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

Class LocallyWeightedDistanceFunction<V extends NumberVector<?>>

java.lang.Object

de.lmu.ifi.dbs.elki.distance.distancefunction.AbstractDatabaseDistanceFunction<O,D>

de.lmu.ifi.dbs.elki.distance.distancefunction.AbstractIndexBasedDistanceFunction<V,FilteredLocalPCAIndex<V>,DoubleDistance>

de.lmu.ifi.dbs.elki.distance.distancefunction.LocallyWeightedDistanceFunction<V>

Type Parameters:

V - the type of NumberVector to compute the distances in between

All Implemented Interfaces:

DistanceFunction<V,DoubleDistance>, FilteredLocalPCABasedDistanceFunction<V,FilteredLocalPCAIndex<V>,DoubleDistance>, IndexBasedDistanceFunction<V,DoubleDistance>, Parameterizable

public class LocallyWeightedDistanceFunction<V extends NumberVector<?>>
extends AbstractIndexBasedDistanceFunction<V,FilteredLocalPCAIndex<V>,DoubleDistance>
implements FilteredLocalPCABasedDistanceFunction<V,FilteredLocalPCAIndex<V>,DoubleDistance>

Provides a locally weighted distance function. Computes the quadratic form distance between two vectors P and Q as follows: result = max{dist_P(P,Q), dist_Q(Q,P)} where dist_X(X,Y) = (X-Y)*M_X*(X-Y)^T and M_X is the weight matrix of vector X.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	LocallyWeightedDistanceFunction.Instance<V extends NumberVector<?>> Instance of this distance for a particular database.
static class	LocallyWeightedDistanceFunction.Parameterizer<V extends NumberVector<?>> Parameterization class.

Field Summary

Fields inherited from class de.lmu.ifi.dbs.elki.distance.distancefunction.AbstractIndexBasedDistanceFunction

indexFactory

Fields inherited from interface de.lmu.ifi.dbs.elki.distance.distancefunction.IndexBasedDistanceFunction

INDEX_ID

Constructor Summary

Constructors

Constructor and Description
LocallyWeightedDistanceFunction(LocalProjectionIndex.Factory<V,FilteredLocalPCAIndex<V>> indexFactory) Constructor

Method Summary

Methods

Modifier and Type	Method and Description
boolean	equals(Object obj)
DoubleDistance	getDistanceFactory() Method to get the distance functions factory.
<T extends V> LocallyWeightedDistanceFunction.Instance<T>	instantiate(Relation<T> database) 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?)
boolean	isSymmetric() Is this function symmetric?

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

getInputTypeRestriction

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

getInputTypeRestriction

Constructor Detail

LocallyWeightedDistanceFunction

public LocallyWeightedDistanceFunction(LocalProjectionIndex.Factory<V,FilteredLocalPCAIndex<V>> indexFactory)

Constructor

Parameters:

indexFactory - Index factory

Method Detail

getDistanceFactory

public DoubleDistance getDistanceFactory()

Description copied from interface: DistanceFunction

Method to get the distance functions factory.

Specified by:

getDistanceFactory in interface DistanceFunction<V extends NumberVector<?>,DoubleDistance>

Specified by:

getDistanceFactory in class AbstractDatabaseDistanceFunction<V extends NumberVector<?>,DoubleDistance>

Returns:

Factory for distance objects

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<V extends NumberVector<?>,DoubleDistance>

Overrides:

isMetric in class AbstractIndexBasedDistanceFunction<V extends NumberVector<?>,FilteredLocalPCAIndex<V extends NumberVector<?>>,DoubleDistance>

Returns:

true when metric.

isSymmetric

public boolean isSymmetric()

Description copied from interface: DistanceFunction

Is this function symmetric?

Specified by:

isSymmetric in interface DistanceFunction<V extends NumberVector<?>,DoubleDistance>

Overrides:

isSymmetric in class AbstractIndexBasedDistanceFunction<V extends NumberVector<?>,FilteredLocalPCAIndex<V extends NumberVector<?>>,DoubleDistance>

Returns:

true when symmetric

instantiate

public <T extends V> LocallyWeightedDistanceFunction.Instance<T> instantiate(Relation<T> database)

Description copied from interface: FilteredLocalPCABasedDistanceFunction

Instantiate with a database to get the actual distance query.

Specified by:

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

Specified by:

instantiate in interface FilteredLocalPCABasedDistanceFunction<V extends NumberVector<?>,FilteredLocalPCAIndex<V extends NumberVector<?>>,DoubleDistance>

Parameters:

database - The representation to use

Returns:

Actual distance query.

equals

public boolean equals(Object obj)

Overrides:

equals in class Object