weka.classifiers.meta

## Class RandomSubSpace

- java.lang.Object
- - weka.classifiers.AbstractClassifier
  - - weka.classifiers.SingleClassifierEnhancer
    - - weka.classifiers.IteratedSingleClassifierEnhancer
      - - weka.classifiers.ParallelIteratedSingleClassifierEnhancer
        - - weka.classifiers.RandomizableParallelIteratedSingleClassifierEnhancer
          - - weka.classifiers.meta.RandomSubSpace

- All Implemented Interfaces:
    java.io.Serializable, java.lang.Cloneable, Classifier, BatchPredictor, CapabilitiesHandler, CapabilitiesIgnorer, CommandlineRunnable, OptionHandler, Randomizable, RevisionHandler, TechnicalInformationHandler, WeightedInstancesHandler

      public class RandomSubSpace
      extends RandomizableParallelIteratedSingleClassifierEnhancer
      implements WeightedInstancesHandler, TechnicalInformationHandler

  This method constructs a decision tree based classifier that maintains highest accuracy on training data and improves on generalization accuracy as it grows in complexity. The classifier consists of multiple trees constructed systematically by pseudorandomly selecting subsets of components of the feature vector, that is, trees constructed in randomly chosen subspaces.
  For more information, see
  Tin Kam Ho (1998). The Random Subspace Method for Constructing Decision Forests. IEEE Transactions on Pattern Analysis and Machine Intelligence. 20(8):832-844. URL http://citeseer.ist.psu.edu/ho98random.html.

  BibTeX:

       @article{Ho1998,
          author = {Tin Kam Ho},
          journal = {IEEE Transactions on Pattern Analysis and Machine Intelligence},
          number = {8},
          pages = {832-844},
          title = {The Random Subspace Method for Constructing Decision Forests},
          volume = {20},
          year = {1998},
          ISSN = {0162-8828},
          URL = {http://citeseer.ist.psu.edu/ho98random.html}
       }

  Valid options are:

       -P
        Size of each subspace:
         < 1: percentage of the number of attributes
         >=1: absolute number of attributes

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

       -I <num>
        Number of iterations.
        (default 10)

       -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.trees.REPTree)

       Options specific to classifier weka.classifiers.trees.REPTree:

       -M <minimum number of instances>
        Set minimum number of instances per leaf (default 2).

       -V <minimum variance for split>
        Set minimum numeric class variance proportion
        of train variance for split (default 1e-3).

       -N <number of folds>
        Number of folds for reduced error pruning (default 3).

       -S <seed>
        Seed for random data shuffling (default 1).

       -P
        No pruning.

       -L
        Maximum tree depth (default -1, no maximum)

  Options after -- are passed to the designated classifier.

  Version:
    $Revision: 11461 $
  Author:
    Bernhard Pfahringer (bernhard@cs.waikato.ac.nz), Peter Reutemann (fracpete@cs.waikato.ac.nz)
  See Also:
    Serialized Form

- - ### Field Summary

    - ### Fields inherited from class weka.classifiers.AbstractClassifier

      `BATCH_SIZE_DEFAULT, NUM_DECIMAL_PLACES_DEFAULT`

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `RandomSubSpace()` Constructor.

  - ### Method Summary

    All Methods Static Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `void` | `buildClassifier(Instances data)` builds the classifier.
    `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.
    `java.lang.String` | `getRevision()` Returns the revision string.
    `double` | `getSubSpaceSize()` Gets the size of each subSpace, as a percentage of the training set size.
    `TechnicalInformation` | `getTechnicalInformation()` Returns an instance of a TechnicalInformation object, containing detailed information about the technical background of this class, e.g., paper reference or book this class is based on.
    `java.lang.String` | `globalInfo()` Returns a string describing classifier
    `java.util.Enumeration<Option>` | `listOptions()` Returns an enumeration describing the available options.
    `static void` | `main(java.lang.String[] args)` Main method for testing this class.
    `void` | `setOptions(java.lang.String[] options)` Parses a given list of options.
    `void` | `setSubSpaceSize(double value)` Sets the size of each subSpace, as a percentage of the training set size.
    `java.lang.String` | `subSpaceSizeTipText()` Returns the tip text for this property
    `java.lang.String` | `toString()` Returns description of the bagged classifier.

