de.lmu.ifi.dbs.elki.algorithm.outlier
Class DBOutlierDetection<O extends DatabaseObject,D extends Distance<D>>

java.lang.Object
  de.lmu.ifi.dbs.elki.logging.AbstractLoggable
      de.lmu.ifi.dbs.elki.algorithm.AbstractAlgorithm<O,R>
          de.lmu.ifi.dbs.elki.algorithm.DistanceBasedAlgorithm<O,D,OutlierResult>
              de.lmu.ifi.dbs.elki.algorithm.outlier.AbstractDBOutlier<O,D>
                  de.lmu.ifi.dbs.elki.algorithm.outlier.DBOutlierDetection<O,D>

Type Parameters:

O - the type of DatabaseObjects handled by this Algorithm

D - the type of Distance used by this Algorithm

All Implemented Interfaces:

Algorithm<O,OutlierResult>, Parameterizable

@Title(value="DBOD: Distance Based Outlier Detection")
@Description(value="If the D-neighborhood of an object contains only very few objects (less than (1-p) percent of the data) this object is flagged as an outlier")
@Reference(authors="E.M. Knorr, R. T. Ng",
           title="Algorithms for Mining Distance-Based Outliers in Large Datasets",
           booktitle="Procs Int. Conf. on Very Large Databases (VLDB\'98), New York, USA, 1998")
public class DBOutlierDetection<O extends DatabaseObject,D extends Distance<D>>
extends AbstractDBOutlier<O,D>

Simple distanced based outlier detection algorithm. User has to specify two parameters An object is flagged as an outlier if at least a fraction p of all data objects has a distance aboce d from c

Reference: E.M. Knorr, R. T. Ng: Algorithms for Mining Distance-Based Outliers in Large Datasets, In: Procs Int. Conf. on Very Large Databases (VLDB'98), New York, USA, 1998. This paper presents several Distance Based Outlier Detection algorithms. Implemented here is a simple index based algorithm as presented in section 3.1.

Author:

Lisa Reichert

Field Summary

private double	p Holds the value of P_PARAM.
static OptionID	P_ID OptionID for P_PARAM
private DoubleParameter	P_PARAM Parameter to specify the minimum fraction of objects that must be outside the D- neighborhood of an outlier, Key: -dbod.p

Fields inherited from class de.lmu.ifi.dbs.elki.algorithm.outlier.AbstractDBOutlier

D_ID, DBOD_SCORE

Fields inherited from class de.lmu.ifi.dbs.elki.algorithm.DistanceBasedAlgorithm

DISTANCE_FUNCTION_ID, DISTANCE_FUNCTION_PARAM

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

debug, logger

Constructor Summary

DBOutlierDetection(Parameterization config)
Constructor, adhering to Parameterizable

Method Summary

protected HashMap<Integer,Double>

computeOutlierScores(Database<O> database, D neighborhoodSize) computes an outlier score for each object of the database.

Methods inherited from class de.lmu.ifi.dbs.elki.algorithm.outlier.AbstractDBOutlier

runInTime

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

getDistanceFactory, getDistanceFunction

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

isTime, isVerbose, run, setTime, setVerbose

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

P_ID

public static final OptionID P_ID

OptionID for P_PARAM

P_PARAM

private final DoubleParameter P_PARAM

Parameter to specify the minimum fraction of objects that must be outside the D- neighborhood of an outlier,

Key: -dbod.p

p

private double p

Holds the value of P_PARAM.

Constructor Detail

DBOutlierDetection

public DBOutlierDetection(Parameterization config)

Constructor, adhering to Parameterizable

Parameters:

config - Parameterization

Method Detail

computeOutlierScores

protected HashMap<Integer,Double> computeOutlierScores(Database<O> database,
                                                       D neighborhoodSize)

Description copied from class: AbstractDBOutlier

computes an outlier score for each object of the database.

Specified by:

computeOutlierScores in class AbstractDBOutlier<O extends DatabaseObject,D extends Distance<D>>