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

Class SquaredEuclideanDistanceFunction

java.lang.Object

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

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

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

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

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

All Implemented Interfaces:

DistanceFunction<NumberVector>, Norm<NumberVector>, NumberVectorDistanceFunction<NumberVector>, PrimitiveDistanceFunction<NumberVector>, SpatialPrimitiveDistanceFunction<NumberVector>

@Alias(value={"squaredeuclidean","de.lmu.ifi.dbs.elki.distance.distancefunction.SquaredEuclideanDistanceFunction"})
public class SquaredEuclideanDistanceFunction
extends AbstractSpatialNorm

Squared Euclidean distance, optimized for SparseNumberVectors. This results in the same rankings as regular Euclidean distance, but saves computing the square root.

Author:

Arthur Zimek

Nested Class Summary

Nested Classes

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

Field Summary

Fields

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

Constructor Summary

Constructors

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

Method Summary

Methods

Modifier and Type	Method and Description
double	distance(NumberVector v1, NumberVector v2) Computes the distance between two given DatabaseObjects according to this distance function.
boolean	equals(Object obj)
SimpleTypeInformation<? super NumberVector>	getInputTypeRestriction() Get the input data type of the function.
boolean	isMetric() Is this distance function metric (in particular, does it satisfy the triangle equation?)
double	minDist(SpatialComparable mbr1, SpatialComparable mbr2) Computes the distance between the two given MBRs according to this distance function.
double	norm(NumberVector v) Compute the norm of object obj.
private double	preDistance(NumberVector v1, NumberVector v2, int start, int end, double agg)
private double	preDistanceMBR(SpatialComparable mbr1, SpatialComparable mbr2, int start, int end, double agg)
private double	preDistanceVM(NumberVector v, SpatialComparable mbr, int start, int end, double agg)
private double	preNorm(NumberVector v, int start, int end, double agg)
private double	preNormMBR(SpatialComparable mbr, int start, int end, double agg)
String	toString()

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

instantiate

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

dimensionality, dimensionality, dimensionality, dimensionality

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.DistanceFunction

isSymmetric

Field Detail

STATIC

public static final SquaredEuclideanDistanceFunction STATIC

Static instance. Use this!

Constructor Detail

SquaredEuclideanDistanceFunction

@Deprecated
public SquaredEuclideanDistanceFunction()

Deprecated. Use static instance!

Constructor - use STATIC instead.

Method Detail

preDistance

private final double preDistance(NumberVector v1,
                 NumberVector v2,
                 int start,
                 int end,
                 double agg)

preDistanceVM

private final double preDistanceVM(NumberVector v,
                   SpatialComparable mbr,
                   int start,
                   int end,
                   double agg)

preDistanceMBR

private final double preDistanceMBR(SpatialComparable mbr1,
                    SpatialComparable mbr2,
                    int start,
                    int end,
                    double agg)

preNorm

private final double preNorm(NumberVector v,
             int start,
             int end,
             double agg)

preNormMBR

private final double preNormMBR(SpatialComparable mbr,
                int start,
                int end,
                double agg)

distance

public double distance(NumberVector v1,
              NumberVector v2)

Description copied from interface: PrimitiveDistanceFunction

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

Specified by:

distance in interface NumberVectorDistanceFunction<NumberVector>

Specified by:

distance in interface PrimitiveDistanceFunction<NumberVector>

Specified by:

distance in class AbstractPrimitiveDistanceFunction<NumberVector>

Parameters:

v1 - first DatabaseObject

v2 - second DatabaseObject

Returns:

the distance between two given DatabaseObjects according to this distance function

norm

public double norm(NumberVector v)

Description copied from interface: Norm

Compute the norm of object obj.

Parameters:

v - Object

Returns:

Norm

minDist

public double minDist(SpatialComparable mbr1,
             SpatialComparable mbr2)

Description copied from interface: SpatialPrimitiveDistanceFunction

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

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>

Overrides:

isMetric in class AbstractPrimitiveDistanceFunction<NumberVector>

Returns:

true when metric.

toString

public String toString()

Overrides:

toString in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

getInputTypeRestriction

public SimpleTypeInformation<? super NumberVector> getInputTypeRestriction()

Description copied from interface: DistanceFunction

Get the input data type of the function.

Specified by:

getInputTypeRestriction in interface DistanceFunction<NumberVector>

Specified by:

getInputTypeRestriction in interface PrimitiveDistanceFunction<NumberVector>

Overrides:

getInputTypeRestriction in class AbstractNumberVectorDistanceFunction

Returns:

Type restriction