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

Class KolmogorovSmirnovDistanceFunction

java.lang.Object

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

de.lmu.ifi.dbs.elki.distance.distancefunction.histogram.KolmogorovSmirnovDistanceFunction

All Implemented Interfaces:

DistanceFunction<NumberVector>, NumberVectorDistanceFunction<NumberVector>, PrimitiveDistanceFunction<NumberVector>

public class KolmogorovSmirnovDistanceFunction
extends AbstractNumberVectorDistanceFunction

Distance function based on the Kolmogorov-Smirnov goodness of fit test.

This distance function assumes there exist a natural order in the vectors, i.e. they should be some 1-dimensional histogram.

The distance is then defined as \[\text{KS}(\vec{x},\vec{y}) := \max_i |\frac{\sum_{j=1}^i x_j}{\sum_{j=1}^d x_j}| - |\frac{\sum_{j=1}^i y_j}{\sum_{j=1}^d y_j}| \] which is the maximum difference of the empirical CDFs, where the divisors normalize the distribution to 1.

Since:

0.6.0

Author:

Erich Schubert

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	KolmogorovSmirnovDistanceFunction.Parameterizer Parameterization class, using the static instance.

Field Summary

Fields

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

Constructor Summary

Constructors

Constructor and Description
KolmogorovSmirnovDistanceFunction() Deprecated. Use static instance!

Method Summary

Modifier and Type	Method and Description
double	distance(NumberVector v1, NumberVector v2) Computes the distance between two given vectors according to this distance function.
boolean	equals(java.lang.Object obj)
int	hashCode()
java.lang.String	toString()

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

dimensionality, dimensionality, dimensionality, dimensionality, dimensionality, dimensionality, dimensionality, dimensionality, getInputTypeRestriction

Methods inherited from class java.lang.Object

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

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

instantiate

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

isMetric, isSquared, isSymmetric

Field Detail

STATIC

public static final KolmogorovSmirnovDistanceFunction STATIC

Static instance. Use this!

Constructor Detail

KolmogorovSmirnovDistanceFunction

@Deprecated
public KolmogorovSmirnovDistanceFunction()

Deprecated. Use static instance!

Constructor for the Kolmogorov-Smirnov distance function.

Method Detail

distance

public double distance(NumberVector v1,
                       NumberVector v2)

Description copied from interface: NumberVectorDistanceFunction

Computes the distance between two given vectors according to this distance function.

Parameters:

v1 - first vector

v2 - second vector

Returns:

the distance between two given vectors according to this distance function

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object