weka.attributeSelection

Class ASEvaluation

java.lang.Object

weka.attributeSelection.ASEvaluation

All Implemented Interfaces:

Serializable, CapabilitiesHandler, RevisionHandler

Direct Known Subclasses:

AttributeSetEvaluator, CfsSubsetEval, ChiSquaredAttributeEval, ConsistencySubsetEval, CostSensitiveASEvaluation, FilteredAttributeEval, FilteredSubsetEval, GainRatioAttributeEval, HoldOutSubsetEvaluator, InfoGainAttributeEval, OneRAttributeEval, ReliefFAttributeEval, SVMAttributeEval, SymmetricalUncertAttributeEval, UnsupervisedAttributeEvaluator, UnsupervisedSubsetEvaluator, WrapperSubsetEval

public abstract class ASEvaluation
extends Object
implements Serializable, CapabilitiesHandler, RevisionHandler

Abstract attribute selection evaluation class

Version:

$Revision: 11851 $

Author:

Mark Hall (mhall@cs.waikato.ac.nz)

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
ASEvaluation()

Method Summary

Modifier and Type	Method and Description
abstract void	buildEvaluator(Instances data) Generates a attribute evaluator.
void	clean() Tells the evaluator that the attribute selection process is complete.
static ASEvaluation	forName(String evaluatorName, String[] options) Creates a new instance of an attribute/subset evaluator given it's class name and (optional) arguments to pass to it's setOptions method.
Capabilities	getCapabilities() Returns the capabilities of this evaluator.
String	getRevision() Returns the revision string.
static ASEvaluation[]	makeCopies(ASEvaluation model, int num) Creates copies of the current evaluator.
int[]	postProcess(int[] attributeSet) Provides a chance for a attribute evaluator to do any special post processing of the selected attribute set.

Methods inherited from class java.lang.Object

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

Constructor Detail

ASEvaluation

public ASEvaluation()

Method Detail

buildEvaluator

public abstract void buildEvaluator(Instances data)
                             throws Exception

Generates a attribute evaluator. Has to initialize all fields of the evaluator that are not being set via options.

Parameters:

data - set of instances serving as training data

Throws:

Exception - if the evaluator has not been generated successfully

postProcess

public int[] postProcess(int[] attributeSet)
                  throws Exception

Provides a chance for a attribute evaluator to do any special post processing of the selected attribute set.

Parameters:

attributeSet - the set of attributes found by the search

Returns:

a possibly ranked list of postprocessed attributes

Throws:

Exception - if postprocessing fails for some reason

forName

public static ASEvaluation forName(String evaluatorName,
                                   String[] options)
                            throws Exception

Creates a new instance of an attribute/subset evaluator given it's class name and (optional) arguments to pass to it's setOptions method. If the evaluator implements OptionHandler and the options parameter is non-null, the evaluator will have it's options set.

Parameters:

evaluatorName - the fully qualified class name of the evaluator

options - an array of options suitable for passing to setOptions. May be null.

Returns:

the newly created evaluator, ready for use.

Throws:

Exception - if the evaluator name is invalid, or the options supplied are not acceptable to the evaluator

makeCopies

public static ASEvaluation[] makeCopies(ASEvaluation model,
                                        int num)
                                 throws Exception

Creates copies of the current evaluator. Note that this method now uses Serialization to perform a deep copy, so the evaluator object must be fully Serializable. Any currently built model will now be copied as well.

Parameters:

model - an example evaluator to copy

num - the number of evaluator copies to create.

Returns:

an array of evaluators.

Throws:

Exception - if an error occurs

getCapabilities

public Capabilities getCapabilities()

Returns the capabilities of this evaluator.

Specified by:

getCapabilities in interface CapabilitiesHandler

Returns:

the capabilities of this evaluator

See Also:

Capabilities

getRevision

public String getRevision()

Returns the revision string.

Specified by:

getRevision in interface RevisionHandler

Returns:

the revision

clean

public void clean()

Tells the evaluator that the attribute selection process is complete. It can then clean up data structures, references to training data as necessary in order to save memory