This class implements a Finite Impulse Response (FIR) Filter. It can support a low pass filter, high pass filter, or band pass filter. More...

#include <FIRFilter.h>

Inheritance diagram for FIRFilter:

Public Types
enum	FilterType { LPF =0, HPF, BPF }

Public Types inherited from PreProcessing
typedef std::map< std::string, PreProcessing ()() >	StringPreProcessingMap

Public Types inherited from MLBase
enum	BaseType { BASE_TYPE_NOT_SET =0, CLASSIFIER, REGRESSIFIER, CLUSTERER, PRE_PROCSSING, POST_PROCESSING, FEATURE_EXTRACTION, CONTEXT }

Public Member Functions
	FIRFilter (const FilterType filterType=LPF, const UINT numTaps=50, const Float sampleRate=100, const Float cutoffFrequency=10, const Float gain=1, const UINT numDimensions=1)

	FIRFilter (const FIRFilter &rhs)

virtual	~FIRFilter ()

FIRFilter &	operator= (const FIRFilter &rhs)

virtual bool	deepCopyFrom (const PreProcessing *preProcessing)

virtual bool	process (const VectorFloat &inputVector)

virtual bool	reset ()

virtual bool	clear ()

virtual bool	save (std::fstream &file) const

virtual bool	load (std::fstream &file)

bool	buildFilter ()

Float	filter (const Float x)

VectorFloat	filter (const VectorFloat &x)

FilterType	getFilterType () const

UINT	getNumTaps () const

Float	getSampleRate () const

Float	getCutoffFrequency () const

Float	getCutoffFrequencyLower () const

Float	getCutoffFrequencyUpper () const

Float	getGain () const

Vector< VectorFloat >	getInputBuffer () const

VectorFloat	getFilterCoefficents () const

bool	setFilterType (const FilterType filterType)

bool	setNumTaps (const UINT numTaps)

bool	setSampleRate (const Float sampleRate)

bool	setCutoffFrequency (const Float cutoffFrequency)

bool	setCutoffFrequency (const Float cutoffFrequencyLower, const Float cutoffFrequencyUpper)

bool	setGain (const Float gain)

Public Member Functions inherited from PreProcessing
	PreProcessing (const std::string &id="")

virtual	~PreProcessing (void)

bool	copyBaseVariables (const PreProcessing *preProcessingModule)

bool	getInitialized () const

VectorFloat	getProcessedData () const

PreProcessing *	create () const

	GRT_DEPRECATED_MSG ("createNewInstance is deprecated, use create() instead.", PreProcessing *createNewInstance() const )

	GRT_DEPRECATED_MSG ("createInstanceFromString(id) is deprecated, use create(id) instead.", static PreProcessing *createInstanceFromString(const std::string &id))

	GRT_DEPRECATED_MSG ("getPreProcessingType is deprecated, use getId() instead", std::string getPreProcessingType() const )

Public Member Functions inherited from MLBase
	MLBase (const std::string &id="", const BaseType type=BASE_TYPE_NOT_SET)

virtual	~MLBase (void)

bool	copyMLBaseVariables (const MLBase *mlBase)

virtual bool	train (ClassificationData trainingData)

virtual bool	train_ (ClassificationData &trainingData)

virtual bool	train (RegressionData trainingData)

virtual bool	train_ (RegressionData &trainingData)

virtual bool	train (RegressionData trainingData, RegressionData validationData)

virtual bool	train_ (RegressionData &trainingData, RegressionData &validationData)

virtual bool	train (TimeSeriesClassificationData trainingData)

virtual bool	train_ (TimeSeriesClassificationData &trainingData)

virtual bool	train (ClassificationDataStream trainingData)

virtual bool	train_ (ClassificationDataStream &trainingData)

virtual bool	train (UnlabelledData trainingData)

virtual bool	train_ (UnlabelledData &trainingData)

virtual bool	train (MatrixFloat data)

virtual bool	train_ (MatrixFloat &data)

virtual bool	predict (VectorFloat inputVector)

virtual bool	predict_ (VectorFloat &inputVector)

virtual bool	predict (MatrixFloat inputMatrix)

virtual bool	predict_ (MatrixFloat &inputMatrix)

virtual bool	map (VectorFloat inputVector)

virtual bool	map_ (VectorFloat &inputVector)

virtual bool	print () const

virtual bool	save (const std::string &filename) const

virtual bool	load (const std::string &filename)

