weka.classifiers.lazy

## Class LWL

- java.lang.Object
- - weka.classifiers.AbstractClassifier
  - - weka.classifiers.SingleClassifierEnhancer
    - - weka.classifiers.lazy.LWL

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

      public class LWL
      extends SingleClassifierEnhancer
      implements UpdateableClassifier, WeightedInstancesHandler, TechnicalInformationHandler

  Locally weighted learning. Uses an instance-based algorithm to assign instance weights which are then used by a specified WeightedInstancesHandler.
  Can do classification (e.g. using naive Bayes) or regression (e.g. using linear regression).
  For more info, see
  Eibe Frank, Mark Hall, Bernhard Pfahringer: Locally Weighted Naive Bayes. In: 19th Conference in Uncertainty in Artificial Intelligence, 249-256, 2003.
  C. Atkeson, A. Moore, S. Schaal (1996). Locally weighted learning. AI Review..

  BibTeX:

       @inproceedings{Frank2003,
          author = {Eibe Frank and Mark Hall and Bernhard Pfahringer},
          booktitle = {19th Conference in Uncertainty in Artificial Intelligence},
          pages = {249-256},
          publisher = {Morgan Kaufmann},
          title = {Locally Weighted Naive Bayes},
          year = {2003}
       }

       @article{Atkeson1996,
          author = {C. Atkeson and A. Moore and S. Schaal},
          journal = {AI Review},
          title = {Locally weighted learning},
          year = {1996}
       }

  Valid options are:

       -A
        The nearest neighbour search algorithm to use (default: weka.core.neighboursearch.LinearNNSearch).

       -K <number of neighbours>
        Set the number of neighbours used to set the kernel bandwidth.
        (default all)

       -U <number of weighting method>
        Set the weighting kernel shape to use. 0=Linear, 1=Epanechnikov,
        2=Tricube, 3=Inverse, 4=Gaussian.
        (default 0 = Linear)

       -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.DecisionStump)

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

       -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), Eibe Frank (eibe@cs.waikato.ac.nz), Ashraf M. Kibriya (amk14[at-the-rate]cs[dot]waikato[dot]ac[dot]nz)
  See Also:
    Serialized Form

- - ### Field Summary

    Fields
    Modifier and Type | Field and Description
    --- | ---
    `static int` | `CONSTANT`
    `static int` | `EPANECHNIKOV`
    `static int` | `GAUSS`
    `static int` | `INVERSE`
    `static int` | `LINEAR` The available kernel weighting methods.
    `static int` | `TRICUBE`

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `LWL()` Constructor.

  - ### 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.util.Enumeration<java.lang.String>` | `enumerateMeasures()` Returns an enumeration of the additional measure names produced by the neighbour search algorithm.
    `Capabilities` | `getCapabilities()` Returns default capabilities of the classifier.
    `int` | `getKNN()` Gets the number of neighbours used for kernel bandwidth setting.
    `double` | `getMeasure(java.lang.String additionalMeasureName)` Returns the value of the named measure from the neighbour search algorithm.
    `NearestNeighbourSearch` | `getNearestNeighbourSearchAlgorithm()` Returns the current nearestNeighbourSearch algorithm in use.
    `java.lang.String[]` | `getOptions()` Gets the current settings of the classifier.
    `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.
    `int` | `getWeightingKernel()` Gets the kernel weighting method to use.
    `java.lang.String` | `globalInfo()` Returns a string describing classifier.
    `java.lang.String` | `KNNTipText()` Returns the tip text for this property.
    `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` | `nearestNeighbourSearchAlgorithmTipText()` Returns the tip text for this property.
    `void` | `setKNN(int knn)` Sets the number of neighbours used for kernel bandwidth setting.
    `void` | `setNearestNeighbourSearchAlgorithm(NearestNeighbourSearch nearestNeighbourSearchAlgorithm)` Sets the nearestNeighbourSearch algorithm to be used for finding nearest neighbour(s).
    `void` | `setOptions(java.lang.String[] options)` Parses a given list of options.
    `void` | `setWeightingKernel(int kernel)` Sets the kernel weighting method to use.
    `java.lang.String` | `toString()` Returns a description of this classifier.
    `void` | `updateClassifier(Instance instance)` Adds the supplied instance to the training set.
    `java.lang.String` | `weightingKernelTipText()` Returns the tip text for this property.

