weka.classifiers.functions.supportVector

Class NormalizedPolyKernel

java.lang.Object

weka.classifiers.functions.supportVector.Kernel

weka.classifiers.functions.supportVector.CachedKernel

weka.classifiers.functions.supportVector.PolyKernel

weka.classifiers.functions.supportVector.NormalizedPolyKernel

All Implemented Interfaces:

Serializable, CapabilitiesHandler, OptionHandler, RevisionHandler

public class NormalizedPolyKernel
extends PolyKernel

The normalized polynomial kernel.
K(x,y) = <x,y>/sqrt(<x,x><y,y>) where <x,y> = PolyKernel(x,y)

Valid options are:

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

 -no-checks
  Turns off all checks - use with caution!
  (default: checks on)

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

 -E <num>
  The Exponent to use.
  (default: 1.0)

 -L
  Use lower-order terms.
  (default: no)

Version:

$Revision: 8034 $

Author:

Eibe Frank (eibe@cs.waikato.ac.nz)

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
NormalizedPolyKernel() default constructor - does nothing
NormalizedPolyKernel(Instances dataset, int cacheSize, double exponent, boolean lowerOrder) Creates a new NormalizedPolyKernel instance.

Method Summary

Methods

Modifier and Type	Method and Description
double	eval(int id1, int id2, Instance inst1) Computes the result of the kernel function for two instances.
String	getRevision() Returns the revision string.
String	globalInfo() Returns a string describing the kernel
void	setExponent(double value) Sets the exponent value (must be different from 1.0).
String	toString() returns a string representation for the Kernel

Methods inherited from class weka.classifiers.functions.supportVector.PolyKernel

clean, exponentTipText, getCapabilities, getExponent, getOptions, getUseLowerOrder, listOptions, setOptions, setUseLowerOrder, useLowerOrderTipText

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

buildKernel, cacheSizeTipText, getCacheSize, numCacheHits, numEvals, setCacheSize

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

checksTurnedOffTipText, debugTipText, forName, getChecksTurnedOff, getDebug, makeCopies, makeCopy, setChecksTurnedOff, setDebug

Methods inherited from class java.lang.Object

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

Constructor Detail

NormalizedPolyKernel

public NormalizedPolyKernel()

default constructor - does nothing

NormalizedPolyKernel

public NormalizedPolyKernel(Instances dataset,
                    int cacheSize,
                    double exponent,
                    boolean lowerOrder)
                     throws Exception

Creates a new NormalizedPolyKernel instance.

Parameters:

dataset - the training dataset used.

cacheSize - the size of the cache (a prime number)

exponent - the exponent to use

lowerOrder - whether to use lower-order terms

Throws:

Exception - if something goes wrong

Method Detail

globalInfo

public String globalInfo()

Returns a string describing the kernel

Overrides:

globalInfo in class PolyKernel

Returns:

a description suitable for displaying in the explorer/experimenter gui

eval

public double eval(int id1,
          int id2,
          Instance inst1)
            throws Exception

Computes the result of the kernel function for two instances. If id1 == -1, eval use inst1 instead of an instance in the dataset. Redefines the eval function of PolyKernel.

Overrides:

eval in class CachedKernel

Parameters:

id1 - the index of the first instance in the dataset

id2 - the index of the second instance in the dataset

inst1 - the instance corresponding to id1 (used if id1 == -1)

Returns:

the result of the kernel function

Throws:

Exception - if something goes wrong

setExponent

public void setExponent(double value)

Sets the exponent value (must be different from 1.0).

Overrides:

setExponent in class PolyKernel

Parameters:

value - the exponent value

toString

public String toString()

returns a string representation for the Kernel

Overrides:

toString in class PolyKernel

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 PolyKernel

Returns:

the revision