Kernel (weka-stable 3.8.5 API)

java.lang.Object
- weka.classifiers.functions.supportVector.Kernel

All Implemented Interfaces:

Serializable, CapabilitiesHandler, OptionHandler, RevisionHandler

Direct Known Subclasses:

CachedKernel, PrecomputedKernelMatrixKernel, StringKernel
```
public abstract class Kernel
extends Object
implements Serializable, OptionHandler, CapabilitiesHandler, RevisionHandler
```
Abstract kernel. Kernels implementing this class must respect Mercer's condition in order to ensure a correct behaviour of SMOreg.

Version:

$Revision: 14534 $

Author:

Eibe Frank ([email protected]), FracPete (fracpete at waikato dot ac dot nz)

See Also:

Serialized Form

Constructor Summary

Constructors
Constructor and Description

Kernel()

Constructors
Constructor and Description
`Kernel()`

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`buildKernel(Instances data)` builds the kernel with the given data
`abstract void`	`clean()` Frees the memory used by the kernel.
`String`	`debugTipText()` Returns the tip text for this property
`abstract double`	`eval(int id1, int id2, Instance inst1)` Computes the result of the kernel function for two instances.
`static Kernel`	`forName(String kernelName, String[] options)` Creates a new instance of a kernel given it's class name and (optional) arguments to pass to it's setOptions method.
`Capabilities`	`getCapabilities()` Returns the Capabilities of this kernel.
`boolean`	`getChecksTurnedOff()`
`boolean`	`getDebug()` Gets whether debugging output is turned on or not.
`boolean`	`getDoNotCheckCapabilities()`
`String[]`	`getOptions()` Gets the current settings of the Kernel.
`String`	`getRevision()` Returns the revision string.
`abstract String`	`globalInfo()` Returns a string describing the kernel
`Enumeration<Option>`	`listOptions()` Returns an enumeration describing the available options.
`static Kernel[]`	`makeCopies(Kernel model, int num)` Creates a given number of deep or shallow (if the kernel implements Copyable) copies of the given kernel using serialization.
`static Kernel`	`makeCopy(Kernel kernel)` Creates a shallow copy of the kernel (if it implements Copyable) otherwise a deep copy using serialization.
`abstract int`	`numCacheHits()` Returns the number of dot product cache hits.
`abstract int`	`numEvals()` Returns the number of kernel evaluation performed.
`void`	`setChecksTurnedOff(boolean value)` These methods remain for backwards compatibility.
`void`	`setDebug(boolean value)` Enables or disables the output of debug information (if the derived kernel supports that)
`void`	`setDoNotCheckCapabilities(boolean doNotCheckCapabilities)` These methods remain for backwards compatibility.
`void`	`setOptions(String[] options)` Parses a given list of options.

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface weka.core.OptionHandler
makeCopy

- Constructor Detail
  - Kernel
```
public Kernel()
```
- Method Detail
  - setDoNotCheckCapabilities
```
@ProgrammaticProperty
public void setDoNotCheckCapabilities(boolean doNotCheckCapabilities)
```
    These methods remain for backwards compatibility. The first one does nothing, the second one always returns true. Checking capabilities is the responsibility of the class using the kernel.
  - getDoNotCheckCapabilities
```
public boolean getDoNotCheckCapabilities()
```
  - globalInfo
```
public abstract String globalInfo()
```
    Returns a string describing the kernel
    
    Returns:
    
