java.lang.Object
- weka.attributeSelection.ASEvaluation
- - weka.attributeSelection.GainRatioAttributeEval

All Implemented Interfaces:

java.io.Serializable, AttributeEvaluator, CapabilitiesHandler, OptionHandler, RevisionHandler
```
public class GainRatioAttributeEval
extends ASEvaluation
implements AttributeEvaluator, OptionHandler
```
GainRatioAttributeEval :

Evaluates the worth of an attribute by measuring the gain ratio with respect to the class.

GainR(Class, Attribute) = (H(Class) - H(Class | Attribute)) / H(Attribute).

Valid options are:
```
 -M
  treat missing values as a seperate value.
 
```
Version:

$Revision: 11219 $

Author:

Mark Hall (mhall@cs.waikato.ac.nz)

See Also:

Discretize, Serialized Form

Constructor Summary

Constructors
Constructor Description

GainRatioAttributeEval()
Constructor

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`buildEvaluator(Instances data)`	Initializes a gain ratio attribute evaluator.
`double`	`evaluateAttribute(int attribute)`	evaluates an individual attribute by measuring the gain ratio of the class given the attribute.
`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.
`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.
`java.lang.String`	`missingMergeTipText()`	Returns the tip text for this property
`int[]`	`postProcess(int[] attributeSet)`	Provides a chance for a attribute evaluator to do any special post processing of the selected attribute set.
`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
clean, forName, makeCopies

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - GainRatioAttributeEval
```
public GainRatioAttributeEval()
```
    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
  - 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 seperate 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 a gain ratio 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 gain ratio of the class given the attribute.
    
    Specified by:
    
    evaluateAttribute in interface AttributeEvaluator
    
    Parameters:
    
    attribute - the index of the attribute to be evaluated
    
    Returns:
    
    the gain ratio
    
    Throws:
    
    java.lang.Exception - if the attribute could not be evaluated
  - 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
  - postProcess
```
public int[] postProcess(int[] attributeSet)
```
    Description copied from class: ASEvaluation
    
    Provides a chance for a attribute evaluator to do any special post processing of the selected attribute set.
    
    Overrides:
    
    postProcess in class ASEvaluation
    
    Parameters:
    
    attributeSet - the set of attributes found by the search
    
    Returns:
    
    a possibly ranked list of postprocessed attributes
  - main
```
public static void main(java.lang.String[] args)
```
    Main method.
    
    Parameters:
    
    args - the options -t training file

Class GainRatioAttributeEval

Constructor Summary

Method Summary

Methods inherited from class weka.attributeSelection.ASEvaluation

Methods inherited from class java.lang.Object

Constructor Detail

GainRatioAttributeEval

Method Detail

globalInfo

listOptions

setOptions

missingMergeTipText

setMissingMerge

getMissingMerge

getOptions

getCapabilities

buildEvaluator

evaluateAttribute

toString

getRevision

postProcess

main