	GRT_DEPRECATED_MSG ("saveModelToFile(std::string filename) is deprecated, use save(const std::string &filename) instead", virtual bool saveModelToFile(const std::string &filename) const )

	GRT_DEPRECATED_MSG ("saveModelToFile(std::fstream &file) is deprecated, use save(std::fstream &file) instead", virtual bool saveModelToFile(std::fstream &file) const )

	GRT_DEPRECATED_MSG ("loadModelFromFile(std::string filename) is deprecated, use load(const std::string &filename) instead", virtual bool loadModelFromFile(const std::string &filename))

	GRT_DEPRECATED_MSG ("loadModelFromFile(std::fstream &file) is deprecated, use load(std::fstream &file) instead", virtual bool loadModelFromFile(std::fstream &file))

virtual bool	getModel (std::ostream &stream) const

virtual std::string	getModelAsString () const

DataType	getInputType () const

DataType	getOutputType () const

BaseType	getType () const

UINT	getNumInputFeatures () const

UINT	getNumInputDimensions () const

UINT	getNumOutputDimensions () const

UINT	getMinNumEpochs () const

UINT	getMaxNumEpochs () const

UINT	getBatchSize () const

UINT	getNumRestarts () const

UINT	getValidationSetSize () const

UINT	getNumTrainingIterationsToConverge () const

Float	getMinChange () const

Float	getLearningRate () const

Float	getRMSTrainingError () const

	GRT_DEPRECATED_MSG ("getRootMeanSquaredTrainingError() is deprecated, use getRMSTrainingError() instead", Float getRootMeanSquaredTrainingError() const )

Float	getTotalSquaredTrainingError () const

Float	getRMSValidationError () const

Float	getValidationSetAccuracy () const

VectorFloat	getValidationSetPrecision () const

VectorFloat	getValidationSetRecall () const

bool	getUseValidationSet () const

bool	getRandomiseTrainingOrder () const

bool	getTrained () const

	GRT_DEPRECATED_MSG ("getModelTrained() is deprecated, use getTrained() instead", bool getModelTrained() const )

bool	getConverged () const

bool	getScalingEnabled () const

bool	getIsBaseTypeClassifier () const

bool	getIsBaseTypeRegressifier () const

bool	getIsBaseTypeClusterer () const

bool	getTrainingLoggingEnabled () const

bool	getTestingLoggingEnabled () const

bool	enableScaling (const bool useScaling)

bool	setMaxNumEpochs (const UINT maxNumEpochs)

bool	setBatchSize (const UINT batchSize)

bool	setMinNumEpochs (const UINT minNumEpochs)

bool	setNumRestarts (const UINT numRestarts)

bool	setMinChange (const Float minChange)

bool	setLearningRate (const Float learningRate)

bool	setUseValidationSet (const bool useValidationSet)

bool	setValidationSetSize (const UINT validationSetSize)

bool	setRandomiseTrainingOrder (const bool randomiseTrainingOrder)

bool	setTrainingLoggingEnabled (const bool loggingEnabled)

bool	setTestingLoggingEnabled (const bool loggingEnabled)

bool	registerTrainingResultsObserver (Observer< TrainingResult > &observer)

bool	registerTestResultsObserver (Observer< TestInstanceResult > &observer)

bool	removeTrainingResultsObserver (const Observer< TrainingResult > &observer)

bool	removeTestResultsObserver (const Observer< TestInstanceResult > &observer)

bool	removeAllTrainingObservers ()

bool	removeAllTestObservers ()

bool	notifyTrainingResultsObservers (const TrainingResult &data)

bool	notifyTestResultsObservers (const TestInstanceResult &data)

MLBase *	getMLBasePointer ()

const MLBase *	getMLBasePointer () const

Vector< TrainingResult >	getTrainingResults () const

Public Member Functions inherited from GRTBase
	GRTBase (const std::string &id="")

virtual	~GRTBase (void)

bool	copyGRTBaseVariables (const GRTBase *GRTBase)

	GRT_DEPRECATED_MSG ("getClassType is deprecated, use getId() instead!", std::string getClassType() const )

std::string	getId () const

std::string	getLastWarningMessage () const

std::string	getLastErrorMessage () const

std::string	getLastInfoMessage () const

bool	setInfoLoggingEnabled (const bool loggingEnabled)

bool	setWarningLoggingEnabled (const bool loggingEnabled)

bool	setErrorLoggingEnabled (const bool loggingEnabled)

bool	setDebugLoggingEnabled (const bool loggingEnabled)

