Package weka.classifiers.functions.supportVector

# Class RBFKernel

java.lang.Object
weka.classifiers.functions.supportVector.Kernel
weka.classifiers.functions.supportVector.CachedKernel
weka.classifiers.functions.supportVector.RBFKernel

All Implemented Interfaces:
  `Serializable`, `CapabilitiesHandler`, `OptionHandler`, `RevisionHandler`

public class RBFKernel extends CachedKernel
The RBF kernel : K(x, y) = exp(-gamma*(x-y)^2)
Valid options are:

     -C <num>
      The size of the cache (a prime number), 0 for full cache and
      -1 to turn it off.
      (default: 250007)

     -G <double>
      The value to use for the gamma parameter (default: 0.01).

     -output-debug-info
      Enables debugging output (if available) to be printed.
      (default: off)

Version:
  $Revision: 14534 $
Author:
  Eibe Frank (eibe@cs.waikato.ac.nz), Shane Legg (shane@intelligenesis.net) (sparse vector code), Stuart Inglis (stuart@reeltwo.com) (sparse vector code)
See Also:
  - Serialized Form

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `RBFKernel()`
  default constructor - does nothing.
  `RBFKernel(Instances data, int cacheSize, double gamma)`
  Creates a new `RBFKernel` instance.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `void`
  `buildKernel(Instances data)`
  Builds the kernel.
  `String`
  `gammaTipText()`
  Returns the tip text for this property
  `Capabilities`
  `getCapabilities()`
  Returns the Capabilities of this kernel.
  `double`
  `getGamma()`
  Gets the gamma value.
  `String`
  `getRevision()`
  Returns the revision string.
  `String`
  `globalInfo()`
  Returns a string describing the kernel
  `void`
  `setGamma(double value)`
  Sets the gamma value.
  `String`
  `toString()`
  returns a string representation for the Kernel

  ### Methods inherited from class weka.classifiers.functions.supportVector.CachedKernel

  `cacheSizeTipText, clean, eval, getCacheSize, getOptions, listOptions, numCacheHits, numEvals, setCacheSize, setOptions`

  ### Methods inherited from class weka.classifiers.functions.supportVector.Kernel

  `debugTipText, forName, getChecksTurnedOff, getDebug, getDoNotCheckCapabilities, makeCopies, makeCopy, setChecksTurnedOff, setDebug, setDoNotCheckCapabilities`

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

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

- ## Constructor Details

  - ### RBFKernel

    public RBFKernel()
    default constructor - does nothing.

  - ### RBFKernel

    public RBFKernel(Instances data, int cacheSize, double gamma) throws Exception
    Creates a new `RBFKernel` instance.
    Parameters:
      `data` - the training dataset used.
      `cacheSize` - the size of the cache (a prime number)
      `gamma` - the gamma to use
    Throws:
      `Exception` - if something goes wrong

- ## Method Details

  - ### buildKernel

    public void buildKernel(Instances data) throws Exception
    Builds the kernel. Calls the super class method and then also initializes the cache for the diagonal of the dot product matrix.
    Overrides:
      `buildKernel` in class `CachedKernel`
    Parameters:
      `data` - the data to base the kernel on
    Throws:
      `Exception` - if something goes wrong

  - ### globalInfo

    public String globalInfo()
    Returns a string describing the kernel
    Specified by:
      `globalInfo` in class `Kernel`
    Returns:
      a description suitable for displaying in the explorer/experimenter gui

  - ### getCapabilities

    public Capabilities getCapabilities()
    Returns the Capabilities of this kernel.
    Specified by:
      `getCapabilities` in interface `CapabilitiesHandler`
    Overrides:
      `getCapabilities` in class `Kernel`
    Returns:
      the capabilities of this object
    See Also:
      - `Capabilities`

  - ### setGamma

    @OptionMetadata(description="The value to use for the gamma parameter (default: 0.01).", displayName="gamma", commandLineParamName="G", commandLineParamSynopsis="-G <double>", displayOrder=1) public void setGamma(double value)
    Sets the gamma value.
    Parameters:
      `value` - the gamma value

  - ### getGamma

    public double getGamma()
    Gets the gamma value.
    Returns:
      the gamma value

  - ### gammaTipText

    public String gammaTipText()
    Returns the tip text for this property
    Returns:
      tip text for this property suitable for displaying in the explorer/experimenter gui

  - ### toString

    public String toString()
    returns a string representation for the Kernel
    Overrides:
      `toString` in class `Object`
    Returns:
      a string representaiton of the kernel

  - ### getRevision

    public String getRevision()
    Returns the revision string.
    Specified by:
      `getRevision` in interface `RevisionHandler`
    Overrides:
      `getRevision` in class `Kernel`
    Returns:
      the revision