weka.classifiers.meta

## Class MultiScheme

- java.lang.Object
- - weka.classifiers.AbstractClassifier
  - - weka.classifiers.MultipleClassifiersCombiner
    - - weka.classifiers.RandomizableMultipleClassifiersCombiner
      - - weka.classifiers.meta.MultiScheme

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

      public class MultiScheme
      extends RandomizableMultipleClassifiersCombiner

  Class for selecting a classifier from among several using cross validation on the training data or the performance on the training data. Performance is measured based on percent correct (classification) or mean-squared error (regression).

  Valid options are:

       -X <number of folds>
        Use cross validation for model selection using the
        given number of folds. (default 0, is to
        use training error)

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

       -B <classifier specification>
        Full class name of classifier to include, followed
        by scheme options. May be specified multiple times.
        (default: "weka.classifiers.rules.ZeroR")

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

  Version:
    $Revision: 10141 $
  Author:
    Len Trigg (trigg@cs.waikato.ac.nz)
  See Also:
    Serialized Form

- - ### Constructor Summary

    Constructors
    Constructor and Description
    `MultiScheme()`

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `void` | `buildClassifier(Instances data)` Buildclassifier selects a classifier from the set of classifiers by minimising error on the training data.
    `java.lang.String` | `classifiersTipText()` Returns the tip text for this property
    `java.lang.String` | `debugTipText()` Returns the tip text for this property
    `double[]` | `distributionForInstance(Instance instance)` Returns class probabilities.
    `int` | `getBestClassifierIndex()` Get the index of the classifier that was determined as best during cross-validation.
    `Classifier` | `getClassifier(int index)` Gets a single classifier from the set of available classifiers.
    `Classifier[]` | `getClassifiers()` Gets the list of possible classifers to choose from.
    `boolean` | `getDebug()` Get whether debugging is turned on
    `int` | `getNumFolds()` Gets the number of folds for cross-validation.
    `java.lang.String[]` | `getOptions()` Gets the current settings of the Classifier.
    `java.lang.String` | `getRevision()` Returns the revision string.
    `int` | `getSeed()` Gets the random number seed.
    `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[] argv)` Main method for testing this class.
    `java.lang.String` | `numFoldsTipText()` Returns the tip text for this property
    `java.lang.String` | `seedTipText()` Returns the tip text for this property
    `void` | `setClassifiers(Classifier[] classifiers)` Sets the list of possible classifers to choose from.
    `void` | `setDebug(boolean debug)` Set debugging mode
    `void` | `setNumFolds(int numFolds)` Sets the number of folds for cross-validation.
    `void` | `setOptions(java.lang.String[] options)` Parses a given list of options.
    `void` | `setSeed(int seed)` Sets the seed for random number generation.
    `java.lang.String` | `toString()` Output a representation of this classifier

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

      `getCapabilities`

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

      `classifyInstance, doNotCheckCapabilitiesTipText, forName, getDoNotCheckCapabilities, makeCopies, makeCopy, runClassifier, setDoNotCheckCapabilities`

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

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

- - ### Constructor Detail

    - #### MultiScheme

          public MultiScheme()

  - ### 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<Option> listOptions()

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

           -X <number of folds>
            Use cross validation for model selection using the
            given number of folds. (default 0, is to
            use training error)

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

           -B <classifier specification>
            Full class name of classifier to include, followed
            by scheme options. May be specified multiple times.
            (default: "weka.classifiers.rules.ZeroR")

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

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

    - #### classifiersTipText

          public java.lang.String classifiersTipText()

      Returns the tip text for this property
      Overrides:
        `classifiersTipText` in class `MultipleClassifiersCombiner`
      Returns:
        tip text for this property suitable for displaying in the explorer/experimenter gui

    - #### setClassifiers

          public void setClassifiers(Classifier[] classifiers)

      Sets the list of possible classifers to choose from.
      Overrides:
        `setClassifiers` in class `MultipleClassifiersCombiner`
      Parameters:
        `classifiers` - an array of classifiers with all options set.

    - #### getClassifiers

          public Classifier[] getClassifiers()

      Gets the list of possible classifers to choose from.
      Overrides:
        `getClassifiers` in class `MultipleClassifiersCombiner`
      Returns:
        the array of Classifiers

    - #### getClassifier

          public Classifier getClassifier(int index)

      Gets a single classifier from the set of available classifiers.
      Overrides:
        `getClassifier` in class `MultipleClassifiersCombiner`
      Parameters:
        `index` - the index of the classifier wanted
      Returns:
        the Classifier

    - #### seedTipText

          public java.lang.String seedTipText()

      Returns the tip text for this property
      Overrides:
        `seedTipText` in class `RandomizableMultipleClassifiersCombiner`
      Returns:
        tip text for this property suitable for displaying in the explorer/experimenter gui

    - #### setSeed

          public void setSeed(int seed)

      Sets the seed for random number generation.
      Specified by:
        `setSeed` in interface `Randomizable`
      Overrides:
        `setSeed` in class `RandomizableMultipleClassifiersCombiner`
      Parameters:
        `seed` - the random number seed

    - #### getSeed

          public int getSeed()

      Gets the random number seed.
      Specified by:
        `getSeed` in interface `Randomizable`
      Overrides:
        `getSeed` in class `RandomizableMultipleClassifiersCombiner`
      Returns:
        the random number seed

    - #### numFoldsTipText

          public java.lang.String numFoldsTipText()

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

    - #### getNumFolds

          public int getNumFolds()

      Gets the number of folds for cross-validation. A number less than 2 specifies using training error rather than cross-validation.
      Returns:
        the number of folds for cross-validation

    - #### setNumFolds

          public void setNumFolds(int numFolds)

      Sets the number of folds for cross-validation. A number less than 2 specifies using training error rather than cross-validation.
      Parameters:
        `numFolds` - the number of folds for cross-validation

    - #### debugTipText

          public java.lang.String debugTipText()

      Returns the tip text for this property
      Overrides:
        `debugTipText` in class `AbstractClassifier`
      Returns:
        tip text for this property suitable for displaying in the explorer/experimenter gui

    - #### setDebug

          public void setDebug(boolean debug)

      Set debugging mode
      Overrides:
        `setDebug` in class `AbstractClassifier`
      Parameters:
        `debug` - true if debug output should be printed

    - #### getDebug

          public boolean getDebug()

      Get whether debugging is turned on
      Overrides:
        `getDebug` in class `AbstractClassifier`
      Returns:
        true if debugging output is on

    - #### getBestClassifierIndex

          public int getBestClassifierIndex()

      Get the index of the classifier that was determined as best during cross-validation.
      Returns:
        the index in the classifier array

    - #### buildClassifier

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

      Buildclassifier selects a classifier from the set of classifiers by minimising error on the training data.
      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

      Returns class probabilities.
      Specified by:
        `distributionForInstance` in interface `Classifier`
      Overrides:
        `distributionForInstance` in class `AbstractClassifier`
      Parameters:
        `instance` - the instance to be classified
      Returns:
        the distribution for the instance
      Throws:
        `java.lang.Exception` - if instance could not be classified successfully

    - #### 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 `AbstractClassifier`
      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]