GRTBase *	getGRTBasePointer ()

const GRTBase *	getGRTBasePointer () const

Float	scale (const Float &x, const Float &minSource, const Float &maxSource, const Float &minTarget, const Float &maxTarget, const bool constrain=false)

Float	SQR (const Float &x) const

Public Member Functions inherited from Observer< TrainingResult >
virtual void	notify (const TrainingResult &data)

Public Member Functions inherited from Observer< TestInstanceResult >
virtual void	notify (const TestInstanceResult &data)

Static Public Member Functions
static std::string	getId ()

Static Public Member Functions inherited from PreProcessing
static PreProcessing *	create (const std::string &id)

Static Public Member Functions inherited from GRTBase
static std::string	getGRTVersion (bool returnRevision=true)

static std::string	getGRTRevison ()

Protected Attributes
FilterType	filterType

UINT	numTaps

Float	sampleRate

Float	cutoffFrequency

Float	cutoffFrequencyLower

Float	cutoffFrequencyUpper

Float	gain

CircularBuffer< VectorFloat >	y

VectorFloat	z

Protected Attributes inherited from PreProcessing
std::string	preProcessingType

bool	initialized

VectorFloat	processedData

Protected Attributes inherited from MLBase
bool	trained

bool	useScaling

bool	converged

DataType	inputType

DataType	outputType

BaseType	baseType

UINT	numInputDimensions

UINT	numOutputDimensions

UINT	numTrainingIterationsToConverge

UINT	minNumEpochs

UINT	maxNumEpochs

UINT	batchSize

UINT	validationSetSize

UINT	numRestarts

Float	learningRate

Float	minChange

Float	rmsTrainingError

Float	rmsValidationError

Float	totalSquaredTrainingError

Float	validationSetAccuracy

bool	useValidationSet

bool	randomiseTrainingOrder

VectorFloat	validationSetPrecision

VectorFloat	validationSetRecall

Random	random

Vector< TrainingResult >	trainingResults

TrainingResultsObserverManager	trainingResultsObserverManager

TestResultsObserverManager	testResultsObserverManager

TrainingLog	trainingLog

TestingLog	testingLog

Protected Attributes inherited from GRTBase
std::string	classId
	Stores the name of the class (e.g., MinDist)

DebugLog	debugLog

ErrorLog	errorLog

InfoLog	infoLog

WarningLog	warningLog

Additional Inherited Members
Protected Member Functions inherited from PreProcessing
bool	init ()

bool	savePreProcessingSettingsToFile (std::fstream &file) const

bool	loadPreProcessingSettingsFromFile (std::fstream &file)

Protected Member Functions inherited from MLBase
bool	saveBaseSettingsToFile (std::fstream &file) const

bool	loadBaseSettingsFromFile (std::fstream &file)

Static Protected Member Functions inherited from PreProcessing
static StringPreProcessingMap *	getMap ()

Detailed Description

This class implements a Finite Impulse Response (FIR) Filter. It can support a low pass filter, high pass filter, or band pass filter.

GRT MIT License Copyright (c) <2012> <Nicholas Gillian, Media Lab, MIT>

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Definition at line 37 of file FIRFilter.h.

Member Enumeration Documentation

enum FIRFilter::FilterType

Enumerator
LPF	Low pass filter.
HPF	High pass filter.
BPF	Band pass filter.

Definition at line 39 of file FIRFilter.h.

Constructor & Destructor Documentation

FIRFilter::FIRFilter	(	const FilterType	filterType = `LPF`,
		const UINT	numTaps = `50`,
		const Float	sampleRate = `100`,
		const Float	cutoffFrequency = `10`,
		const Float	gain = `1`,
		const UINT	numDimensions = `1`
	)

Constructor, sets the filter factor, gain and dimensionality of the low pass filter. If the cutoffFrequency and delta values are set then the filter will be initialized with these values rather than the filterFactor. If the cutoffFrequency and delta values are kept at their default values of -1 then the values will be ignored and the filter factor will be used instead. Otherwise the fiterFactor will control the low pass filter, with a larger filterFactor (i.e. 0.99) resulting in a more aggresive smoothing of the input signal. The filterFactor should be in the range [0.0 1.0].

Parameters

filterType sets the filter type, this should be one of the FilterTypes enums. Default is low pass filter, LPF

Definition at line 33 of file FIRFilter.cpp.

