de.lmu.ifi.dbs.elki.algorithm.statistics
Class EvaluateRankingQuality<V extends NumberVector<V,?>,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.EvaluateRankingQuality<V,D>

Type Parameters:

V - Vector type

D - Distance type

All Implemented Interfaces:

Algorithm<V,CollectionResult<DoubleVector>>, Parameterizable

@Title(value="Evaluate Ranking Quality")
@Description(value="Evaluates the effectiveness of a distance function via the obtained rankings.")
public class EvaluateRankingQuality<V extends NumberVector<V,?>,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: Allow fixed binning range, configurable TODO: Add sampling

Author:

Erich Schubert

Field Summary

static OptionID	HISTOGRAM_BINS_ID OptionID for HISTOGRAM_BINS_OPTION
private IntParameter	HISTOGRAM_BINS_OPTION Option to configure the number of bins to use.
(package private) int	numbins Number of bins to use.

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

EvaluateRankingQuality(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

Field Detail

HISTOGRAM_BINS_ID

public static final OptionID HISTOGRAM_BINS_ID

OptionID for HISTOGRAM_BINS_OPTION

HISTOGRAM_BINS_OPTION

private final IntParameter HISTOGRAM_BINS_OPTION

Option to configure the number of bins to use.

numbins

int numbins

Number of bins to use.

Constructor Detail

EvaluateRankingQuality

public EvaluateRankingQuality(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 NumberVector<V,?>,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).