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: 14512 $

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