stella.sensor
Class DerivativeSensor

java.lang.Object
  util.PropertyContainer
      util.PropertyResources
          util.PropertyBundles
              util.rmi.RmiPropertyContainer
                  util.rmi.AbstractRmiCaster
                      stella.sensor.AbstractSensor
                          stella.sensor.TimerTaskSensor
                              stella.sensor.DataSensor
                                  stella.sensor.CumulativeSensor
                                      stella.sensor.PredictiveSensor
                                          stella.sensor.SmoothingSensor
                                              stella.sensor.DerivativeSensor

All Implemented Interfaces:

Cloneable, Remote, Caster, DataCaster, RmiDataCaster, RmiErrorCaster, Cumulating, Deriving, Predicting, Smoothing, Telemetering, ExitCleaning, Initializable, LocalizedSupplying, PropertySupplying, ResourceSupplying, RmiCaster, RmiPropertyBearing

Direct Known Subclasses:

WeatherSensor

public abstract class DerivativeSensor
extends SmoothingSensor
implements Deriving

A derivating sensor adds the capability of calculating the first derivative of the sensor readings. Because it is generally not advisable to allow the calculation of a numerical derivative from noisy data, this class extends a smoothing sensor. Additionally, calcing derivatives is only provided for Savitzky-Golay smoothing. Note that the smoothing coefficients may (and should!) differ from the smoothing used for the plain readings. In particular, consider using higher polynomial degrees in the Savitzky-Golay algorithm for derivatives!

The properties are scanned for the file name to derive a Savitzky-Golay smoothing filter with the KEY_DERIVE. If the property is not set no derivator is registered. This is one exception to the general rule that the use of default constructors guarantees the proper key to be present in the properties after the construction phase. This is necessary because Map do not allow null keys or values.

Implementation note: This routine relies on heavy conversion from Double objects to double primitive types. If this turns out to be unacceptable slow, replace the Shelf with a double array.

This sensor adds the following properties if they are not set already:

• derivator (null): The algorithm to use for the first derivative.

See Also:

Shelf

Nested Class Summary

Nested classes/interfaces inherited from class stella.sensor.TimerTaskSensor

TimerTaskSensor.SensorRead

Nested classes/interfaces inherited from class util.PropertyResources

PropertyResources.URLResource

Field Summary

private static boolean	DEFDERIVATIVEADVISE The default advisory behaviour.
private static String	DEFDERIVE The default smoother.
(package private) static DecimalFormat	DEFRAWDERIVATIVE The default format string for the values.
private SavitzkyGolaySmoothing	derivator The smoothing algorithm to use.
protected Shelf<Double>	derive Stores the first derivatives.
static String	KEY_DERIVATIVEADVISE The key defining only advisory functionality if set to true.
static String	KEY_DERIVE The key mapping to the derivative filter file.
static String	KEY_PATH The key pointing to the derivative filter dir.
static String	KEY_RAWDERIVATIVE The key to the raw derivative-data format string.
(package private) double[]	z A double arrays.

Fields inherited from class stella.sensor.SmoothingSensor

f, g, KEY_SMOOTH, KEY_SMOOTHADVISE

Fields inherited from class stella.sensor.PredictiveSensor

KEY_BASE, KEY_CHI, KEY_EXTRAPOLATE, KEY_FUTURE, KEY_PREDICTADVISE, predict

Fields inherited from class stella.sensor.CumulativeSensor

KEY_AVERAGE, KEY_MEMORY, KEY_PACK

Fields inherited from class stella.sensor.DataSensor

DEFRAWFORMAT, DEFREPORT, DEFSIGMAFORMAT, KEY_RAWFORMAT, KEY_REPORT, KEY_SIGMAFORMAT

Fields inherited from class stella.sensor.TimerTaskSensor

KEY_RESPAWN

Fields inherited from class stella.sensor.AbstractSensor

KEY_BIND, KEY_BINDNAME, KEY_CONVERT, KEY_DESCRIPTION, KEY_SENSORNAME

Fields inherited from class util.rmi.AbstractRmiCaster

ALTERNATEHOST, ALTERNATEPORT, KEY_EXPORTPORT, KEY_REGISTRYHOST, KEY_REGISTRYPORT

Fields inherited from class util.PropertyBundles

KEY_LOCALECOUNTRY, KEY_LOCALELANGUAGE, KEY_RESOURCEBUNDLES

Fields inherited from class util.PropertyResources

KEY_NOINITONCREATE, localurl, locate, POSTFIX_DIR, POSTFIX_EXT, POSTFIX_FILE, POSTFIX_LIST, POSTFIX_URL, urlset

Fields inherited from class util.PropertyContainer

KEY_LISTSEPARATOR, KEY_MAPKEYVALUECHAR, KEY_MAPSEPARATOR

Fields inherited from interface stella.rmi.RmiDataCaster

NAMING_EXTENSION

Fields inherited from interface util.PropertySupplying

CONFIG, KEY_CLASS

Fields inherited from interface util.ResourceSupplying

KEY_URLRESOURCES, KEY_URLUSECONFIG, KEY_URLUSECURRENT, KEY_URLUSEHOME

Constructor Summary

protected

DerivativeSensor(Map<String,String> qualify) Constructs a fully-qualified derivative sensor, with a given size of measurements to keep. Use of this constructor guarantees that the Map keys name and respawn are always set.

