CostSensitiveClassifier

java.lang.Object
- weka.classifiers.Classifier
- - weka.classifiers.SingleClassifierEnhancer
  - - weka.classifiers.RandomizableSingleClassifierEnhancer
    - - weka.classifiers.meta.CostSensitiveClassifier

All Implemented Interfaces:: java.io.Serializable, java.lang.Cloneable, CapabilitiesHandler, Drawable, OptionHandler, Randomizable, RevisionHandler

public class CostSensitiveClassifier
extends RandomizableSingleClassifierEnhancer
implements OptionHandler, Drawable

A metaclassifier that makes its base classifier cost-sensitive. Two methods can be used to introduce cost-sensitivity: reweighting training instances according to the total cost assigned to each class; or predicting the class with minimum expected misclassification cost (rather than the most likely class). Performance can often be improved by using a Bagged classifier to improve the probability estimates of the base classifier.

Valid options are:

 -M
  Minimize expected misclassification cost. Default is to
  reweight training instances according to costs per class

 -C <cost file name>
  File name of a cost matrix to use. If this is not supplied,
  a cost matrix will be loaded on demand. The name of the
  on-demand file is the relation name of the training data
  plus ".cost", and the path to the on-demand file is
  specified with the -N option.

 -N <directory>
  Name of a directory to search for cost files when loading
  costs on demand (default current directory).

 -cost-matrix <matrix>
  The cost matrix in Matlab single line format.

 -S <num>
  Random number seed.
  (default 1)

 -D
  If set, classifier is run in debug mode and
  may output additional info to the console

 -W
  Full name of base classifier.
  (default: weka.classifiers.rules.ZeroR)

 
 Options specific to classifier weka.classifiers.rules.ZeroR:

 -D
  If set, classifier is run in debug mode and
  may output additional info to the console

Options after -- are passed to the designated classifier.

Version:: $Revision: 1.29 $
Author:: Len Trigg (len@reeltwo.com)
See Also:: Serialized Form

Field Summary

Fields
Modifier and Type	Field and Description
`static int`	`MATRIX_ON_DEMAND` load cost matrix on demand
`static int`	`MATRIX_SUPPLIED` use explicit cost matrix
`static Tag[]`	`TAGS_MATRIX_SOURCE` Specify possible sources of the cost matrix

Fields inherited from interface weka.core.Drawable
BayesNet, Newick, NOT_DRAWABLE, TREE

Constructor Summary

Constructors
Constructor and Description

CostSensitiveClassifier()
Default constructor.

Constructors
Constructor and Description
`CostSensitiveClassifier()` Default constructor.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`buildClassifier(Instances data)` Builds the model of the base learner.
`java.lang.String`	`costMatrixSourceTipText()`
`java.lang.String`	`costMatrixTipText()`
`double[]`	`distributionForInstance(Instance instance)` Returns class probabilities.
`Capabilities`	`getCapabilities()` Returns default capabilities of the classifier.
`CostMatrix`	`getCostMatrix()` Gets the misclassification cost matrix.
`SelectedTag`	`getCostMatrixSource()` Gets the source location method of the cost matrix.
`boolean`	`getMinimizeExpectedCost()` Gets the value of MinimizeExpectedCost.
`java.io.File`	`getOnDemandDirectory()` Returns the directory that will be searched for cost files when loading on demand.
`java.lang.String[]`	`getOptions()` Gets the current settings of the Classifier.
`java.lang.String`	`getRevision()` Returns the revision string.
`java.lang.String`	`globalInfo()`
`java.lang.String`	`graph()` Returns graph describing the classifier (if possible).
`int`	`graphType()` Returns the type of graph this classifier represents.
`java.util.Enumeration`	`listOptions()` Returns an enumeration describing the available options.
`static void`	`main(java.lang.String[] argv)` Main method for testing this class.
`java.lang.String`	`minimizeExpectedCostTipText()`
`java.lang.String`	`onDemandDirectoryTipText()`
`void`	`setCostMatrix(CostMatrix newCostMatrix)` Sets the misclassification cost matrix.
`void`	`setCostMatrixSource(SelectedTag newMethod)` Sets the source location of the cost matrix.
`void`	`setMinimizeExpectedCost(boolean newMinimizeExpectedCost)` Set the value of MinimizeExpectedCost.
`void`	`setOnDemandDirectory(java.io.File newDir)` Sets the directory that will be searched for cost files when loading on demand.
`void`	`setOptions(java.lang.String[] options)` Parses a given list of options.
`java.lang.String`	`toString()` Output a representation of this classifier

