weka.classifiers
Class DecisionStump

java.lang.Object
  |
  +--weka.classifiers.Classifier
        |
        +--weka.classifiers.DistributionClassifier
              |
              +--weka.classifiers.DecisionStump
All Implemented Interfaces:
java.lang.Cloneable, java.io.Serializable, Sourcable, WeightedInstancesHandler

public class DecisionStump
extends DistributionClassifier
implements WeightedInstancesHandler, Sourcable

Class for building and using a decision stump. Usually used in conjunction with a boosting algorithm. Typical usage:

java weka.classifiers.LogitBoost -I 100 -W weka.classifiers.DecisionStump -t training_data

Author:
Eibe Frank (eibe@cs.waikato.ac.nz)
See Also:
Serialized Form

Constructor Summary
DecisionStump()
           
 
Method Summary
 void buildClassifier(Instances instances)
          Generates the classifier.
 double[] distributionForInstance(Instance instance)
          Calculates the class membership probabilities for the given test instance.
static void main(java.lang.String[] argv)
          Main method for testing this class.
 java.lang.String toSource(java.lang.String className)
          Returns the decision tree as Java source code.
 java.lang.String toString()
          Returns a description of the classifier.
 
Methods inherited from class weka.classifiers.DistributionClassifier
classifyInstance
 
Methods inherited from class weka.classifiers.Classifier
forName, makeCopies
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

DecisionStump

public DecisionStump()
Method Detail

buildClassifier

public void buildClassifier(Instances instances)
                     throws java.lang.Exception
Generates the classifier.
Overrides:
buildClassifier in class Classifier
Parameters:
instances - set of instances serving as training data
Throws:
java.lang.Exception - if the classifier has not been generated 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 DistributionClassifier
Parameters:
instance - the instance to be classified
Returns:
predicted class probability distribution
Throws:
java.lang.Exception - if distribution can't be computed

toSource

public java.lang.String toSource(java.lang.String className)
                          throws java.lang.Exception
Returns the decision tree as Java source code.
Specified by:
toSource in interface Sourcable
Returns:
the tree as Java source code
Throws:
java.lang.Exception - if something goes wrong

toString

public java.lang.String toString()
Returns a description of the classifier.
Overrides:
toString in class java.lang.Object
Returns:
a description of the classifier as a string.

main

public static void main(java.lang.String[] argv)
Main method for testing this class.
Parameters:
argv - the options