keys) & emitter (values) dates

getReceiverDatesList

public List<AbsoluteDate> getReceiverDatesList()

Getter for the list of the receiver dates of the occurred events.

For N events occurred, the List describes N elements.

Returns:

the list of the receiver dates

getWrappedDetector

public AbstractSignalPropagationDetector getWrappedDetector()

Returns the underlying wrapped detector.

Returns:

the underlying wrapped detector

getDatationChoice

public AbstractSignalPropagationDetector.DatationChoice getDatationChoice()

Specify if the datation choice corresponds to the emitter date or the receiver date.

Returns:

the corresponding datation choice

toString

public String toString()

Overrides:

toString in class Object