Methods inherited from class weka.classifiers.RandomizableSingleClassifierEnhancer
getSeed, seedTipText, setSeed

Methods inherited from class weka.classifiers.SingleClassifierEnhancer
classifierTipText, getClassifier, setClassifier

Methods inherited from class weka.classifiers.Classifier
classifyInstance, debugTipText, forName, getDebug, makeCopies, makeCopy, setDebug

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

- Field Detail
  - MATRIX_ON_DEMAND
```
public static final int MATRIX_ON_DEMAND
```
    load cost matrix on demand
    
    See Also:
    
    Constant Field Values
  - MATRIX_SUPPLIED
```
public static final int MATRIX_SUPPLIED
```
    use explicit cost matrix
    
    See Also:
    
    Constant Field Values
  - TAGS_MATRIX_SOURCE
```
public static final Tag[] TAGS_MATRIX_SOURCE
```
    Specify possible sources of the cost matrix
- Constructor Detail
  - CostSensitiveClassifier
```
public CostSensitiveClassifier()
```
    Default constructor.
- Method Detail
  - listOptions
```
public java.util.Enumeration listOptions()
```
    Returns an enumeration describing the available options.
    
    Specified by:
    
    listOptions in interface OptionHandler
    
    Overrides:
    
    listOptions in class RandomizableSingleClassifierEnhancer
    
    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
  Minimize expected misclassification cost. Default is to
  reweight training instances according to costs per class
```
```
 -C <cost file name>
  File name of a cost matrix to use. If this is not supplied,
  a cost matrix will be loaded on demand. The name of the
  on-demand file is the relation name of the training data
  plus ".cost", and the path to the on-demand file is
  specified with the -N option.
```
```
 -N <directory>
  Name of a directory to search for cost files when loading
  costs on demand (default current directory).
```
```
 -cost-matrix <matrix>
  The cost matrix in Matlab single line format.
```
```
 -S <num>
  Random number seed.
  (default 1)
```
```
 -D
  If set, classifier is run in debug mode and
  may output additional info to the console
```
```
 -W
  Full name of base classifier.
  (default: weka.classifiers.rules.ZeroR)
```
```
 