FIRFilter::FIRFilter ( const FIRFilter & rhs )

Copy Constructor, copies the FIRFilter from the rhs instance to this instance

Parameters

rhs	another instance of the FIRFilter class from which the data will be copied to this instance

Definition at line 62 of file FIRFilter.cpp.

FIRFilter::~FIRFilter ( )

virtual

Default Destructor

Definition at line 67 of file FIRFilter.cpp.

Member Function Documentation

bool FIRFilter::buildFilter ( )

Builds the filter, using the current filter parameters.

Returns: true if the filter was built, false otherwise

Definition at line 306 of file FIRFilter.cpp.

bool FIRFilter::clear ( )

virtual

Sets the PreProcessing clear function, overwriting the base PreProcessing function. This function clears the filter values and de-initiliazes the filter.

Returns: true if the filter was reset, false otherwise

Reimplemented from PreProcessing.

Definition at line 143 of file FIRFilter.cpp.

bool FIRFilter::deepCopyFrom ( const PreProcessing * preProcessing )

virtual

Sets the PreProcessing deepCopyFrom function, overwriting the base PreProcessing function. This function is used to deep copy the values from the input pointer to this instance of the PreProcessing module. This function is called by the GestureRecognitionPipeline when the user adds a new PreProcessing module to the pipeline.

Parameters

preProcessing a pointer to another instance of a FIRFilter, the values of that instance will be cloned to this instance

Returns: true if the deep copy was successful, false otherwise

Reimplemented from PreProcessing.

Definition at line 88 of file FIRFilter.cpp.

Float FIRFilter::filter ( const Float x )

Filters the input, this should only be called if the dimensionality of the filter was set to 1.

Parameters

x	the value to filter, this should only be called if the dimensionality of the filter was set to 1

Returns: the filtered value. Zero will be returned if the value was not filtered

Definition at line 372 of file FIRFilter.cpp.

VectorFloat FIRFilter::filter ( const VectorFloat & x )

Filters the input, the dimensionality of the input vector should match that of the filter.

Parameters

x	the values to filter, the dimensionality of the input vector should match that of the filter

Returns: the filtered values. An empty vector will be returned if the values were not filtered

Definition at line 392 of file FIRFilter.cpp.

Float FIRFilter::getCutoffFrequency ( ) const

Gets the cutoff frequency that was used to design the filter. This is only relevant for a low-pass or high-pass filter.

Returns: a Float representing the cutoff frequency that was used to design the filter

Definition at line 433 of file FIRFilter.cpp.

Float FIRFilter::getCutoffFrequencyLower ( ) const

Gets the lower cutoff frequency that was used to design the filter. This is only relevant for a band-pass filter.

Returns: a Float representing the lower cutoff frequency that was used to design the filter

Definition at line 437 of file FIRFilter.cpp.

Float FIRFilter::getCutoffFrequencyUpper ( ) const

Gets the upper cutoff frequency that was used to design the filter. This is only relevant for a band-pass filter.

Returns: a Float representing the upper cutoff frequency that was used to design the filter

Definition at line 441 of file FIRFilter.cpp.

VectorFloat FIRFilter::getFilterCoefficents ( ) const

Returns the filter coefficents as a VectorFloat.

Returns: the filtered values. An empty vector will be returned if the filter has not been initalized

Definition at line 456 of file FIRFilter.cpp.

FIRFilter::FilterType FIRFilter::getFilterType ( ) const

Gets the filter type, this should be one of the FilterTypes enums.

Returns: an enum representing the filter type

Definition at line 421 of file FIRFilter.cpp.

Float FIRFilter::getGain ( ) const

Gets the current gain value.

Returns: the current gain value

Definition at line 445 of file FIRFilter.cpp.

std::string FIRFilter::getId ( )

static

Gets a string that represents the ID of this class.

Returns: returns a string containing the ID of this class

Definition at line 28 of file FIRFilter.cpp.

Vector< VectorFloat > FIRFilter::getInputBuffer ( ) const

Returns the last N value(s) that were input to the filter.

Returns: the filtered values. An empty vector will be returned if the filter has not been initalized

Definition at line 449 of file FIRFilter.cpp.

UINT FIRFilter::getNumTaps ( ) const

Gets the number of taps in the filter.

Returns: an UINT representing the number of taps in the filter

Definition at line 425 of file FIRFilter.cpp.

Float FIRFilter::getSampleRate ( ) const

Gets the sample rate that was used to design the filter.

Returns: a Float representing the sample rate that was used to design the filter

Definition at line 429 of file FIRFilter.cpp.

bool FIRFilter::load ( std::fstream & file )

virtual

This loads the FIRFilter settings from a file. This overrides the load function in the PreProcessing base class.

