de.lmu.ifi.dbs.elki.algorithm.outlier.lof

Class LoOP<O,D extends NumberDistance<D,?>>

java.lang.Object

de.lmu.ifi.dbs.elki.algorithm.AbstractAlgorithm<OutlierResult>

de.lmu.ifi.dbs.elki.algorithm.outlier.lof.LoOP<O,D>

Type Parameters:

O - type of objects handled by this algorithm

D - type of distances used

All Implemented Interfaces:

Algorithm, OutlierAlgorithm, Parameterizable

@Title(value="LoOP: Local Outlier Probabilities")
@Description(value="Variant of the LOF algorithm normalized using statistical values.")
@Reference(authors="H.-P. Kriegel, P. Kr\u00f6ger, E. Schubert, A. Zimek",
           title="LoOP: Local Outlier Probabilities",
           booktitle="Proceedings of the 18th International Conference on Information and Knowledge Management (CIKM), Hong Kong, China, 2009",
           url="http://dx.doi.org/10.1145/1645953.1646195")
@Alias(value={"de.lmu.ifi.dbs.elki.algorithm.outlier.LoOP","LoOP","outlier.LoOP"})
public class LoOP<O,D extends NumberDistance<D,?>>
extends AbstractAlgorithm<OutlierResult>
implements OutlierAlgorithm

LoOP: Local Outlier Probabilities Distance/density based algorithm similar to LOF to detect outliers, but with statistical methods to achieve better result stability.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	LoOP.Parameterizer<O,D extends NumberDistance<D,?>> Parameterization class.

Field Summary

Fields

Modifier and Type	Field and Description
static OptionID	COMPARISON_DISTANCE_FUNCTION_ID The distance function to determine the reachability distance between database objects.
protected DistanceFunction<? super O,D>	comparisonDistanceFunction Preprocessor Step 2.
(package private) int	kcomp Holds the value of KCOMP_ID.
static OptionID	KCOMP_ID Parameter to specify the number of nearest neighbors of an object to be considered for computing its LOOP_SCORE, must be an integer greater than 1.
(package private) int	kreach Holds the value of KREACH_ID.
static OptionID	KREACH_ID Parameter to specify the number of nearest neighbors of an object to be considered for computing its LOOP_SCORE, must be an integer greater than 1.
(package private) double	lambda Hold the value of LAMBDA_ID.
static OptionID	LAMBDA_ID Parameter to specify the number of nearest neighbors of an object to be considered for computing its LOOP_SCORE, must be an integer greater than 1.
private static Logging	LOG The logger for this class.
(package private) static boolean	objectIsInKNN Include object itself in kNN neighborhood.
static OptionID	REACHABILITY_DISTANCE_FUNCTION_ID The distance function to determine the reachability distance between database objects.
protected DistanceFunction<? super O,D>	reachabilityDistanceFunction Preprocessor Step 1.

Constructor Summary

Constructors

Constructor and Description
LoOP(int kreach, int kcomp, DistanceFunction<? super O,D> reachabilityDistanceFunction, DistanceFunction<? super O,D> comparisonDistanceFunction, double lambda) Constructor with parameters.

Method Summary

Methods

Modifier and Type	Method and Description
TypeInformation[]	getInputTypeRestriction() Get the input type restriction used for negotiating the data query.
protected Pair<KNNQuery<O,D>,KNNQuery<O,D>>	getKNNQueries(Database database, Relation<O> relation, StepProgress stepprog) Get the kNN queries for the algorithm.
protected Logging	getLogger() Get the (STATIC) logger for this class.
OutlierResult	run(Database database, Relation<O> relation) Performs the LoOP algorithm on the given database.

Methods inherited from class de.lmu.ifi.dbs.elki.algorithm.AbstractAlgorithm

makeParameterDistanceFunction, run

Methods inherited from class java.lang.Object

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

Methods inherited from interface de.lmu.ifi.dbs.elki.algorithm.outlier.OutlierAlgorithm

run

Field Detail

LOG

private static final Logging LOG

The logger for this class.

REACHABILITY_DISTANCE_FUNCTION_ID

public static final OptionID REACHABILITY_DISTANCE_FUNCTION_ID

The distance function to determine the reachability distance between database objects.

COMPARISON_DISTANCE_FUNCTION_ID

public static final OptionID COMPARISON_DISTANCE_FUNCTION_ID

The distance function to determine the reachability distance between database objects.

KREACH_ID

public static final OptionID KREACH_ID

Parameter to specify the number of nearest neighbors of an object to be considered for computing its LOOP_SCORE, must be an integer greater than 1.

KCOMP_ID

public static final OptionID KCOMP_ID

Parameter to specify the number of nearest neighbors of an object to be considered for computing its LOOP_SCORE, must be an integer greater than 1.

LAMBDA_ID

public static final OptionID LAMBDA_ID

Parameter to specify the number of nearest neighbors of an object to be considered for computing its LOOP_SCORE, must be an integer greater than 1.

kreach

int kreach

Holds the value of KREACH_ID.

kcomp

int kcomp

Holds the value of KCOMP_ID.

lambda

double lambda

Hold the value of LAMBDA_ID.

reachabilityDistanceFunction

protected DistanceFunction<? super O,D extends NumberDistance<D,?>> reachabilityDistanceFunction

Preprocessor Step 1.

comparisonDistanceFunction

protected DistanceFunction<? super O,D extends NumberDistance<D,?>> comparisonDistanceFunction

Preprocessor Step 2.

objectIsInKNN

static boolean objectIsInKNN

Include object itself in kNN neighborhood.

Constructor Detail

LoOP

public LoOP(int kreach,
    int kcomp,
    DistanceFunction<? super O,D> reachabilityDistanceFunction,
    DistanceFunction<? super O,D> comparisonDistanceFunction,
    double lambda)

Constructor with parameters.

Parameters:

kreach - k for reachability

kcomp - k for comparison

reachabilityDistanceFunction - distance function for reachability

comparisonDistanceFunction - distance function for comparison

lambda - Lambda parameter

Method Detail

getKNNQueries

protected Pair<KNNQuery<O,D>,KNNQuery<O,D>> getKNNQueries(Database database,
                                              Relation<O> relation,
                                              StepProgress stepprog)

Get the kNN queries for the algorithm.

Parameters:

database - Database to analyze

relation - Relation to analyze

stepprog - Progress logger, may be null

Returns:

result

run

public OutlierResult run(Database database,
                Relation<O> relation)

Performs the LoOP algorithm on the given database.

Parameters:

database - Database to process

relation - Relation to process

Returns:

Outlier result

getInputTypeRestriction

public TypeInformation[] getInputTypeRestriction()

Description copied from class: AbstractAlgorithm

Get the input type restriction used for negotiating the data query.

Specified by:

getInputTypeRestriction in interface Algorithm

Specified by:

getInputTypeRestriction in class AbstractAlgorithm<OutlierResult>

Returns:

Type restriction

getLogger

protected Logging getLogger()

Description copied from class: AbstractAlgorithm

Get the (STATIC) logger for this class.

Specified by:

getLogger in class AbstractAlgorithm<OutlierResult>

Returns:

the static logger