weka.classifiers.meta
Class AdaBoostM1

java.lang.Object
  |
  +--weka.classifiers.Classifier
        |
        +--weka.classifiers.SingleClassifierEnhancer
              |
              +--weka.classifiers.IteratedSingleClassifierEnhancer
                    |
                    +--weka.classifiers.RandomizableIteratedSingleClassifierEnhancer
                          |
                          +--weka.classifiers.meta.AdaBoostM1
All Implemented Interfaces:
java.lang.Cloneable, OptionHandler, Randomizable, java.io.Serializable, Sourcable, WeightedInstancesHandler
Direct Known Subclasses:
MultiBoostAB

public class AdaBoostM1
extends RandomizableIteratedSingleClassifierEnhancer
implements WeightedInstancesHandler, Sourcable

Class for boosting a classifier using Freund & Schapire's Adaboost M1 method. For more information, see

Yoav Freund and Robert E. Schapire (1996). Experiments with a new boosting algorithm. Proc International Conference on Machine Learning, pages 148-156, Morgan Kaufmann, San Francisco.

Valid options are:

-D
Turn on debugging output.

-W classname
Specify the full class name of a classifier as the basis for boosting (required).

-I num
Set the number of boost iterations (default 10).

-P num
Set the percentage of weight mass used to build classifiers (default 100).

-Q
Use resampling instead of reweighting.

-S seed
Random number seed for resampling (default 1).

Options after -- are passed to the designated classifier.

Version:
$Revision: 1.23 $
Author:
Eibe Frank (eibe@cs.waikato.ac.nz), Len Trigg (trigg@cs.waikato.ac.nz)
See Also:
Serialized Form

Constructor Summary
AdaBoostM1()
          Constructor.
 
Method Summary
 void buildClassifier(Instances data)
          Boosting method.
 double[] distributionForInstance(Instance instance)
          Calculates the class membership probabilities for the given test instance.
 java.lang.String[] getOptions()
          Gets the current settings of the Classifier.
 boolean getUseResampling()
          Get whether resampling is turned on
 int getWeightThreshold()
          Get the degree of weight thresholding
 java.lang.String globalInfo()
          Returns a string describing classifier
 java.util.Enumeration listOptions()
          Returns an enumeration describing the available options.
static void main(java.lang.String[] argv)
          Main method for testing this class.
 void setOptions(java.lang.String[] options)
          Parses a given list of options.
 void setUseResampling(boolean r)
          Set resampling mode
 void setWeightThreshold(int threshold)
          Set weight threshold
 java.lang.String toSource(java.lang.String className)
          Returns the boosted model as Java source code.
 java.lang.String toString()
          Returns description of the boosted classifier.
 java.lang.String useResamplingTipText()
          Returns the tip text for this property
 java.lang.String weightThresholdTipText()
          Returns the tip text for this property
 
Methods inherited from class weka.classifiers.RandomizableIteratedSingleClassifierEnhancer
getSeed, seedTipText, setSeed
 
Methods inherited from class weka.classifiers.IteratedSingleClassifierEnhancer
getNumIterations, numIterationsTipText, setNumIterations
 
Methods inherited from class weka.classifiers.SingleClassifierEnhancer
classifierTipText, getClassifier, setClassifier
 
Methods inherited from class weka.classifiers.Classifier
classifyInstance, debugTipText, forName, getDebug, makeCopies, setDebug
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

AdaBoostM1

public AdaBoostM1()
Constructor.

Method Detail

globalInfo

public java.lang.String globalInfo()
Returns a string describing classifier

Returns:
a description 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
Overrides:
listOptions in class RandomizableIteratedSingleClassifierEnhancer
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:

-D
Turn on debugging output.

-W classname
Specify the full class name of a classifier as the basis for boosting (required).

-I num
Set the number of boost iterations (default 10).

-P num
Set the percentage of weight mass used to build classifiers (default 100).

-Q
Use resampling instead of reweighting.

-S seed
Random number seed for resampling (default 1).

Options after -- are passed to the designated classifier.

Specified by:
setOptions in interface OptionHandler
Overrides:
setOptions in class RandomizableIteratedSingleClassifierEnhancer
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 RandomizableIteratedSingleClassifierEnhancer
Returns:
an array of strings suitable for passing to setOptions

weightThresholdTipText

public java.lang.String weightThresholdTipText()
Returns the tip text for this property

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

setWeightThreshold

public void setWeightThreshold(int threshold)
Set weight threshold


getWeightThreshold

public int getWeightThreshold()
Get the degree of weight thresholding

Returns:
the percentage of weight mass used for training

useResamplingTipText

public java.lang.String useResamplingTipText()
Returns the tip text for this property

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

setUseResampling

public void setUseResampling(boolean r)
Set resampling mode


getUseResampling

public boolean getUseResampling()
Get whether resampling is turned on

Returns:
true if resampling output is on

buildClassifier

public void buildClassifier(Instances data)
                     throws java.lang.Exception
Boosting method.

Overrides:
buildClassifier in class IteratedSingleClassifierEnhancer
Parameters:
data - the training data to be used for generating the boosted classifier.
Throws:
java.lang.Exception - if the classifier could not be built successfully

distributionForInstance

public double[] distributionForInstance(Instance instance)
                                 throws java.lang.Exception
Calculates the class membership probabilities for the given test instance.

Overrides:
distributionForInstance in class Classifier
Parameters:
instance - the instance to be classified
Returns:
predicted class probability distribution
Throws:
java.lang.Exception - if instance could not be classified successfully

toSource

public java.lang.String toSource(java.lang.String className)
                          throws java.lang.Exception
Returns the boosted model as Java source code.

Specified by:
toSource in interface Sourcable
Parameters:
className - the name that should be given to the source class.
Returns:
the tree as Java source code
Throws:
java.lang.Exception - if something goes wrong

toString

public java.lang.String toString()
Returns description of the boosted classifier.

Overrides:
toString in class java.lang.Object
Returns:
description of the boosted classifier as a string

main

public static void main(java.lang.String[] argv)
Main method for testing this class.

Parameters:
argv - the options


Copyright (c) 2003 David Lindsay, Computer Learning Research Centre, Dept. Computer Science, Royal Holloway, University of London