org.android.activityminer.logic.features
Class FeatureExtractionHelper<T extends Enum<T> & Dimensions>

java.lang.Object
  org.android.activityminer.logic.features.FeatureExtractionHelper<T>

Type Parameters:

T - the enumeration type for the dimensions

All Implemented Interfaces:

EventObserver<FeatureVector>

public class FeatureExtractionHelper<T extends Enum<T> & Dimensions>
extends Object
implements EventObserver<FeatureVector>

Nested Class Summary

private class	FeatureExtractionHelper.Entry Helper class for time stamp lookups
class	FeatureExtractionHelper.ProgressEvent The observable progress event (to notify progress on a single sequence processing)

Field Summary

private T	accGXId Dimension id for gravitation vector x value.
private T	accGYId Dimension id for gravitation vector y value.
private T	accGZId Dimension id for gravitation vector z value.
private T	accXId Dimension id for x acceleration.
private T	accYId Dimension id for y acceleration.
private T	accZId Dimension id for z acceleration.
private Context	context The context.
private AtomicInteger	currentFeatureVectorCount The current feature vector count
private DBManager	dbManager A reference to the database manager.
private AbstractFeatureExtractorForDBRecordings<T>	featureExtractor The feature extractor to use
private LowPassFilter	filter The low pass filter for the accelerometer data.
private GravitationFilter	gFilter The gravitation filter
private boolean	hasToAdaptToConfiguration The flag for configuration based adaption.
private boolean	isUseOwnGravitationFilter The gravitation filter usage flag
private Exception	lastException last exception reference if one occurs during asynchronous saves
private ObservableEventSource<FeatureExtractionHelper.ProgressEvent>	progressEventSource The observable delegator for progress events
private ConcurrentLinkedQueue<FeatureExtractionHelper.Entry>	queueTs2IDMapping The queue to store mappings for time stamps and recording identifiers in
private long	sampleRate The configured sample rate
private int	sampleRateAdaptionFactor The adaption factor for the sample rate is the relation of the configured sample rate to the one used for recordings.

Constructor Summary

private

FeatureExtractionHelper(DBManager dbManager, Configuration config, AbstractFeatureExtractorForDBRecordings<T> featureExtractor, AbstractFeatureFactory<T> factory, Context context, boolean hasToAdaptToConfiguration) Constructor

Method Summary

private SensorObservationCutout<T,Double>	adaptToConfiguration(SensorObservationCutout<T,Double> cutOut, Long lastTs) Method to apply the configured sample rate and the optional filter to the cut-out window of a recording.
static <T extends Enum<T> & Dimensions> FeatureExtractionHelper<T>	createFeatureExtractionHelper(Context context, DBManager dbManager, Configuration config, AbstractFeatureExtractorForDBRecordings<T> featureExtractor, AbstractFeatureFactory<T> factory, boolean hasToAdaptToConfiguration) Method to create a feature extraction helper instance.
protected DBManager	getDbManager() Getter for the dbManager
String	getErrorNotificationMsg(List<Long> failedIds) Getter for the error notification message
protected Exception	getLastException() Getter for the last exception
double	getLastExtractionTime() Getter for the last extraction time from the feature extractor
String	getResultNotificationMsg(int extractedSampleCount, double avgTimeForFeatureExtraction, double processingTime) Getter for the result notification message
void	onDestroy() Destruction.
void	onEvent(ObservableEventSource<? extends FeatureVector> eventSource, FeatureVector featureVector)
int	process(long sequenceId, EventObserver<FeatureExtractionHelper.ProgressEvent> progressObserver) Does process a sequence of continuous recordings.
protected void	setLastException(Exception lastException) Setter for the last exception

Methods inherited from class java.lang.Object

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

Field Detail

filter

private final LowPassFilter filter

The low pass filter for the accelerometer data.

featureExtractor

private final AbstractFeatureExtractorForDBRecordings<T extends Enum<T> & Dimensions> featureExtractor

The feature extractor to use

progressEventSource

private final ObservableEventSource<FeatureExtractionHelper.ProgressEvent> progressEventSource

The observable delegator for progress events

dbManager

private final DBManager dbManager

A reference to the database manager.

queueTs2IDMapping

private final ConcurrentLinkedQueue<FeatureExtractionHelper.Entry> queueTs2IDMapping

The queue to store mappings for time stamps and recording identifiers in

currentFeatureVectorCount

private final AtomicInteger currentFeatureVectorCount

The current feature vector count

lastException

private Exception lastException

last exception reference if one occurs during asynchronous saves

sampleRateAdaptionFactor

private final int sampleRateAdaptionFactor

The adaption factor for the sample rate is the relation of the configured sample rate to the one used for recordings. In fact this parameter denotes the multiplication factor for the recording rate to get the configured sample rate.

