Package weka.attributeSelection
Class InfoGainAttributeEval
- java.lang.Object
-
- weka.attributeSelection.ASEvaluation
-
- weka.attributeSelection.InfoGainAttributeEval
-
- All Implemented Interfaces:
java.io.Serializable
,AttributeEvaluator
,CapabilitiesHandler
,OptionHandler
,RevisionHandler
public class InfoGainAttributeEval extends ASEvaluation implements AttributeEvaluator, OptionHandler
InfoGainAttributeEval :
Evaluates the worth of an attribute by measuring the information gain with respect to the class.
InfoGain(Class,Attribute) = H(Class) - H(Class | Attribute).
Valid options are:-M treat missing values as a seperate value.
-B just binarize numeric attributes instead of properly discretizing them.
- Version:
- $Revision: 5511 $
- Author:
- Mark Hall (mhall@cs.waikato.ac.nz)
- See Also:
Discretize
,NumericToBinary
, Serialized Form
-
-
Constructor Summary
Constructors Constructor Description InfoGainAttributeEval()
Constructor
-
Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description java.lang.String
binarizeNumericAttributesTipText()
Returns the tip text for this propertyvoid
buildEvaluator(Instances data)
Initializes an information gain attribute evaluator.double
evaluateAttribute(int attribute)
evaluates an individual attribute by measuring the amount of information gained about the class given the attribute.boolean
getBinarizeNumericAttributes()
get whether numeric attributes are just being binarized.Capabilities
getCapabilities()
Returns the capabilities of this evaluator.boolean
getMissingMerge()
get whether missing values are being distributed or notjava.lang.String[]
getOptions()
Gets the current settings of WrapperSubsetEval.java.lang.String
getRevision()
Returns the revision string.java.lang.String
globalInfo()
Returns a string describing this attribute evaluatorjava.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 propertyvoid
setBinarizeNumericAttributes(boolean b)
Binarize numeric attributes.void
setMissingMerge(boolean b)
distribute the counts for missing values across observed valuesvoid
setOptions(java.lang.String[] options)
Parses a given list of options.java.lang.String
toString()
Describe the attribute evaluator-
Methods inherited from class weka.attributeSelection.ASEvaluation
clean, forName, makeCopies, postProcess
-
-
-
-
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
-
listOptions
public java.util.Enumeration listOptions()
Returns an enumeration describing the available options.- Specified by:
listOptions
in interfaceOptionHandler
- 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 seperate value.
-B just binarize numeric attributes instead of properly discretizing them.
- Specified by:
setOptions
in interfaceOptionHandler
- Parameters:
options
- the list of options as an array of strings- Throws:
java.lang.Exception
- if an option is not supported
-
getOptions
public java.lang.String[] getOptions()
Gets the current settings of WrapperSubsetEval.- Specified by:
getOptions
in interfaceOptionHandler
- Returns:
- an array of strings suitable for passing to setOptions()
-
binarizeNumericAttributesTipText
public java.lang.String binarizeNumericAttributesTipText()
Returns the tip text for this property- Returns:
- tip text for this property suitable for displaying in the explorer/experimenter gui
-
setBinarizeNumericAttributes
public void setBinarizeNumericAttributes(boolean b)
Binarize numeric attributes.- Parameters:
b
- true=binarize numeric attributes
-
getBinarizeNumericAttributes
public boolean getBinarizeNumericAttributes()
get whether numeric attributes are just being binarized.- Returns:
- true if missing values are being distributed.
-
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.
-
getCapabilities
public Capabilities getCapabilities()
Returns the capabilities of this evaluator.- Specified by:
getCapabilities
in interfaceCapabilitiesHandler
- Overrides:
getCapabilities
in classASEvaluation
- Returns:
- the capabilities of this evaluator
- See Also:
Capabilities
-
buildEvaluator
public void buildEvaluator(Instances data) throws java.lang.Exception
Initializes an information gain attribute evaluator. Discretizes all attributes that are numeric.- Specified by:
buildEvaluator
in classASEvaluation
- 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 amount of information gained about the class given the attribute.- Specified by:
evaluateAttribute
in interfaceAttributeEvaluator
- Parameters:
attribute
- the index of the attribute to be evaluated- Returns:
- the info gain
- Throws:
java.lang.Exception
- if the attribute could not be evaluated
-
toString
public java.lang.String toString()
Describe the attribute evaluator- Overrides:
toString
in classjava.lang.Object
- Returns:
- a description of the attribute evaluator as a string
-
getRevision
public java.lang.String getRevision()
Returns the revision string.- Specified by:
getRevision
in interfaceRevisionHandler
- Overrides:
getRevision
in classASEvaluation
- Returns:
- the revision
-
main
public static void main(java.lang.String[] args)
Main method for testing this class.- Parameters:
args
- the options
-
-