weka.classifiers.lazy

## Class KStar

- java.lang.Object
- - weka.classifiers.AbstractClassifier
  - - weka.classifiers.lazy.KStar

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

      public class KStar
      extends AbstractClassifier
      implements KStarConstants, UpdateableClassifier, TechnicalInformationHandler

  K* is an instance-based classifier, that is the class of a test instance is based upon the class of those training instances similar to it, as determined by some similarity function. It differs from other instance-based learners in that it uses an entropy-based distance function.
  For more information on K*, see
  John G. Cleary, Leonard E. Trigg: K*: An Instance-based Learner Using an Entropic Distance Measure. In: 12th International Conference on Machine Learning, 108-114, 1995.

  BibTeX:

       @inproceedings{Cleary1995,
          author = {John G. Cleary and Leonard E. Trigg},
          booktitle = {12th International Conference on Machine Learning},
          pages = {108-114},
          title = {K*: An Instance-based Learner Using an Entropic Distance Measure},
          year = {1995}
       }

  Valid options are:

       -B <num>
        Manual blend setting (default 20%)

       -E
        Enable entropic auto-blend setting (symbolic class only)

       -M <char>
        Specify the missing value treatment mode (default a)
        Valid options are: a(verage), d(elete), m(axdiff), n(ormal)

  Version:
    $Revision: 10141 $
  Author:
    Len Trigg (len@reeltwo.com), Abdelaziz Mahoui (am14@cs.waikato.ac.nz) - Java port
  See Also:
    Serialized Form

- - ### Field Summary

    Fields
    Modifier and Type | Field and Description
    --- | ---
    `static Tag[]` | `TAGS_MISSING` Define possible missing value handling methods

    - ### Fields inherited from interface weka.classifiers.lazy.kstar.KStarConstants

      `B_ENTROPY, B_SPHERE, EPSILON, FLOOR, FLOOR1, INITIAL_STEP, LOG2, M_AVERAGE, M_DELETE, M_MAXDIFF, M_NORMAL, NUM_RAND_COLS, OFF, ON, ROOT_FINDER_ACCURACY, ROOT_FINDER_MAX_ITER`

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `KStar()`

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `void` | `buildClassifier(Instances instances)` Generates the classifier.
    `double[]` | `distributionForInstance(Instance instance)` Calculates the class membership probabilities for the given test instance.
    `java.lang.String` | `entropicAutoBlendTipText()` Returns the tip text for this property
    `Capabilities` | `getCapabilities()` Returns default capabilities of the classifier.
    `boolean` | `getEntropicAutoBlend()` Get whether entropic blending being used
    `int` | `getGlobalBlend()` Get the value of the global blend parameter
    `SelectedTag` | `getMissingMode()` Gets the method to use for handling missing values.
    `java.lang.String[]` | `getOptions()` Gets the current settings of K*.
    `java.lang.String` | `getRevision()` Returns the revision string.
    `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` | `globalBlendTipText()` Returns the tip text for this property
    `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` | `missingModeTipText()` Returns the tip text for this property
    `void` | `setEntropicAutoBlend(boolean e)` Set whether entropic blending is to be used.
    `void` | `setGlobalBlend(int b)` Set the global blend parameter
    `void` | `setMissingMode(SelectedTag newMode)` Sets the method to use for handling missing values.
    `void` | `setOptions(java.lang.String[] options)` Parses a given list of options.
    `java.lang.String` | `toString()` Returns a description of this classifier.
    `void` | `updateClassifier(Instance instance)` Adds the supplied instance to the training set

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

      `classifyInstance, debugTipText, doNotCheckCapabilitiesTipText, forName, getDebug, getDoNotCheckCapabilities, makeCopies, makeCopy, runClassifier, setDebug, setDoNotCheckCapabilities`

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

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

- - ### Field Detail

    - #### TAGS_MISSING

          public static final Tag[] TAGS_MISSING

      Define possible missing value handling methods

  - ### Constructor Detail

    - #### KStar

          public KStar()

  - ### 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

    - #### getCapabilities

          public Capabilities getCapabilities()

      Returns default capabilities of the classifier.
      Specified by:
        `getCapabilities` in interface `Classifier`
      Specified by:
        `getCapabilities` in interface `CapabilitiesHandler`
      Overrides:
        `getCapabilities` in class `AbstractClassifier`
      Returns:
        the capabilities of this classifier
      See Also:
        `Capabilities`

    - #### buildClassifier

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

      Generates the classifier.
      Specified by:
        `buildClassifier` in interface `Classifier`
      Parameters:
        `instances` - set of instances serving as training data
      Throws:
        `java.lang.Exception` - if the classifier has not been generated successfully

    - #### updateClassifier

          public void updateClassifier(Instance instance)
                                throws java.lang.Exception

      Adds the supplied instance to the training set
      Specified by:
        `updateClassifier` in interface `UpdateableClassifier`
      Parameters:
        `instance` - the instance to add
      Throws:
        `java.lang.Exception` - if instance could not be incorporated 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:
        predicted class probability distribution
      Throws:
        `java.lang.Exception` - if an error occurred during the prediction

    - #### missingModeTipText

          public java.lang.String missingModeTipText()

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

    - #### getMissingMode

          public SelectedTag getMissingMode()

      Gets the method to use for handling missing values. Will be one of M_NORMAL, M_AVERAGE, M_MAXDIFF or M_DELETE.
      Returns:
        the method used for handling missing values.

    - #### setMissingMode

          public void setMissingMode(SelectedTag newMode)

      Sets the method to use for handling missing values. Values other than M_NORMAL, M_AVERAGE, M_MAXDIFF and M_DELETE will be ignored.
      Parameters:
        `newMode` - the method to use for handling missing values.

    - #### listOptions

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

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

    - #### globalBlendTipText

          public java.lang.String globalBlendTipText()

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

    - #### setGlobalBlend

          public void setGlobalBlend(int b)

      Set the global blend parameter
      Parameters:
        `b` - the value for global blending

    - #### getGlobalBlend

          public int getGlobalBlend()

      Get the value of the global blend parameter
      Returns:
        the value of the global blend parameter

    - #### entropicAutoBlendTipText

          public java.lang.String entropicAutoBlendTipText()

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

    - #### setEntropicAutoBlend

          public void setEntropicAutoBlend(boolean e)

      Set whether entropic blending is to be used.
      Parameters:
        `e` - true if entropic blending is to be used

    - #### getEntropicAutoBlend

          public boolean getEntropicAutoBlend()

      Get whether entropic blending being used
      Returns:
        true if entropic blending is used

    - #### setOptions

          public void setOptions(java.lang.String[] options)
                          throws java.lang.Exception

      Parses a given list of options.

      Valid options are:

           -B <num>
            Manual blend setting (default 20%)

           -E
            Enable entropic auto-blend setting (symbolic class only)

           -M <char>
            Specify the missing value treatment mode (default a)
            Valid options are: a(verage), d(elete), m(axdiff), n(ormal)

      Specified by:
        `setOptions` in interface `OptionHandler`
      Overrides:
        `setOptions` in class `AbstractClassifier`
      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 K*.
      Specified by:
        `getOptions` in interface `OptionHandler`
      Overrides:
        `getOptions` in class `AbstractClassifier`
      Returns:
        an array of strings suitable for passing to setOptions()

    - #### toString

          public java.lang.String toString()

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

    - #### main

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

      Main method for testing this class.
      Parameters:
        `argv` - should contain command line options (see setOptions)

    - #### getRevision

          public java.lang.String getRevision()

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