weka.attributeSelection
Class SignificanceAttributeEval

java.lang.Object
  weka.attributeSelection.ASEvaluation
      weka.attributeSelection.SignificanceAttributeEval

All Implemented Interfaces:

java.io.Serializable, AttributeEvaluator, CapabilitiesHandler, OptionHandler, RevisionHandler, TechnicalInformationHandler

public class SignificanceAttributeEval
extends ASEvaluation
implements AttributeEvaluator, OptionHandler, TechnicalInformationHandler

Significance :

Evaluates the worth of an attribute by computing the Probabilistic Significance as a two-way function.
(attribute-classes and classes-attribute association)

For more information see:

Amir Ahmad, Lipika Dey (2004). A feature selection technique for classificatory analysis.

Valid options are:

 -M
  treat missing values as a separate value.

BibTeX:

 @phdthesis{Ahmad2004,
    author = {Amir Ahmad and Lipika Dey},
    month = {October},
    publisher = {ELSEVIER},
    title = {A feature selection technique for classificatory analysis},
    year = {2004}
 }
 

Version:

$Revision: 5447 $

Author:

Adrian Pino (apinoa@facinf.uho.edu.cu)

See Also:

Serialized Form

Constructor Summary

SignificanceAttributeEval()
Constructor

Method Summary

double	associationAttributeClasses(double[][] counts) evaluates an individual attribute by measuring the attribute-classes association
double	associationClassesAttribute(double[][] counts) evaluates an individual attribute by measuring the classes-attribute association
void	buildEvaluator(Instances data) Initializes the Significance attribute evaluator.
double	evaluateAttribute(int attribute) evaluates an individual attribute by measuring the Significance
Capabilities	getCapabilities() Returns the capabilities of this evaluator.
boolean	getMissingMerge() get whether missing values are being distributed or not
java.lang.String[]	getOptions() Gets the current settings of WrapperSubsetEval.
java.lang.String	getRevision() Returns the revision string.
TechnicalInformation	getTechnicalInformation() Returns an instance of a TechnicalInformation object, containing detailed information about the technical background of this class, e.g., paper reference or book this class is based on.
java.lang.String	globalInfo() Returns a string describing this attribute evaluator
java.util.Enumeration	listOptions() Returns an enumeration describing the available options.
static void	main(java.lang.String[] args) Main method for testing this class.
java.lang.String	missingMergeTipText() Returns the tip text for this property
void	setMissingMerge(boolean b) distribute the counts for missing values across observed values
void	setOptions(java.lang.String[] options) Parses a given list of options.
java.lang.String	toString() Return a description of the evaluator

Methods inherited from class weka.attributeSelection.ASEvaluation

forName, makeCopies, postProcess

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

SignificanceAttributeEval

public SignificanceAttributeEval()

Constructor

Method Detail

globalInfo

public java.lang.String globalInfo()

Returns a string describing this attribute evaluator

Returns:

a description of the evaluator suitable for displaying in the explorer/experimenter gui

getTechnicalInformation

public TechnicalInformation getTechnicalInformation()

Returns an instance of a TechnicalInformation object, containing detailed information about the technical background of this class, e.g., paper reference or book this class is based on.

Specified by:

getTechnicalInformation in interface TechnicalInformationHandler

Returns:

the technical information about this class

listOptions

public java.util.Enumeration listOptions()

Returns an enumeration describing the available options.

Specified by:

listOptions in interface OptionHandler

Returns:

an enumeration of all the available options.

setOptions

public void setOptions(java.lang.String[] options)
                throws java.lang.Exception

Parses a given list of options.

Valid options are:

 -M
  treat missing values as a separate value.

Specified by:

setOptions in interface OptionHandler

Parameters:

options - the list of options as an array of strings

Throws:

java.lang.Exception - if an option is not supported

missingMergeTipText

public java.lang.String missingMergeTipText()

Returns the tip text for this property

Returns:

tip text for this property suitable for displaying in the explorer/experimenter gui

setMissingMerge

public void setMissingMerge(boolean b)

distribute the counts for missing values across observed values

Parameters:

b - true=distribute missing values.

getMissingMerge

public boolean getMissingMerge()

get whether missing values are being distributed or not

Returns:

true if missing values are being distributed.

getOptions

public java.lang.String[] getOptions()

Gets the current settings of WrapperSubsetEval.

Specified by:

getOptions in interface OptionHandler

Returns:

an array of strings suitable for passing to setOptions()

getCapabilities

public Capabilities getCapabilities()

Returns the capabilities of this evaluator.

Specified by:

getCapabilities in interface CapabilitiesHandler

Overrides:

getCapabilities in class ASEvaluation

Returns:

the capabilities of this evaluator

See Also:

Capabilities

buildEvaluator

public void buildEvaluator(Instances data)
                    throws java.lang.Exception

Initializes the Significance attribute evaluator. Discretizes all attributes that are numeric.

Specified by:

buildEvaluator in class ASEvaluation

Parameters:

data - set of instances serving as training data

Throws:

java.lang.Exception - if the evaluator has not been generated successfully

evaluateAttribute

public double evaluateAttribute(int attribute)
                         throws java.lang.Exception

evaluates an individual attribute by measuring the Significance

Specified by:

evaluateAttribute in interface AttributeEvaluator

Parameters:

attribute - the index of the attribute to be evaluated

Returns:

the Significance of the attribute in the data base

Throws:

java.lang.Exception - if the attribute could not be evaluated

associationAttributeClasses

public double associationAttributeClasses(double[][] counts)

evaluates an individual attribute by measuring the attribute-classes association

Parameters:

counts - the Contingency table where are the frecuency counts values

Returns:

the discriminating power of the attribute

associationClassesAttribute

public double associationClassesAttribute(double[][] counts)

evaluates an individual attribute by measuring the classes-attribute association

Parameters:

counts - the Contingency table where are the frecuency counts values

Returns:

the separability power of the classes

toString

public java.lang.String toString()

Return a description of the evaluator

Overrides:

toString in class java.lang.Object

Returns:

description as a string

getRevision

public java.lang.String getRevision()

Returns the revision string.

Specified by:

getRevision in interface RevisionHandler

Overrides:

getRevision in class ASEvaluation

Returns:

the revision

main

public static void main(java.lang.String[] args)

Main method for testing this class.

Parameters:

args - the options