Method Summary

void	deriveAt(double raw) The implementation of the deriving interface.
protected DataEvent	generateDataEvent() Takes the last sensor derivative data and adds it to the SmoothDataEvent produced by the parental method.
NumberFormat	getDerivativeFormat() Returns the decimal format of the raw derivative value.
String	getDerivativeToggleInfo() Returns extra info on a derivative toggle event.
SavitzkyGolaySmoothing	getDerivator() Returns the derivator used.
List<Double>	getLastDerivative(int nr) The interface method for retrieving the last nr derivatives.
boolean	isDerivativeAdvise() Returns true if the derivative functionality of this sensor is only meant for advisory behaviour.
boolean	isDeriving() Return true if the derivator object is non-null.
protected void	newData(double raw, Date time) Conducts a single measure by calling this class's super method.
double	regetDerive() Returns the most-recently added first derivative as a primitive double.
void	registerDerivator(SavitzkyGolaySmoothing deriver) This method registers a linear smoothing algorithm for use with this sensor.

Methods inherited from class stella.sensor.SmoothingSensor

getLastSmooth, getSmoother, getSmoothToggleInfo, isSmoothAdvise, isSmoothing, regetSmooth, registerSmoother, smoothOne

Methods inherited from class stella.sensor.PredictiveSensor

getExtrapolation, getLastPredict, getPredictToggleInfo, isPredictAdvise, isPredicting, isReliable, predictFrom, regetPredict

Methods inherited from class stella.sensor.CumulativeSensor

cumulateOne, getLastRaw, getLastTime, getMaxSize, getMemory, getSize

Methods inherited from class stella.sensor.DataSensor

addDataListener, addRmiDataListener, conductOneMeasure, exit, getRawFormat, getSigmaFormat, removeDataListener, removeRmiDataListener, report

Methods inherited from class stella.sensor.TimerTaskSensor

cancel, equals, getRawToggleInfo, getReading, getRespawn, getTimeOfRead, hashCode, initSensorTimerTask, isReady, readSensor, regetRaw, setTimeOfRead, validReading

Methods inherited from class stella.sensor.AbstractSensor

addRmiErrorListener, createSensor, getBindName, getConvert, getSensorDescription, getSensorInitInfo, getSensorName, init, notifyErrorListener, removeRmiErrorListener, setConvert, status, toString

Methods inherited from class util.rmi.AbstractRmiCaster

bindAlternate, bindToRegistry, bindToRegistry, bindToRegistry, casterExit, casterExit, getBindName, isValid, unbindFromRegistry, unbindFromRegistry

Methods inherited from class util.rmi.RmiPropertyContainer

containsRemoteProperty, getRemoteProperties, getRemoteProperty, setRemoteProperty

Methods inherited from class util.PropertyBundles

clone, getLocalized, getLocalized, getLocalizedString, getLocalizedString, loadResource

Methods inherited from class util.PropertyResources

createFrom, createFrom, createFrom, getApplet, getAsResources, getLocalClassLoader, getPropertiesToKey, getPropertiesToKey, getResource, getResourceAsStream, getResourceFromKey, getResources, keyCreate, keyCreate, reload, setApplet

Methods inherited from class util.PropertyContainer

augment, augment, augment, defaultBoolean, defaultChar, defaultDouble, defaultFloat, defaultInt, defaultLong, defaultObject, defaultObject, defaultProperties, defaultProperty, getAsBoolean, getAsChar, getAsDouble, getAsEnums, getAsFloat, getAsInt, getAsList, getAsLong, getAsMap, getAsMap, getAsObject, getAsObject, getProperties, getProperty, has, isNew, parseObject, reload, removeProperty, rescanned, setObject, setProperties, setProperty, stringProperties

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface stella.sensor.Cumulating

cumulateOne, getLastRaw, getLastTime, getMaxSize, getSize, getTimeOfRead, regetRaw

Methods inherited from interface util.rmi.RmiCaster

bindToRegistry, isValid, unbindFromRegistry

Methods inherited from interface stella.sensor.Telemetering

validReading

Methods inherited from interface util.PropertySupplying

defaultBoolean, defaultChar, defaultDouble, defaultFloat, defaultInt, defaultLong, defaultObject, defaultObject, defaultProperties, defaultProperty, getAsBoolean, getAsChar, getAsDouble, getAsFloat, getAsInt, getAsList, getAsLong, getAsMap, getAsObject, getAsObject, getProperties, getProperty, has, parseObject, removeProperty, setObject, setProperty, stringProperties

Methods inherited from interface util.ResourceSupplying

getResource, getResourceAsStream, getResources

Field Detail

KEY_PATH

public static final String KEY_PATH

The key pointing to the derivative filter dir.