 Options specific to classifier weka.classifiers.rules.ZeroR:
 
```
```
 -D
  If set, classifier is run in debug mode and
  may output additional info to the console
```
    Options after -- are passed to the designated classifier.
    Specified by:
    
    setOptions in interface OptionHandler
    
    Overrides:
    
    setOptions in class RandomizableSingleClassifierEnhancer
    
    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 the Classifier.
    
    Specified by:
    
    getOptions in interface OptionHandler
    
    Overrides:
    
    getOptions in class RandomizableSingleClassifierEnhancer
    
    Returns:
    
    an array of strings suitable for passing to setOptions
  - globalInfo
```
public java.lang.String globalInfo()
```
    Returns:
    
    a description of the classifier suitable for displaying in the explorer/experimenter gui
  - costMatrixSourceTipText
```
public java.lang.String costMatrixSourceTipText()
```
    Returns:
    
    tip text for this property suitable for displaying in the explorer/experimenter gui
  - getCostMatrixSource
```
public SelectedTag getCostMatrixSource()
```
    Gets the source location method of the cost matrix. Will be one of MATRIX_ON_DEMAND or MATRIX_SUPPLIED.
    
    Returns:
    
    the cost matrix source.
  - setCostMatrixSource
```
public void setCostMatrixSource(SelectedTag newMethod)
```
    Sets the source location of the cost matrix. Values other than MATRIX_ON_DEMAND or MATRIX_SUPPLIED will be ignored.
    
    Parameters:
    
    newMethod - the cost matrix location method.
  - onDemandDirectoryTipText
```
public java.lang.String onDemandDirectoryTipText()
```
    Returns:
    
    tip text for this property suitable for displaying in the explorer/experimenter gui
  - getOnDemandDirectory
```
public java.io.File getOnDemandDirectory()
```
    Returns the directory that will be searched for cost files when loading on demand.
    
    Returns:
    
    The cost file search directory.
  - setOnDemandDirectory
```
public void setOnDemandDirectory(java.io.File newDir)
```
    Sets the directory that will be searched for cost files when loading on demand.
    
    Parameters:
    
    newDir - The cost file search directory.
  - minimizeExpectedCostTipText
```
public java.lang.String minimizeExpectedCostTipText()
```
    Returns:
    
    tip text for this property suitable for displaying in the explorer/experimenter gui
  - getMinimizeExpectedCost
```
public boolean getMinimizeExpectedCost()
```
    Gets the value of MinimizeExpectedCost.
    
    Returns:
    
    Value of MinimizeExpectedCost.
  - setMinimizeExpectedCost
```
public void setMinimizeExpectedCost(boolean newMinimizeExpectedCost)
```
    Set the value of MinimizeExpectedCost.
    
    Parameters:
    
    newMinimizeExpectedCost - Value to assign to MinimizeExpectedCost.
  - costMatrixTipText
```
public java.lang.String costMatrixTipText()
```
    Returns:
    
    tip text for this property suitable for displaying in the explorer/experimenter gui
  - getCostMatrix
```
public CostMatrix getCostMatrix()
```
    Gets the misclassification cost matrix.
    
    Returns:
    
    the cost matrix
  - setCostMatrix
```
public void setCostMatrix(CostMatrix newCostMatrix)
```
    Sets the misclassification cost matrix.
    
    Parameters:
    
    newCostMatrix - the cost matrix
  - getCapabilities
```
public Capabilities getCapabilities()
```
    Returns default capabilities of the classifier.
    
    Specified by:
    
    getCapabilities in interface CapabilitiesHandler
    
    Overrides:
    
    getCapabilities in class SingleClassifierEnhancer
    
    Returns:
    
    the capabilities of this classifier
    
    See Also:
    
    Capabilities
  - buildClassifier
```
public void buildClassifier(Instances data)
                     throws java.lang.Exception
```
    Builds the model of the base learner.
    
    Specified by:
    
    buildClassifier in class Classifier
    
    Parameters:
    
    data - the training data
    
    Throws:
    
    java.lang.Exception - if the classifier could not be built successfully
  - distributionForInstance
```
public double[] distributionForInstance(Instance instance)
                                 throws java.lang.Exception
```
    Returns class probabilities. When minimum expected cost approach is chosen, returns probability one for class with the minimum expected misclassification cost. Otherwise it returns the probability distribution returned by the base classifier.
    
    Overrides:
    
    distributionForInstance in class Classifier
    
    Parameters:
    
    instance - the instance to be classified
    
    Returns:
    
    the computed distribution for the given instance
    
    Throws:
    
    java.lang.Exception - if instance could not be classified successfully
  - graphType
```
public int graphType()
```
    Returns the type of graph this classifier represents.
    
    Specified by:
    
    graphType in interface Drawable
    
    Returns:
    
    the type of graph this classifier represents
  - graph
```
public java.lang.String graph()
                       throws java.lang.Exception
```
    Returns graph describing the classifier (if possible).
    
    Specified by:
    
    graph in interface Drawable
    
    Returns:
    
    the graph of the classifier in dotty format
    
    Throws:
    
    java.lang.Exception - if the classifier cannot be graphed
  - toString
```
public java.lang.String toString()
```
    Output a representation of this classifier
    
    Overrides:
    
    toString in class java.lang.Object
    
    Returns:
    
    a string representation of the classifier
  - getRevision
```
public java.lang.String getRevision()
```
    Returns the revision string.
    
    Specified by:
    
    getRevision in interface RevisionHandler
    
    Overrides:
    
    getRevision in class Classifier
    
    Returns:
    
    the revision
  - main
```
public static void main(java.lang.String[] argv)
```
    Main method for testing this class.
    
    Parameters:
    
    argv - should contain the following arguments: -t training file [-T test file] [-c class index]

Class CostSensitiveClassifier

Field Summary

Fields inherited from interface weka.core.Drawable

Constructor Summary

Method Summary

Methods inherited from class weka.classifiers.RandomizableSingleClassifierEnhancer

Methods inherited from class weka.classifiers.SingleClassifierEnhancer

Methods inherited from class weka.classifiers.Classifier

Methods inherited from class java.lang.Object

Field Detail

MATRIX_ON_DEMAND

MATRIX_SUPPLIED

TAGS_MATRIX_SOURCE

Constructor Detail

CostSensitiveClassifier

Method Detail

listOptions

setOptions

getOptions

globalInfo

costMatrixSourceTipText

getCostMatrixSource

setCostMatrixSource

onDemandDirectoryTipText

getOnDemandDirectory

setOnDemandDirectory

minimizeExpectedCostTipText

getMinimizeExpectedCost

setMinimizeExpectedCost

costMatrixTipText

getCostMatrix

setCostMatrix

getCapabilities

buildClassifier

distributionForInstance

graphType

graph

toString

getRevision

main