de.lmu.ifi.dbs.elki.preprocessing
Class KnnQueryBasedLocalPCAPreprocessor<V extends NumberVector<V,?>>

java.lang.Object
  de.lmu.ifi.dbs.elki.logging.AbstractLoggable
      de.lmu.ifi.dbs.elki.preprocessing.LocalPCAPreprocessor<V>
          de.lmu.ifi.dbs.elki.preprocessing.KnnQueryBasedLocalPCAPreprocessor<V>

Type Parameters:

V - the type of NumberVector handled by this Preprocessor

All Implemented Interfaces:

Preprocessor<V>, Parameterizable

@Title(value="Knn Query Based Local PCA Preprocessor")
@Description(value="Materializes the local PCA and the locally weighted matrix of objects of a database. The PCA is based on k nearest neighbor queries.")
public class KnnQueryBasedLocalPCAPreprocessor<V extends NumberVector<V,?>>
extends LocalPCAPreprocessor<V>
implements Parameterizable

Provides the local neighborhood to be considered in the PCA as the k nearest neighbors of an object.

Author:

Elke Achtert

See Also:

LocalPCAPreprocessor

Field Summary

private Integer	k Holds the value of K_PARAM.
static OptionID	K_ID OptionID for K_PARAM
private IntParameter	K_PARAM Optional parameter to specify the number of nearest neighbors considered in the PCA, must be an integer greater than 0.

Fields inherited from class de.lmu.ifi.dbs.elki.preprocessing.LocalPCAPreprocessor

DEFAULT_PCA_DISTANCE_FUNCTION, PCA_DISTANCE_ID, PCA_DISTANCE_PARAM, pcaDistanceFunction

Fields inherited from class de.lmu.ifi.dbs.elki.logging.AbstractLoggable

debug, logger

Constructor Summary

KnnQueryBasedLocalPCAPreprocessor(Parameterization config)
Constructor, adhering to Parameterizable

Method Summary

protected List<DistanceResultPair<DoubleDistance>>

objectsForPCA(Integer id, Database<V> database) Returns the objects to be considered within the PCA for the specified query object.

Methods inherited from class de.lmu.ifi.dbs.elki.preprocessing.LocalPCAPreprocessor

run

Methods inherited from class de.lmu.ifi.dbs.elki.logging.AbstractLoggable

debugFine, debugFiner, debugFinest, exception, progress, verbose, warning

Methods inherited from class java.lang.Object

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

Field Detail

K_ID

public static final OptionID K_ID

OptionID for K_PARAM

K_PARAM

private final IntParameter K_PARAM

Optional parameter to specify the number of nearest neighbors considered in the PCA, must be an integer greater than 0. If this parameter is not set, k is set to three times of the dimensionality of the database objects.

Key: -localpca.k

Default value: three times of the dimensionality of the database objects

k

private Integer k

Holds the value of K_PARAM.

Constructor Detail

KnnQueryBasedLocalPCAPreprocessor

public KnnQueryBasedLocalPCAPreprocessor(Parameterization config)

Constructor, adhering to Parameterizable

Parameters:

config - Parameterization

Method Detail

objectsForPCA

protected List<DistanceResultPair<DoubleDistance>> objectsForPCA(Integer id,
                                                                 Database<V> database)

Description copied from class: LocalPCAPreprocessor

Returns the objects to be considered within the PCA for the specified query object.

Specified by:

objectsForPCA in class LocalPCAPreprocessor<V extends NumberVector<V,?>>

Parameters:

id - the id of the query object for which a PCA should be performed

database - the database holding the objects

Returns:

the list of the objects (i.e. the ids and the distances to the query object) to be considered within the PCA