DBOutlierDetection (ELKI: Environment for DeveLoping KDD-Applications Supported by Index-Structures)

java.lang.Object
- elki.outlier.distance.AbstractDBOutlier<O>
- - elki.outlier.distance.DBOutlierDetection<O>

Type Parameters:

O - the type of objects handled by this algorithm

All Implemented Interfaces:

elki.Algorithm, OutlierAlgorithm
```
@Title("DBOD: Distance Based Outlier Detection")
@Description("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="Proc. Int. Conf. on Very Large Databases (VLDB\'98)",
           url="http://www.vldb.org/conf/1998/p392.pdf",
           bibkey="DBLP:conf/vldb/KnorrN98")
public class DBOutlierDetection<O>
extends AbstractDBOutlier<O>
```
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 above d from c.
Reference:
E.M. Knorr, R. T. Ng:
Algorithms for Mining Distance-Based Outliers in Large Datasets,
In: Proc. Int. Conf. on Very Large Databases (VLDB'98)
This paper presents several Distance Based Outlier Detection algorithms. Implemented here is a simple index based algorithm as presented in section 3.1.

Since:

0.3

Author:

Lisa Reichert

Nested Class Summary

Nested Classes
Modifier and Type Class Description

static class DBOutlierDetection.Par<O>
Parameterization class.
- Nested classes/interfaces inherited from interface elki.Algorithm
  elki.Algorithm.Utils

Field Summary

Fields
Modifier and Type Field Description

private static elki.logging.Logging LOG
The logger for this class.

private double p
Density threshold percentage p.
- Fields inherited from class elki.outlier.distance.AbstractDBOutlier
  d, distance

Constructor Summary

Constructors
Constructor	Description
`DBOutlierDetection(elki.distance.Distance<? super O> distance, double d, double p)`	Constructor with actual parameters.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`protected elki.database.datastore.DoubleDataStore`	`computeOutlierScores(elki.database.relation.Relation<O> relation, double d)`	computes an outlier score for each object of the database.

Methods inherited from class elki.outlier.distance.AbstractDBOutlier
getInputTypeRestriction, run

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface elki.outlier.OutlierAlgorithm
autorun

- Field Detail
  - LOG
```
private static final elki.logging.Logging LOG
```
    The logger for this class.
  - p
```
private double p
```
    Density threshold percentage p.
- Constructor Detail
  - DBOutlierDetection
```
public DBOutlierDetection(elki.distance.Distance<? super O> distance,
                          double d,
                          double p)
```
    Constructor with actual parameters.
    
    Parameters:
    
    distance - distance function parameter
    
    d - distance query radius
    
    p - percentage parameter
- Method Detail
  - computeOutlierScores
```
protected elki.database.datastore.DoubleDataStore computeOutlierScores(elki.database.relation.Relation<O> relation,
                                                                       double d)
```
    Description copied from class: AbstractDBOutlier
    
    computes an outlier score for each object of the database.
    
    Specified by:
    
    computeOutlierScores in class AbstractDBOutlier<O>
    
    Parameters:
    
    relation - Relation
    
    d - distance
    
    Returns:
    
    computed scores