de.lmu.ifi.dbs.elki.index.preprocessed.knn

Class PartitionApproximationMaterializeKNNPreprocessor<O>

java.lang.Object

de.lmu.ifi.dbs.elki.index.preprocessed.AbstractPreprocessorIndex<O,KNNList>

de.lmu.ifi.dbs.elki.index.preprocessed.knn.AbstractMaterializeKNNPreprocessor<O>

de.lmu.ifi.dbs.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>, Result

@Title(value="Partitioning Approximate kNN Preprocessor")
 @Description(value="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 and Description
static class	PartitionApproximationMaterializeKNNPreprocessor.Factory<O> The parameterizable factory.

Field Summary

Fields

Modifier and Type	Field and 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 de.lmu.ifi.dbs.elki.index.preprocessed.knn.AbstractMaterializeKNNPreprocessor

distanceFunction, distanceQuery, k

Fields inherited from class de.lmu.ifi.dbs.elki.index.preprocessed.AbstractPreprocessorIndex

relation, storage

Constructor Summary

Constructors

Constructor and Description
PartitionApproximationMaterializeKNNPreprocessor(Relation<O> relation, DistanceFunction<? super O> distanceFunction, int k, int partitions, RandomFactory rnd) Constructor

Method Summary

Modifier and Type	Method and Description
protected Logging	getLogger() Get the classes static logger.
java.lang.String	getLongName() A "pretty" name for the result, for use in titles, captions and menus.
java.lang.String	getShortName() A short name for the result, useful for file names.
void	logStatistics() Send statistics to the logger, if enabled.
protected void	preprocess() Perform the preprocessing step.

Methods inherited from class de.lmu.ifi.dbs.elki.index.preprocessed.knn.AbstractMaterializeKNNPreprocessor

createStorage, get, getDistanceQuery, getK, getKNNQuery, initialize

Methods inherited from class java.lang.Object

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

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,
                                                        DistanceFunction<? super O> distanceFunction,
                                                        int k,
                                                        int partitions,
                                                        RandomFactory rnd)

Constructor

Parameters:

relation - Relation to process

distanceFunction - 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: AbstractPreprocessorIndex

Get the classes static logger.

Specified by:

getLogger in class AbstractPreprocessorIndex<O,KNNList>

Returns:

Logger

getLongName

public java.lang.String getLongName()

Description copied from interface: Result

A "pretty" name for the result, for use in titles, captions and menus.

Returns:

result name

getShortName

public java.lang.String getShortName()

Description copied from interface: Result

A short name for the result, useful for file names.

Returns:

result name

logStatistics

public void logStatistics()

Description copied from interface: Index

Send statistics to the logger, if enabled. Note: you must have set the logging level appropriately before initializing the index! Otherwise, the index might not have collected the desired statistics.