    - ### Methods inherited from class weka.classifiers.RandomizableParallelIteratedSingleClassifierEnhancer

      `getSeed, seedTipText, setSeed`

    - ### Methods inherited from class weka.classifiers.ParallelIteratedSingleClassifierEnhancer

      `getNumExecutionSlots, numExecutionSlotsTipText, setNumExecutionSlots`

    - ### Methods inherited from class weka.classifiers.IteratedSingleClassifierEnhancer

      `getNumIterations, numIterationsTipText, setNumIterations`

    - ### Methods inherited from class weka.classifiers.SingleClassifierEnhancer

      `classifierTipText, getCapabilities, getClassifier, postExecution, preExecution, setClassifier`

    - ### Methods inherited from class weka.classifiers.AbstractClassifier

      `batchSizeTipText, classifyInstance, debugTipText, distributionsForInstances, doNotCheckCapabilitiesTipText, forName, getBatchSize, getDebug, getDoNotCheckCapabilities, getNumDecimalPlaces, implementsMoreEfficientBatchPrediction, makeCopies, makeCopy, numDecimalPlacesTipText, run, runClassifier, setBatchSize, setDebug, setDoNotCheckCapabilities, setNumDecimalPlaces`

    - ### Methods inherited from class java.lang.Object

      `equals, getClass, hashCode, notify, notifyAll, wait, wait, wait`

- - ### Constructor Detail

    - #### RandomSubSpace

          public RandomSubSpace()

      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

    - #### getTechnicalInformation

          public TechnicalInformation getTechnicalInformation()

      Returns an instance of a TechnicalInformation object, containing detailed information about the technical background of this class, e.g., paper reference or book this class is based on.
      Specified by:
        `getTechnicalInformation` in interface `TechnicalInformationHandler`
      Returns:
        the technical information about this class

    - #### listOptions

          public java.util.Enumeration<Option> listOptions()

      Returns an enumeration describing the available options.
      Specified by:
        `listOptions` in interface `OptionHandler`
      Overrides:
        `listOptions` in class `RandomizableParallelIteratedSingleClassifierEnhancer`
      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:

           -P
            Size of each subspace:
             < 1: percentage of the number of attributes
             >=1: absolute number of attributes

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

           -I <num>
            Number of iterations.
            (default 10)

           -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.trees.REPTree)

           Options specific to classifier weka.classifiers.trees.REPTree:

           -M <minimum number of instances>
            Set minimum number of instances per leaf (default 2).

           -V <minimum variance for split>
            Set minimum numeric class variance proportion
            of train variance for split (default 1e-3).

           -N <number of folds>
            Number of folds for reduced error pruning (default 3).

           -S <seed>
            Seed for random data shuffling (default 1).

           -P
            No pruning.

           -L
            Maximum tree depth (default -1, no maximum)

      Options after -- are passed to the designated classifier.

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

    - #### subSpaceSizeTipText

          public java.lang.String subSpaceSizeTipText()

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

    - #### getSubSpaceSize

          public double getSubSpaceSize()

      Gets the size of each subSpace, as a percentage of the training set size.
      Returns:
        the subSpace size, as a percentage.

    - #### setSubSpaceSize

          public void setSubSpaceSize(double value)

      Sets the size of each subSpace, as a percentage of the training set size.
      Parameters:
        `value` - the subSpace size, as a percentage.

    - #### buildClassifier

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

      builds the classifier.
      Specified by:
        `buildClassifier` in interface `Classifier`
      Overrides:
        `buildClassifier` in class `ParallelIteratedSingleClassifierEnhancer`
      Parameters:
        `data` - the training data to be used for generating the 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.
      Specified by:
        `distributionForInstance` in interface `Classifier`
      Overrides:
        `distributionForInstance` in class `AbstractClassifier`
      Parameters:
        `instance` - the instance to be classified
      Returns:
        preedicted class probability distribution
      Throws:
        `java.lang.Exception` - if distribution can't be computed successfully

    - #### toString

          public java.lang.String toString()

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

    - #### getRevision

          public java.lang.String getRevision()

      Returns the revision string.
      Specified by:
        `getRevision` in interface `RevisionHandler`
      Overrides:
        `getRevision` in class `AbstractClassifier`
      Returns:
        the revision

    - #### main

          public static void main(java.lang.String[] args)

      Main method for testing this class.
      Parameters:
        `args` - the options