    a description suitable for displaying in the explorer/experimenter gui
  - eval
```
public abstract 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.
    
    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
  - clean
```
public abstract void clean()
```
    Frees the memory used by the kernel. (Useful with kernels which use cache.) This function is called when the training is done. i.e. after that, eval will be called with id1 == -1.
  - numEvals
```
public abstract int numEvals()
```
    Returns the number of kernel evaluation performed.
    
    Returns:
    
    the number of kernel evaluation performed.
  - numCacheHits
```
public abstract int numCacheHits()
```
    Returns the number of dot product cache hits.
    
    Returns:
    
    the number of dot product cache hits, or -1 if not supported by this kernel.
  - listOptions
```
public Enumeration<Option> listOptions()
```
    Returns an enumeration describing the available options.
    
    Specified by:
    
    listOptions in interface OptionHandler
    
    Returns:
    
    an enumeration of all the available options.
  - setOptions
```
public void setOptions(String[] options)
                throws Exception
```
    Parses a given list of options.
    
    Specified by:
    
    setOptions in interface OptionHandler
    
    Parameters:
    
    options - the list of options as an array of strings
    
    Throws:
    
    Exception - if an option is not supported
  - getOptions
```
public String[] getOptions()
```
    Gets the current settings of the Kernel.
    
    Specified by:
    
    getOptions in interface OptionHandler
    
    Returns:
    
    an array of strings suitable for passing to setOptions
  - setDebug
```
public void setDebug(boolean value)
```
    Enables or disables the output of debug information (if the derived kernel supports that)
    
    Parameters:
    
    value - whether to output debugging information
  - getDebug
```
public boolean getDebug()
```
    Gets whether debugging output is turned on or not.
    
    Returns:
    
    true if debugging output is produced.
  - debugTipText
```
public String debugTipText()
```
    Returns the tip text for this property
    
    Returns:
    
    tip text for this property suitable for displaying in the explorer/experimenter gui
  - setChecksTurnedOff
```
@ProgrammaticProperty
public void setChecksTurnedOff(boolean value)
```
    These methods remain for backwards compatibility. The first one does nothing, the second one always returns true. Checking capabilities is the responsibility of the class using the kernel.
  - getChecksTurnedOff
```
public boolean getChecksTurnedOff()
```
  - getCapabilities
```
public Capabilities getCapabilities()
```
    Returns the Capabilities of this kernel. Derived kernels have to override this method to enable capabilities.
    
    Specified by:
    
    getCapabilities in interface CapabilitiesHandler
    
    Returns:
    
    the capabilities of this object
    
    See Also:
    
    Capabilities
  - getRevision
```
public String getRevision()
```
    Returns the revision string.
    
    Specified by:
    
    getRevision in interface RevisionHandler
    
    Returns:
    
    the revision
  - buildKernel
```
public void buildKernel(Instances data)
                 throws Exception
```
    builds the kernel with the given data
    
    Parameters:
    
    data - the data to base the kernel on
    
    Throws:
    
    Exception - if something goes wrong
  - makeCopy
```
public static Kernel makeCopy(Kernel kernel)
                       throws Exception
```
    Creates a shallow copy of the kernel (if it implements Copyable) otherwise a deep copy using serialization.
    
    Parameters:
    
    kernel - the kernel to copy
    
    Returns:
    
    a shallow or deep copy of the kernel
    
    Throws:
    
    Exception - if an error occurs
  - makeCopies
```
public static Kernel[] makeCopies(Kernel model,
                                  int num)
                           throws Exception
```
    Creates a given number of deep or shallow (if the kernel implements Copyable) copies of the given kernel using serialization.
    
    Parameters:
    
    model - the kernel to copy
    
    num - the number of kernel copies to create.
    
    Returns:
    
    an array of kernels.
    
    Throws:
    
    Exception - if an error occurs
  - forName
```
public static Kernel forName(String kernelName,
                             String[] options)
                      throws Exception
```
    Creates a new instance of a kernel given it's class name and (optional) arguments to pass to it's setOptions method.
    
    Parameters:
    
    kernelName - the fully qualified class name of the classifier
    
    options - an array of options suitable for passing to setOptions. May be null.
    
    Returns:
    
    the newly created classifier, ready for use.
    
    Throws:
    
    Exception - if the classifier name is invalid, or the options supplied are not acceptable to the classifier

Class Kernel

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface weka.core.OptionHandler

Constructor Detail

Kernel

Method Detail

setDoNotCheckCapabilities

getDoNotCheckCapabilities

globalInfo

eval

clean

numEvals

numCacheHits

listOptions

setOptions

getOptions

setDebug

getDebug

debugTipText

setChecksTurnedOff

getChecksTurnedOff

getCapabilities

getRevision

buildKernel

makeCopy

makeCopies

forName