Package elki.index.preprocessed.knn

Class PartitionApproximationMaterializeKNNPreprocessor<O>

java.lang.Object

elki.index.preprocessed.knn.AbstractMaterializeKNNPreprocessor<O>

elki.index.preprocessed.knn.PartitionApproximationMaterializeKNNPreprocessor<O>

Type Parameters:

O - the type of database objects the preprocessor can be applied to

All Implemented Interfaces:

Index, KNNIndex<O>

@Title("Partitioning Approximate kNN Preprocessor")
@Description("Caterializes the (approximate) k nearest neighbors of objects of a database by partitioning and only computing kNN within each partition.")
public class PartitionApproximationMaterializeKNNPreprocessor<O>
extends AbstractMaterializeKNNPreprocessor<O>

A preprocessor for annotation of the k nearest neighbors (and their distances) to each database object. Used for example by LOF.

Since:

0.2

Author:

Erich Schubert

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	PartitionApproximationMaterializeKNNPreprocessor.Factory<O>	The parameterizable factory.

Field Summary

Fields

Modifier and Type	Field	Description
private static Logging	LOG	Logger to use
private int	partitions	Number of partitions to use.
private RandomFactory	rnd	Random generator

Fields inherited from class elki.index.preprocessed.knn.AbstractMaterializeKNNPreprocessor

distance, distanceQuery, k, relation, storage

Constructor Summary

Constructors

Constructor	Description
PartitionApproximationMaterializeKNNPreprocessor(Relation<O> relation, Distance<? super O> distance, int k, int partitions, RandomFactory rnd)	Constructor

Method Summary

Modifier and Type	Method	Description
protected Logging	getLogger()	Get the classes static logger.
protected void	preprocess()	Perform the preprocessing step.

Methods inherited from class elki.index.preprocessed.knn.AbstractMaterializeKNNPreprocessor

createStorage, get, getDistanceQuery, getK, initialize, kNNByDBID, kNNByObject

Methods inherited from class java.lang.Object

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

Methods inherited from interface elki.index.Index

logStatistics

Field Detail

LOG

private static final Logging LOG

Logger to use

partitions

private final int partitions

Number of partitions to use.

rnd

private final RandomFactory rnd

Random generator

Constructor Detail

PartitionApproximationMaterializeKNNPreprocessor

public PartitionApproximationMaterializeKNNPreprocessor(Relation<O> relation,
                                                        Distance<? super O> distance,
                                                        int k,
                                                        int partitions,
                                                        RandomFactory rnd)

Constructor

Parameters:

relation - Relation to process

distance - the distance function to use

k - query k

partitions - Number of partitions

rnd - Random number generator

Method Detail

preprocess

protected void preprocess()

Description copied from class: AbstractMaterializeKNNPreprocessor

Perform the preprocessing step.

Specified by:

preprocess in class AbstractMaterializeKNNPreprocessor<O>

getLogger

protected Logging getLogger()

Description copied from class: AbstractMaterializeKNNPreprocessor

Get the classes static logger.

Specified by:

getLogger in class AbstractMaterializeKNNPreprocessor<O>

Returns:

Logger