de.lmu.ifi.dbs.elki.datasource.filter.normalization.instancewise

Class HellingerHistogramNormalization<V extends NumberVector>

java.lang.Object

de.lmu.ifi.dbs.elki.datasource.filter.AbstractStreamFilter

de.lmu.ifi.dbs.elki.datasource.filter.AbstractStreamConversionFilter<I,O>

de.lmu.ifi.dbs.elki.datasource.filter.AbstractVectorStreamConversionFilter<V,V>

de.lmu.ifi.dbs.elki.datasource.filter.normalization.instancewise.HellingerHistogramNormalization<V>

Type Parameters:

V - vector type

All Implemented Interfaces:

BundleStreamSource, Normalization<V>, ObjectFilter, StreamFilter

public class HellingerHistogramNormalization<V extends NumberVector>
extends AbstractVectorStreamConversionFilter<V,V>
implements Normalization<V>

Normalize histograms by scaling them to unit absolute sum, then taking the square root of the absolute value in each attribute, times the normalization constant \(1/\sqrt{2}\).

\[ H(x_i)=\tfrac{\sqrt{|x_i|/\Sigma}}{\sqrt{2}} \quad\text{ with } \Sigma=\sum\nolimits_i |x_i| \]

Using Euclidean distance (linear kernel) and this transformation is the same as using Hellinger distance: HellingerDistanceFunction

Since:

0.7.0

Author:

Erich Schubert

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	HellingerHistogramNormalization.Parameterizer Parameterization class.

Nested classes/interfaces inherited from interface de.lmu.ifi.dbs.elki.datasource.bundle.BundleStreamSource

BundleStreamSource.Event

Field Summary

Fields

Modifier and Type	Field and Description
static HellingerHistogramNormalization<NumberVector>	STATIC Static instance.

Fields inherited from class de.lmu.ifi.dbs.elki.datasource.filter.AbstractVectorStreamConversionFilter

factory

Fields inherited from class de.lmu.ifi.dbs.elki.datasource.filter.AbstractStreamFilter

source

Constructor Summary

Constructors

Constructor and Description
HellingerHistogramNormalization() Constructor.

Method Summary

Modifier and Type	Method and Description
protected SimpleTypeInformation<? super V>	convertedType(SimpleTypeInformation<V> in) Get the output type from the input type after conversion.
protected V	filterSingleObject(V featureVector) Normalize a single instance.
protected SimpleTypeInformation<? super V>	getInputTypeRestriction() Get the input type restriction used for negotiating the data query.

Methods inherited from class de.lmu.ifi.dbs.elki.datasource.filter.AbstractVectorStreamConversionFilter

initializeOutputType

Methods inherited from class de.lmu.ifi.dbs.elki.datasource.filter.AbstractStreamConversionFilter

data, getMeta, nextEvent

Methods inherited from class de.lmu.ifi.dbs.elki.datasource.filter.AbstractStreamFilter

asMultipleObjectsBundle, assignDBID, filter, hasDBIDs, init, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface de.lmu.ifi.dbs.elki.datasource.filter.normalization.Normalization

restore, transform

Methods inherited from interface de.lmu.ifi.dbs.elki.datasource.filter.ObjectFilter

filter

Field Detail

STATIC

public static final HellingerHistogramNormalization<NumberVector> STATIC

Static instance.

Constructor Detail

HellingerHistogramNormalization

public HellingerHistogramNormalization()

Constructor.

Method Detail

filterSingleObject

protected V filterSingleObject(V featureVector)

Description copied from class: AbstractStreamConversionFilter

Normalize a single instance. You can implement this as UnsupportedOperationException if you override both public "normalize" functions!

Specified by:

filterSingleObject in class AbstractStreamConversionFilter<V extends NumberVector,V extends NumberVector>

Parameters:

featureVector - Database object to normalize

Returns:

Normalized database object

convertedType

protected SimpleTypeInformation<? super V> convertedType(SimpleTypeInformation<V> in)

Description copied from class: AbstractStreamConversionFilter

Get the output type from the input type after conversion.

Specified by:

convertedType in class AbstractStreamConversionFilter<V extends NumberVector,V extends NumberVector>

Parameters:

in - input type restriction

Returns:

output type restriction

getInputTypeRestriction

protected SimpleTypeInformation<? super V> getInputTypeRestriction()

Description copied from class: AbstractStreamConversionFilter

Get the input type restriction used for negotiating the data query.

Specified by:

getInputTypeRestriction in class AbstractStreamConversionFilter<V extends NumberVector,V extends NumberVector>

Returns:

Type restriction