Package weka.classifiers.evaluation

Class Dice

java.lang.Object

weka.classifiers.evaluation.AbstractEvaluationMetric

weka.classifiers.evaluation.Dice

All Implemented Interfaces:

Serializable, weka.classifiers.evaluation.InformationRetrievalEvaluationMetric, weka.classifiers.evaluation.StandardEvaluationMetric

public class Dice
extends weka.classifiers.evaluation.AbstractEvaluationMetric
implements weka.classifiers.evaluation.StandardEvaluationMetric, weka.classifiers.evaluation.InformationRetrievalEvaluationMetric

Sørensen–Dice coefficient: https://en.wikipedia.org/wiki/S%C3%B8rensen%E2%80%93Dice_coefficient

Author:

fracpete (fracpete at waikato dot ac dot nz)

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class weka.classifiers.evaluation.AbstractEvaluationMetric

weka.classifiers.evaluation.AbstractEvaluationMetric.UnknownStatisticException

Field Summary

Fields

Modifier and Type	Field	Description
static String	NAME

Fields inherited from class weka.classifiers.evaluation.AbstractEvaluationMetric

m_baseEvaluation

Constructor Summary

Constructors

Constructor	Description
Dice()

Method Summary

Modifier and Type	Method	Description
boolean	appliesToNominalClass()	Return true if this evaluation metric can be computed when the class is nominal
boolean	appliesToNumericClass()	Return true if this evaluation metric can be computed when the class is numeric
double	getClassWeightedAverageStatistic(String statName)	Get the weighted (by class) average for this statistic.
String	getMetricDescription()	Get a short description of this metric (algorithm, forumulas etc.).
String	getMetricName()	Get the name of this metric
double	getStatistic(String statName)	Get the value of the named statistic - for the first class label.
double	getStatistic(String statName, int classIndex)	Get the value of the named statistic for the given class index.
List<String>	getStatisticNames()	Get a list of the names of the statistics that this metrics computes.
String	toSummaryString()	Return a formatted string (suitable for displaying in console or GUI output) containing all the statistics that this metric computes.
void	updateStatsForClassifier(double[] predictedDistribution, weka.core.Instance instance)	Updates the statistics about a classifiers performance for the current test instance.
void	updateStatsForPredictor(double predictedValue, weka.core.Instance instance)	Updates the statistics about a predictors performance for the current test instance.

Methods inherited from class weka.classifiers.evaluation.AbstractEvaluationMetric

getPluginMetrics, setBaseEvaluation, statisticIsMaximisable

Methods inherited from class java.lang.Object

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

Field Detail

NAME

public static final String NAME

See Also:

Constant Field Values

Constructor Detail

Dice

public Dice()

Method Detail

getMetricName

public String getMetricName()

Get the name of this metric

Specified by:

getMetricName in class weka.classifiers.evaluation.AbstractEvaluationMetric

Returns:

the name of this metric

getMetricDescription

public String getMetricDescription()

Get a short description of this metric (algorithm, forumulas etc.).

Specified by:

getMetricDescription in class weka.classifiers.evaluation.AbstractEvaluationMetric

Returns:

a short description of this metric

appliesToNominalClass

public boolean appliesToNominalClass()

Return true if this evaluation metric can be computed when the class is nominal

Specified by:

appliesToNominalClass in class weka.classifiers.evaluation.AbstractEvaluationMetric

Returns:

true if this evaluation metric can be computed when the class is nominal

appliesToNumericClass

public boolean appliesToNumericClass()

Return true if this evaluation metric can be computed when the class is numeric

Specified by:

appliesToNumericClass in class weka.classifiers.evaluation.AbstractEvaluationMetric

Returns:

true if this evaluation metric can be computed when the class is numeric

getStatisticNames

public List<String> getStatisticNames()

Get a list of the names of the statistics that this metrics computes. E.g. an information theoretic evaluation measure might compute total number of bits as well as average bits/instance

Specified by:

getStatisticNames in class weka.classifiers.evaluation.AbstractEvaluationMetric

Returns:

the names of the statistics that this metric computes

getStatistic

public double getStatistic(String statName)

Get the value of the named statistic - for the first class label.

Specified by:

getStatistic in class weka.classifiers.evaluation.AbstractEvaluationMetric

Parameters:

statName - the name of the statistic to compute the value for

Returns:

the computed statistic or Utils.missingValue() if the statistic can't be computed for some reason

See Also:

getStatistic(String, int)

getStatistic

public double getStatistic(String statName,
                           int classIndex)

Get the value of the named statistic for the given class index.

If the implementing class is extending AbstractEvaluationMetric then the implementation of getStatistic(String statName) should just call this method with a classIndex of 0.

Specified by:

getStatistic in interface weka.classifiers.evaluation.InformationRetrievalEvaluationMetric

Parameters:

statName - the name of the statistic to compute the value for

classIndex - the class index for which to compute the statistic

Returns:

the value of the named statistic for the given class index or Utils.missingValue() if the statistic can't be computed for some reason

getClassWeightedAverageStatistic

public double getClassWeightedAverageStatistic(String statName)

Get the weighted (by class) average for this statistic.

Specified by:

getClassWeightedAverageStatistic in interface weka.classifiers.evaluation.InformationRetrievalEvaluationMetric

Parameters:

statName - the name of the statistic to compute

Returns:

the weighted (by class) average value of the statistic or Utils.missingValue() if this can't be computed (or isn't appropriate).

toSummaryString

public String toSummaryString()

Return a formatted string (suitable for displaying in console or GUI output) containing all the statistics that this metric computes.

Specified by:

toSummaryString in interface weka.classifiers.evaluation.StandardEvaluationMetric

Returns:

a formatted string containing all the computed statistics

updateStatsForClassifier

public void updateStatsForClassifier(double[] predictedDistribution,
                                     weka.core.Instance instance)
                              throws Exception

Updates the statistics about a classifiers performance for the current test instance. Gets called when the class is nominal. Implementers need only implement this method if it is not possible to compute their statistics from what is stored in the base Evaluation object.

Specified by:

updateStatsForClassifier in interface weka.classifiers.evaluation.InformationRetrievalEvaluationMetric

Specified by:

updateStatsForClassifier in interface weka.classifiers.evaluation.StandardEvaluationMetric

Parameters:

predictedDistribution - the probabilities assigned to each class

instance - the instance to be classified

Throws:

Exception - if the class of the instance is not set

updateStatsForPredictor

public void updateStatsForPredictor(double predictedValue,
                                    weka.core.Instance instance)
                             throws Exception

Updates the statistics about a predictors performance for the current test instance. Gets called when the class is numeric. Implementers need only implement this method if it is not possible to compute their statistics from what is stored in the base Evaluation object.

Specified by:

updateStatsForPredictor in interface weka.classifiers.evaluation.StandardEvaluationMetric

Parameters:

predictedValue - the numeric value the classifier predicts

instance - the instance to be classified

Throws:

Exception - if the class of the instance is not set