de.lmu.ifi.dbs.elki.distance.distancefunction
Class SquaredEuclideanDistanceFunction

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.SquaredEuclideanDistanceFunction

All Implemented Interfaces:

DistanceFunction<NumberVector<?,?>,DoubleDistance>, PrimitiveDistanceFunction<NumberVector<?,?>,DoubleDistance>, PrimitiveDoubleDistanceFunction<NumberVector<?,?>>, SpatialPrimitiveDistanceFunction<NumberVector<?,?>,DoubleDistance>, SpatialPrimitiveDoubleDistanceFunction<NumberVector<?,?>>, InspectionUtilFrequentlyScanned, Parameterizable

public class SquaredEuclideanDistanceFunction
extends AbstractVectorDoubleDistanceFunction
implements SpatialPrimitiveDoubleDistanceFunction<NumberVector<?,?>>

Provides the squared Euclidean distance for FeatureVectors. This results in the same rankings, but saves computing the square root as often.

Nested Class Summary

static class

SquaredEuclideanDistanceFunction.Parameterizer Parameterization class.

Field Summary

static SquaredEuclideanDistanceFunction

STATIC Static instance.

Constructor Summary

SquaredEuclideanDistanceFunction()
Deprecated. Use static instance!

Method Summary

DoubleDistance	centerDistance(SpatialComparable mbr1, SpatialComparable mbr2) Computes the distance between the centroids of the two given MBRs according to this distance function.
double	doubleCenterDistance(SpatialComparable mbr1, SpatialComparable mbr2) Computes the distance between the centroids of the two given MBRs according to this distance function.
double	doubleDistance(NumberVector<?,?> v1, NumberVector<?,?> v2) Provides the squared Euclidean distance between the given two vectors.
double	doubleMinDist(SpatialComparable mbr1, SpatialComparable mbr2) Computes the distance between the two given MBRs according to this distance function.
protected double	doubleMinDistObject(SpatialComparable mbr, NumberVector<?,?> v)
boolean	equals(Object obj)
<T extends NumberVector<?,?>> SpatialPrimitiveDistanceQuery<T,DoubleDistance>	instantiate(Relation<T> relation) Instantiate with a database to get the actual distance query.
boolean	isMetric() Is this distance function metric (in particular, does it satisfy the triangle equation?)
DoubleDistance	minDist(SpatialComparable mbr1, SpatialComparable mbr2) Computes the distance between the two given MBRs according to this distance function.
String	toString()

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

distance, getDistanceFactory, getInputTypeRestriction

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

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.PrimitiveDistanceFunction

distance, getInputTypeRestriction

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

getDistanceFactory, isSymmetric

Field Detail

STATIC

public static final SquaredEuclideanDistanceFunction STATIC

Static instance. Use this!

Constructor Detail

SquaredEuclideanDistanceFunction

@Deprecated
public SquaredEuclideanDistanceFunction()

Deprecated. Use static instance!

Provides a Euclidean distance function that can compute the Euclidean distance (that is a DoubleDistance) for FeatureVectors.

Method Detail

doubleDistance

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

Provides the squared Euclidean distance between the given two vectors.

Specified by:

doubleDistance in interface PrimitiveDoubleDistanceFunction<NumberVector<?,?>>

Parameters:

v1 - first Object

v2 - second Object

Returns:

the squared Euclidean distance between the given two vectors as raw double value

doubleMinDistObject

protected double doubleMinDistObject(SpatialComparable mbr,
                                     NumberVector<?,?> v)

doubleMinDist

public double doubleMinDist(SpatialComparable mbr1,
                            SpatialComparable mbr2)

Description copied from interface: SpatialPrimitiveDoubleDistanceFunction

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

Specified by:

doubleMinDist in interface SpatialPrimitiveDoubleDistanceFunction<NumberVector<?,?>>

Parameters:

mbr1 - the first MBR object

mbr2 - the second MBR object

Returns:

the distance between the two given MBRs according to this distance function

doubleCenterDistance

public double doubleCenterDistance(SpatialComparable mbr1,
                                   SpatialComparable mbr2)

Description copied from interface: SpatialPrimitiveDoubleDistanceFunction

Computes the distance between the centroids of the two given MBRs according to this distance function.

Specified by:

doubleCenterDistance in interface SpatialPrimitiveDoubleDistanceFunction<NumberVector<?,?>>

Parameters:

mbr1 - the first MBR object

mbr2 - the second MBR object

Returns:

the distance between the centroids of the two given MBRs according to this distance function

centerDistance

public DoubleDistance centerDistance(SpatialComparable mbr1,
                                     SpatialComparable mbr2)

Description copied from interface: SpatialPrimitiveDistanceFunction

Computes the distance between the centroids of the two given MBRs according to this distance function.

Specified by:

centerDistance in interface SpatialPrimitiveDistanceFunction<NumberVector<?,?>,DoubleDistance>

Parameters:

mbr1 - the first MBR object

mbr2 - the second MBR object

Returns:

the distance between the centroids of the two given MBRs according to this distance function

minDist

public DoubleDistance minDist(SpatialComparable mbr1,
                              SpatialComparable mbr2)

Description copied from interface: SpatialPrimitiveDistanceFunction

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

Specified by:

minDist in interface SpatialPrimitiveDistanceFunction<NumberVector<?,?>,DoubleDistance>

Parameters:

mbr1 - the first MBR object

mbr2 - the second MBR object

Returns:

the distance between the two given MBRs according to this distance function

isMetric

public boolean isMetric()

Description copied from interface: DistanceFunction

Is this distance function metric (in particular, does it satisfy the triangle equation?)

Specified by:

isMetric in interface DistanceFunction<NumberVector<?,?>,DoubleDistance>

Overrides:

isMetric in class AbstractPrimitiveDistanceFunction<NumberVector<?,?>,DoubleDistance>

Returns:

true when metric.

instantiate

public <T extends NumberVector<?,?>> SpatialPrimitiveDistanceQuery<T,DoubleDistance> instantiate(Relation<T> relation)

Description copied from class: AbstractPrimitiveDistanceFunction

Instantiate with a database to get the actual distance query.

Specified by:

instantiate in interface DistanceFunction<NumberVector<?,?>,DoubleDistance>

Specified by:

instantiate in interface SpatialPrimitiveDistanceFunction<NumberVector<?,?>,DoubleDistance>

Overrides:

instantiate in class AbstractPrimitiveDistanceFunction<NumberVector<?,?>,DoubleDistance>

Parameters:

relation - Representation

Returns:

Actual distance query.

toString

public String toString()

Overrides:

toString in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object