context

private Context context

The context.

accXId

private T extends Enum<T> & Dimensions accXId

Dimension id for x acceleration.

accYId

private T extends Enum<T> & Dimensions accYId

Dimension id for y acceleration.

accZId

private T extends Enum<T> & Dimensions accZId

Dimension id for z acceleration.

accGXId

private T extends Enum<T> & Dimensions accGXId

Dimension id for gravitation vector x value.

accGYId

private T extends Enum<T> & Dimensions accGYId

Dimension id for gravitation vector y value.

accGZId

private T extends Enum<T> & Dimensions accGZId

Dimension id for gravitation vector z value.

gFilter

private final GravitationFilter gFilter

The gravitation filter

isUseOwnGravitationFilter

private final boolean isUseOwnGravitationFilter

The gravitation filter usage flag

sampleRate

private final long sampleRate

The configured sample rate

hasToAdaptToConfiguration

private final boolean hasToAdaptToConfiguration

The flag for configuration based adaption.

Constructor Detail

FeatureExtractionHelper

private FeatureExtractionHelper(DBManager dbManager,
                                Configuration config,
                                AbstractFeatureExtractorForDBRecordings<T> featureExtractor,
                                AbstractFeatureFactory<T> factory,
                                Context context,
                                boolean hasToAdaptToConfiguration)

Constructor

Parameters:

dbManager - a reference to the database manager

config - the configuration

featureExtractor - the feature extractor

factory - the feature factory

context - the context

hasToAdaptToConfiguration - flag if adaption is required (can only happen in batch export mode)

Method Detail

getDbManager

protected DBManager getDbManager()

Getter for the dbManager

Returns:

the dbManager

getLastException

protected final Exception getLastException()

Getter for the last exception

Returns:

the last exception

setLastException

protected final void setLastException(Exception lastException)

Setter for the last exception

Parameters:

lastException - the last exception to set

getErrorNotificationMsg

public final String getErrorNotificationMsg(List<Long> failedIds)

Getter for the error notification message

Parameters:

failedIds - a list with failed record id's

Returns:

the error notification message

getResultNotificationMsg

public String getResultNotificationMsg(int extractedSampleCount,
                                       double avgTimeForFeatureExtraction,
                                       double processingTime)

Getter for the result notification message

Parameters:

extractedSampleCount - the count of extracted training samples

avgTimeForFeatureExtraction - the average time for feature extraction in milliseconds

processingTime - the whole processing time in seconds

Returns:

the result notification message

getLastExtractionTime

public final double getLastExtractionTime()

Getter for the last extraction time from the feature extractor

Returns:

the last extraction time from the feature extractor

process

public final int process(long sequenceId,
                         EventObserver<FeatureExtractionHelper.ProgressEvent> progressObserver)
                  throws Exception

Does process a sequence of continuous recordings.

Parameters:

sequenceId - the identifier of the continuous recordings sequence to extract features from

progressObserver - the optional progress observer

Returns:

the count of extracted feature vectors

Throws:

Exception

adaptToConfiguration

private SensorObservationCutout<T,Double> adaptToConfiguration(SensorObservationCutout<T,Double> cutOut,
                                                               Long lastTs)

Method to apply the configured sample rate and the optional filter to the cut-out window of a recording. As recordings are always sampled with the maximum rate the count of sensor observations must be reduced in a appropriate way.

Parameters:

cutOut - the cut-out window

lastTs - time stamp from last

Returns:

the adapted cut-out window

onDestroy

public final void onDestroy()

Destruction.

onEvent

public void onEvent(ObservableEventSource<? extends FeatureVector> eventSource,
                    FeatureVector featureVector)

Specified by:

onEvent in interface EventObserver<FeatureVector>

createFeatureExtractionHelper

public static final <T extends Enum<T> & Dimensions> FeatureExtractionHelper<T> createFeatureExtractionHelper(Context context,
                                                                                                             DBManager dbManager,
                                                                                                             Configuration config,
                                                                                                             AbstractFeatureExtractorForDBRecordings<T> featureExtractor,
                                                                                                             AbstractFeatureFactory<T> factory,
                                                                                                             boolean hasToAdaptToConfiguration)

Method to create a feature extraction helper instance.

Parameters:

context - the application context

dbManager - the database manager

config - the configuration

featureExtractor - the feature extractor

factory - the factory

hasToAdaptToConfiguration - flag if adaption is required (can only happen in batch export mode)

Returns:

the feature extraction helper