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

      `classifierTipText, getClassifier, setClassifier`

    - ### 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

    - #### LINEAR

          public static final int LINEAR

      The available kernel weighting methods.
      See Also:
        Constant Field Values

    - #### EPANECHNIKOV

          public static final int EPANECHNIKOV

      See Also:
        Constant Field Values

    - #### TRICUBE

          public static final int TRICUBE

      See Also:
        Constant Field Values

    - #### INVERSE

          public static final int INVERSE

      See Also:
        Constant Field Values

    - #### GAUSS

          public static final int GAUSS

      See Also:
        Constant Field Values

    - #### CONSTANT

          public static final int CONSTANT

      See Also:
        Constant Field Values

  - ### Constructor Detail

    - #### LWL

          public LWL()

      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

    - #### enumerateMeasures

          public java.util.Enumeration<java.lang.String> enumerateMeasures()

      Returns an enumeration of the additional measure names produced by the neighbour search algorithm.
      Returns:
        an enumeration of the measure names

    - #### getMeasure

          public double getMeasure(java.lang.String additionalMeasureName)

      Returns the value of the named measure from the neighbour search algorithm.
      Parameters:
        `additionalMeasureName` - the name of the measure to query for its value
      Returns:
        the value of the named measure
      Throws:
        `java.lang.IllegalArgumentException` - if the named measure is not supported

    - #### listOptions

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

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

           -A
            The nearest neighbour search algorithm to use (default: weka.core.neighboursearch.LinearNNSearch).

           -K <number of neighbours>
            Set the number of neighbours used to set the kernel bandwidth.
            (default all)

           -U <number of weighting method>
            Set the weighting kernel shape to use. 0=Linear, 1=Epanechnikov,
            2=Tricube, 3=Inverse, 4=Gaussian.
            (default 0 = Linear)

           -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.DecisionStump)

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

           -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 `SingleClassifierEnhancer`
      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 `SingleClassifierEnhancer`
      Returns:
        an array of strings suitable for passing to setOptions

    - #### KNNTipText

          public java.lang.String KNNTipText()

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

    - #### setKNN

          public void setKNN(int knn)

      Sets the number of neighbours used for kernel bandwidth setting. The bandwidth is taken as the distance to the kth neighbour.
      Parameters:
        `knn` - the number of neighbours included inside the kernel bandwidth, or 0 to specify using all neighbors.

    - #### getKNN

          public int getKNN()

      Gets the number of neighbours used for kernel bandwidth setting. The bandwidth is taken as the distance to the kth neighbour.
      Returns:
        the number of neighbours included inside the kernel bandwidth, or 0 for all neighbours

    - #### weightingKernelTipText

          public java.lang.String weightingKernelTipText()

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

    - #### setWeightingKernel

          public void setWeightingKernel(int kernel)

      Sets the kernel weighting method to use. Must be one of LINEAR, EPANECHNIKOV, TRICUBE, INVERSE, GAUSS or CONSTANT, other values are ignored.
      Parameters:
        `kernel` - the new kernel method to use. Must be one of LINEAR, EPANECHNIKOV, TRICUBE, INVERSE, GAUSS or CONSTANT.

    - #### getWeightingKernel

          public int getWeightingKernel()

      Gets the kernel weighting method to use.
      Returns:
        the new kernel method to use. Will be one of LINEAR, EPANECHNIKOV, TRICUBE, INVERSE, GAUSS or CONSTANT.

    - #### nearestNeighbourSearchAlgorithmTipText

          public java.lang.String nearestNeighbourSearchAlgorithmTipText()

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

    - #### getNearestNeighbourSearchAlgorithm

          public NearestNeighbourSearch getNearestNeighbourSearchAlgorithm()

      Returns the current nearestNeighbourSearch algorithm in use.
      Returns:
        the NearestNeighbourSearch algorithm currently in use.

    - #### setNearestNeighbourSearchAlgorithm

          public void setNearestNeighbourSearchAlgorithm(NearestNeighbourSearch nearestNeighbourSearchAlgorithm)

      Sets the nearestNeighbourSearch algorithm to be used for finding nearest neighbour(s).
      Parameters:
        `nearestNeighbourSearchAlgorithm` - - The NearestNeighbourSearch 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 `SingleClassifierEnhancer`
      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:
        preedicted class probability distribution
      Throws:
        `java.lang.Exception` - if distribution can't be computed successfully

    - #### 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.

    - #### 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` - the options