Parameters

file	a reference to the file to load the settings from

Returns: returns true if the model was loaded successfully, false otherwise

Reimplemented from MLBase.

Definition at line 192 of file FIRFilter.cpp.

FIRFilter & FIRFilter::operator= ( const FIRFilter & rhs )

Sets the equals operator, copies the data from the rhs instance to this instance

Parameters

rhs	another instance of the FIRFilter class from which the data will be copied to this instance

Returns: a reference to this instance of FIRFilter

Definition at line 71 of file FIRFilter.cpp.

bool FIRFilter::process ( const VectorFloat & inputVector )

virtual

Sets the PreProcessing process function, overwriting the base PreProcessing function. This function is called by the GestureRecognitionPipeline when any new input data needs to be processed (during the prediction phase for example). This function calls the FIRFilter's filter function.

Parameters

inputVector the inputVector that should be processed. Must have the same dimensionality as the PreProcessing module

Returns: true if the data was processed, false otherwise

Reimplemented from PreProcessing.

Definition at line 105 of file FIRFilter.cpp.

bool FIRFilter::reset ( )

virtual

Sets the PreProcessing reset function, overwriting the base PreProcessing function. This function is called by the GestureRecognitionPipeline when the pipelines main reset() function is called. This function resets the filter values by re-initiliazing the filter.

Returns: true if the filter was reset, false otherwise

Reimplemented from PreProcessing.

Definition at line 126 of file FIRFilter.cpp.

bool FIRFilter::save ( std::fstream & file ) const

virtual

This saves the current settings of the FIRFilter to a file. This overrides the save function in the PreProcessing base class.

Parameters

file	a reference to the file the settings will be saved to

Returns: returns true if the settings were saved successfully, false otherwise

Reimplemented from MLBase.

Definition at line 154 of file FIRFilter.cpp.

bool FIRFilter::setCutoffFrequency ( const Float cutoffFrequency )

Sets the cutoff frequency of the filter. This should be used with either a low-pass or high-pass filter. The cutoffFrequency should be in Hz. This will deinitalize the filter, you should rebuild the filter after changing this value.

Parameters

cutoffFrequency the cutoff frequency of the filter in Hz

Returns: true if the cutoffFrequency value was set, false otherwise

Definition at line 502 of file FIRFilter.cpp.

bool FIRFilter::setCutoffFrequency	(	const Float	cutoffFrequencyLower,
		const Float	cutoffFrequencyUpper
	)

Sets the lower and upper cutoff frequency for a band-pass filter. The cutoffFrequencies should be in Hz. This will deinitalize the filter, you should rebuild the filter after changing this value.

Parameters

cutoffFrequencyLower	the lower cutoff frequency of the band-pass filter in Hz
cutoffFrequencyUpper	the upper cutoff frequency of the band-pass filter in Hz

Returns: true if the parameters were set, false otherwise

Definition at line 519 of file FIRFilter.cpp.

bool FIRFilter::setFilterType ( const FilterType filterType )

Sets the filter type, this should be one of the FilterTypes enums. This will deinitalize the filter, you should rebuild the filter after changing this value.

Parameters

filterType the new filterType

Returns: true if the filterType value was set, false otherwise

Definition at line 463 of file FIRFilter.cpp.

bool FIRFilter::setGain ( const Float gain )

Sets the gain of the low pass filter.

Parameters

gain	the new gain value, this multiples the filtered values by a constant ampltidue

Returns: true if the gain value was set, false otherwise

Definition at line 541 of file FIRFilter.cpp.

bool FIRFilter::setNumTaps ( const UINT numTaps )

Sets the number of taps in the filter, this controls the filter size and accuracy. More taps will give you a more responsive filter, less taps will give you a faster filter. This will deinitalize the filter, you should rebuild the filter after changing this value.

Parameters

numTaps the number of taps in your filter

Returns: true if the numTaps value was set, false otherwise

Definition at line 476 of file FIRFilter.cpp.

bool FIRFilter::setSampleRate ( const Float sampleRate )

Sets the sample rate of your signal. This will deinitalize the filter, you should rebuild the filter after changing this value.

Parameters

sampleRate the new sampleRate value

Returns: true if the sampleRate value was set, false otherwise

Definition at line 489 of file FIRFilter.cpp.

The documentation for this class was generated from the following files:

Public Types

Public Member Functions

Static Public Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation