de.lmu.ifi.dbs.elki.index.vafile

Class PartialVAFile<V extends NumberVector>

java.lang.Object

de.lmu.ifi.dbs.elki.index.AbstractIndex<O>

de.lmu.ifi.dbs.elki.index.AbstractRefiningIndex<V>

de.lmu.ifi.dbs.elki.index.vafile.PartialVAFile<V>

Type Parameters:

V - Vector type

All Implemented Interfaces:

Index, KNNIndex<V>, RangeIndex<V>, Result

@Reference(authors="Hans-Peter Kriegel, Peer Kr\u00f6ger, Matthias Schubert, Ziyue Zhu",
           title="Efficient Query Processing in Arbitrary Subspaces Using Vector Approximations",
           booktitle="Proc. 18th Int. Conf. on Scientific and Statistical Database Management (SSDBM 06)",
           url="https://doi.org/10.1109/SSDBM.2006.23",
           bibkey="DBLP:conf/ssdbm/KriegelKSZ06")
public class PartialVAFile<V extends NumberVector>
extends AbstractRefiningIndex<V>
implements KNNIndex<V>, RangeIndex<V>

PartialVAFile. In-memory only implementation.

Reference:

Hans-Peter Kriegel, Peer Kröger, Matthias Schubert, Ziyue Zhu
Efficient Query Processing in Arbitrary Subspaces Using Vector Approximations
Proc. 18th Int. Conf. on Scientific and Statistical Database Management (SSDBM 06)

Since:

0.5.0

Author:

Thomas Bernecker, Erich Schubert

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	PartialVAFile.Factory<V extends NumberVector> Index factory class.
protected static class	PartialVAFile.PartialVACandidate Object in a VA approximation.
class	PartialVAFile.PartialVAFileKNNQuery KNN query for this index.
class	PartialVAFile.PartialVAFileRangeQuery Range query for this index.
static class	PartialVAFile.Statistics Class for tracking Partial VA file statistics.
protected static class	PartialVAFile.WorstCaseDistComparator Compare DAfiles by their worst case distance.

Nested classes/interfaces inherited from class de.lmu.ifi.dbs.elki.index.AbstractRefiningIndex

AbstractRefiningIndex.AbstractKNNQuery, AbstractRefiningIndex.AbstractRangeQuery

Field Summary

Fields

Modifier and Type	Field and Description
(package private) java.util.List<DAFile>	daFiles Partial VA files.
private static Logging	LOG Class logger.
private int	pageSize Page size.
private int	partitions Number of partitions.
private double[][]	splitPartitions Splitting grid.
protected PartialVAFile.Statistics	stats Statistics.
private java.util.ArrayList<VectorApproximation>	vectorApprox The (full - we are in-memory only right now) vector approximations.

Fields inherited from class de.lmu.ifi.dbs.elki.index.AbstractIndex

relation

Constructor Summary

Constructors

Constructor and Description
PartialVAFile(int pageSize, Relation<V> relation, int partitions) Constructor.

Method Summary

Modifier and Type	Method and Description
protected VectorApproximation	calculateFullApproximation(DBID id, V dv) Calculate the VA file position given the existing borders.
protected static VectorApproximation	calculatePartialApproximation(DBID id, NumberVector dv, java.util.List<DoubleObjPair<DAFile>> daFiles) Calculate partial vector approximation.
protected static void	calculateSelectivityCoeffs(java.util.List<DoubleObjPair<DAFile>> daFiles, NumberVector query, double epsilon) Calculate selectivity coefficients.
KNNQuery<V>	getKNNQuery(DistanceQuery<V> distanceQuery, java.lang.Object... hints) Get a KNN query object for the given distance query and k.
Logging	getLogger() Get the class logger.
java.lang.String	getLongName() A "pretty" name for the result, for use in titles, captions and menus.
RangeQuery<V>	getRangeQuery(DistanceQuery<V> distanceQuery, java.lang.Object... hints) Get a range query object for the given distance query and k.
java.lang.String	getShortName() A short name for the result, useful for file names.
void	initialize() Initialize the index.
void	logStatistics() Send statistics to the logger, if enabled.

