de.lmu.ifi.dbs.elki.distance.distancefunction.correlation

Class SquaredPearsonCorrelationDistanceFunction

java.lang.Object

de.lmu.ifi.dbs.elki.distance.distancefunction.AbstractPrimitiveDistanceFunction<NumberVector<?>,DoubleDistance>

de.lmu.ifi.dbs.elki.distance.distancefunction.AbstractVectorDoubleDistanceFunction

de.lmu.ifi.dbs.elki.distance.distancefunction.correlation.SquaredPearsonCorrelationDistanceFunction

All Implemented Interfaces:

DistanceFunction<NumberVector<?>,DoubleDistance>, NumberVectorDistanceFunction<DoubleDistance>, PrimitiveDistanceFunction<NumberVector<?>,DoubleDistance>, PrimitiveDoubleDistanceFunction<NumberVector<?>>, Parameterizable

public class SquaredPearsonCorrelationDistanceFunction
extends AbstractVectorDoubleDistanceFunction

Squared Pearson correlation distance function for feature vectors. The squared Pearson correlation distance is computed from the Pearson correlation coefficient r as: 1-r 2. Hence, possible values of this distance are between 0 and 1. The distance between two vectors will be low (near 0), if their attribute values are dimension-wise strictly positively or negatively correlated. For Features with uncorrelated attributes, the distance value will be high (near 1).

Nested Class Summary

Nested Classes

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

Field Summary

Fields

Modifier and Type	Field and Description
static SquaredPearsonCorrelationDistanceFunction	STATIC Static instance.

Constructor Summary

Constructors

Constructor and Description
SquaredPearsonCorrelationDistanceFunction() Deprecated. use static instance!

Method Summary

Methods

Modifier and Type	Method and Description
double	doubleDistance(NumberVector<?> v1, NumberVector<?> v2) Computes the squared Pearson correlation distance for two given feature vectors.
boolean	equals(Object obj)
String	toString()

Methods inherited from class de.lmu.ifi.dbs.elki.distance.distancefunction.AbstractVectorDoubleDistanceFunction

dimensionality, dimensionality, dimensionality, dimensionality, distance, getDistanceFactory, getInputTypeRestriction

Methods inherited from class de.lmu.ifi.dbs.elki.distance.distancefunction.AbstractPrimitiveDistanceFunction

instantiate, isMetric, isSymmetric

Methods inherited from class java.lang.Object

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

Methods inherited from interface de.lmu.ifi.dbs.elki.distance.distancefunction.DistanceFunction

instantiate, isMetric, isSymmetric

Field Detail

STATIC

public static final SquaredPearsonCorrelationDistanceFunction STATIC

Static instance.

Constructor Detail

SquaredPearsonCorrelationDistanceFunction

@Deprecated
public SquaredPearsonCorrelationDistanceFunction()

Deprecated. use static instance!

Provides a SquaredPearsonCorrelationDistanceFunction.

Method Detail

doubleDistance

public double doubleDistance(NumberVector<?> v1,
                    NumberVector<?> v2)

Computes the squared Pearson correlation distance for two given feature vectors. The squared Pearson correlation distance is computed from the Pearson correlation coefficient r as: 1-r 2. Hence, possible values of this distance are between 0 and 1.

Parameters:

v1 - first feature vector

v2 - second feature vector

Returns:

the squared Pearson correlation distance for two given feature vectors v1 and v2

toString

public String toString()

Overrides:

toString in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object