See Also:

Constant Field Values

KEY_DERIVE

public static final String KEY_DERIVE

The key mapping to the derivative filter file.

See Also:

Constant Field Values

KEY_RAWDERIVATIVE

public static final String KEY_RAWDERIVATIVE

The key to the raw derivative-data format string.

See Also:

Constant Field Values

KEY_DERIVATIVEADVISE

public static final String KEY_DERIVATIVEADVISE

The key defining only advisory functionality if set to true.

See Also:

Constant Field Values

DEFDERIVE

private static final String DEFDERIVE

The default smoother. If null no smoother is used as default.

DEFDERIVATIVEADVISE

private static final boolean DEFDERIVATIVEADVISE

The default advisory behaviour.

See Also:

Constant Field Values

DEFRAWDERIVATIVE

static final DecimalFormat DEFRAWDERIVATIVE

The default format string for the values.

derive

protected Shelf<Double> derive

Stores the first derivatives.

derivator

private SavitzkyGolaySmoothing derivator

The smoothing algorithm to use.

z

double[] z

A double arrays. Initialize once, use often.

Constructor Detail

DerivativeSensor

protected DerivativeSensor(Map<String,String> qualify)

Constructs a fully-qualified derivative sensor, with a given size of measurements to keep.
Use of this constructor guarantees that the Map keys name and respawn are always set.

Parameters:

size - The maximum number of measurements to keep.

group - The ThreadGroup this thread belongs to.

name - The name of this thread (sensor).

qualify - The Map object describing this sensor.

Method Detail

newData

protected void newData(double raw,
                       Date time)

Conducts a single measure by calling this class's super method. If no deriving algorithm is specified, the derivative is set to zero. Additionally, as long as the data shelf does not contain enough points to allow deriving, zero is stored the derivator Shelf.

Overrides:

newData in class SmoothingSensor

deriveAt

public void deriveAt(double raw)

The implementation of the deriving interface. This class uses a Savitzky-Golay filter for a first derivative to approximate the derivative. An appropriate filter may be registerd using the registerDerivator(vec_math.SavitzkyGolaySmoothing) method.

Specified by:

deriveAt in interface Deriving

Parameters:

raw - The actual raw reading of the sensor.

regetDerive

public double regetDerive()

Returns the most-recently added first derivative as a primitive double. If no derivative value has been added to the shelf, Double.NaN is returned

Specified by:

regetDerive in interface Deriving

getLastDerivative

public List<Double> getLastDerivative(int nr)

The interface method for retrieving the last nr derivatives.

Specified by:

getLastDerivative in interface Deriving

See Also:

Deriving

registerDerivator

public void registerDerivator(SavitzkyGolaySmoothing deriver)

This method registers a linear smoothing algorithm for use with this sensor. If this algorithm is not causal, or the Shelf sizes are too small, an IndexOutOfBoundsException is thrown.

Parameters:

smoother - The linear smoothing algorithm to use.

getDerivator

public SavitzkyGolaySmoothing getDerivator()

Returns the derivator used.

isDeriving

public boolean isDeriving()

Return true if the derivator object is non-null.

Specified by:

isDeriving in interface Deriving

isDerivativeAdvise

public boolean isDerivativeAdvise()

Returns true if the derivative functionality of this sensor is only meant for advisory behaviour. In this case, bad weather events will only show up in the syslog, but will never produce bad weather events.

getDerivativeFormat

public NumberFormat getDerivativeFormat()

Returns the decimal format of the raw derivative value. Required by Deriving.

Specified by:

getDerivativeFormat in interface Deriving

getDerivativeToggleInfo

public String getDerivativeToggleInfo()

Returns extra info on a derivative toggle event. If no additional info is required, return null.

generateDataEvent

protected DataEvent generateDataEvent()

Takes the last sensor derivative data and adds it to the SmoothDataEvent produced by the parental method. If no derivator is specified, the undisturbed data event is returned. If the CumulativeSensor.KEY_PACK property points to a value greater than one, the data event produced carries the average of the last derivative data.

Overrides:

generateDataEvent in class SmoothingSensor

Returns:

A DerivativeDataEvent