weka.classifiers.functions.supportVector

Class CachedKernel

java.lang.Object

weka.classifiers.functions.supportVector.Kernel

weka.classifiers.functions.supportVector.CachedKernel

All Implemented Interfaces:

java.io.Serializable, CapabilitiesHandler, OptionHandler, RevisionHandler

Direct Known Subclasses:

PolyKernel, Puk, RBFKernel

public abstract class CachedKernel
extends Kernel

Base class for RBFKernel and PolyKernel that implements a simple LRU. (least-recently-used) cache if the cache size is set to a value > 0. Otherwise it uses a full cache.

Version:

$Revision: 4549 $

Author:

Eibe Frank (eibe@cs.waikato.ac.nz), Shane Legg (shane@intelligenesis.net) (sparse vector code), Stuart Inglis (stuart@reeltwo.com) (sparse vector code), J. Lindgren (jtlindgr{at}cs.helsinki.fi) (RBF kernel), Steven Hugg (hugg@fasterlight.com) (refactored, LRU cache), Bernhard Pfahringer (bernhard@cs.waikato.ac.nz) (full cache)

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
CachedKernel() default constructor - does nothing.

Method Summary

Modifier and Type	Method and Description
void	buildKernel(Instances data) builds the kernel with the given data.
java.lang.String	cacheSizeTipText() Returns the tip text for this property
void	clean() Frees the cache used by the kernel.
double	eval(int id1, int id2, Instance inst1) Implements the abstract function of Kernel using the cache.
int	getCacheSize() Gets the size of the cache
java.lang.String[]	getOptions() Gets the current settings of the Kernel.
java.util.Enumeration	listOptions() Returns an enumeration describing the available options.
int	numCacheHits() Returns the number of cache hits on dot products.
int	numEvals() Returns the number of time Eval has been called.
void	setCacheSize(int value) Sets the size of the cache to use (a prime number)
void	setOptions(java.lang.String[] options) Parses a given list of options.

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

checksTurnedOffTipText, debugTipText, forName, getCapabilities, getChecksTurnedOff, getDebug, getRevision, globalInfo, makeCopies, makeCopy, setChecksTurnedOff, setDebug

Methods inherited from class java.lang.Object

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

Constructor Detail

CachedKernel

public CachedKernel()

default constructor - does nothing.

Method Detail

listOptions

public java.util.Enumeration listOptions()

Returns an enumeration describing the available options.

Specified by:

listOptions in interface OptionHandler

Overrides:

listOptions in class Kernel

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.

Specified by:

setOptions in interface OptionHandler

Overrides:

setOptions in class Kernel

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 Kernel.

Specified by:

getOptions in interface OptionHandler

Overrides:

getOptions in class Kernel

Returns:

an array of strings suitable for passing to setOptions

eval

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

Implements the abstract function of Kernel using the cache. This method uses the evaluate() method to do the actual dot product.

Specified by:

eval in class Kernel

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:

java.lang.Exception - if something goes wrong

numEvals

public int numEvals()

Returns the number of time Eval has been called.

Specified by:

numEvals in class Kernel

Returns:

the number of kernel evaluation.

numCacheHits

public int numCacheHits()

Returns the number of cache hits on dot products.

Specified by:

numCacheHits in class Kernel

Returns:

the number of cache hits.

clean

public void clean()

Frees the cache used by the kernel.

Specified by:

clean in class Kernel

setCacheSize

public void setCacheSize(int value)

Sets the size of the cache to use (a prime number)

Parameters:

value - the size of the cache

getCacheSize

public int getCacheSize()

Gets the size of the cache

Returns:

the cache size

cacheSizeTipText

public java.lang.String cacheSizeTipText()

Returns the tip text for this property

Returns:

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

buildKernel

public void buildKernel(Instances data)
                 throws java.lang.Exception

builds the kernel with the given data. Initializes the kernel cache. The actual size of the cache in bytes is (64 * cacheSize).

Overrides:

buildKernel in class Kernel

Parameters:

data - the data to base the kernel on

Throws:

java.lang.Exception - if something goes wrong