org.placelab.example
Class CentroidTrackerExample

java.lang.Object
  org.placelab.client.tracker.Tracker
      org.placelab.example.CentroidTrackerExample

All Implemented Interfaces:

SpotterListener

public class CentroidTrackerExample

extends Tracker

This sample is a tracker that calculates the centroid of the observed readings. This tracker estimates the device position to be the geometric center of the readings that have the same timestamp.

Constructor Summary

CentroidTrackerExample(Mapper m)

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 *
static void	main(java.lang.String[] args)
protected void	resetImpl() Subclasses should implement this to reset themselves to their initial state.
void	updateEstimateImpl(Measurement m) updateEstimateImpl uses the passed measurement to compute a simple geometic center.
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.Tracker

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

Methods inherited from class java.lang.Object

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

Constructor Detail

CentroidTrackerExample

public CentroidTrackerExample(Mapper m)

Method Detail

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

updateEstimateImpl

public void updateEstimateImpl(Measurement m)

updateEstimateImpl uses the passed measurement to compute a simple geometic center.

Specified by:

updateEstimateImpl in class Tracker

Parameters:

m - use this to update your Estimate

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.

Specified by:

acceptableMeasurement in class Tracker

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

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

main

public static void main(java.lang.String[] args)