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

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.WeightedSquaredEuclideanDistanceFunction

All Implemented Interfaces:

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

public class WeightedSquaredEuclideanDistanceFunction
extends AbstractVectorDoubleDistanceFunction

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

Field Summary

protected double[]

weights Weight array

Constructor Summary

WeightedSquaredEuclideanDistanceFunction(double[] weights)
Constructor.

Method Summary

double	doubleDistance(NumberVector<?,?> v1, NumberVector<?,?> v2) Provides the squared Euclidean distance between the given two vectors.
boolean	equals(Object obj)
boolean	isMetric() Is this distance function metric (in particular, does it satisfy the triangle equation?)

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

instantiate, isSymmetric

Methods inherited from class java.lang.Object

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

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

instantiate, isSymmetric

Field Detail

weights

protected double[] weights

Weight array

Constructor Detail

WeightedSquaredEuclideanDistanceFunction

public WeightedSquaredEuclideanDistanceFunction(double[] weights)

Constructor.

Parameters:

weights -

Method Detail

doubleDistance

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

Provides the squared Euclidean distance between the given two vectors.

Parameters:

v1 - first Object

v2 - second Object

Returns:

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

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.

equals

public boolean equals(Object obj)

Overrides:

equals in class Object