org.placelab.client.tracker
Class ParticleFilterTracker

java.lang.Object
  org.placelab.client.tracker.Tracker
      org.placelab.client.tracker.BeaconTracker
          org.placelab.client.tracker.ParticleFilterTracker

All Implemented Interfaces:

SpotterListener, VisualizableParticleFilter

public class ParticleFilterTracker

extends BeaconTracker

implements VisualizableParticleFilter

A Tracker that uses a probabilistic technique to produce Estimates.

Sophisticated users could write a motion model and plug it into the BeaconParticleFilter used by this class to produce more accurate results than those produced by the CentroidTracker.

Nested Class Summary

class

ParticleFilterTracker.TEST_PROBE2

Field Summary

Fields inherited from class org.placelab.client.tracker.BeaconTracker

WIFI_MAX_DISTANCE

Constructor Summary

ParticleFilterTracker(Mapper m)

ParticleFilterTracker(Mapper m, double maxX, double maxY, double gridIncr)

Method Summary

boolean	acceptableMeasurement(Measurement m) Returns true if the tracker can make use of this reading to meaningfully update the estimate.
Estimate	getEstimate() return an estimate based on the last set of measurements we saw *
BeaconParticleFilter	getParticleFilter()
java.util.Vector	getParticleList()
protected void	resetImpl() Subclasses should implement this to reset themselves to their initial state.
java.lang.String	toString()
protected void	updateEstimateImpl(Measurement m) Subclasses should implement this to do the actual work of updating their Estimate with the given Measurement.
void	updateWithoutMeasurement(long durationMillis) This method notifies a tracker that time has elapsed without a new mesurement.

Methods inherited from class org.placelab.client.tracker.BeaconTracker

findBeacon, findBeacon, getMapper, pickBeacon, pickBeacon

Methods inherited from class org.placelab.client.tracker.Tracker

addEstimateListener, fireEstimateUpdate, getLastUpdatedTime, gotMeasurement, numberOfMeasurements, removeEstimateListener, reset, spotterExceptionThrown, updateEstimate

Methods inherited from class java.lang.Object

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

Constructor Detail

ParticleFilterTracker

public ParticleFilterTracker(Mapper m)

ParticleFilterTracker

public ParticleFilterTracker(Mapper m,
                             double maxX,
                             double maxY,
                             double gridIncr)

Method Detail

toString

public java.lang.String toString()

getParticleList

public java.util.Vector getParticleList()

Specified by:

getParticleList in interface VisualizableParticleFilter

Returns:

A Vector of the paritcles in this particle filter to be used by the visualization framework (like in MapDemo) to draw particles on the screen.

resetImpl

protected void resetImpl()

Description copied from class: Tracker

Subclasses should implement this to reset themselves to their initial state.

Specified by:

resetImpl in class Tracker

acceptableMeasurement

public boolean acceptableMeasurement(Measurement m)

Description copied from class: Tracker

Returns true if the tracker can make use of this reading to meaningfully update the estimate.

Overrides:

acceptableMeasurement in class BeaconTracker

Parameters:

m - return true if this is a BeaconMeasurement

updateEstimateImpl

protected void updateEstimateImpl(Measurement m)

Description copied from class: Tracker

Subclasses should implement this to do the actual work of updating their Estimate with the given Measurement.

Specified by:

updateEstimateImpl in class Tracker

Parameters:

m - use this to update your Estimate

getEstimate

public Estimate getEstimate()

return an estimate based on the last set of measurements we saw *

Specified by:

getEstimate in class Tracker

Returns:

The Tracker's latest Estimate

getParticleFilter

public BeaconParticleFilter getParticleFilter()

updateWithoutMeasurement

public void updateWithoutMeasurement(long durationMillis)

Description copied from class: Tracker

This method notifies a tracker that time has elapsed without a new mesurement. This gives the tracker a chance to update its estimate to account for predicted motion.

Specified by:

updateWithoutMeasurement in class Tracker