NumericalDiscreteFeature Class Reference

#include <Numerical.h>

Inheritance diagram for NumericalDiscreteFeature:

List of all members.

Public Member Functions
virtual double	getPosition () const
virtual double	getDistance (Feature *f) const
virtual void	moveTowards (Feature *f, double factor)
virtual string	serialize () const
virtual void	unserialize (string value)
virtual featureparams	write () const
virtual void	read (featureparams *param)
virtual Feature *	clone () const
virtual void	aggregate (aggregatelist samples)
virtual FeatureType	getType () const
virtual const string	getName () const
const long	getVal () const
const long	getMin () const
const long	getMax () const
virtual string	toString () const
Protected Member Functions
	NumericalDiscreteFeature (long *minval, long *maxval)
	NumericalDiscreteFeature (long *minval, long *maxval, long val)
Protected Attributes
double	val
long *	minval
long *	maxval

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Detailed Description

Abstract discrete numerical feature

A feature of type numerical_discrete. This class imeplements the getType method of the Feature interface and, as a base class for special features, implements the complete handling of numerical discrete values. This includes the implementations of getDistance and moveTowards as well as getPosition, serialize and unserialize. Additionally, minimum and maximum seen values are stored as persistant values of the feature and used for computing the normalized distance and position. Although these values are handled inside this class, the storage for them has to be provided by the subclasses (or generally the factory that creates objects of this class).

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Constructor & Destructor Documentation

NumericalDiscreteFeature::NumericalDiscreteFeature (  long *  minval, long *  maxval )  [protected]

Feature constructor This constructor initializes the feature with a random value and should thus only be used for creating e.g. prototypes of points in a clustering space. For creating a specific sample of a feature, the second constructor should be used. Parameters: minval  A reference to a static variable (it must be same for all created objects of _one_ feature) for persistantly storing the minimum value. maxval  A reference to a static variable (it must be same for all created objects of _one_ feature) for persistantly storing the maximum value.

NumericalDiscreteFeature::NumericalDiscreteFeature (  long *  minval, long *  maxval, long  val )  [protected]

Sample constructor This constructor initializes the feature with a specific value and should thus be used for samples. Parameters: minval  A reference to a static variable (it must be same for all created objects of _one_ feature) for persistantly storing the minimum value. maxval  A reference to a static variable (it must be same for all created objects of _one_ feature) for persistantly storing the maximum value. val  The sample value.

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Member Function Documentation

void NumericalDiscreteFeature::aggregate (  aggregatelist  samples  )  [virtual]

Aggregate a sample values from other sources Parameters: samples  A list of <timestamp, sample> tuples. Implements Feature.

Feature * NumericalDiscreteFeature::clone (   )  const [virtual]

Clone a feature A feature must be able to clone itself. This is typically implemented with a copy constructor, but should return a new object. Implements Feature.

double NumericalDiscreteFeature::getDistance (  Feature *  f  )  const [virtual]

Calculates the distance between two features Parameters: f  Feature used for distance measurement. Returns: Distance between the two samples. The return value has to be in the interval [0; 1] to guarantee comparability among samples of different features. Implements Feature.

virtual const string NumericalDiscreteFeature::getName (   )  const [inline, virtual]

Query a features name Returns: Name of the Feature in the format "Featureprovider.Feature" Implements Feature. Reimplemented in AudioPeakFeature, BluetoothNumPeersFeature, and WlanNumPeersFeature.

double NumericalDiscreteFeature::getPosition (   )  const [virtual]

Query a features position Returns: The distance to the origin. Every implementation must take care that only values in the interval [0; 1] are returned. Remarks: This function is only for the purpose of internal search operations and visualisation and should not be used in any other context. Implements Feature.

virtual FeatureType NumericalDiscreteFeature::getType (   )  const [inline, virtual]

Query a features type Returns: The type of the Feature. Implements Feature.

const long NumericalDiscreteFeature::getVal (   )  const [inline]

Returns: The value of the feature.

void NumericalDiscreteFeature::moveTowards (  Feature *  f, double  factor )  [virtual]

Move feature Moves the feature towards a given sample value by the specified factor (factor times the distance). If the factor is 0, the old feature value must not change. If the factor is 1, the new feature value should be equivalent to the sample s. Parameters: f  Feature used for distance measurement. factor  Distance weight. Implements Feature.

void NumericalDiscreteFeature::read (  featureparams *  param  )  [virtual]

Load feature from persistant data Initializes the persistant feature data from the given representation. Parameters: param  Persistant feature data. See also: write Implements PersistantFeature.

string NumericalDiscreteFeature::serialize (   )  const [virtual]

Serialize a samples data to a string Returns: String representation of the samples data. Implements Feature.

string NumericalDiscreteFeature::toString (   )  const [virtual]

This is only for testing. Implements Feature. Reimplemented in AudioPeakFeature, BluetoothNumPeersFeature, and WlanNumPeersFeature.

void NumericalDiscreteFeature::unserialize (  string  value  )  [virtual]

Unserialize a samples data from a string Parameters: value  String representation of the samples data. Implements Feature.

featureparams NumericalDiscreteFeature::write (   )  const [virtual]

Externalize feature Returns: Persistant feature data. See also: read Implements PersistantFeature.

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Member Data Documentation

long* NumericalDiscreteFeature::maxval [protected]

A reference to the static, persistant maximum value seen so far.

long* NumericalDiscreteFeature::minval [protected]

A reference to the static, persistant minimum value seen so far.

double NumericalDiscreteFeature::val [protected]

The feature value.

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

• amw/src/cpp/cross/contextprediction/framework/Features/Numerical.h
• amw/src/cpp/cross/contextprediction/framework/Features/Numerical.cpp

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