de.lmu.ifi.dbs.elki.algorithm.statistics
Class RankingQualityHistogram<V extends DatabaseObject,D extends NumberDistance<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<V,D,CollectionResult<DoubleVector>>
              de.lmu.ifi.dbs.elki.algorithm.statistics.RankingQualityHistogram<V,D>

Type Parameters:

V - Vector type

D - Distance type

All Implemented Interfaces:

Algorithm<V,CollectionResult<DoubleVector>>, Parameterizable

@Title(value="Ranking Quality Histogram")
@Description(value="Evaluates the effectiveness of a distance function via the obtained rankings.")
public class RankingQualityHistogram<V extends DatabaseObject,D extends NumberDistance<D,?>>
extends DistanceBasedAlgorithm<V,D,CollectionResult<DoubleVector>>

Evaluate a distance function with respect to kNN queries. For each point, the neighbors are sorted by distance, then the ROC AUC is computed. A score of 1 means that the distance function provides a perfect ordering of relevant neighbors first, then irrelevant neighbors. A value of 0.5 can be obtained by random sorting. A value of 0 means the distance function is inverted, i.e. a similarity. TODO: Make number of bins configurable TODO: Add sampling

Author:

Erich Schubert

Field Summary

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

RankingQualityHistogram(Parameterization config)
Constructor, adhering to Parameterizable

Method Summary

protected CollectionResult<DoubleVector>

runInTime(Database<V> database) Run the algorithm.

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

Constructor Detail

RankingQualityHistogram

public RankingQualityHistogram(Parameterization config)

Constructor, adhering to Parameterizable

Parameters:

config - Parameterization

Method Detail

runInTime

protected CollectionResult<DoubleVector> runInTime(Database<V> database)
                                            throws IllegalStateException

Run the algorithm.

Specified by:

runInTime in class AbstractAlgorithm<V extends DatabaseObject,CollectionResult<DoubleVector>>

Parameters:

database - the database to run the algorithm on

Returns:

the Result computed by this algorithm

Throws:

IllegalStateException - if the algorithm has not been initialized properly (e.g. the setParameters(String[]) method has been failed to be called).