Methods inherited from class de.lmu.ifi.dbs.elki.index.AbstractRefiningIndex

countRefinements, refine

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

Class logger.

daFiles

java.util.List<DAFile> daFiles

Partial VA files.

partitions

private final int partitions

Number of partitions.

pageSize

private final int pageSize

Page size.

splitPartitions

private double[][] splitPartitions

Splitting grid.

stats

protected PartialVAFile.Statistics stats

Statistics.

vectorApprox

private java.util.ArrayList<VectorApproximation> vectorApprox

The (full - we are in-memory only right now) vector approximations.

Constructor Detail

PartialVAFile

public PartialVAFile(int pageSize,
                     Relation<V> relation,
                     int partitions)

Constructor.

Parameters:

pageSize - Page size

relation - Data relation

partitions - Number of partitions

Method Detail

initialize

public void initialize()
                throws java.lang.IllegalStateException

Description copied from interface: Index

Initialize the index. For static indexes, this is the moment the index is bulk loaded.

Specified by:

initialize in interface Index

Throws:

java.lang.IllegalStateException

getShortName

public java.lang.String getShortName()

Description copied from interface: Result

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

Specified by:

getShortName in interface Result

Specified by:

getShortName in class AbstractIndex<V extends NumberVector>

Returns:

result name

getLongName

public java.lang.String getLongName()

Description copied from interface: Result

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

Specified by:

getLongName in interface Result

Specified by:

getLongName in class AbstractIndex<V extends NumberVector>

Returns:

result name

getLogger

public Logging getLogger()

Description copied from class: AbstractRefiningIndex

Get the class logger.

Specified by:

getLogger in class AbstractRefiningIndex<V extends NumberVector>

Returns:

Logger

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.

Specified by:

logStatistics in interface Index

Overrides:

logStatistics in class AbstractRefiningIndex<V extends NumberVector>

calculateFullApproximation

protected VectorApproximation calculateFullApproximation(DBID id,
                                                         V dv)

Calculate the VA file position given the existing borders.

Parameters:

id - Object ID

dv - Data vector

Returns:

Vector approximation

getKNNQuery

public KNNQuery<V> getKNNQuery(DistanceQuery<V> distanceQuery,
                               java.lang.Object... hints)

Description copied from interface: KNNIndex

Get a KNN query object for the given distance query and k. This function MAY return null, when the given distance is not supported!

Specified by:

getKNNQuery in interface KNNIndex<V extends NumberVector>

Parameters:

distanceQuery - Distance query

hints - Hints for the optimizer

Returns:

KNN Query object or null

getRangeQuery

public RangeQuery<V> getRangeQuery(DistanceQuery<V> distanceQuery,
                                   java.lang.Object... hints)

Description copied from interface: RangeIndex

Get a range query object for the given distance query and k. This function MAY return null, when the given distance is not supported!

Specified by:

getRangeQuery in interface RangeIndex<V extends NumberVector>

Parameters:

distanceQuery - Distance query

hints - Hints for the optimizer

Returns:

KNN Query object or null

calculateSelectivityCoeffs

protected static void calculateSelectivityCoeffs(java.util.List<DoubleObjPair<DAFile>> daFiles,
                                                 NumberVector query,
                                                 double epsilon)

Calculate selectivity coefficients.

Parameters:

daFiles - List of files to use

query - Query vector

epsilon - Epsilon radius

calculatePartialApproximation

protected static VectorApproximation calculatePartialApproximation(DBID id,
                                                                   NumberVector dv,
                                                                   java.util.List<DoubleObjPair<DAFile>> daFiles)

Calculate partial vector approximation.

Parameters:

id - Object ID

dv - Object vector

daFiles - List of approximations to use

Returns:

Vector approximation