Class OzaBoost

  • All Implemented Interfaces:
    Configurable, Serializable, CapabilitiesHandler, Classifier, MultiClassClassifier, AWTRenderable, Learner<Example<Instance>>, MOAObject, OptionHandler

    public class OzaBoost
    extends AbstractClassifier
    implements MultiClassClassifier
    Incremental on-line boosting of Oza and Russell.

    See details in:
    N. Oza and S. Russell. Online bagging and boosting. In Artificial Intelligence and Statistics 2001, pages 105–112. Morgan Kaufmann, 2001.

    For the boosting method, Oza and Russell note that the weighting procedure of AdaBoost actually divides the total example weight into two halves – half of the weight is assigned to the correctly classified examples, and the other half goes to the misclassified examples. They use the Poisson distribution for deciding the random probability that an example is used for training, only this time the parameter changes according to the boosting weight of the example as it is passed through each model in sequence.

    Parameters:

    • -l : Classifier to train
    • -s : The number of models to boost
    • -p : Boost with weights only; no poisson
    Version:
    $Revision: 7 $
    Author:
    Richard Kirkby (rkirkby@cs.waikato.ac.nz)
    See Also:
    Serialized Form
    • Field Detail

      • baseLearnerOption

        public ClassOption baseLearnerOption
      • ensembleSizeOption

        public IntOption ensembleSizeOption
      • pureBoostOption

        public FlagOption pureBoostOption
      • scms

        protected double[] scms
      • swms

        protected double[] swms
    • Constructor Detail

      • OzaBoost

        public OzaBoost()
    • Method Detail

      • resetLearningImpl

        public void resetLearningImpl()
        Description copied from class: AbstractClassifier
        Resets this classifier. It must be similar to starting a new classifier from scratch.

        The reason for ...Impl methods: ease programmer burden by not requiring them to remember calls to super in overridden methods. Note that this will produce compiler errors if not overridden.
        Specified by:
        resetLearningImpl in class AbstractClassifier
      • trainOnInstanceImpl

        public void trainOnInstanceImpl​(Instance inst)
        Description copied from class: AbstractClassifier
        Trains this classifier incrementally using the given instance.

        The reason for ...Impl methods: ease programmer burden by not requiring them to remember calls to super in overridden methods. Note that this will produce compiler errors if not overridden.
        Specified by:
        trainOnInstanceImpl in class AbstractClassifier
        Parameters:
        inst - the instance to be used for training
      • getEnsembleMemberWeight

        protected double getEnsembleMemberWeight​(int i)
      • getVotesForInstance

        public double[] getVotesForInstance​(Instance inst)
        Description copied from interface: Classifier
        Predicts the class memberships for a given instance. If an instance is unclassified, the returned array elements must be all zero.
        Specified by:
        getVotesForInstance in interface Classifier
        Specified by:
        getVotesForInstance in class AbstractClassifier
        Parameters:
        inst - the instance to be classified
        Returns:
        an array containing the estimated membership probabilities of the test instance in each class
      • isRandomizable

        public boolean isRandomizable()
        Description copied from interface: Learner
        Gets whether this learner needs a random seed. Examples of methods that needs a random seed are bagging and boosting.
        Specified by:
        isRandomizable in interface Learner<Example<Instance>>
        Returns:
        true if the learner needs a random seed.
      • getModelDescription

        public void getModelDescription​(StringBuilder out,
                                        int indent)
        Description copied from class: AbstractClassifier
        Returns a string representation of the model.
        Specified by:
        getModelDescription in class AbstractClassifier
        Parameters:
        out - the stringbuilder to add the description
        indent - the number of characters to indent
      • getModelMeasurementsImpl

        protected Measurement[] getModelMeasurementsImpl()
        Description copied from class: AbstractClassifier
        Gets the current measurements of this classifier.

        The reason for ...Impl methods: ease programmer burden by not requiring them to remember calls to super in overridden methods. Note that this will produce compiler errors if not overridden.
        Specified by:
        getModelMeasurementsImpl in class AbstractClassifier
        Returns:
        an array of measurements to be used in evaluation tasks